of the rainy season.

The credibility of regional climate simulations over West Africa stands and falls with the ability to reproduce its key climatic feature, the West African Monsoon. This seasonal shift in large-scale wind patterns plays a pivotal role in every day's life, and any shift caused by climate change will greatly impact the future of this region. In our analysis, we therefore focus on the representation of the WAM in the regionally downscaled models. For the validation of the models, ERA-Interim re-analysis data is used as lateral boundary condition for the period from 1980 to 2013. We verify the models against observational data from gridded climate observational products such as GPCC, TRMM, and CRU. In addition, we employ a novel gridded precipitation database for the West African region, which is compiled from daily and monthly in-situ observations merged from various global and regional meteorological archives (GHCN, GSOD, AMMA, GLOWA) and from precipitation data provided by the national weather services and the novel WASCAL observation network.

In this contribution, we present the overall concept of the WASCAL regional climate projections and provide information on the availability of the data and its dissemination to the community. We discuss the model performance over the validation period for two of the three regional climate models employed, the Weather Research and Forecasting tool (WRF) and the COSMO model in Cimel Mode (COSMO-CLM), and give details about the novel precipitation database used to verify the models. We further present results on the climate change signal obtained from the WRF model runs for the periods 2020-2050 and 2070-2100.

## P-1104-05

### Challenges of scales

**S. Huq (1)**

(1) International Center for Climate Change and Development (ICCCAD), Dhaka, Bangladesh

There are several aspects of governance related to adaptation to climate change that need to be addressed to ensure equity and fairness in the way adaptation is implemented on the ground. Firstly, at the global level, there is the issue of governing climate change funding for adaptation in an equitable manner to ensure that the most vulnerable countries and communities are prioritised for receiving adaptation funds.

Similarly, at national level, it is important for national decision makers to also prioritise the needs of the most vulnerable communities within each country. This is true for both developing as well as developed countries.

One of the main issue in current climate governance is that the poorest communities within countries, and the poorest countries globally, possess a relatively less important voice in decision making at global and national scales. Hence, in order to adapt successfully to the adverse impacts of climate change, the empowerment of the most vulnerable within the climate governance system is a precondition.

## P-1104-06

### The Contribution of Climate Services to Climate Change Adaptation through the Global Framework for Climate Services (GFCS)

**F. Lucio (1)**

(1) World Meteorological Organization, Global Framework for Climate Services Office, Geneva, Switzerland

Climate determines the extent to which human kind can sustain livelihoods and well-being. Thus, as the effects of climate change are becoming more evident and acute, the need for effective climate services is greater than ever before. Climate services here are considered to be the provision of climate information to assist decision-making in climate sensitive sectors. Climate services require a range of activities from generating to providing information based on past, present and future climate and its impacts on natural and human systems. These services can range from simple information such as historical climate data sets to more complex products such as predictions on monthly, seasonal and decadal time

frames. Ultimately, climate services provide information and expert advice that help users make the right decisions for climate change adaptation.

Seasonal to multiyear climate forecasting has advanced to a point where it can now provide actionable information. Sophisticated climate services combine climate forecasts with information from other sectors to inform decisions on public health, agriculture, water management, disaster risk and other climate-sensitive sectors.

Recognizing the value and contribution of climate services, the international community established the Global Framework for Climate Services (GFCS) at the Third World Climate Conference (WCC-3, 2009) to promote operational climate services at the national and regional levels. The GFCS aims at facilitating the development and use of services to ensure that best efforts are made to reduce the impacts of climate-related disasters and to adapt to climate change. It is catalyzing a paradigm shift from supply-driven service provision to the creation of services driven by user needs, by orienting scientific research towards practical applications to respond to those needs. Building on past and current climate service initiatives, it is enabling new services to be developed to increase the value and need access to climate knowledge products for those who need them the most.

Climate services underpin climate action and adaptation in climate sensitive sectors; contribute to enhancing disaster preparedness and planning for effective response and to allow societies to build back better after a disaster.

An essential starting point for adaptation is a quantitative assessment combining characterization of hazards with vulnerabilities to derive specific services to various users. This is often hampered by the capabilities to conduct effective analysis of past data and assess changing characteristics and trends of hazards in light of climate change to support risk and impact assessment.

This paper provides an account of how the GFCS is supporting countries in the development and use of climate services for climate change adaptation.

## P-1104-07

### Appraising the climate services accessible to indigenous communities in Uganda

**AR. Mwangu (1)**

(1) Makerere University, Kampala, Uganda

Climate change is one of the most pressing challenges of our generation. Scientists predict that it will even have more adverse effects on the population in the future. Studies indicate that climate change impacts most affect people in the developing countries especially the women, elderly and children because these groups have little access to the information on climate change, they are illiterate and are concealed in poverty. Yet a big constituent of these groups especially the women are by default key resource managers whose knowledge and actions are critical in environment and natural resource management. Climate services are seldom offered in Uganda and as a result climate change is as much abstract to a wide section of people. This study will urge that in circumstances where climate services have been offered they have not been conceptualized for comprehension by the masses. Climate change continues to be portrayed as a highly scientific phenomenon far and above the indigenous communities yet they are the most affected by its impacts. The examples used in talking about climate change are distant and unfamiliar that people hardly make sense of them. Besides climate change is only linked to anthropogenic activities yet natural phenomenon like local land-use changes can have a serious impact.

With data collected through Focus Group Discussions and Key Informant Interviews, this study urges that robust climate services are urgently needed in Uganda to tackle the serious adverse effects of climate change that is choking the local communities. Disastrous effects like floods and landslides as a result of heavy rains in the Mountain Elgon region have continuously led to fatalities yet the local communities are unaware and cannot devise adaptive and mitigation strategies. Correspondingly the seasons have changed but the local farmers continue to plan their planting seasons based on the previous seasons that has eventually led to a decline in crop yields resulting into food shortages and its associated ills of malnutrition.
It is critical that climate services are customized to the local situations for long lasting impact.

P-1104-08

## Decadal climate information for improved decision-making and resilience in small-scale farming systems in Africa: Lessons from East and Southern Africa

### A. Nyamwanza (1)

(1) University of Cape Town, African Climate and Development Initiative, Cape Town, South Africa

Small-scale farming systems in Africa are facing increasingly erratic and variable climate dynamics, in addition to other multiple and reinforcing non-climatic stresses and shocks. Effective responses and ultimately resilience to these adversities require, among other factors, access to and use of adequate climate information for the coming seasons and years to enable players within these systems to make informed, timely and appropriate decisions not only in the short term, but also in the medium to long term. Climate information is in agriculture on a range of timescales, from days (weather), months (seasonal outlooks) to decades (climate change scenarios) (Hellmuth et al. 2011). In most African countries, adaptation to climate risk has focused either on the seasonal timescale or the assessment of climate change impacts several decades into the future. Awareness of and adaptation to climate risk on the decadal timescale (up to 10 years) has received less attention. Yet much policy planning and investment decision-making falls short of this time horizon, especially in areas of importance to small-scale farming systems in developing countries such as farm planning cycles, introduction of new varieties and the setting up of such projects as catchment-wide infrastructure for irrigation and water storage (Goddard et al. 2010; Stafford-Smith et al. 2011, Vermeulen, 2012). There is also increasing evidence that climate change is altering the likelihood of extreme events that impact on agriculture within the decadal timescale (IPCC 2012). It is against this background that this analysis explores the utility of climate information in small-scale farming systems in Africa on the decadal timescale. Using cases of small-scale farming systems in the Kilimanjaro Region of Tanzania, the mid-Zambezi Valley Region of Zimbabwe, and the Southern Region of Malawi, the analysis shows decadal climate information as potentially providing opportunities for innovative, flexible and proactive decision-making in response to projected climate change. This analysis shows that although farmers will be the major beneficiaries of decadal climate information, other players, particularly service providers and intermediaries, also stand to gain thus providing a holistic perspective in dealing with the decision-making context of small-scale farming systems in Africa. The paper however also points on the need for building institutional capacity vis-à-vis coming up with stronger knowledge and information networks between climate scientists, policy makers and local communities as well as attending to issues of credibility, legitimacy and scale in the production and dissemination of decadal climate information in Africa so as to ensure uptake and appropriate use. The discussion, therefore, brings to the fore the need for the recognition of the increasing importance and role of decadal climate information vis-à-vis decision making towards resilient and adaptive small-scale farming systems in Africa.

P-1104-09

## Drias, the futures of climate: a service for the benefit of adaptation

JM. Soubeyroux (1) ; P. Josse (2) ; R. Vautard (3) ; C. Page (4) ; S. Planton (5)

(1) Météo-France, Dlim, Toulouse, France; (2) Météo France, Direction de la Climatologie et des Services Climatiques, Toulouse, France; (3) Laboratoire des Sciences du Climat et de l'Environnement, Salay, France; (4) CERFACS, Toulouse, France; (5) Météo-France, CNRM, Toulouse, France

The project Drias for 'Deliver Regional climate scenarios for Impacts and Adaptation of our environment and Society' was built with the basic idea that a facility was now needed for climate information delivery. Drias was funded by the Management and Impact of Climate Change programme of the French Ministry for Sustainable Development. It

focuses on existing French regional climate projections obtained from national modelling groups: IPSL, CERFACS, and CNRM and was coordinated by the Department of Climatology at Météo-France, which is in charge of climatological operations and services

The resulting portal, opened in 2012, offers easy access to data and products, including a quick-look discovery, as well as the associated expertise to facilitate impact and adaptation studies:

* Several greenhouse gas emission scenarios, using different regional climate models and downscaling methods, because it is critical that users work with the idea that climate projections have to be addressed in a probabilistic mode

* Standard formats, easy access, quick looks and simple products for a wide range of users, baring in mind that many communities do not share the technical skills of climate modelers

* Expertise and guidance, especially addressing the various sources of uncertainty, and promoting best practices and know-how - one of the first requirements of users, as shown in every user needs survey.

The Drias web portal comprises three main areas: Delivery, Support, and Discovery. The Discovery area contains general information for a wide range of people, allowing them to grasp climate scenarios and visualize outputs. In the Support area, a range of documents is offered to help users make the best use of available climate information (dictionary, description of methods and climate models, frequently asked questions). A hotline mechanism involving experts is also implemented at this level. The Delivery area enables users to order, in digitized format, data and products they have identified in the Discovery area.

A user committee was created at the beginning of the project, to help define effective and strategic needs, evaluate prototypes using beta testers, validate the choices made by the project team, and ensure that Drias will continue to meet user's expectations.

Drias is positioned at the interface between actors. A layer of intermediate users - or translators - is appearing in the form of engineers from the meteorological service, or from private companies already deploying activities in the field of environment, or climate experts hired by local organizations.

The partnerships around Drias must also be highlighted. Nothing could be done without the research groups or the meteorological service. A strong tribute must be paid to the governing bodies that have supported the initiative, and have placed it high on the agenda at the ministerial level, making Drias one of the most prominent actions of the French National Plan for Adaptation.

New indices, dataset and other enhances have been gradually introduced for the last three years, with confidence intervals instead of the single scenario originally, results of impact studies on water resources (ClimSec project) and more recently with the newest regionalized scenarios for France, based on the 'Representative Concentration Pathways'.

But can we say that we are on the right track? Will our citizens be more convinced because such facilities are now in place? Undoubtedly there are many aspects of the human conscience that must be activated in order to reach the appropriate level of commitment regarding climate change. The real challenge for climate services may also appear in the training and education arena, and definitely has to deal with a wide range of human and political sciences.

P-1104-10

## Climate Information for Public Health in Africa in the context of Climate Change Adaptation

M. Thomson (1) ; P. Ceccato (1) ; A. Woyessa (2) ; T. Dinku (1) ; S. Connor (3)

(1) International Research Institute for Climate and Society, Columbia University, New York, New York, United States of America; (2) Ethiopian Public Health Institute, Department of bacterial, parasitic & zoonotic diseases research, Addis Ababa, Ethiopia; (3) Liverpool University, Geography, Liverpool, United Kingdom
Climate impacts on health are well established. Building climate smart and resilient communities is therefore essential in the face of climate variability and change. Climate information can play a role in helping societies to better manage health risks brought about by climate variability and change. However, for climate informed health decision-making to become an everyday reality, a broad coalition of partners focused on improved health adaptation and mitigation strategies is essential.

This paper describes the approach taken at the International Research Institute for Climate and Society (IRI) [1] and its partners to integrate research, operational applications and capacity building alongside policy development and advocacy in the area of climate and health in Africa. The initial focus of the IRI's health work on the development of early warning systems for climate-sensitive diseases (for example malaria and meningococcal meningitis) was built upon the Institute's applied research capacity in seasonal climate forecasting. However, over time, the agenda has broadened in response to articulated user needs for information on the past, present and future climate to also better understand the mechanisms by which climate impacts on disease, map populations at risk both geographically and by season, develop early warning systems, better understand trends in disease incidence associated with climate shifts and improve the evaluation of the impacts of climate-sensitive interventions.

Central to IRI's experience throughout has been a keen awareness that climate information and products, in Africa as elsewhere, must be relevant to the health community and development partners and reflect prioritized needs within political and donor processes, while also offering innovations grounded in relevant and reliable observational data obtained through effective, efficient, credible and transparent means. The relevance of this approach to infectior disease, health outcomes of disasters and nutrition will be presented.

[1] IRI is a WHO/PAHO Collaborating Center for Malaria Early Warning and Other Climate Sensitive Diseases.

P-1104-11

Using agro weather tool for enhanced productivity under climate change and variability by communities in Kenya

J. Wamari (1)

(1) Kenya Agricultural and Livestock Research Organization, National Agricultural Research Laboratories, Nairobi, Kenya

The farming communities in Kenya produce 65% of Kenya's exports and offer employment to 80% of the population therefore ensuring food security. A survey from three counties of Makachos, Nakuru and Kakamega predominantly growing Maize-Beans-Pigeon peas, Maize-Beans-Irish potatoes and Maize-Beans-Sweet potatoes respectively showed heavy maize yield on rainfall (≥90). These rains have however become increasingly variable spatially, shattering for example the average maize yields of 3.1, 10.4 and 5 bags-1 acre at the respective sites. Spatial and temporal changes of seasonality under climate change and variability call for changing methods to maintain these cropping systems and alternative varieties and agronomic practices as adaptation strategies for sustainable realization yield variations.

The information required by these communities need to be accurate and timely and manageably packaged and presented in easily interpretable and understandable manner. It should additionally factor indigenous knowhow and include insurance possibilities to enable confidence in its utility. An agro-weather tool using the mobile phone owned by a majority of rural folk jointly developed for this purpose. It involved collaboration with World Bank as development partner, Government of Kenya lead-departments of agriculture and meteorology, mobile line service provider Safaricom and local agro-dealers targeting 5000 households in its pilot phase and was successfully unveiled for Embu County in 2014. The tool targeted coffee and tea as cash crops and maize and beans subsistence crops dominantly grown in this county and is scheduled for up-scaling in other areas.

Beneficial information relayed included daily, weekly and seasonal forecasts, possible disasters, climate stress severity with direct and indirect severe impacts on crop production. It also offered interventional measures of suitable varieties and their productivity potential and appropriate farming activities to be undertaken to reduce, adapt and/or mitigate the negative impacts related to weather and climate.

The use the tool will be out scaled to other counties but also for pastoral communities who will require weather-related information on areas of depressed rainfall, periods of availability, frequency/resurgence of pastures/forage and the likely occurrence of killer diseases and environmental degradation. Also necessary is weather information that would cause floods/drought that would drown/kill livestock and potential benefits of using alternative methodologies.

1105a - Assessing climate observations

ORAL PRESENTATIONS

K-1105a-01

Space-based Climate Observing systems

S. Briggs (1) ; JL Fellous (2) ; P. Lecomte, (1) ; P. Ultré-Guérard (3) ; A. Ratier (4) ; J. Bates, (5)

(1) European Space Agency, Harwell, United Kingdom;

(2) COSPAR, Executive Director, Paris, France; (3) CNES,

Dps/tec/d, Paris, France; (4) EUMETSAT, Director general,

Darmstadt, Germany; (5) NCDC, Nashville, United States of America

The Global Climate Observing System (GCOS) provides a framework for the coordination of observations in support of the UNFCCC. The 2003 GCOS Adequacy report to UNFCCC SBSTA introduced the concept of Essential Climate Variables, variables which were considered fundamental to the understanding and reporting of climate. These were updated in the GCOS 2010 Implementation Plan, and currently comprise a list of some fifty variables. A satellite supplement focusing on the needs of the climate community for observations from Earth observing satellites was produced by GCOS in 2011, and this forms the basis for the current support of space agencies to GCOS. The Commite on Earth Observation Satellites (CEOS) has formally responded on his with a document published in 2012. Satellite observations are critical for about two thirds of the fifty ECVs. In addition, the Committee on Space Research (COSPAR) has sponsored a roadmap study

for Integrated Earth System Science in the period 2015-2025.

This paper will describe briefly the status of the GCOS and highlight the needs for satellite data which derive from it. An overview of current Earth observation satellite systems will be given, together with an analysis of how these contribute to the provision of the ECVs. Examples of satellite observations and key derived products for climate will be given.

K-1105a-02

Climate Observing Systems: Where are we and where do we need to be in the future

C. Baker (1)

(1) NOAA, Oar/arl/atdd, Oak Ridge, TN, United States of America

Climate research and monitoring requires an observational strategy that blends long term, carefully calibrated measurements as well as short-term, focused process studies. Operating climate observing networks and providing climate services, have a significant role to play in assisting the development of national adaptation policies and in facilitating national economic development. Climate observing systems will require a strong research element for a long time to come. This requires improved observations of the state variables and the ability to set them in a coherent physical (and chemical and biological) framework with models. Climate research and monitoring
requires an integrated strategy of land/ocean/ atmosphere observations, including both in situ and remote sensing platforms, and modeling and analysis. It is clear that we still need more research and analysis on climate processes, sampling strategies, and processing algorithms.

K-1105a-03

Sea Level, an Essential Climate Variable
and an integrator of climate change

A. Cazenave (1) ; M. Ablain, (2) ; JF. Legeais (3) ; B. Meyssignac (1)

(1) CNES, LEGOS, Toulouse, France; (2) CLS, DOS, PMC, Ramonville St Agne, France; (3) CLS, Space Oceanography Division, Ramonville St Agne, France

Sea level is an important climate variable and a
major indicator of climate change. In effect, sea level
integrates changes and interactions of all components
of the climate system (ocean, atmosphere, cryosphere,
hydrosphere); it varies globally and regionally in response
to internal climate variability and external -natural and
anthropogenic- forcing factors. Sea level is one of the
50 Essential Climate Variables (ECVs) defined by the
Global Climate Observing System for climate change

monitoring and one of the 15 ECVs accurately measured from space within the ESA Climate Change Initiative (CCI) project. While sea level is routinely measured by high-precision satellite altimetry since 20 years, providing a long, homogeneous and accurate sea level record using all altimeters satellites in orbit is the objective of the CCI 'Sea Level' project. This allows addressing major issues related to climate change and sea level (e.g., how much is the global mean sea level currently rising? Has it accelerated during the 20th century? Can we close the sea level budget? What are the factors causing non-uniform sea level change? Are observed spatial trend patterns due to internal climate variability only or can we already detect the signature of anthropogenic forcing?, etc.). The sea level products already obtained in the context of the CCI project have been proved to be superior to other existing products and are of great value for climate change studies. Moreover, combining different CCI-based ECVs (e.g., glaciers and ice sheet mass balances, in addition to the sea level ECV) plus Argo-based ocean thermal expansion leads to better closure of the sea level budget, allowing addressing important new issues, such as the amount of deep ocean warming (not measured by Argo) and its role in the present 'hiatus'. Finally, such long, accurate new ECV records are essential to validate climate models used to simulate future changes expected in response to anthropogenic global warming.

1105b - Quality and availability of data for global sustainability

ORAL PRESENTATIONS

K-1105b-01

Parameterisation, ground-truthing and
benchmarking: the importance of in-situ
data for global sustainability

S. Harrison (1)

(1) University of Reading, Reading, United Kingdom

Many key aspects of the global system can only be
measured in-situ. In-situ measurements are required
for ground-truthing remotely-sensed products. More
importantly, they are vital for developing process-
based models and individual model parameterisations.
Furthermore, in-situ measurements are used as
b benchmarks for model evaluation, including the historical
and palaeoclimate observations used for out-of-sample
model testing. Problematic features of in-situ data include
being collected by individuals, using different and evolving
methods, and often the same type of data is collected for
different purposes. Thus, key steps in using such data
are documentation, harmonization and synthesis. There
has been considerable progress in creating unified data
sets of in-situ measurements, but more effort is required
specifically in terms of data rescue, data documentation,
communal access and data stewardship. Given the utility of
in-situ data in developing and evaluating models that
are used to predict the likely trajectory of future climate
and environmental changes, organisations such as the
World Data Service and Future Earth need to provide
attention to and support for data rescue, synthesis and
sustainability of in-situ data.

K-1105b-02

Future Earth data and information needs

H. Mario (1) ; D. Ojima (2)

(1) Future Earth Engagement Committee, Future earth,
Geneva, Switzerland; (2) Colorado State University and Future
Earth US Hub, Natural Resource Ecology Laboratory, Fort
Collins, United States of America

Future Earth has been set up as a platform to deliver
solution-orientated research for sustainability, linking
environmental change and development challenges to
satisfy human needs for food, water, energy, health. This
will require an effective interdisciplinary collaboration
across natural and social sciences, humanities, economics,
and technology development, to find the best scientific
solutions to multi-faceted problems. The main aim is
to provide timely information for policy-makers by
generating the knowledge that will support existing

and new global and regional integrated assessments.
Therefore the main stakeholders are a heterogeneous
group of researchers (all scientific disciplines) and policy-
makers, all of them working jointly in co-designing and
collaborating with each other and knowledge. One
particular priority is in developing countries, mainly in
support to the Sustainable Development Goals (SDGs).

Recent advances in data collection and analysis provides
a unique opportunity to observe, detect and analyze the
earth dynamics at multiple scales and across interacting
social ecological system processes. This data explosion
has emerged through advances in remote sensing,
citizen science networks, and census efforts. These data
are being used in ways to enhance our understanding
and to inform management decisions on ways to reduce
the impact and reducing the harmful consequences and
enhancing opportunities as they arise. This information
era has benefits to food and water management, response
to hazard, forecasting of weather and extreme events,
alerting communities of dangers associated with plumes
of pollutants, and detecting the presence and movement
of rate and sensitive wildlife on land and in the seas. A
variety of biophysical and social-economic data sets
and observations are available and through coordinated
integration provide additional knowledge of the state and
transition of social-ecological systems across the globe in
order to better inform decision makers.

Such a very ambitious goal requires a wide range of data and information. Jointly with data, it also requires the expert knowledge networks associated with such data. The main challenge is for each individual scientific discipline, to further add value to their data and to re-packaged it, so that it can be understandable, usable and integrated with the data coming from all other disciplines and what is more important accessible to decision makers.

Future Earth hopes to initiate a suite of activities, such as:

* Data inventory, integration, harmonization and experts networks of data-knowledge to support Sustainable Development

* Co-development of data harmonization to facilitate integration of social-biophysical data to derive information in support of transformations toward sustainability

* Assessing data and information needs, and data use in support to the UNFCCC Adaptation activities

Enhancing capacity to enable the flow of interdisciplinary science in support of the decision making process (resilience, water management, sustainable development).
# Developing Indicators to Support Climate Adaptation and Sustainability Decision Making

R. Chen (1) ; A. De Sherbinin (1) ; M. Levy, (1)

(1) Columbia University, CIESN, Palisades, NY, United States of America

Every day, decision makers ranging from individuals to governments make important decisions based on composite economic and social indicators on topics such as unemployment, inflation, trade, debt, and prices. These indicators reflect the shared understanding that our global economy is a very complex, interconnected system that operates on multiple temporal and spatial scales. Yet, even though the global environment is at least as complex and interconnected as the global economy—and equally critical to humanity's survival—the world lacks integrated indicators of critical environmental systems and climate change that can provide the resolution, and relevance to support both individual and collective decision making on both short and long time frames.

We summarize experience to date in developing policy-relevant environmental indicators at global, national, and subnational levels and in tackling a range of scientific, technical, and institutional challenges related to designing and implementing useful indicators. Despite the growing diversity and volume of environmental data becoming available through new technologies, mobilizing and harnessing this "data revolution" to support sustainability science and decision making requires careful attention to user needs, establishment of suitable organizational and review processes to ensure "buy in" by stakeholders, and close collaboration with the relevant scientific communities and observational and data networks.

The ongoing development of a new set of Sustainable Development Goals (SDGs) and associated targets provides a unique opportunity to promote the integration of environmental, socioeconomic, and health data within a coherent framework of policy-relevant indicators. Such a framework would not only provide justification for continued or expanded investment in data collection and integration, but also a means to prioritize data collection efforts and improve their efficiency and efficacy. As with conventional economic indicators, the development of integrated environmental indicators is also likely to promote their use in both formal and informal decision making in both the public and private sectors.

# Marine community initiatives building biodiversity data systems and products in support of global change research

K. Deneudit (1) ; S. Dekeyzer, (1) ; B. Vanhoorne (1) ; L.

Vandepitte, (1) ; S. Claus, (1) ; F. Hernandez, (1)

(1) VLIZ - Flanders Marine Institute, Oostende, France

Global change research requires high quality and readily available biodiversity datasets that are standardized based on internationally accepted standards and can easily be used in integrative analyses that transcend geographic or administrative boundaries. The marine biodiversity community is progressively organizing itself to offer advanced data services and high quality data products. Diverse aspects of this work are ongoing in the framework of initiatives like the World Register of Marine Species (WoRMS), the Ocean Biogeographic Information System (OBIS), the European Marine Observation Network biological (EMODNet Biology) project and the LifeWatch European Research Infrastructure on biodiversity and ecosystem research.

The World register of Marine Species is an authoritative list of names of marine organisms. The content of WoRMS is controlled by more than 200 taxonomic experts, each of them responsible for a specific taxonomic group. The register currently holds over 419,000 species names described in literature worldwide, of which 190,400 (45%) were deemed duplicate identities. The register is a key instrument in biodiversity research, as it is used on a daily basis for taxonomic standardization and quality control of biological research and monitoring datasets.

The Ocean Biogeographic Information System is a network of OBIS nodes integrating biogeographic information for marine organisms on a global scale. Individual nodes contribute local or thematic datasets to the global system after standardizing these data based on OBIS and Darwin Core data schemas. OBIS holds 41.93 million distribution records of marine organisms from over 1,700 individual datasets.

In the framework of the LifeWatch taxonomic backbone and the EMODNet biology project large scale efforts are being initiated to collect species traits information and link this ecological attribute information to WoRMS and OBIS. These recent developments allow the creation of specific tools that have large potential for supporting applied global change research. An example is the World Register of Introduced Species, a newly launched portal that in its current state, we already lists over 1,400 introduced and invasive alien marine species worldwide, compiled through study of over close to 2,500 publications and collaboration with related international initiatives. In the framework of EMODNet a series of DIVA interpolated gridded abundance maps is being created for selected species reconstructing remarkable distribution patterns over time.

The generated data products are of direct relevance to global change studies on aspects like species distribution shifts, species extinction and migration, exploitation of ocean ecosystems and fish stock collapse, etc...

# Multi-Disciplinary Framework for BioEnergy Assessment

W. Hugo (1)

(1) ICSU-WDS, SAEON, Western Cape, South Africa

The BioEnergy Atlas for South Africa is the result of a project funded by the South African Department of Science and Technology, and executed by SAEON/NRF with the assistance of a number of collaborators in academia, research institutions, and government.

Bioenergy assessments have been characterized in the past by poor availability and quality of data, an over-emphasis on potentials and availability studies instead of feasibility assessment, and lack of comprehensive evaluation in competition with alternatives – both competing bioenergy resources and other renewable and non-renewable options. The BioEnergy Atlas addresses some of these deficiencies, and identifies specific areas of interest where future research and effort can be directed.

We develop an approach that successfully constrains biomass that is potentially available with environmental, social, financial, technical, and economic constraints, leading to an objective selection of appropriate feedstocks, land allocation, technology, and feasible projects for detailed investigation. We discuss methodology, availability of biomass and potentials, and the feasibility results of four case studies in respect of biomass application: (1) co-firing of woody biomass for electricity generation; (2) use of oil-bearing crops for biodiesel production, (3) applications for organic components of domestic solid waste and wastewater; and (4) use of woody biomass as a feedstock for an existing GTL refinery.

## Findings include

* Availability is not a fixed quantum. Availability of biomass and resulting energy products are sensitive to both the exclusionary measures one applies (food security, environmental, social and economic impacts) and the price at which final products will be competitive.

* Availability is low. Even without allowing for feasibility and final product costs, the availability of biomass is low.

* Waste streams are important. There are significant waste streams from domestic solid waste and sewage, some agricultural production, and commercial forestry.

* Rural firewood use is problematic. This is a significant resource, plays a large role in the energy budget of poor and rural households, and current use means that it will have little impact on the GHG emissions balance.

* Process technologies are not all mature, cost-competitive or efficient: We have investigated 52 different process technologies in respect of costs, economy of scale,
energy efficiency, greenhouse gas emission and job creation impacts, and maturity of technology.

* Solutions are probably 'packages'. One has to balance the diversity of available resource streams and processing technologies against the need to focus resources on development of critical mass (workforce skills, support industries, expertise). Combining feedstocks and aligning with other government initiatives or subsidies can achieve such critical mass more easily.

* Solutions must be robust in future too. Feasibility studies that focus on the current situation only ignore the fact that future sustainability is strongly dependent on assumptions on relative economic growth (influences household and industrial energy consumption, and the limiting cost of energy), cost of capital and inflation (affects choices of capital-intensive industries), exchange rates and fossil fuel prices (huge effect on selection of alternatives).

* The most promising biomass source is medium-term mining and eradication of invasive alien plants, but this source is limited in time and, if exploited as proposed, will not be available after about 20 years.

There is a need to focus research and development efforts in respect of specific technology/ feedstock combinations that show future promise.

## O-1105b-04

### Soil data harmonisation and geostatistical modelling efforts in support of improved studies of global sustainability

N. Batjes (1); B. Kempen (1); J. Leenaars (1); R. Vandenbogaard (1)

(1) ISRIC – World Soil Information, Wageningen, Netherlands

Future Earth and other large international research and development programmes aim to provide the scientific evidence base required for developing into a sustainable future. Soil, which is an important provider of ecosystem services, remains one of the least developed data layers in global land models. Uncertainties are large. In this context, there is a pressing need for improved, quality-assessed soil information at multiple scale levels. ISRIC – World Soil Information, in its capacity of World Data Centre for Soils within the ICSU World Data System, is developing inter-operable web-based facilities aimed at facilitating collaborative soil mapping. The Global Soil Information Facilities (GSIF) provide a global spatial framework for collating, standardising resp. harmonising, and analysing soil data profile obtained from disparate sources. At present, the facility includes a 3D soil information services for the world at 1 km resolution (SoilGrids1km), which draws on analytical data for some 100,000 soil profiles and over 70 co-variate layers representing soil-forming factors. Global regression models were used to predict values (mean and 90%-confidence interval) for selected soil attributes (e.g. soil pH, clay content, bulk density, and organic carbon content) for six depth intervals up to a depth of 2 meter. Cross-validation for the initial run showed prediction accuracies of 23%-51%, which is promising. Being based on reproducible automated procedures, the geo-statistical predictions are improved on a regular basis. New releases will consider a larger complement of harmonised soil profiles for the World, as collated and shared for example within the broader collaborative framework of the Global Soil Partnership (GSP), as well as more advanced geo-statistical approaches into three high-level categories: curtailed data products, research partnerships, and cyberinfrastructure and development.

as well as to create the necessary expertise and capacity to further develop and test the system worldwide. The system can also be used as the basis for a distributed system, where national soil institutes build and provide standardised databases and digital soil maps for their respective regions, which can then be 'combined' with the SoilGrids-derived information to arrive at a product with global coverage and local ownership, possibly within the framework of the Global Soil Partnership.

## O-1105b-05

### Supporting Climate Science with Cryospheric Data from the National Snow and Ice Data Center DAAC

B. Johnson (1); S. Tanner, (1); A. Leon, (1)

(1) National Snow and Ice Data Center, NSIDC DAAC, Boulder, CO, United States of America

Global satellite observations are central to understanding and monitoring our climate system. The physical processes operating in the Earth's cryosphere and their interactions with climate are tightly coupled. A change in one of its component will drive change in another. To improve our understanding of how a changing climate may drive these changes and how feedback processes in the cryosphere affect climate requires continuation of long-term satellite observations, intensive field and airborne campaigns and new ways to analyze observational data and to integrate them with large-scale Earth system models. Polar science has historically involved interdisciplinary research programs, and the collection and management of large, diverse data sets.

The National Snow and Ice Data Center (NSIDC) at the University of Colorado at Boulder is a primary archive for snow and ice data in the United States. NSIDC's mission is to improve understanding of the Earth's frozen realties. This includes floating sea ice, lake ice, glaciers, ice sheets, snow cover, and frozen ground, collectively known as the cryosphere. The NSIDC Distributed Active Archive Center (DAAC) is one of NASA's Earth Observing System Data and Information System (EOSDIS) Data Centers archiving, documenting, and distributing data from NASA's Earth Observing System (EOS) satellites and field measurement programs. NSIDC DAAC data management involves activity at all stages of the data lifecycle, from planning through acquisition, preservation, publication, and distribution.¹ A key goal for NSIDC is to meet our data user needs in a way that facilitates data use. This is accomplished through improvements in data inter-operability, usability, data searching, and visualization and analysis tools.

## O-1105b-06

### The World Data Service at the University of Colorado Boulder and National Snow and Ice Data Center: Data and services supporting science

L. Yarmey (1); R. Duerr (1)

(1) WDS-UCB National Snow and Ice Data Center, Boulder, CO, United States of America

The World Data Service at the University of Colorado Boulder (UCB) led by the National Snow and Ice Data Center (NSIDC) is a leader in connecting data and science. These connections are built through targeted programs brought together under the NSIDC umbrella categorized into three high-level categories: curtailed data products, research partnerships, and cyberinfrastructure and development.

The 432 datasets in the WDS-UCB/NSIDC catalog include some of the most popular and visible datasets at the Data Center, for instance the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration as well as decades-long sea ice extent, concentration, and thickness time-series. The Frozen Ground Data Center at WDS-UCB/NSIDC is in the process of being updated and integrated with the new Global Terrestrial Network for Permafrost system. In-situ field data such as from the Snow Data Assimilation System (SNOWDAS) are available alongside products such as the MODIS Mosaic of Antarctica Image map. All of the digital datasets are augmented by critical legacy data often in analog form, for instance the global Glacier Photo collection as well as many resources from
the rich history of the International Geophysical and Polar Years.

Ensuring a strong connection with not only scientists in both the data contributor and data re-user roles, but also the general US public and indigenous Arctic communities, WDS-CU researchers maintain tight partnerships with stakeholder communities. The Exchange for Local Observations and Knowledge of the Arctic (ELOKA) programs has spent years building relationships that support and connect Community-Based Monitoring programs embedded in Arctic communities with each other and with environmental scientists. Projects looking to document sea ice knowledge, partner WDS-UCB/NSIDC researchers with shipping operations, Arctic community, and semantic experts to map understandings and advance understanding across different perspectives. A growing Arctic social science data program at WDS-UCB/NSIDC reaches out to another domain community to expand interdisciplinary context and participation in data sharing efforts. Connecting WDS-NSIDC resources to stakeholder communities requires clear communication and a shared understanding of use cases and stakeholder needs. An emphasis on usability work with website interfaces has improved connections and communication of content.

Supporting and leveraging both the management of well-described data holdings and tight connections with partners and stakeholders, WDS-UCB/NSIDC maintains a strong cyberinfrastructure research and development focus. Expertise in metadata and data brokering enables distributed data search and has been showcased in diverse venues over recent years. Web crawling for science data of relevance moves the community closer to ubiquitous data discovery. Once relevant data are found, reading and analysis tools support data use and integration for new scientific discoveries.

All of these targeted programs and more come together under the virtual umbrella of the WDS-UCB/NSIDC. Active participation in the WDS community and connections to the aligned Solar activities and systems are key to advancing our common vision.

1105 - POSTER PRESENTATIONS

P-1105-01

WDC - Solar Activity/BASS2000

J. Aboudarham (1); X. Bonnin (1)

(1) Observatoire de Paris, LESIA - OV Paris, Meudon, France

The understanding of space weather, solar-terrestrial relationship as well as the possible correlation with Earth's climate and solar activity is related to the possibility to study long-term behaviors. World Data Centre for Solar Activity BASS2000 (http://bass2000.obspfm.fr) provides added-values on solar activity that can be used for such studies. It provides daily observations of the Sun for about 20 years, and older images, starting in 1919 are currently digitalized.

Moreover, in collaboration with the European HELIO project, a features catalogue has been developed giving detailed information on various solar and heliospheric features (filaments, prominences, sunspots, active regions, coronal holes, radio sources, type III bursts) for near 20 years also for some of them. And previous data have been digitalized from tables obtained from the Synoptic Maps of Solar Activity since 1919. When the insertion of those data in the features catalogue will be done, nearly one century of data will be available, providing the longest time signature of Solar activity, with around 8 solar cycles available.

P-1105-02

The role of the GCOS Reference Upper-Air Network (GRUAN) in climate research

G. Bodeker (1); M. Sommer (2) ; R. Dirksen, (2) ; P. Thorne, (3)

(1) Bodeker Scientific, Alexandra, New Zealand; (2) Deutscher Wetterdienst, Lindenberg, Germany; (3) Maynooth University, Department of geography, Maynooth, Ireland

Measurements of primary state variables of the troposphere and stratosphere (primarily temperature, water vapour and

pressure) are typically made to provide the input required by numerical weather prediction models. These same measurements then also constitute the primary source for meteorological reanalyses and climate analyses. The balloon-borne, ground-based and satellite-based systems used to make these measurements often undergo changes in instrumentation, data processing methods, retrieval techniques, and calibration. These changes are often poorly documented and very seldom are measured series reprocessed to ensure long-term homogeneity of the climate data record. Such unphysical discontinuities in measurement can lead to deterioration of the quality of meteorological reanalyses. To address this specific deficiency of the global climate monitoring network, WMO and GCOS called for the establishment of a new state-of-the-art global network of high quality measurements of essential climate variables in the upper atmosphere, through the 2004 GCOS Implementation Plan (GCOS-92). The establishment of GCOS Reference Upper-Air Network) is now underway and sites are providing reference quality measurements that adhere to GRUAN operating protocols.

This presentation will provide an overview of the achievements of GRUAN to date as summarized in Bodeker et al. (in press 2015). It highlights:

- the protocols that have been established to ensure that measurements are of reference quality;

- what measurement systems are (and will be) operating at GRUAN sites;

- what data products are expected to flow from those systems;

- the data currently flowing from GRUAN sites, technical advancements within GRUAN to meet the needs of user of GRUAN data products; and

- research that has been conducted in support of GRUAN operations.

A network expansion workshop held in June 2012 provided a scientific context for the expansion of GRUAN and this presentation will include an update on how the outcomes of that workshop have guided GRUAN expansion to date. The goal of GRUAN is not only to produce long-term, carefully calibrated measurements with well-defined measurement uncertainties, but to also produce high quality data suitable for focussed process studies. How GRUAN balances operational and research goals will be included in the presentation. A key user of GRUAN data is the satellite calibration and validation community. Progress within GRUAN to meet the needs of this community will also be addressed. The presentation will finish with an overview of the challenges that GRUAN faces and plans for overcoming those challenges.

References

Bodeker, G.E.; Bojinski, S.; Cimini, D.; Dirksen, R.J.; Haeffelin, M.; Hannigan, J.W.; Hurst, D.F.; Leblanc, T.; Madonna, F.; Maturilli, M.; Mikalsen, A.C.; Philipona, R.; Reale, T.; Seidel, D.J.; Tan, D.G.H.; Thorne, P.W.; Vömel, H. and Wang, J., Reference upper-air observations for climate: From concept to reality, Bull. Amer. Meteor. Soc. 2015, GCOS-92, Implementation plan for the global observing system for climate in support of the UNFCCC.WMO/TD No. 1219, 2004.

P-1105-03

A Climate Observatory in South West Indian Ocean: The Maïdo Observatory in La Réunion. Current achievements and Future Prospects

JP. Cammas (1) ; C. Barthe (2) ; E. Blanc (3) ; C. Brognez (4) ; A. Colomb (5) ; V. Dufloit (1) ; P. Goloub (4) ; A. Hauchecorne (6) ; N. Kaempfer (7) ; P. Keckhut (8) ; G. Payen (1) ; T. Potaïfaix (2) ; F. Posny (2) ; M. Ramonet (9) ; J. Sciare (9) ; K. Sellegrui (5) ; P. Tulet (2) ; F. Vimeux (9) ; DJB. Leclair (1) ; MM. De (10)

(1) CNRS & Université de La Réunion, OSU-Reunion, Saint Denis de la Réunion, France; (2) CNRS & Université de La Réunion, Lacy, Saint Denis de la Réunion, France; (3) CEA, DASE, Arpajon, France; (4) CNRS and Université de Lille, Loa, Lille, France; (5) CNRS and Université Blaise Pascal, Lamp, Clermont-Ferrand, France; (6) CNRS, Latmos, Guyancourt,
in order to continuously monitor shallow (-10 to -16 m) seawater temperature for use in climate and tropical cyclone prediction models. The shallow water thermistors monitor temperature on a 600-second sampling interval and are averaged every 6 to 10 months, with the data being uploaded on the GOPS/ReefTEMPS data portal for free use by researchers and students. Currently the Fiji monitoring network consists of 10 sites (both in the lagoon and outer reef slope) spanning the northernmost isolated island of Rotuma to Kadavu Island in the south. Further shallow-water sites to be deployed this year (including the southernmost Ceva-i-Ra reef) should bring the total to 14. To date, some 13 datasets representing over 100 months of continuous seawater temperature monitoring for Fiji have been obtained in the context of this ongoing project. Preliminary analysis of the data has shown that the highest seawater temperatures occur in the months of February and March, with episodes that can last several days above 29°C, creating favourable conditions for tropical cyclone generation and also heightening the risk of major coral bleaching events. Such in-situ data is also essential to ground-validate data from the Satellite Virtual Station time series graphs of sea surface temperature (SST) and Coral Bleaching Degree Heating Weeks (DHW) provided by the US National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch Satellite Virtual Station in Fiji (REEF) -18.5° lat. 178.5° lon). Over the course of 2015, the monitoring network will be further expanded in depth, with a line of thermistors deployed at -55, -75 and -90 m to measure rapid temperature variations, helping to monitor ENSO effect on the thermocline depth in coastal areas, with implications for the distribution of fish and marine invertebrates and the detection of seasonal upwelling zones of cooler waters that could mitigate coral bleaching. The deeper sensors, with sampling intervals of 30 to 60 seconds, will also help to monitor rapid variations in temperature linked to internal waves in Fijian coastal areas, with implications for the understanding of the deep transfer of mass, momentum and heat which is critical for developing more accurate climate models. This would be the first time such a study is carried out in the Southern Pacific Ocean.

## P-1105-06

### Monitoring the Climate of the Upper Troposphere and Lower Stratosphere with Radio Occultation Data

U. Foelsche (1); B. Scherllin-Pirscher (2); J. Danzer (2), F. Ladstädter (1); A. Steiner (3); G. Kirchergast (2)

(1) University of Graz, Institute for Geophysics, Astrophysics, and Meteorology, Graz, Austria; (2) University of Graz, Wegener Center for Climate and Global Change, Graz, Austria; (3) Wegener Center for Climate and Global Change, University of Graz, Graz, Austria

The Radio Occultation (RO) technique has originally been developed in the 1960s for the study of planetary atmospheres and ionospheres. Accurate RO measurements of the Earth's atmosphere became feasible in the 1990s, with the precise radio signals of the GPS satellite system (guaranteed by on-board atomic clocks). A few hundred times per day, a satellite in low Earth orbit (LEO) sees one of the GPS satellites setting or rising behind the Earth's horizon. In this situation, geometry, the GPS satellite's signals have to pass through the Earth's atmosphere and they are characteristically influenced (slowed and bent), depending on the density of the atmosphere. The respective motion of the satellites provides a scan through the atmosphere. Accurate measurements of the change in the GPS signal (onboard the LEO satellite) therefore allow to reconstruct the atmospheric density and, subsequently, profiles of pressure, wind and temperature. Measurements can be performed during days, nights over oceans and land, and even inside clouds. During the last few years, RO measurements have been increasingly used by weather centers around the globe, and they a surprisingly large positive impact on the quality of atmospheric analyses (which are used as starting points for weather forecasts).

RO data a very well suited for climate applications, since they do not require external calibration and only short-term measurement stability over the occultation event duration (1 - 2 min), which is provided by the atomic clocks onboard the GPS satellites. With this "self-calibration", it is possible to combine data from different sensors and different occultation missions without need for inter-calibration and overlap (which is extremely hard to achieve for conventional satellite data).

Using the same retrieval for all datasets we obtained monthly refractivity and temperature climate records from multiple radio occultation satellites, which are consistent within 0.05 % and 0.05 K in almost any case (taking global averages over the altitude range 10 km to 30 km). Longer-term average deviations are even smaller. Even though the RO record is still comparatively short, its high quality already allows to see statistically significant temperature trends in the lower stratosphere.

## P-1105-07

### Aerosol optical properties and dynamic variability of climatic seasons in west Africa: Case study of Ouagadougou

B. Korgo (1); J.C. Roger (2); J. Bathiebo (3)

(1) University of Ouagadougou, Physique, Ouagadougou, Burkina Faso; (2) University of Maryland, Geography, Washington, United States of America; (3) University of Ouagadougou, Physics, Ouagadougou, Burkina Faso

We present in this paper a climatological study of the optical properties of the atmosphere in West Africa. Using the measurement and photometric inversions data of AERONET in Ouagadougou, we analyze the main optical characteristics such as optical thickness, Angstrom exponent, the single scattering albedo and the asymmetry factor. These properties give quite varied information about the size and chemical nature of atmospheric aerosols in West Africa, particularly in the Sahel region. A study of different variabilities of these properties on a monthly and yearly scale, shows a strong connection with the seasonal succession of dry period marked by the predominance of harnettian winds from the Sahara Desert, laden with dust and wet period characterized by the thrust of the monsoon flow wet period laden with moisture, specific to this part of the world. The spatial and temporal evolution of these atmospheric variables coupled with the dynamics of West African climate allows monitoring of the ascent to the north of the intertropical front marking the beginning of the wet season and its come back to the south at the end of this season. An appropriate positioning of AERONET photometric measurements points can allow a long-term monitoring at the regional level of the beginning, the end and the length of seasons and as such appears as a real tool for monitoring climate change in West Africa.

## P-1105-08

### Geospatial land use analysis and its relation to the climate change

M. Lavreniuk (1); A. Shelestov (2); N. Kussul (1); S. Skakun (3)

(1) Space research institute NASU-SSAU, Kyiv, Ukraine; (2) National University of Life and Environmental Sciences of Ukraine, Kyiv, Ukraine; (3) Integration-Plus Ltd, Kyiv, Ukraine

Land use analysis plays an important role in studying and understanding processes in ecosystems and solving many applied problems based on satellite monitoring. In particular, it allows to improve the accuracy of classification and areas estimation and to analyze climate change and its impact on agricultural production and whole biosphere. Since the 1980s there are many land use datasets based on satellite images, but they had low spatial resolution and accuracy. Also, in 2013-2014 years, several global maps have been made available, but they are not accurate enough at regional level. Low-resolution maps underestimate or overestimate certain land cover types. Therefore, creation of global and regional land cover maps based on high-resolution satellite images (such as Landsat series at 30 m) is an extremely important task. In this study, we produced land cover maps for the whole territory of Ukraine based on the Landsat-4/5/7 images for three decades: 1990s, 2000s and 2010s. These maps allow estimation of the general trends of land cover/use in Ukraine and discovering how geospatial land use influence on the climate change. This paper discusses methodological aspects to obtain a retrospective maps of land cover based on Landsat images at regional scale, including all preprocessing steps for satellite imagery/formation of training and test sets, classification method and result analysis.

Training (50%) and test (50%) sets consist of six main land cover classes: artificial surface, cropland, grassland, forest, bare land and water. We formed sets using a photo
interpretation method with uniform spatial distribution over the target territory and proportional representation of all classes. Images contained six spectral bands and three bands with shadow, cloud and cloud contours masks. We selected images with less than 50% of cloud cover for classification. First, we restored cloudy pixels from time-series of images using self-organizing Kohonen maps (SOMs). After that, we provided classification based on the time-series of restored images available for the certain year [1]. Classification was done using an ensemble of neural networks, namely multilayer perceptrons (MLPs) and such an approach have been provided better result than single neural network. After classification, each neural network gave a posteriori probability of the input pixel belonging to each class. In an ensemble, we estimated the average a posteriori probability from all networks and assign to the pixel class with the highest probability.

We estimated the accuracy of classification on independent test set. The overall classification accuracy achieved in the study was approximately 95%. Accuracies for each individual class were more than 70%. The lowest accuracy was for grassland since it is difficult to separate grassland from cropland. At the same time, we compare the obtained areas and official statistics for each oblast and for the whole territory of Ukraine for each time period (1990, 2000, 2010). In addition, we compared the accuracy of our classification for Ukraine with global land cover map GlobeLand30-2010 at 30 m resolution. The overall classification accuracy for Ukraine was 5% higher than GlobeLand30-2010. Accuracy of grassland classification was +10% (producer accuracy) and +45% (user accuracy) better than GlobeLand30-2010.

This paper presented a retrospective land cover mapping methodology for the territory of Ukraine based on Landsat data at 30 m resolution. The proposed methodology involved classification of multi-temporal satellite images with neural networks on previously restored cloudy pixels. The map was produced for the whole territory of Ukraine. The use of the proposed approached allowed us to achieve overall classification accuracy of 95% for three different time periods and improve quality of maps comparing to other land cover maps available for Ukraine, namely GlobeLand30-2010. At the presentation the results of climate changes influence on land use will be discussed in more detail.

[1] F.J. Gallego, N. Kussul, S. Skakun, O. Kravchenko, A. Shelestov, and O. Kussul, "Efficiency assessment of using satellite data for crop area estimation in Ukraine," International Journal of Applied Earth Observation and Geoinformation, vol. 29, pp. 22–30, 2014.

## P-1105-09

### The BIOMASS satellite mission: quantifying global biomass, an essential variable of the climate system

T. Le Toan (1); P. Ciais (2); S. Quegan (3); K. Scipal (4)

(1) CESBIO, Toulouse, France; (2) IPSL, Lsce, Gif sur Yvette, France; (3) University of Sheffield, Sheffield, United Kingdom; (4) ESA, Estec, Noordwijk, Netherlands

Quantifying the global carbon cycle is essential to understanding many of the changes taking place in the Earth system and improving future projections. There is strong evidence that over the last 50 years, the terrestrial biosphere has acted as a net carbon sink, removing from the atmosphere approximately one third of the CO2 emitted by fossil fuel combustion. However, the status, dynamics and evolution of the terrestrial biosphere is the least understood and most uncertain element in the carbon cycle. Coupling between the terrestrial carbon cycle and climate has been identified by the IPCC as one of the major areas of uncertainties in the distribution of carbon stocks and carbon exchange, in the estimates of carbon emissions due to forest disturbances, and in the uptake of carbon through forest growth. A fundamental parameter characterising the spatial distribution of carbon in the biosphere is biomass, and forest comprise~80% of the terrestrial above ground biomass. Most of the biomass is in tropical forest that are projected by models to be vulnerable to drought in the future.

Because of its importance for climate, biomass is identified by the UNFCCC as an Essential Climate Variable needed to reduce uncertainties in our knowledge of the climate system (GCOS, 2010). Furthermore, sequestration of

carbon in forest biomass is a critical mechanism for mitigating climate change, as recognised by REDD+ initiatives, which use market and financial incentives to reduce the emissions of GHG from deforestation and forest degradation.

The BIOMASS mission is the Seventh ESA Earth Explorer mission, selected in May 2013, for a launch in 2020. The primary goal of the BIOMASS mission is to measure the global distribution of above-ground forest biomass (AGB) and its changes in order to provide greatly improved quantification of the size and distribution of the terrestrial carbon pool, and much improved estimates of terrestrial carbon fluxes. In particular, by monitoring and quantifying disturbances and growth in forests, BIOMASS will yield new knowledge about the size and location of terrestrial carbon sources and sinks, and how forest disturbance trigger loss of biomass and subsequent forest regeneration.

Biomass will measure and map forest carbon stock, as well as forest height, over tropical, temperate and boreal forests at a spatial resolution of around 200 m every 6 months throughout the five years of the mission. However, the particular focus is on the carbon-rich dense tropical forests which contribute by far the largest portion of stock biomass. In addition also the largest of the same sensor, will significantly reduce the uncertainties in biomass retrievals and contribute to meeting the target of 20% accuracy in AGB at a resolution of 200 m. The spatial consistency of these products together with their provision as time series, means that they will contribute significantly to improving the accuracy of the Land Use Change flux and better quantifying dynamic spatial processes in the world's forests. These BIOMASS products can also be used as unbiased reference data for national reporting for initiatives such as REDD+.

The combination of three measurement techniques, namely polarimetric SAR, interferometric interferometric SAR and polarimetric SAR all using the same sensor, will significantly reduce the uncertainties in biomass retrievals and contribute to meeting the target of 20% accuracy in AGB at a resolution of 200 m. The spatial consistency of these products together with their provision as time series, means that they will contribute significantly to improving the accuracy of the Land Use Change flux and better quantifying dynamic spatial processes in the world's forests. These BIOMASS products can also be used as unbiased reference data for national reporting for initiatives such as REDD+.

Comparing BIOMASS data with biomass calculated by carbon models, or assimilating biomass in those models, will provide a way of testing the models and also give indications on the sources of discrepancy. Comparison of existing models indicates that they are very difficult to estimate the absolute magnitude of biomass and its spatial distribution, and that a large part of the misrepresentation of biomass comes from the lack of considerations of disturbances and land use change and incorrect modeling ecosystem processes such as mortality.

The paper will present an overview of the BIOMASS mission, and will discuss the use of BIOMASS data to improve a forest productivity modeling and to allow forcing of Dynamic Vegetation Model simulations under future climatic scenarios.

## P-1105-10

### The Pacific Islands Global Climate Observing System (PI GCOS): Where to Next?

PF. Lefale (1); HJ. Diamond, (2)

(1) Bodeker Scientific, Wellington, New Zealand; (2) Victoria University of Wellington, Geography department, Wellington, New Zealand

The Tropical Western Pacific (TWP) is the 'ground zero' engine of the global climate system. It is home to some of the largest natural drivers of the climate system; the biggest ocean on the planet, including the El Nino Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO). Despite this, the TWP is one of the least observed and monitored regions of the world. Yet, the needs for climate system monitoring, climate change detection and monitoring the impacts and the response to climate change, especially marine ecosystem, ocean acidification and mean sea level rise, and research toward improved understanding, modelling and prediction of the climate system are fundamental in understanding the properties and evolution of the earth's climate system.

The Pacific Islands-Global Climate Observing System (PI-GCOS) is one of only a few international-sponsored regional programs established in the early 2000s to assist
Pacific Islands and the international scientific community to observe and monitor the TWP region. The PI GCOs program started in Apia, Samoa, in 2000. It is a sub-program of the international GCOs aimed specifically at meeting climate and related observing needs of Pacific Islands. The outcomes of the Apia GCOs workshop, combined with the findings and recommendations of the Secretary of the Pacific Regional Environmental Program (SPREP)/World Meteorological Organization (WMO) led Pacific Regional Services Project (PMSNAP) report in 2000, provided the foundation for the development of the PI-GCOs Program. As a result, a PI GCOs Action Plan (Salinger et al., 2002) was developed to help establish and guide the program by identifying GCOs requirements in the region and outline an approach to address these needs in a short strategy document (see http://www.wmo.int/pages/prog/gcos/documents/PI-GCOs_Ap.pdf). The regional PI GCOs Officer was hired and hosted by the SPREP in Apia, Samoa from 2004 to 2012 to manage the program. Unfortunately, due to a lack of sustained resources, the program was only active until 2012 at which point it went dormant.

This presentation will summarise key preliminary findings & recommendations of the Review of the PI GCOs ("the Review") that is currently underway to look at resurrecting the program on behalf of GCOs region as part of a formal bilateral climate activity between New Zealand and the United States agreed to in September 2014. The Review assesses the balance and relevance of the PI GCOs, its achievements, relations between PI GCOs and partner organizations and Members, its functions and governance mechanisms, and vision and future plans. The Review arises from the realization that there is an urgent need to re-establish the PI GCOs Program in light of the increasing demand for climate and related services in the Pacific Islands and internationally. The need for improved climate observations in the Pacific region has already been identified and if efforts such as the delivery of climate monitoring, research and services in the Pacific through the UNFCCC, the IPCC and Global Framework for Climate Services (GFCS) are to be successful, then re-establishing the PI GCOs is an essential pre-requisite.

P-1105-11

Tipping point analysis of atmospheric
oxygen concentration

V. Livina (1) ; V. Teresa (2) ; A. Forbes (1)

(1) National Physical Laboratory, Tidworth, United Kingdom; (2) John Innes Centre, Norwich, United Kingdom

We apply tipping point analysis to nine observational oxygen concentration records around the globe, analyse their dynamics and perform projections under possible future scenarios leading to oxygen deficiency in the atmosphere. The analysis is based on statistical physics framework with stochastic modelling, where we represent the observed data as a composition of deterministic and stochastic components estimated from the observed data using Bayesian and wavelet techniques.

P-1105-12

OneGeology - A distributed data system that enables access to up-to-date global geoscience data

K. Marko (1) ; D. Tim (2) ; F. Robida (3) ; H. Matt (2) ; A. Lee (4)

(1) OneGeology, Keyworth, United Kingdom; (2) BGS, Keyworth, United Kingdom; (3) BRGM, Orleans, France; (4) Arizona Geological Survey, Tucson, United States of America

OneGeology is an initiative of Geological Survey
Organisations (GSO) around the globe that dates back to
Brighton, UK in 2007. Since then OneGeology has been a
leader in developing geological online map data using a
new international standard a geological exchange
language known as the 'GeoSciML' (currently version 3.2
exists, which enables instant interoperability of the data).
Increased use of this new language allows geological
data to be shared and integrated across the planet with
other organisations. One of very important goals of
OneGeology was a transfer of valuable know-how to the
developing world, hence shortening the digital learning
curve. In autumn 2013 OneGeology launched a Consortium with a clearly defined governance structure,
making its structure more official, its operability more

flexible and its membership more open where in addition to GSO also to other type of organisations that manage geoscience data can join and contribute. The next stage of the OneGeology initiative will hence be focused into increasing the openness and richness of that data from individual countries to create a multi-thermal global geological data resource on the rocks beneath our feet. Authoritative information on hazards and minerals will help to prevent natural disasters, explore for resources (water, minerals and energy) and identify risks to human health on a planetary scale. With this new stage also renewed OneGeology objectives were defined and these are 1) to be the provider of geosciences data globally, 2) to ensure exchange of know-how and skills so all can participate, and 3) to use the global profile of IG to increase awareness of the geosciences and their relevance among professional and general public. We live in a digital world that enables prompt access to vast amounts of open access data. Understanding our world, the geology beneath our feet and environmental challenges related to geology calls for accessibility of geoscience data and OneGeology Portal (portal.onegeology.org) is the place to find them.

P-1105-13

Getting Back to the Source: A review of
Earth science data citation and access

M. Parsons (1)

(1) Research Data Alliance, Boulder, France

Creating a great data set can be a life's work (consider Charles Keeling). Yet, scientists not receive much recognition for creating rigorous, useful data. At the same time in a post "climateable" world there is increased scrutiny on science and a greater need than ever to adhere to scientific principles of transparency and reproducibility. In this sense it is clear that scientific assertions must be backed up by precise pointers to the actual evidence used. In many cases this should take the form of a data citation. Indeed the IPCC has increasingly rigorous data citation requirements for its assessment.

The concept of data citation has gained significant traction in recent years. This is most apparent in the Joint Declaration of Data Citation Principles. Some communities such as DataVerse, CitationCite, and the Earth Science Information Partners have developed specific guidelines on how to actually cite data. Challenges remain, however, on how to precisely cite specific subsets of very dynamic data. Moreover, there is still some confusion on the purposes of data citation.

This presentation will review the current state of the art in data citation with a special emphasis on new developments coming out of the Research Data Alliance, Force1, and elsewhere. It will make concrete recommendations on the purposes and approaches of data citation, especially in the context of climate research and assertions.

P-1105-14

ICOS Atmospheric Thematic Center

L. Rivier, (1) ; L. Hazan (1) ; O. Laurent, (2) ; T. Laurila (3) ; M. Ramonet (4) ; J. Tarniewicz (1) ; C. Yver-Kwok, (2) ; S. Karri (3) ; H. Aaltonen (3) ; O. Jossoud (1) ; A. Guemri (1) ; C. Garrec (1) ; C. Milcent (1) ; A. Abbaris (1) ; J. Helle, (5) ; C. Philippon (1) ; S. Delalande (1) ; N. Kachroudi (1) ; S. Ars (1) (1) LSCE, Gif sur Yvette, France; (2) LSCE, Gif-sur-Yvette, France; (3) FMI, Helsinki, Finland; (4) CNRS and Université de Versailles Saint Quentin, Lsie, Gif Sur Yvette, France; (5) LSCE, Cea/cnrs/uvsq, Gif-sur-Yvette, France

ICOS is a recently-launched, world-class research infrastructure dedicated to the monitoring and improved understanding of carbon sources and sinks. It consists of complementary, harmonized networks of long-term monitoring stations focusing on Europe and adjacent regions. The ICOS networks will comprise about 40 operational atmospheric stations (measuring atmospheric composition in greenhouse gases and other core parameters), 40 ecosystem stations (measuring fluxes from ecosystems) and about 20 oceanic measurement platforms.

The networks are coordinated through a set of central
facilities: three thematic centres respectively for
atmospheric, ecosystem and ocean data, and a central
analytical lab.The Atmospheric Thematic Center (ATC) has
two main functions:

1. Operate the atmospheric data processing chains, going from data transmission from stations to the routine delivery of quality checked data-stream

2. Carry out regular measurement technology survey, analysis and enable development of new sensors and their testing prior to field deployment in ICOS

The presentation will describe state of the art of atmospheric GHG measurement and data processing with a special focus on quality assessment. It will also present new measurement technique, like isotopic measurement, that can attribute GHG concentration changes to different emission sources.

## P-1105-15

### Steps toward effective multi-disciplinary research data management systems

D. Schade (1)

(1) National Research Council Canada, Canadian Astronomy Data Centre, Victoria, BC., France

Astronomy is often viewed as a discipline whose data management needs are well taken care of whereas a great many other research disciplines (the "long tail") are suffering from the absence of good data management systems. Technology and data management practice evolve rapidly and I would argue that no area of research, including astronomy, has any real degree of security for the future of its data collections. Nevertheless, astronomy has a long history of digital data handling and thus has considerable experience and expertise that should be shared with other fields. It is important to acknowledge that astronomy is only one of many disciplines that could collectively share experience with other, less "well-served" communities. It is also important to recognize that we all have much to learn from one another and that interaction with "long tail" research communities will result in better data management practices for astronomy.

Astronomy was part of the "long-tail" or research data 25 years ago. It's data collections were small, heterogeneous, lacked common standards, and were not interoperable. The properties of the data and data management have changed dramatically (although we still face many challenges) and they have changed because of the hard work of dedicated cross-disciplinary teams of scientists and technologists. But our field has some demonstrable successes to our credit and has learned some profound lessons.

The central problem in creating multi-disciplinary data management systems is the development of Common Data Models that cross disciplinary boundaries. That means managing metadata in a way that supports the use cases of the multi-disciplinary research communities. This is true for all fields, including those that address climate change. The reality of astronomy data is that it is still produced in formats that represent thousands of "native data models" from thousands of different instruments. (A "data model", in our vocabulary, is the structure that carries the meaning of the data and metadata.) The challenge is to develop a data model that supports the transformation of a large set of heterogeneous native data models into a Common Data Model. The Common Data Model (CDM) supports the data management functions (curation, discovery, data access, data security) spanning diverse data collections.

This is the same problem that we face in creating multi-disciplinary data management systems. The process for solving the problem will be very similar. Collect research use cases and define requirements. Identify the metadata elements that are required to satisfy those requirements. Analyse where, in the native data models, those elements can be sourced or which elements can be transformed to produce the needed elements. It is true that we have diverse ways of representing even fundamental quantities like time and place (astronomy faces the same problem itself) but these can be reconciled.

Two points are worth mentioning with respect to Common Data Models. First, there exists no ideal, complete, and all-encompassing Common Data Model. Second, there is no "lossless" Common Data Model. Compromises are involved and loss of information may take place. A Common Data Model is implemented for the purpose of unifying

diverse data collections. At the Canadian Astronomy Data Centre we ended 25 years of creating silos for each data collection by integrating 119 native data models into a single common model. Now there is a single path (shared by all interfaces) to using our data collections. The next step is to move into other research domains by building significant collaborations with other data management communities.

## P-1105-16

### Current status and strategies of biodiversity data integration in Taiwan

KT. Shao (1)

(1) Biodiversity Research Center, Academia Sinica, Taipei, France

The integration of Taiwan's biodiversity databases started in 2001, the same year that the Ministry of Science & Technology launched the National Digital Archives Program, the Executive Yuan began the Biodiversity Promotion Plan, and Taiwan joined GBIF as an Associate Participant. Taiwan, hence, embarked on a decade of integrating biodiversity data. Afterward, the "Catalog of Life in Taiwan" (TaiCOL) [57,000+ native species], Taiwan's node of GBIF (TaiBIF) [2.8 M+ georeferenced distributional data], the "Cryobanking and Barcode of Life for Wildlife Genetic Material in Taiwan" (TaiBOL) [3,000 species with 12,000 barcode] and "Taiwan Encyclopedia of Life" (TaiEOL) [18,000+ species pages] are established, integrated and open to public access. The databases aim to promote the collection and integration of national biodiversity data and should be useful for future climate change researches. These databases intimately collaborate with their corresponding global databases of COL, GBIF, BOL and EOL, respectively. Raw data, especially those of ecological distribution generated by different government agencies or NGOs, are nevertheless still dispersed due to assorted reasons. Most people agree that it is imperative to integrate databases, but many researchers are unwilling to invest in database building — a kind of academic services — under the current academic evaluation system. Thus a cross-agency committee of GBIF / Chinese, Taipei was established in Academia Sinica in 2008 to formulate policies on data collection and integration, and the mechanism to make data available to the public. Any commissioned project was hereafter asked to include these policy requirements in the contract. Furthermore, a new project to build the "National Biodiversity Monitoring and Reporting System" (TaiBON) will be initiated soon which will integrate all the long-term biodiversity monitoring and bioindicator data from various agencies in Taiwan as well as collaborate with AP-BON and GEO BON.

## P-1105-17

### Climate change revealed from mass balance of mountain glaciers and polar ice sheets - GLACIOCLIM, the French Glaciers Observatory

D. Six (1); C. Vincent (2); A. Rabatel (3); V. Favier (1); P. Wagnon (4)
(1) LGGE - CNRS/UJF, Saint-Martin d'Hères, France; (2)
LGGE - CNRS/UJF, Saint-Martin d'Hères, France; (3) UJF,
Lgge, Grenoble, France; (4) LTHE - IRD, Saint Martin d'Hères,
France

Mountain glaciers are widely recognized as excellent indicators of climate change over recent centuries (e.g. IPCC, 2013). Glacier mass balance variations are a useful tool to assess climate changes over the 20th and 21st centuries and anticipate future challenges related to water resources and sea level rise.

A multi-level monitoring combining in-situ and remotely-sensed measurements within different climate regions constitutes the strategy recommended by the Global Terrestrial Network for Glaciers (GTN-G) supported by the United Nations Framework Convention on Climate Change (UNFCC). It should provide the basic data sets required for integrative studies and assessments of the distribution and changes of glaciers and ice caps.

In this context, the French national observatory of glaciers "GLACIOCLIM", supported by INSU, IRD, IPEV and University of Grenoble in collaboration with local partners, has been developing such a strategy for several decades
on glaciers in the French Alps, the tropical Andes, the
GLACIOCLIM in terms of data sharing relies on: (1) free
access through an interactive database which has been
recently redesigned; (2) a contribution to the World Glacier
Monitoring Service database, sustained by a MoU; and (3)
a contribution to the GLIMS initiative for multi-temporal
glacier inventories. Our monitoring strategy is based
on a comprehensive, consistent set of data, including
glaciological measurements (mass balance, ice velocity,
length and thickness variations), along with hydrological
and meteorological measurements. Contrary to the length
variations which result from complex ice flow dynamics,
mass balance fluctuations are direct indicators as they
record solid precipitation via accumulation and surface
energy fluxes via ablation. Given that most mountainous
glaciers are temperate (i.e. close to the pressure melting
point), the excess energy flux at the glacier surface
during the ablation season serves mainly for melting.
Consequently, it is necessary to measure both winter
and summer mass balance terms over long periods to
investigate long-term climate trends. The full network
then provides the opportunity to thoroughly analyze
the relationships between surface mass balance and
 meteorological variables on selected glaciers in the world.

Most of the glaciers in the world have been decreasing
over the last decades and ice temperature measurements
in boreholes at very high altitudes provide a clear evidence
of atmospheric warming. The goal of this presentation is
to analyze the climate - glacier relationships and to
provide the cause of this decrease in selected mountainous
regions (Alps, Himalayas and Andes) based on in-situ
measurements, remote sensing data and results from
simple to complex models. The surprising paradox of
Eastern Europe is that the surface mass balance changes are
still limited will also be justified in view of data from the
GLACIOCLIM observatory.

P-1105-18

Observing Climate Variability and Change
with GPS Radio Occultation

AK. Steiner (1); B. Scherlin-Pirscher (1); F. Ladstädter (1);
L. Brunner (1); M. Schwärz (1); R. Biond (1); J. Fritzer (1);
J. Schwarz (1); U. Foelsche (2); G. Kirchendast (1)
(1) Wegener Center for Climate and Global Change,
University of Graz, Graz, Austria; (2) Institute for Geophysics,
Astrophysics, and Meteorology/Institute of Physics,
University of Graz, Graz, Austria

Overall agreement on global warming of the troposphere
and cooling of the stratosphere exists from conventional
observations. However, uncertainty in trend rates and
their vertical structure limits the ability to draw robust and
consistent inferences as stated in the recent report of long-term trends, a key issue as stated in the present year. The Intergovernmental
Panel on Climate Change. Monitoring atmospheric
variability and climate change requires climate data
records which are continuous and homogeneous, long-
term stable, and traceable to standards of the international
system of units (SI). The uncertainty of essential climate
variables, such as temperature, must be smaller than the
signals expected from long-term change.

Radio Occultation (RO) observations based on Global
Positioning System (GPS) signals meet these requirements.
The traceability to fundamental time standards with precise
atomic clocks assures a long-term stable and consistent
data record with global coverage and all-weather utility.
RO data are available from 2001 onwards. Information on
error characteristics is provided as well. Data products
comprise vertical profiles and gridded climatological fields of
refractory atmospheric variables including bending angle,
reflectivity, pressure, geopotential height, temperature,
and specific humidity. Derived quantities such as
tropopause parameters or geostrophic winds are also
available. Highest quality and vertical resolution (about
0.5 km to 1.5 km) is delivered over the upper troposphere
and lower troposphere, offering the distinct advantage to
assess the vertical thermodynamic structure.

We present an overview on the accomplishments and
diverse applications of the RO record for monitoring
climate variability and climate change in the atmosphere.
Results show the ability of RO to capture the El Niño-
Southern Oscillation (ENSO), Quasi-biennial Oscillation
(QBO), atmospheric waves and thermal tides, and
extreme weather events such as tropical cyclones with

unprecedented vertical resolution. Despite of the relatively
short RO record, its utility for climate change detection
is demonstrated as a global climate observing system.
Current and future challenges are discussed for the
establishment of an RO climate data record, which will
contribute to improving our knowledge on atmospheric
structure and trends.

P-1105-19

Global-Scale Atmosphere Monitoring by
In-Service Aircraft – Current Achievements
and Future Prospects of the European
Research Infrastructure IAGOS

V. Thouret (1); P. Metzold (2); C. Brenninkmeier (3); JP.
Cammas (4); P. Dandin (5); JM. Flaud (6); M. Gallagher (7);
C. Gerbig (8); M. Hermann (9); P. Nedelec (1); M. Pontaud
(5); H. Smit (12); A. Volz-Thomas (10); A. Wahner (11); A.
Zahn (12); H. Ziереis (13)

(1) CNRS et Université Paul Sabatier – Observatoire Mid- Pyrénées, Laboratoire d'Aérologie, Toulouse, France; (2) Forschungszentrum Jülich GmbH, Institute of energy and climate research 8 – troposphere, Jülich, Germany; (3) Max Planck Institute for Chemistry, Jülich GmbH, Germany; (4) CNRS et Université Paul Sabatier – Observatoire Mid-Pyrénées, Now at osu la réunion, Toulouse / Saint-Denis, France; (5) Météo- France, Centre National de Recherches Météorologiques, Toulouse, France; (6) CNRS, Paris, France; (7) University of Manchester, Manchester, United Kingdom; (8) Max Planck Institute for Biogeochemistry, Jena, Germany; (9) Leibniz Institute for Tropospheric Research, Leipzig, Germany; (10) IAGOS-AISBL, Bruxelles, Belgium; (11) Forschungszentrum Jülich GmbH, Institute of energy and climate research 8 – troposphere, Jülich, Germany; (12) Karlsruhe Institute of Technology, Karlsruhe, Germany; (13) DLR Institute of Atmospheric Physics, Oberpfaffenhofen, Germany

Reliable predictions of the future climate using climate
models are central and fundamental requirements for
determining future mitigation strategies. The use of
commercial aircraft allows the collection of highly relevant
observations on a scale and in sheer quantity impossible to
achieve using research aircraft, and at altitudes where other
measurement methods (e.g., satellites) fall short. It has
been extensively demonstrated by 3 ongoing international
projects in Europe and Japan now that commercial aircraft
are ideal platforms to record vertical profiles from ground
to 12 km to the tropopause region over areas never or
poorly sampled by other programs (e.g. surface or radio
sounding networks) and to sample the atmosphere
between 9 and 12 km at high horizontal and vertical
resolution corresponding to the critical upper troposphere
/ lower stratosphere (UT/LS) region at mid-latitudes,
where most long-range aircraft fly. The European Research
Infrastructure IAGOS (In-service Aircraft for a Global
Observing System; www.iagos.org) operates a global-scale
monitoring system for atmospheric composition, aerosols
and clouds by using Airbus A340 and/or A330 long-
range aircraft performing regular intercontinental flights.
Today's participating airlines, Lufthansa, Air France, China
Airlines, Cathay Pacific and Iberia, ensure global-scale
coverage by the infrastructure (see map of the flight on
http://www.iagos.fr), which is designed for a lifetime of at
least 20 years. IAGOS complements the global observing
system in addition to ground-based networks, dedicated
research campaigns, satellites, balloons, and ships. The
infrastructure builds on the heritage of former research
projects MOZAIC (Measurement of Ozone and Water
Vapour on Airbus In-service Aircraft: http://www.iagos.
fr/mozaic and CARIBIC (Civil Aircraft for the Regular
Investigation of the Atmosphere Based on an Instrument
Container; http://www.caribic-atmospheric.com). IAGOS
is now the European Research Infrastructure combining
and coordinating these two different and complementary
approaches/methodologies which comprise (i) IAGOS-
core based on MOZAIC (a fleet of 15 to 20 aircraft flying
a reduced set of aircraft) and (ii) IAGOS-CARIBIC based on
CARIBIC (1 aircraft flying a 1.5 ton
laboratory with 16 instruments deployed once a month for
4 flights). IAGOS combines research centres, universities,
national weather services, airline operators and aviation
industry. It provides data for users in science and policy
including air quality forecasting, verification of CO2
emissions and Kyoto monitoring, numerical weather
prediction, and validation of global chemical transport
model, global climate model, and atmospheric boundary
layer products. Since its participation in the on-going MACC
projects (http://www.iagos.fr/macc), and demonstration
and delivery of core data in near real time (NRT) and soon in real time for a subset of information, IAGOS is considered a major contributor to the in-situ component of Copernicus Atmosphere Monitoring Services (CAMS). The IAGOS infrastructure is currently the only approach to providing regular in-situ observations in the UT/LS over mid-latitudes at high spatial resolution (4 seconds or 1 km horizontally) and vertical profiles (4 seconds or 30 meters vertically) of reactive gases, greenhouse gases, and aerosol concentration in the troposphere over continental sites, never or sparsely sampled by other programs, (e.g. in Africa, South East Asia, and South America). In combinations with its predecessor programs MOZAIC and CARIBIC, IAGOS has been providing long-term observational data of atmospheric chemical composition in the UT/LS since 1994 with to date 20 year time series of temperature, H2O and O3, and 9-15 years of aerosol, CO, NOy, CH4, N2O, SF6, Hg, acetone, ~30 HFCs, ~20 NMHC data. This presentation will give an overview of the original results achieved so far and a number of highlights to illustrate the promise IAGOS data hold for the future (new measured compounds along with near real time and real time transmission of data), taking full advantage of coupled chemistry-dynamics atmospheric models, allowing new applications and analysis for a broad community of users. One of the most striking examples we will highlight concerns evaluation of forecast runs with IAGOS NRT data as proposed in the frame of CAMS.

## P-1105-20

### Toward improved metadata catalogue services for WDS members in China

J. Wang (1)

(1) Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China

There are about 9 regular members of WDS in China, which covers multi-disciplines, such as geography and environment, space, astronomy, ocean, polar, microbe, and so on. It is difficult to provide uniform metadata catalogue services and update the related information dynamically. Face to this problem, WDS China family design and build the clearing house for metadata interoperability. It includes three important part, i.e., metadata standard, data update mechanism, clearing house portal.

A uniform metadata exchange standard is designed for WDS members in China. In order to advance the data and metadata services quality, an integrated data and metadata update mechanism are proposed based on the review and training mechanism supported by WDS China secret office. Finally, a new clearing house portal is provided which can be accessed by WDS portal directly.

## P-1105-21

### 60-year Database of Cosmic-Ray Neutron Fluxes held by the WDC for Cosmic Rays

T. Watanabe (1)

(1) National Institute of Information and Communications Technology, Integrated Data System Research Laboratory, Koganei, Tokyo, Japan

It has been suggested by a number of authors that fluctuations in the cosmic-ray, which are known to be caused by changes in solar activity with the time scale of eleven years or longer, could play a role in climate change. The World Data Center (WDC) for Cosmic Rays of Solar-Terrestrial Environment Laboratory, Nagoya University, is almost unique data center providing with pressure-corrected and scale-adjusted one-hour fluxes of cosmic-ray, supplied by ground-based stations (about 50 at presently distributed in a wide range of the longitude and the latitude, including polar and equatorial regions). Quality controlled data since 1953 in unified formats are opened through the Web page whose ULR is given below. Beside of well-known "11-year" solar-cycle variations of the cosmic-ray flux, appearing in the opposite sense of the variations of sunspot number, a weak increasing trend can be recognized in this several solar cycles, reflecting a weakening tendency of the solar activity. Although a weak inverse correlation is seen between the cosmic-ray flux and the global temperature in 1953-2006, the correlation analysis is strongly affected by the global cooling presumably caused by two major volcanic eruptions (El Chichon in 1982, and Pinatubo in 1991). Both eruptions were "accidentally" taken place in two subsequent solar-cycle maxima.

http://center.stelab.nagoya-u.ac.jp/WDCCR/

# 1106 - The Earth's energy imbalance and exchanges at the atmosphere-ocean interface: from fundamental research to societal concern

## ORAL PRESENTATIONS

### K-1106-01

#### Earth's energy imbalance: current knowledge and future challenges

M. Palmer (1)

(1) Met Office, Hadley Centre, Exeter, United Kingdom

Anthropogenic climate change arises from the accumulation of excess solar energy in the Earth system through increases in heat-trapping greenhouse gases associated with human activities. The various aspects of observed climate change (surface temperature rise, increased rainfall rates, loss of glaciers, global sea level rise, changes in climatic extremes) are all symptoms of this accumulation of energy, of which ~90% is manifested in the Earth system, and the remaining ~10% is attributed to climate change is defined by Earth's energy imbalance (EEI) and this represents the most fundamental quantity for monitoring ongoing global warming.

Ultimately, the impacts of climate change will be determined by the future evolution of EEI and how this additional energy interacts with the flows of energy within the Earth system, and how this will influence the scientific motivation for better monitoring of EEI and review the recent progress that has been made through improved

Earth system observations. I will discuss the future challenges in improving our estimates of this critical aspect of global change and advocate for EEI and ocean heat storage becoming central to both our thinking and communication on climate change.

### K-1106-02

#### SOLAS, a decade of international research at the air-sea interface: main accomplishments and future goals

C. Guieu (1)

(1) CNRS-UPMC, Villefranche sur mer, France

The surface ocean and lower atmosphere domain is a complex, highly dynamic component of the Earth system. Air-sea fluxes of biogeochemically-active materials and energy exert a major impact on global biogeochemistry and climate. Some of the largest uncertainties in projecting future global environmental trends are attributable to an insufficient understanding of the physical and biogeochemical interactions and feedbacks between the ocean and atmosphere (IPCC, 2013).

The overarching goal of SOLAS (Surface Ocean-Lower Atmosphere Study) international program launched in 2004, is to achieve a quantitative understanding of the key biogeochemical-physical interactions and feedbacks between the ocean and atmosphere, and how this coupled
system affects and is affected by global change. Our understanding of the exchanges of energy, gases and particles at the atmosphere-ocean interface has advanced over the past decade but there are still large uncertainties to adequately parameterize fundamental controlling processes as identified in the new research strategies of the international SOLAS group (Law et al., 2013). In this context, the scientific questions driving SOLAS research are highly challenging, inherently multidisciplinary, and broad in scope. They include: (1) What controls the ocean-atmosphere exchange of climate-relevant gases and particles? (2) How does the atmospheric deposition of materials impact ocean biogeochemistry? (3) What are the links between ocean biology, aerosols, and clouds? (4) What are the biogeochemical controls on emissions of highly reactive gases that impact atmospheric photochemistry and stratospheric ozone?

Climate mitigation policies based on greenhouse gas budgets must take into account the role of ocean-atmosphere fluxes for future projections. In that context, several of the geoengineering schemes currently debated for climate mitigation are directly linked to the oceanic atmosphere system, including ocean iron fertilization, sea spray generators, ocean foams, and modification of the ocean upwelling. Informed assessment of their feasibility, efficacy, and potentially unintended effects will derive from SOLAS science.

This presentation will overview the SOLAS 2004-2014 goals and main accomplishments and present the SOLAS 2015-2025 rationale and scientific scope.

## O-1106-01

### Origin of the Recent Tropical Atlantic SST warming: the role of ocean dynamics?

J. Servain (1); G. Caniaux (2); A. Hounsou-Gbo (3); Y. Kouado (4); M. McPhaden (5); M. Aруajo (3)

(1) IRD/UMR-182, Locean, Paris, France; (2) CNRM/GAME (Métode-France/CNRS), TOULOUSE, France; (3) Universidade de Pernambouco, Departamento de oceanografia, Recife, Brazil; (4) University Felix Houpouet Boigny - Cocody - Abidjan, Physic, Abidjan, Ivory Coast; (5) NOAA, Pmel, Seattle, United States of America

During the last decades, the sea surface temperatures (SSTs) of the whole tropical Atlantic has substantially increased. Since the 1960s, the mean SST series of the tropical Atlantic [30°N-20°S, 60°W-15°E] has gained some 0.8°C. Moreover, when considering the main per year points which affect the time series, the most significant trend occurred since 1995, at a rate of 0.25°C per decade for the whole basin. When regionalized, the most severe warming affects the north-western part of the basin with values up to 1°C, as well as the coastal upwelling regions offshore Africa. Surprisingly the trade wind system, that drives the equatorial upwelling, strengthened since the 1960s and specially since the 1980s. These changes has been established by considering various independent observational data sets, allowing to prove the robustness of the results.

The origin of the SST change has been investigated by analyzing the changes of the air-sea surface fluxes and of the water column by considering integral quantities like sea level anomalies and upper level heat contents. It appears that the SST warming is not directly related to the local surface heat fluxes, which tend to increase the ocean heat loss. This implies that the signal is not coming from the atmosphere but rather from the ocean itself, i.e. due to recent changes in the ocean dynamics. Moreover, lagged correlation patterns between heat content and SSTs, suggest the existence of a relationship between the SST warming and the circulation in the northern tropical Atlantic. Finally, several hypotheses are presented to conciliate both the strengthening of the wind-stress, the SST and upper water upwelling, as well as the break point dates which affect the trends.

## O-1106-02

### Oceanic biotic components, production mechanism of organic aerosol in Marine Boundary Layer and Cloud-climate system

MC. Fcachini (1); CD. O'dowd (2); R. Danovaro (3)

(1) National Research Council (CNR), Institute of Atmospheric

Sciences and Climate (ISAC), Bologna, France; (2) National University of Ireland Galway, School of physics and centre for climate & air pollution studies, ryan institute, Galway, Ireland; (3) Polytechnic University of Marche, Department of life and environmental sciences, Ancona, Italy

Studies performed during the past years strongly suggest that biogenic organic compounds play an important role in submicron marine aerosol chemical composition over biologically productive, high latitude, marine regions, in both hemispheres and new biogenic oceanic sources of primary and secondary origin of OA were revealed. We discuss on the global importance of biogenic OA marine sources and their high spatial and temporal variability and the complex interaction with gaseous biogenic precursors and oceanic biotic components (Phytoplankton, viruses and bacteria). Submicron marine organic aerosol are a complex mixture of biogenic materials transferred from the ocean surface by the sea spray or by oxidative gas to particle conversion of volatile organics emitted by decomposition processes of oceanic dissolved organic carbon. The role of marine biota on the evolution of plankton bloom and on the partitioning of oceanic organic carbon in POC and DOC reservoirs and transfer mechanisms into MBL will be discussed.

## 1106-POSTER PRESENTATIONS

### P-1106-01

#### Comparative assessment of surface fluxes from different sources: a framework based on probability distributions

S. Gulev (1)

(1) RAS Institute for Oceanology, SAIL, Moscow, Russia

Surface turbulent heat fluxes from modern era and first generation reanalyses (NCEP-DOE, ERA-Interim, MERRA NCEP-CFSR, JRA) as well as from satellite products (SEAFLUX, IFREMER, HOAPS) were inter compared using framework of probability distributions for sensible and latent heat fluxes. For approximation of probability distributions and estimation of extreme flux values Modified Fisher-Tippett (MFT) distributions has been used. Besides mean flux values, consideration is given to the comparative analysis of (i) parameters of the MFT probability density functions (scale and location), (ii) extreme flux values corresponding high order percentiles of fluxes (e.g. 99th and higher) and (iii) fractional contribution of extreme surface flux events in the total surface turbulent fluxes integrated over months and seasons. The latter was estimated using both fractional distribution derived from MFT and empirical estimates based upon occurrence histograms. The strongest differences in the parameters of probability distributions of surface fluxes and extreme surface flux values between different reanalyses are found in the western boundary current extension regions and high latitudes, while the highest differences in the fractional contributions of surface fluxes may occur in mid ocean regions being closely associated with atmospheric synoptic dynamics. Generally, satellite surface flux products demonstrate relatively stronger extreme fluxes compared to reanalyses, even in the Northern Hemisphere midlatitudes where data assimilation input in reanalyses is quite dense compared to the Southern Ocean regions. Our assessment also discriminated different reanalyses and satellite products with respect to their ability to quantify the role of extreme surface turbulent fluxes in forming ocean heat release in different regions.

### P-1106-02

#### The New Planetary Energetic Budget, the New Climate and the New Water Cycle in the North Atlantic Ocean and its edges

MS. Karrouk (1)

(1) University Hassan II, Climatology Research Centre (CEREC), Geography, Climatology, Casablanca, Morocco

Global warming has now reached the energetic phase of H2O's return to the ground after the saturation of the atmosphere in evaporation since the 80s and 90s of the last century, which were characterized by severe droughts, mainly in Africa.
This phase is the result of the accumulation of thermal energy exchanges in the Earth-Ocean-Atmosphere system that resulted in the thrust reversal of the energy balance toward the poles. This situation is characterized by a new thermal distribution: above the ocean, the situation is more in surplus compared to the mainland, or even opposite when the balance is negative on the land, and in the atmosphere, warm thermal advection easily reach the North Pole (planetary crests), as well as cold advection push deep into North Africa and the Gulf of Mexico (planetary valleys).

This «New Ground Energy Balance» establishes a «New Meridian Atmospheric Circulation (MAC)» with an undulating character throughout the year, including the winter characterized by intense latitudinal very active energy exchanges between the surplus areas (tropical) and the deficit (polars) on the one hand, and the atmosphere, the ocean and the continent on the other.

The excess radiation balance increases the potential evaporation of the atmosphere and provides a new geographical distribution of H2O worldwide: the excess water vapor is easily converted by cold advection (polar vortex) to heavy rains that cause floods or snow storms that paralyze the normal functioning of human activities, which creates many difficulties for users and leaves damage and casualties, but ensures water availability missing since a long time in many parts of the world, in Africa, Europe and America.

The new thermal distribution reorganizes the geography of atmospheric pressure: the ocean energy concentration is transmitted directly to the atmosphere, and the excess torque is pushed northward. The Azores anticyclone is strengthened and is a global lock by the Atlantic ridge at Greenland, which imposes on the jet stream a positive ripple, very strongly marked poleward, bringing cold cosmic advection of polar air masses winter over from Europe to North Africa. Hence the enormous meridian heat exchanges north-south, and south-north.

This new spatial thermal provision therefore imposes on the jet-stream a positive ripple on the North Atlantic (Greenland) and eastern Pacific (Alaska); this is the cause of the heat and drought of California, followed by negative waves in eastern US, and Europe.

This is the «New Atmospheric Circulation» predominantly «Meridian», due to the «New Climate» caused by global warming.

## P-1106-03

### Changes in global energy imbalance at the top of atmosphere and surface 1985-2014

CL. Liu (1); R. Allan (1); N. Loeb (2); M. Palmer (3); D. Smith (3); P. Hyder (3)

(1) Department of Meteorology, University of reading, reading, United Kingdom; (2) NASA Langley research Centre, Hampton, United States of America; (3) Met Office, Hadley Centre, Exeter, United Kingdom

Combining satellite data, atmospheric reanalyses and climate model simulations, variability in the net downward radiative flux imbalance at the top of Earth's atmosphere (N) are reconstructed and linked to recent climate change. Over the period 1985-2012 we estimate N=0.47±0.54 Wm⁻² (uncertainties at 90% confidence level). Variability relates primarily to the eruption of Mt. Pinatubo in 1991 and El Niño Southernern Oscillation with good agreement (r~0.6) between the monthly reconstruction and atmospheric simulations using prescribed sea surface temperature and radiative forcings. Combining with a simple energy balance climate model we argue that increased ocean heat uptake below the mixed layer is required to reconcile changes in N and surface temperature since 1985.

The surface net fluxes can be estimated based upon the reconstructed N and the atmospheric energy tendencies

and transports from the ERA-Interim reanalysis. The energy divergences over the oceans are adjusted to remove an unphysical residual global mean atmospheric energy divergence. The estimated net surface energy fluxes are compared with reanalysis and atmospheric model simulations. The spatial correlation coefficients of multi-annual means between the estimations made here and other data sets are all around 0.9. There are good agreements in area mean anomaly variability over the global ocean. The inter-hemispheric heating differences and precipitation biases are also discussed.

## P-1106-04

### Uncoupling the ocean and sea-ice from the atmosphere: Challenges of Coordinated Ocean-ice Reference Experiments (CORES)

AM. Treguier (1); G. Danabasoglu (2); S. Marsland (3); S. Griffies (4); W. Omdp Members (5)

(1) CNRS, LPOE, Université de Paris 10 (2); NCAR, Boulder, United States of America (3) CSIRO, Melbourne, Australia; (4) NOAA – GFDL, Princeton, United States of America; (5) CLIVAR ICPO, State oceanographic administration first institute of oceanography, Qingdao, China

Earth system models are complex, and the interactions and nonlinear feedbacks between their different components are poorly understood. Climate predictions benefit from an inherent consolidation of each component model, before coupling them together. Atmospheric Model Intercomparison Projects, which involve forcing the atmospheric models with observed sea surface temperatures (SST) and sea-ice cover, have existed since the early days of IPCC. In contrast, a similar exercise for ocean - sea-ice models has been difficult to implement, because there are long time scale interactions between the ocean-ice-atmosphere system and there are large uncertainties in observations within the atmospheric boundary layer.

Under the umbrella of the World Climate Research Program's (WCRP) Climate and Ocean Variability, Predictability and Change (CLIVAR) Project, the Ocean Model Development Panel (OMDP) has worked over for a decade to develop a meaningful validation of ocean - sea-ice models for our present climate and has produced a common protocol. Coordinated Ocean-ice Reference Experiments (CORES). CORE consists of running ocean - sea-ice coupled models with a fixed atmospheric state (observed air temperature, humidity, boundary layer winds, downward radiation, precipitation, and river runoff). This atmospheric state has been obtained in such a way to produce realistic globally averaged heat and freshwater fluxes when combined with observed SST. Existing atmospheric reanalysis products such as NCEP or ERA are not yet suitable for this purpose without corrections. Prescribing the air temperature, rather than heat flux, is necessary in order to allow the feedbacks between the evolving SSTs and the air-sea heat fluxes: this feedback is essential to ensure the stability of the ocean-ice system.

The main challenge in the CORE framework stems from the lack of sufficient feedbacks in the water cycle. If evaporation increases over the ocean, the extra water is likely to return to the ocean as rain or runoff on long time scales. Because this nonlocal feedback is neglected when the atmospheric state is fixed, it has been necessary to introduce an arbitrary relaxation of the surface salinity to observations. In part due to this salinity forcing, CORE simulations subject to the same atmospheric state exhibit very different large scale ocean circulations: this finding underlines limited capacity to fully validate the ocean - sea-ice components of earth system models used for climate scenarios, independently of the atmosphere. Nevertheless, a recent suite of CORE experiments carried out with over 20 different models brings new insights into the reproducibility and robustness of essential climate variables such as regional sea level patterns and the North Atlantic overturning circulation.
# 1107 - Sea level rise and ice sheets

## ORAL PRESENTATIONS

### K-1107-01

#### Measuring Earth's polar ice sheets from space

**A. Shepherd (1) ; E. Ivins, (2)**

(1) University of Leeds, School of earth and environment, Leeds, United Kingdom; (2) Caltech, Pasadena, United States of America

Earth's ice responds rapidly to climate forcing, and satellite observations have become an essential tool with which to measure and understand these changes. Although considerable progress has been made in quantifying recent fluctuations in ice sheet mass balance, significant challenges remain in attempting to predict future ice sheet losses. This is because past changes have been too small to reliably judge the performance of the ice sheet models upon which predictions are currently based. In consequence, there is a continued need for satellite-based observations of the polar ice sheets - both to inform the development of ice sheet models, and to deliver synoptic assessments of their contribution to contemporary sea level rise.

There are three popular satellite-based techniques for estimating the sea level contribution due losses from the polar ice sheets; satellite altimetry can measure changes in ice sheet volume; satellite interferometry (NASA) as an attempt to resolve the apparent disagreement between geodetic estimates of ice sheet mass balance. Within IMBIE, estimates of ice sheet mass balance are developed from all three geodetic techniques using a common spatial and temporal reference frame and a common appreciation of the contributions due to external signals. The project brings together the laboratories and space agencies that have been instrumental in developing independent estimates of ice sheet mass balance to date.

In 2012, the first IMBIE assessment was delivered. It included 19-years of satellite radar altimeter data, 5-years of satellite laser altimeter data, 18 years of satellite radar interferometer data, 7-years of satellite gravimetry data, 32-years of surface mass balance model predictions, and predictions from a suite of post glacial rebound models. Since then further changes have occurred in Antarctica and Greenland, and the record of satellite observations has been extended through continued operation of existing missions, such as GRACE, and through the availability of measurements from new sensors, including CryoSat-2 and Sentinel-1a.

This presentation will review the latest satellite measurements of Antarctica and Greenland, and will outline progress towards a second ice sheet mass balance inter-comparison exercise.

### K-1107-02

#### Polar ice sheets and sea-level rise: threats and uncertainties

**G. Durand (1)**

(1) LGGE / CNRS, St Martin d'Hères, France

During the last 20 years, the Greenland and Antarctic ice sheets have been losing mass with an increasing rate. They now significantly contribute to sea-level rise and will most probably continue in the foreseeable future. Their potential total contribution is tremendous as ice sheets contain tens of meters of sea level equivalent. However, the rate of their coming outflow remains speculative. In particular both ice sheets may exhibit some instability

processes that could be initiated once oceanic or atmospheric perturbations exceed a given threshold. Once engaged in such instabilities, ice sheet mass loss is self-entertained and large regions may collapse. This lecture will describe the essential processes at the origin of the observed ice sheets' imbalance, our current knowledge on potential tipping points and highlight the main reasons of the uncertainties in the projection of ice sheets' contribution to sea level.

### O-1107-01

#### Present-day sea level rise

**A. Cazenave (1)**

(1) CNES, LEGOS, Toulouse, France

We review most recent progress realized in measuring global mean sea level (GMSL) over recent decades and satellite altimetry era (starting in 1993), as well as in understanding the causes of the observed rise (i.e., ocean thermal expansion, land ice loss and terrestrial water storage change). The IPCC 5th Assessment Report revisited the sea level budget for the last few decades and came to rather good agreement between observed GMSL rise and sum of climate and non-climate contributions. Over the satellite altimetry era, GMSL rise (of 3.2 mm/yr) is reasonably well explained by ocean thermal expansion (contributing ~ 37%) and land ice loss from glaciers and ice sheets (contributing ~ 55%). Terrestrial water storage change (mostly due to ground water pumping) is supposed to explain the remaining, but this component is quite uncertain. For about 10 years, new observing systems from space and in situ (e.g., GRACE space gravimetry, Argo profiling floats) allow improved estimates of the various contributions to sea level rise, in particular direct estimate of ocean mass change. These observations indicate that over 2005-2013, ocean thermal expansion rose less rapidly than during the 1990s (with a contribution of only 28%) while the ocean mass increase now explains ~ 66% of the GMSL rise. This mostly results from ice mass loss acceleration from the ice sheets. This improved sea level budget approach allows us to put constraints on the contribution of the deep ocean (not seen by Argo) and its role in the current 'hiatus'.

### O-1107-02

#### Projections of sea level change

**J. Gregory (1)**

(1) NCAS, University of Reading and Met Office Hadley Centre, Reading, United Kingdom

It is very likely that the rate of global mean sea level rise (GMSLR) during the 21st century will exceed the rate during 1971-2010, due to increases in ocean warming and loss of mass from glaciers and ice sheets. Ocean thermal expansion is the largest contributor to projections of GMSLR during the 21st century. For a given scenario, there is a substantial spread in climate model projections of thermal expansion, and in the geographical pattern of sea level change due to ocean density and circulation change. Larger uncertainty in projections of GMSLR comes from the land-ice contributions, especially ice-sheet dynamical change. These contributions also influence regional sea-level change, through their effect on gravity and the solid Earth. GMSLR by 2100 is likely to be in the range 0.28-0.61 m above the 1986-2005 mean under a scenario of strong mitigation (RCP2.6), and 0.52-0.98 m under a scenario of high emissions (RCP8.5). Unlike surface temperature change, GMSL depends on the pathway of CO2 emissions, not only on the total: earlier emissions of the same total lead to greater GMSLR. By the end of the century, the rate of GMSLR under RCP2.6 could stabilise the equilibrium of the early 21st century, while under RCP8.5 it could approach the average rates that occurred during the last deglaciation. It is very likely that regional sea level rise will be positive over about 95% of the world ocean, and about 70% of the global coastlines are projected to experience a relative sea level change within 20% of the global mean. Based on current understanding, only the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause GMSLR above the likely ranges during this century, but GMSLR
will continue for many subsequent centuries, because of the long timescales of ice-sheet change and deep-ocean warming, and could be partly irreversible.

## 1107-POSTER PRESENTATIONS

### P-1107-01

#### Two Decades of Global and Regional Sea Level Observations from the ESA Climate Change Initiative Sea Level Project

M. Ablain, (1); J. Légeais (2); A. Cazenave (3); B. Meissignac (4); G. Larnicol, (1); J. Benveniste, (5)

(1)CLS, DOS, PMC, Ramonville St Agne, France; (2)CLS, Space Oceanography Division, Ramonville St Agne, France;

(3) CNRS-CNES, Laboratoire d'études en géophysique et oceanographie spatiales, Toulouse, France; (4) CNES, Legos, Toulouse, France; (5) ESA, Esrin, Frascati, Italy

Sea level is a very sensitive index of climate change and variability. Sea level integrates the ocean warming, mountain glaciers and ice sheet melting. Understanding the sea level variability and changes implies an accurate monitor of the sea level variable at climate scales, in addition to understanding the ocean variability and exchange between ocean, land, cryosphere, and atmosphere. That is why Sea Level is one of the Essential Climate Variables (ECV) selected in the frame of the ESA Climate Change Initiative (CCI) program. It aims at providing long-term monitoring of the sea level ECV with regular updates, as required for climate studies. After a first phase (2011-2013), the program has started in 2014 a second phase of 3 years. The objectives of this second phase are to involve the climate research community to refine their needs and collect their feedbacks on product quality, to develop, test and select the best algorithms and standards to generate an updated climate time series and to produce and validate the Sea Level ECV product. This will better answer the climate user needs by improving the quality of the Sea Level products and maintain a sustain service for an up-to-date production. To this extent, the ECV time series has been extended and it now covers the period 1993-2013.

We will firstly present the main achievements of the ESA CCI Sea Level Project. On the one hand, the major steps required to produce the 21 years climate time series are briefly described: collect and refine the user requirements, development of adapted algorithms for climate applications and specification of the production system. On the other hand, the product characteristics are described as well as the results from product validation, performed by several groups of the ocean and climate modeling community. At last, the work plan and key challenges of the second phase of the project are described.

### P-1107-02

#### Error characterization of global Mean Sea Level time series deduced from TOPEX, Jason-1 and Jason-2 altimeter missions

M. Ablain, (1); L. Zawadzki, (1); P. Prandi, (1)
(1)CLS, DOS, PMC, Ramonville St Agne, France

With the satellite altimetry missions, the global mean sea level (GMSL) has been calculated on a continual basis since January 1993. 'Verification' phases, during which the satellites follow each other in close succession (TOPEX/ Poseidon-Jason-1, then Jason-1-Jason-2), help to link up these different missions by precisely determining any bias between them. The global mean sea level (MSL) deduced from these 3 altimetric missions provides a global rate of 3.2 mm from 1993 to 2013 applying the post glacial rebound (MSL AVISO website http://www. jason.oceanobs.com/mls/)

Within the ESA Climate Change Initiative program, the users requirements have been collected and for the users of the Sea Level ECV, it is crucial to know as much as possible the errors impacting the MSL calculation in order to analyze the MSL variations and in fine to interpret correctly the geophysical mechanisms underlying these variations. The characterization of these errors was performed over the whole altimetric period separating several time scales as the long-term evolution (mean sea level trend), but also

the inter-annual and periodic signals.

However, it will also be very useful to provide the confidence envelop (or error envelop) of the global MSL time series in order to know the exact error level at each time step. In this paper, we propose to describe in details the approach developed to compute this confidence envelop. We will also present the results obtained and how to interpret them.

### P-1107-03

#### Altimeter sea level rise assessment with tide gauge measurements

M. Ablain, (1); P. Prandi, (1); G. Valladeau, (1)

(1)CLS, DOS, PMC, Ramonville St Agne, France

Since the first altimeter missions and the improvements performed in the accuracy of sea surface height measurements from 1992 onwards, the importance of global quality assessment of altimeter data can be observed increasing. Global CalVal studies usually assess this performance by the analysis of internal consistency and cross-comparison between all missions. The overall quality assessment of altimeter data can be performed by analyses of their internal consistency and the cross- comparison between all missions.

As a complementary approach, tide gauge measurements are used as an external and independent reference to enable further quality assessment of the altimeter sea level and provide a better estimate of the multiple altimeter performances. In this way, both altimeter and tide gauge observations are compared to climate applications, require a rigorous quality control. The tide gauge time series considered in this study derive from several networks (GLOSS/CLIVAR, PSML, REFMAR) and provide sea-level heights with a physical content comparable with altimetry sea level estimates.

Concerning altimeter data, the long-term drift assessment can be evaluated thanks to a widespread network of tide gauges. Thus, in-situ measurements are compared with altimeter sea level for the main altimeter missions. If altimeter time series are long enough, tide gauge data provide a relevant estimation of the global Mean Sea Level (MSL) drift calculated for all the missions. Moreover, comparisons with sea level products merging all the altimeter missions together have also been performed using several datasets, among which the AVISO delayed-time Sea Level Anomaly grids.

### P-1107-04

#### Probabilistic surface reconstruction of coastal sea level rise during the twentieth century

G. Choblet (1); H. Laurent (2); T. Bodin (3)
(1)CNRS - Université de Nantes, Laboratoire de Planétologie et Géodynamique, Nantes, France; (2) CNRS - Université Joseph Fourier, Isterre, Grenoble, France; (3) UC Berkeley, Earth and planetary science, Berkeley, United States of America

We present a new surface reconstruction procedure based on the Bayesian inference method for coastal relative sea level variation during the twentieth century. Average rates are computed from tide gauge records. Models based on a Voronoi tessellation adapt to the level of information which proves well suited to the strong heterogeneity of data. Each point of the reconstructed surface is defined through a probability density function, a format particularly well adapted to this climate-related datum. The resolution of reconstructed surfaces strongly varies among the six large regions considered and within a given region. Anomalous sea level variations recorded locally are shown to reflect either anthropogenic effects or well- identified fast tectonics. For a poor data coverage, these can cause a problematic distortion of the reconstructed surface. Europe, North America, Australia, and Africa present a single trend with a decreasing precision of the reconstructed surface as a function of resolution of the tide gauge record. The most prominent feature in Europe is the pronounced uplift of Fennoscandia. Coasts of United States of America have the best resolution in North America and present stronger rates of sea level rise on the Atlantic than their European counterparts. Australia (especially in
the North) and Africa are poorly resolved. Asia and South America depart clearly from this trend: a relatively uniform rise is obtained for Asia in spite of a good tide gauge record. Conversely, the reconstructed surface of South America presents an exceptional degree of roughness, at odds with a relatively poor record. Overall, this method not only offers a new assessment of sea level change (validating earlier results) but also quantifies the reliability of estimates.

We finally apply a similar procedure to GPS vertical data. First results on vertical ground motion which therefore allow the local evaluation of absolute sea-level rise during the twentieth century will be presented.

P-1107-05

Climatic information from unexplored
areas of East Antarctica: The French ITASE
Contribution

V. Favier (1); L. Arnaud (1); G. Delaygue (1); M. Fily (1); H. Gallée (1); C. Genthon (1); B. Jourdain (1); G. Krinner (1); A. Landais (2); M. Legrand (1); ME. Le (1); O. Magand (1); V. Masson-Delmotte (2); B. Minster (2); G. Picard (1); S. Preunkert (1); F. Prié (2); F. Remy (3); J. Savarino (1)
(1) LGGE, Grenoble, France; (2) LSCE, Gif-sur-Yvette, France; (3) LEGOS, Toulouse, France

Antarctica is the largest ice reservoir on Earth. In the context of climate change, the surface mass balance (SMB) of Antarctica will play a major role in the evolution of sea level. Knowledge of the current variations of Antarctic SMB is thus a major challenge. However, for Antarctica the spatially averaged SMB is still poorly constrained because field data are sparse. The IPCC fifth assessment report (AR5) has highlighted this uncertainty as one of the main scientific challenges in climate science.

How the surface mass balance of Antarctica will change
in the future?

In spite of decades of studies, an international effort is still necessary to reduce the important remaining uncertainties. Especially, large regions of Antarctica are still unexplored. Hence, scientific traversers have been designed in the framework of SCAR-ITASE program (International Trans-Antarctic Scientific Expeditions) to collect invaluable samples and observations in the field. In the context of ITASE project, the French glaciology community has launched a program to get new information on surface mass balance. During the 2009-10, 2011-2012 and 2013-14 summers, scientific traversers have been performed over large distances on the Antarctic plateau. However, the coast-to-plateau transition zone has been largely unexplored, whereas this is where most of future changes are expected to occur. Hence, a new traverse is planned in this area for the summer 2016-17. Using up-to-date techniques, we propose to collect information on snow physical properties to analyze the processes responsible for their spatial and temporal variations. A special attention will be paid on the way to use remote sensing data to infer the physical characteristics of snow. This knowledge is expected to allow us to interpret future sensing signal in terms of surface mass balance. Getting information on how the origin and transport of moisture affect chemical and isotopic signals stored in firn and ice will also be a priority. This knowledge will help us to validate climate and surface mass balance models, which are used to forecast future surface mass balance. The goal of this presentation is to describe recent results obtained by the French ITASE community, and to describe its strategy for future research performed in Antarctica.

P-1107-06

Testing the sensitivity of the East Antarc-
tic Ice Sheet to Southern Ocean dynamics:
past changes and future implications

C. Fogwill (1); C. Turney, (1); K. Meissner, (1); N. Golledge, (2); P. Spence, (1); J. Roberts, (3); M. England (4); R. Jones, (5); L. Carter, (2)
(1) University of New South Wales, Climate Change Research Centre, Sydney, NSW, Australia; (2) Victoria University of Wellington, Antarctic research centre, Wellington, New Zealand; (3) Australian Antarctic Division, Institute of marine and atmospheric studies, Hobart, Australia; (4) The

University of New South Wales, Climate change research
centre, Sydney, Australia; (5) University of Exeter, Geography,
Exeter, United Kingdom

The stability of Antarctic ice sheets and their potential
contribution to sea level under projected future warming
remains highly uncertain. The Last Interglacial (135,000-
116,000 years ago) provides a potential analogue, with
global temperatures 2°C higher and rates of sea-level rise
>6.6 ka-1, leading to sea levels 6.6-9.4 m higher than
present. The source(s) of this sea-level rise remain fiercely
debated.

Here we report a series of independent model simulations
exploring the effects of migrating Southern Hemisphere
Westerlies (SWs) on Southern Ocean circulation and
Antarctic ice-sheet dynamics. We suggest that southerly
shifts in winds may have significantly impacted the sub-
polar gyres, inducing pervasive warming (0.2-0.8°C in the
upper 1,200 m) adjacent to sectors of the East Antarctic
Ice Sheet (E AIS), which due to their geometries and
connectivity to the Southern Ocean are highly sensitive
to ocean forcing. We conclude that the E AIS potentially
made a substantial, hitherto unsuspected, contribution to
interglacial sea levels, and given 21st-century projections
in the Southern Annular Mode and associated SH
migration, we highlight how pervasive circum-Arctic
pervasive warming may threaten E AIS stability.

P-1107-07

Uncertainties on the surface mass balance
of Antarctica

C. Genthon (1); C. Palerne (1); H. Barral (2); C. Amory (2)
(1) CNRS, Laboratoire de Glaciologie et Géophysique
de l'Environnement, Saint Martin d'Hères, France; (2)
Université de Grenoble Alpes, Laboratoire de glaciologie
et géophysique de l'environnement, Saint Martin d'Hères,
France

On average, the ~12 106 km³ of the grounded Antarctic ice sheet accumulates ~15 cm of water equivalent per year at its surface. The main term in the surface mass balance equation is precipitation, mainly in the form of snowfall. Other terms include evaporation/frost deposition, melting and runoff to the oceans, and blowing snow effects. Climate models may or may not account for these terms, if they do with varying degrees of realism which can only be evaluated against past or present day observations. All climate models simulate precipitation and predict an increase of antarctic snowfall but disagree on the magnitude of the increase. A 20 % increase (everything else unchanged) would induce a ~1 mm/year moderation of sea-level rise due to other causes of sea-level change. Unfortunately, there are no in situ observations of antarctic snowfall that can be used to confidently assess model performance and sort out their reliability. Satellite data suggest that most models overestimate antarctic precipitation. Those models closest to the satellite data predict a larger precipitation increase and impact on sea-level. Blowing snow is a frequent phenomenon on the peripheral slopes of the antarctic ice sheet where catabatic winds blow, but none of the past IPCC climate models have accounted for this process and a possible contribution to surface mass balance change. There are few observations of antarctic blowing snow and those available suggest systematic model biases in blowing snow conditions. Although the current mean surface mass balance of Antarctica is relatively well known from glaciological measurements, there is a deficit of evaluation and validation of the independent components and thus of the physical processes which may be individually and differently altered in a changing climate.

P-1107-08

Avoided Sea Level Rise from thermal
expansion for RCP4.5 versus RCP8.5

A. Hu (1) ; S. Bates, (1)
(1) National Center for Atmospheric Research, Boulder, CO,
United States of America

Observational evidence shows that as the global mean
temperature increases, the global mean sea level is also
rising. The rising sea level could impose significant impacts
on coastal communities, especially when this rising sea
is compounded with storm surges. Here, by analyzing
results from two sets of ensemble simulations using the Community Earth System Model version 1, we study the potential avoided sea level rise over the 21st century on global and regional scales if a climate pathway of RCP4.5 is followed versus RCP8.5. Results show that the global mean sea level rise averaged over 2061–2080 due thermal expansion of sea water can be reduced by about 25% (–3.7 cm). Regionally, this avoided sea level rise can be marginal in some areas, such Melbourne, Australia (14cm vs. 13cm), and can be very large in others, such as New York (35cm vs. 25cm) due to regional changes in dynamical forcing.

P-1107-09

Analyses of altimetry errors using Argo and GRACE data

JF. Legeais (1); P. Prandi, (2); M. Ablain, (2); N. Picot (3)
(1)CLS, Space Oceanography Division, Ramonville St Agne, France; (2)CLS, Dos, pmc, Ramonville St Agne, France; (3)CNES, Toulouse, France

Since the first altimeter missions and the improvements performed in the accuracy of sea surface height measurements from 1992 onwards, the importance of global quality assessment of altimeter data has been increasing. Global Cal/Val studies are usually performed by the analysis of internal consistency and cross-comparison between all missions. In this study, the steric and mass contributions to the sea level provided by Argo profiling floats and the Gravity Recovery And Climate Experiment (GRACE) mission respectively are used as independent sources of comparison to analyze the altimetry errors.

Argo profiling floats are spread out over almost the global open ocean since 2004. However, they measure temperature and salinity vertical profiles, providing only the steric contribution to the total sea level content measured by altimeters. The missing mass contribution is derived from the GRACE data set from 2003 onwards.

The comparison is performed with the first objective of detecting a global and regional altimeter sea level drifts. A second goal is to assess the impact of new altimeter standards (orbit, geophysical corrections, ground processing) and new versions of altimeter merged products such as the 2014 ARISOVA复probing or the Sea Level CCI data set. We also focus our work on sensitivity analyses of the method of comparison to various parameters. In particular, we determine to which extent the altimeter quality assessment is affected by a different pre-processing of altimeter data, a sub sampling of the Argo network and a change of the reference depth used to compute Argo dynamic heights.

P-1107-10

An upper limit of future sea-level rise

A. Levermann (1)
(1) Potsdam Institute for Climate Impact Research, Research Domain Sustainable Solutions, Potsdam, France

For coastal protection an upper limit of future sea-level rise is of much higher value than the likely range provided by the Intergovernmental Panel on Climate Change AR-5. Based on state-of-the-art process-based simulations and physical considerations, an upper limit for the global mean sea-level rise of the 21st century is presented. It is shown that this upper limit is consistent with the likely range provided by the IPCC-AR5, but far exceeds the upper value of this likely range. For practical purposes a full probability distribution is suggested which is both consistent with the IPCC-range and the upper limit estimate.

P-1107-11

Climate change impacts on Nef Glacier and repercussions on the hydrological regime of Nef River (Patagonia, Chile)

P. Lopez (1); B. Pouyaud, (2); P. Chevallier, (2); G. Casassa, (3); F. Espinosa, (4); J. Salas, (5); P. Nahuelpelar, (5); J. O'kueinghtons, (5); L. Longuevergne (6)
(1) CNRS, University Rennes 1, Geosciences Rennes, Rennes, France; (2) Laboratoire Hydrosciences UMR 5569 (CNRS, IRD, Université de Montpellier), Montpellier, France; (3) Geostudios Ltda and Universidad de Magallanes, Santiago

and Punta Arenas, Chile; (4) Independent consultant, Coyhaique, Chile; (5) Dirección General de Aguas, Coyhaique, Chile; (6) CNRS, University Rennes 1, Geosciences Rennes, Rennes, France

The Nef River, with its origin in the Nef Glacier, located on the Northern Patagonia Icefield (Chile), drains a glacierized basin of 800 km². In this study, fluctuations between the 1961–1990 and 2001–2005 periods are analyzed. Throughout the whole data series, the discharge follows a seasonal fluctuation with a mean discharge of 27.1 m3/s and 78.3 m3/s for the fall/winter and spring/summer season, respectively. During autumn, spring, and summer, several floods are related in terms of temperature peaks. The highest flood of the whole period (189 m3/s) was observed on 11 March 2009 and occurred as a result of a significant increased of the air temperature (from –0.9°C to +12.5°C) appeared during the 5 previous days to the flood triggering increase of glacier melting.

In order to quantify the Nef Glacier's melting (in function to the air temperature) during spring and summer seasons, a simplified degree-day method was applied for the 2007–2008 hydrological year (which is the only period without gaps on the data series). The glacier melt water contributed for 30% to the total discharge; meanwhile precipitation represents only a 7.2%.

In addition, we found that Glacial Lake Outburst Flood (GLOF) events occurred at Nef Norte Lake (a small proglacial lake originated on a lateral front of Nef Glacier) can contribute significantly to the total discharge of Nef River. Indeed, the surface area of the lake was monitored using SPOT 5 satellite images and DEMs. By 23rd March 2008, the lake lost at least 25% of the surface measured in 13th March and the water level of the lake was 33.6 m lower (equivalent to 6*106 m3). This amount is therefore coherent with the increase of discharge of 25.5 m3/s recorded between 15th and 20th March 2008. In consequence, we suggest that a GLOF event was responsible of the 4th highest flood (156.8 m3/s) of the 2005 – 2010 period.

GLOF events, which increased their frequency in Patagonia during the last decade, are the clear evidence of constant glacier thinning as response to climate change. The ablation area of Nef Glacier thinned 1.8 m between 2001 and 2011.

These results confirm that a hydrological approach applied to the glacial runoff can correctly estimate glacier melting coming from ablation area, which is largely unknown at basin scale in the Northern Patagonia Icefield.

P-1107-12

Recent acceleration of glacier retreat in the Northern Patagonia Icefield based on an updated decennial evolution

P. Lopez (1); G. Casassa, (2)
(1) Geosciences Rennes, Rennes, France; (2) Geostudios Ltda and Universidad de Magallanes, Santiago and Punta Arenas, Chile

The glacier length fluctuations and the surface area evolution between 2001 and 2011 of 25 glaciers of the Northern Patagonia Icefield (NPI) were studied: the information extracted from the Landsat ETM+ satellite image of 11 March 2001 was compared to the measurements performed based on the Landsat ETM+ satellite image of 19 February 2011. From a global point of view, the majority of the studied glaciers thinned, retreated and lost surface between 2001 and 2011, only few glaciers (Leones, Nef, Pared Sur and Soler) located on the eastern side of the NPI have been stable. Glaciers located on the western side of the NPI suffered a stronger wasting compared to the glaciers located on the eastern side.

Between 2001 and 2011, a noteworthy retreat of 1.9 km was experienced by Gualas Glacier and by Reichelt Glacier with 1.6 km, both located on the north-western side of the NPI. On the south-western side of the NPI, during the same decennia, Steffen Glacier experienced a remarkable retreat of 1.6 km as well. During the 2001–2011 period, Steffen Glacier more than doubled its rate of retreat (compared to the 1979–2001 period) and experienced the disintection of its main front as well as a lateral tongue that retreated
3.1 km. The most significant retreat observed on the eastern side was experienced by Colonia Glacier (1 km).

Area loss was also relevant during the period 2001-2011. Overall, the icefield experienced a reduction of 50.6 km² which represents a 1.3% relative to the surface area calculated for 2001 year. The most remarkable surface reduction was observed for HPN-1 Glacier that lost 3.2% of its surface estimated in 2001, followed by Steffen Glacier (2.8%).

We suggest that the glacier shrinking observed in the NPI is controlled firstly by atmospheric warming, as it has been reported in this area. Nevertheless, updated climatic studies are needed in order to confirm this suggestion. If the detected past climate trends persist, in the future, glaciers of the NPI will continuously or even increase their rate of shrinking generating important consequences for this region like the production of Glacier Lake Outburst Flood events or the decrease of the melt-water runoff in the long-term future.

P-1107-13

## Use of Differential SAR Interferometry for vertical ground motions monitoring in coastal cities

D. Raucoules (1); G. Woppelmann (2); G. Le Cozannet (1) (1) BRGM, ORLEANS, France; (2) LIENSS - univ la Rochelle, La Rochelle, France

(1) BRGM, ORLEANS, France; (2) LIENSS - univ la Rochelle, La Rochelle, France

Before the altimetry era, tide gauge are a unique source of information to evaluate past sea-level changes. However, they can be affected by vertical ground motions acting at different space scales. We use synthetic aperture radar techniques to assess these ground motions and their consequences for geodetic instruments such as Tide Gauge, GPS, Doris stations. Summarizing results obtained at Alexandria (Egypt; Woppelmann et al., 2013), Manila (Philippines; Raucoules et al., 2013) and Dakar (Senegal; Le Cozannet et al., subm.), we identify different situations in terms of data availability and ground motion context: – when strong ground motions affect the tide gauge, the technique can easily help rejecting tide gauges records from the database of reliable datasets (Case of Manila) – however, when no ground motions can be observed using InSAR in the vicinity of geodetic instruments (Case of Alexandria and Dakar), it remains challenging to reach the accuracy required to confirm that tide gauge records are indeed suitable for monitoring sea level changes. To reach the required accuracy of this InSAR application, a large set of SAR data must have been acquired over the area. For future science application of Sentinel-1 in the field of geodesy underpinning sea level science, it will be necessary to define appropriate background missions covering coastal sites where key records have been acquired.

P-1107-14

## Sea level rise and Geoid: Factor analysis approach

A. Sadovski (1); H. Song, (2); G. Jeffries, (2)

(1) Texas A&M University-Corpus Christi, Corpus Christi, TX, United States of America; (2) Texas A&M University-Corpus Christi, Conrad blucher institute for surveying, Corpus Christi, United States of America

Sea levels are rising around the world, and this is a particular concern along most of the coasts of the United States. A 1989 EPA report shows that sea levels rose 5-6 inches more than the global average along the Mid-Atlantic and Gulf Coasts in the last century. The main reason for this is coastal land subsidence. This sea level rise is considered more as relative sea level rise than global sea level rise. Thus, instead of studying sea level rise globally, this paper describes a statistical approach by using factor analysis of regional sea level rates of change. Unlike physical models and semi-empirical models that attempt to approach how much and how fast sea levels are changing, this methodology allows for a discussion of the factor(s) that statistically affects sea level rates of change, and seeks patterns to explain spatial correlations.

Cartographers and geodesists, those who study the measurement of the size and shape of the earth, are

interested in sea level as an elevation datum. This datum is called the geoid, which is defined as the equipotential gravity surface of the Earth, and theoretically best fits global mean sea level in ocean areas. Hence, the rate of change in mean sea level directly affects changes to the geoid and the elevation datum used as the reference for topographic mapping.

Many methods have been used in sea level rise modeling. These methods can be divided into two categories: physical models, based on the conservation of mass (global water mass and ice mass measurements), and semi-empirical models, studying measured rates of change of sea level and measured changes in global temperatures along with the error estimates of measurements to predict future trends. These two approaches are complementary. For example, no one really understands the dynamics of each another, even if every glaciologist agrees that glaciologists from physical models, hence the use of semi-empirical methods described in the majority of studies of sea level rise. This paper introduces a different approach by using factor analysis of regional sea level rates of change as a statistical analysis tool. Instead of answering the question of how much and how fast sea levels are changing, this paper computes and discusses which mathematical factor statistically affects sea level rates of change and seeks patterns to explain spatial correlation. The paper also seeks to hypothesize that any insights into the factors influencing sea level change also apply to the changes to the geoid.

P-1107-15

## Strategy and new statistical downscaling method for the on-line derivation of the Greenland ice sheet surface mass balance in a GCM

D. Salas Y Melia (1); M. Geyer (1); E. Brun (2); M. Dumont (3)

(1) CNRM-GAME (METEO-FRANCE/CNRS), GMGEC/ASTER, Toulouse, France; (2) ONERC, Paris, France; (3) CEN, Grenoble, France

Current CMIP5 (Coupled Model Intercomparison Project Phase 5) coupled Global Climate Models (GCMs) cannot realistically represent ice sheet/climate feedbacks. This is due to their coarse horizontal resolution, which hampers the correct representation of Surface Mass Balance (SMB) spatial variability, to weaknesses in the representation of physical processes at the ice Sheetsurface and to the lack of interactive ice sheet models which are necessary to>torepresent the ice loss due to dynamics. As a contribution to the future inclusion of interactive ice sheet models in coupled GCMs, we discuss various potential methods. We present a downscaling method designed for the online derivation of the SMB field over the Greenland ice sheet (GrIS). This method uses statistical relationships between SMB and temperature variations which have been established from off-line simulations of the SMB performed on a high resolution grid with a detailed snowpack model. We used this technique to downscale 150 km horizontal resolution SMB output from the CNRM-CM5.1 GCM to a 15 km resolution grid. A comparison with output from the MAR regional model shows that the downscaling clearly improves the spatial distribution of the SMB, particularly along the GrIS margins, where steep topography gradients are not correctly represented at low-resolution. A simulation where CNRM-CM5.1 was nudged with ERA-Interim demonstrates the ability of the method to reproduce reasonably well the interannual variability of the total GrIS SMB from 1979 to 2012. From a technical point of view, the method is generic enough to be applied to outputs from other GCMs, though it cannot completely filter model biases, especially in the interior of the GrIS.

P-1107-16

## Sea-level change and projection for future flooding along the coast off Egypt

M. Shaltout (1)

(1) Faculty of Science, Alexandria University, Egypt., Physical Oceanography, Alexandria, Egypt

The current study analyses the recent changes in the daily satellite altimetry data along the southern Levantine sub-basin and cost off Egypt over the period 1993-2013. First,
the accuracy of using satellite altimetry data, represented by dynamical topography (DT) as a measure of coastal sea levels, is examined based on tide gauges observations. Second, daily and annual satellite altimetry data are related to five atmospheric/oceanic factors to evaluate their effect on DT changes. Third, the qualities of three realisations of the Geophysical Fluid Dynamics Laboratory (GFDL) global climate model (GCM) are examined by comparing these with the satellite altimetry dataset. Finally, the simulations of the present satellite altimetry data are used to describe the uncertainties in projection of the sea level changes along the study area.

The results indicate that the satellite altimetry data represented by DT can be used to study coastal and deep sea level changes in the study area. Southern Levantine sub-basin sea level display a recent average sea level rise of 3.1 cm decade⁻¹ and exhibits a significant annual sea level variation from -17 cm (deep water) to 8 cm (shallow water). The sea level variations are significantly affected by several factors such as and in order of importance: sea level variations west of Gibraltar Strait, steric sea level variations and sea surface temperature. The GCMs that most realistically describe the recent sea level over the study area is GFDL-CM3, outputs from this model are used to study the projected sea level along the study area for different emission scenarios. GFDL-CM3 model results indicate that the coast of Egypt will experience sea level rise in the current century. Uncertainty in the projected sea level rise over the studied area ranged from 4 to 22 cm rise by 2100 and was explained by three different sources of uncertainties, of which the emission assumed dominated. Comparing of uncertainty in the projected sea level rise with digital elevation data shows that the Egyptian Mediterranean coast will only become safe from flooded by the end of 21st century if effective adaptation methods are applied.

P-1107-17

## Earth's changing oceans: Effects and implications for iceberg calving from Antarctica's ice shelves

C. Walker (1)

(1) Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA, France

Ice shelves are freely floating seaward extensions of the Antarctic ice sheet. They can extend hundreds of kilometers into the ocean and drain the vast majority of ice from Antarctic ice sheet to the ocean. Iceberg calving from these ice shelves is the primary means of discharging ice from the Antarctic Ice Sheet into the Southern Ocean and, although calving events occur sporadically, when they occur they remove large amounts of mass in a nearly instantaneously. This cycle forms part of the natural cycle of ice shelf advance and retreat with typical recurrence times between major calving events of the order of several decades. However, changes in calving rates have also been implicated in some of the most rapidly changing regions of Antarctica. Scambos et al. (2003) showed that the abrupt disintegration of both Larsen A and Larsen B ice shelves occurred following a series of abnormally warm summers. Not only were these disintegrations surprising in terms of size, but also in the speed at which they occurred; approximately 13,500 km/s^2s of ice was lost by the collective Antarctic ice shelves due to collapse in the last three decades of the 20^5th^ century, deemed to be possibly related to the approximately 3 degrees C increase in temperature at the Antarctic Peninsula over the last half of the century (Steffen et al., 2010). Despite the fact that calving accounts for at least half of the mass loss from the ice sheet (Rignot et al., 2013), but its relation to the changing climate remains poorly understood.

Many a major and minor ice shelves of Antarctica exist in a colder climate further South than the peninsular ice shelves and have not experienced comparable surface warming nor are they currently showing any signs of peninsular-style disintegration. They have, however, experienced increased basal melting over the past decade with some speculation that these ice shelves may especially be susceptible to ocean forcing. To realistically assess the evolution of ice shelves it is necessary to investigate the precursor to calving: the initiation and propagation of rifts through the ice. As ice flows toward the open water rifts eventually become the boundaries at which icebergs separate from their parent ice shelf. An example of such a rift was detected in October 2011, at Pine Island Glacier (PIG) in West Antarctica. The PIG flows outward into the Amundsen Sea, creating a 30-km floating ice tongue. As the floating shelf elongates from the grounding line, cracks eventually form and icebergs calve off later. Rifts can initiate far upstream of the calving front and propagation for decades before an iceberg detaches. While many studies have examined the dynamics of vertical crevasse penetration, fewer studies have examined lateral propagation and little is currently known about the forces and underlying mechanisms that drive rift propagation. For example, it has been proposed that rifting is the cumulative result of many environmental factors, such as ocean swell induced flexure caused by pulses of ocean swell or that rifting is primarily the result of internal mechanical stresses acting to fracture the ice.

In this study we continue the monitoring work that was published in 2013, conducting observations of 15 ice shelves around Antarctica over a 15 year period between 2000 and 2015. While previously we only compared tidal swell data with rift propagation data sets, we now use a variety of oceanic data and model results to better characterize the effect of ocean changes on ice sheet and specifically the evolving effect that Earth's changing oceans might have on solid ice discharge rates from Antarctica's ice shelves.

P-1107-18

## The Irreversibility of Sea Level Rise

K. Zickfeld (1); K. Tokarska (2)

(1) Simon Fraser University, Vancouver, BC, Canada; (2) University of Victoria, Victoria, Canada

Recent research has shown that sea level continues to rise even if carbon dioxide emission will be halted completely. Here we explore whether artificial atmospheric carbon dioxide (CO₂) removal (also referred to as “negative emissions”) has the potential to reverse thermosteric sea level rise on timescales relevant to human civilization. Specifically, we investigate how much CO₂ needs to be removed from the atmosphere for sea level rise to be reversed and stabilize permanently, and the degree to which the reversibility of sea level rise depends on the amount and duration of CO₂ emissions prior to the time of artificial CO₂ removal. To investigate these questions, an Earth System model of intermediate complexity is forced with a range of emission scenarios entailing different amounts of net negative CO₂ emissions. We find that in order to reverse and stabilize sea level rise, atmospheric CO₂ concentrations need to be returned to pre-industrial levels. Thermosteric sea level rise is linked to the intake of far net radiation flux at the top of the atmosphere, and will stop rising only when this flux becomes negative (i.e. when there is a net radiation loss to space). Our results suggest that while sea level rise can be reversed temporarily with negative emission technologies deployed at a scale that is currently deemed to be technologically feasible, reversal and permanent stabilization of sea level rise requires the removal of all anthropogenic CO₂ from the atmosphere.
# 1108 - Middle Atmosphere influence on Climate

## ORAL PRESENTATIONS

### K-1108-01

#### Future stratospheric ozone in a changing climate

**U. Langematz (1)**

(1) Freie Universität Berlin, Institut für Meteorologie, Berlin, Germany

As a result of the Montreal Protocol on Substances that Deplete the Ozone Layer and its subsequent amendments and adjustments that constrained the production and consumption of halocarbons, the decline of stratospheric global ozone seems to have ceased. Model projections suggest a future recovery of the global mean ozone column to levels around the year 1980, when only low levels of ozone depleting substances (ODSs) existed in the stratosphere. However, the timing of the return of ozone to historical levels depends not only on the concentrations of ODSs but is also affected by thermal and dynamical changes associated with increasing greenhouse gas concentrations. For example, while the amounts of ODSs steadily decrease in the stratosphere, with appropriate meteorological conditions and given the long lifetimes of ODSs, individual years with strong ozone decrease still may occur in the near future.

Here, an overview of future projections of the ozone layer based on chemistry-climate model simulations will be presented. The impact of climate change on stratospheric ozone recovery will be discussed.

### K-1108-02

#### Stratosphere-Troposphere Coupling in a Changing Climate

**M. Baldwin (1)**

(1) University of Exeter, Exeter, United Kingdom

Stratospheric variability and change has substantial effects on surface weather and climate, especially on the Annular Modes, with shifts in the jet streams, storm tracks, precipitation, and likelihood of blocking events. Despite unambiguous observations of this phenomenon, as well as numerical simulations, a clear physical explanation of this downward coupling has been elusive. In this talk I will discuss recent advances in our understanding—how pressure changes (movement of mass) in the stratosphere affects surface climate. However, movement of mass in the stratosphere is not sufficient to fully explain the observed surface changes—surface effects are than would be expected theoretically, and are larger than at the tropopause. This “tropospheric amplification” is easily quantified, and suggests a role for eddy feedbacks in response to the movement of mass. I will discuss the future implications for surface climate, jets, storm tracks, etc.—assuming that we know how the stratosphere will change during the remainder of this century.

### O-1108-01

#### Sub-seasonal climate predictability associated with an anomalously strong stratospheric polar vortex

**A. Charlton-Perez (1) ; O. Tripathi, (1) ; M. Sigmond, (2) ; F. Vitart, (3)**

(1) University of Reading, Meteorology, Reading, Berkshire, United Kingdom; (2) Environment Canada, Canadian centre for climate modelling and analysis, Victoria, Canada; (3) ECMWF, Reading, Berkshire, United Kingdom

There has been a great deal of recent interest in producing weather forecasts for the 2–6 week “sub-seasonal timescale” which bridges the gap between medium–range (0–10 day) and seasonal (3–6 month) forecasts. While much of this interest is focused on the potential applications of skillful forecasts on the sub-seasonal range, understanding the potential sources of sub-seasonal forecast skill is a

challenging and interesting problem particularly because of the likely state-dependence of this skill (Hudson et al., 2011). One such potential source of state-dependent skill for the Northern Hemisphere in winter is the occurrence of stratospheric sudden warming (SSW) events (Sigmond et al., 2013). Here we show, by analysing a set of sub-seasonal hindcasts, that there is enhanced predictability of surface temperature and circulation not only when the stratospheric vortex is anomalously weak following SSWs but also when the vortex is extremely strong. During the third and fourth weeks following anomalously strong polar vortex conditions northern Europe and northern Russia are on average three degrees Celsius warmer than their climate norm, with similarly sized cold anomalies over northwestern North America. Sub-seasonal forecasts initialised during strong vortex events are able to successfully capture their associated surface temperature and circulation anomalies. This results, for some regions, in a significant enhancement of forecast skill compared to forecasts initialised during cases when the stratospheric state is close to climatology. We demonstrate that the enhancement of skill for forecasts initiated during periods of strong vortex conditions is comparable to that achieved for forecasts initialised during SSW events. This result indicates that additional confidence can be placed in sub-seasonal forecasts when the stratospheric polar vortex is significantly disturbed from its normal state. This presentation will discuss this result and its implications for understanding the impact of stratospheric climate change and its tropospheric impact.

### O-1108-02

#### Characteristics of stratospheric warming events during Northern Winter

**P. Maury (1) ; C. Claud (1) ; E. Manzini (2) ; A. Hauchecorne (3) ; P. Keckhut (4) ; K. Kodera (5)**

(1) CNRS, Ispil/Imd, Palaiseau, France; (2) Max Planck Institut, Hamburg, Germany; (3) CNRS, Latmos, Guyancourt, France; (4) LATMOS-IPSL, Guyancourt, France; (5) Solar–Terrestrial Environment Laboratory, Nagoya university, Nagoya, Japan

The polar mid-stratosphere is characterized by the setting up of westerly winds around the pole during the wintertime; the so-called polar vortex. The polar vortex is one of the most variable features of the zonal–mean circulation of the stratosphere. It is a high non–linear interaction between the zonal–scale Rossby waves and the zonal flow. Indeed, the interaction between the upward tropospheric propagating waves and the polar vortex leads to a zonal flow weakening, implying a large day-to-day vortex variability. In the most dramatic cases, the polar vortex breaks down, the stratospheric polar flow can reverse its direction and the temperatures can rise locally by more than 50K in a span of a few days. Such phenomena are known as major Sudden Stratospheric Warmings (SSWs) and constitute, since their discovery in 1952 (Scherhag, 1952) the most impressive dynamical events in the physical climate system. On the contrary, situations where the temperature increase is not associated to a polar vortex breakdown are known as minor SSWs.

There is actually a renewed interest about SSWs since Baldwin and Dunkerton (2001) have shown that the major SSWs can influence weather in the troposphere. This stratospheric-tropospheric linkage has been statistically highlighted but no physical explanation has been proposed. Also, other studies, that incorporate both major and minor SSWs, show that events in the stratospheric zonal flow associated with SSWs present downward-propagating anomalies that can reach the troposphere (Limpasuvan et al, 2004), implying that minor SSWs have to be also considered in the study of the stratospheric-tropospheric dynamical coupling.

In this study, we propose a global characterization of stratospheric warnings situations based on a temperature threshold in the 50–10hPa layer between 70N–90N, in order to better assess the properties of daily stratospheric temperature variability during the northern winter. The originality of this approach consists in evaluating the weather variables in positive and negative temperatures in terms of intensity and duration without distinction between minor and major SSWs. We will show that there is a wide
spectrum of warming types, where major SSWs are the most extreme, but other events – the minor SSWs – share some common properties with them. They can even have a surface signature if one look the stratospheric wave reflection on the polar vortex.

## O-1108-03

### Update of stratospheric temperature interannual variability and trends from space sounders and ground-based lidars observations

A. Hauchecorne (1); P. Keckhut (1); C. Claud (2); B. Funatsu (3), S. Khaykin (1); G. Angot, (1); P. Maury, (2)

(1) LATMOS-IPSL, Guyancourt, France; (2) CNRS, Ipler/Imd, Palaiseau, France; (3) CNRS, Letgren-rennes costel, universite rennes2, Rennes, France

The stratosphere is expected to cool, in conjunction with the global warming at the surface and in the troposphere, due to the increase of greenhouse gas concentration in the atmosphere, and also to stratospheric ozone loss. This is already observed but the rate of cooling is not constant and there is still a debate on its amplitude. Several other factors may influence the evolution of the stratospheric temperature. External forcings, like the solar variability that modulate the UV solar flux, strong volcanic eruptions injecting aerosols in the stratosphere, participate to its decadal variability. The variability of the stratospheric dynamics is also adding some complexity to the system. For instance global climate models predicts an increase of the occurrence frequency of sudden stratospheric warming events, not yet confirmed by the observations. A monitoring of the stratospheric temperature evolution is crucially needed to better understand the complexity of the processes playing a role in the coupling between the stratosphere, the troposphere and the climate.

The stratospheric temperature is measured at a global scale by satellite instruments; mainly microwave sounders AMSU (Advanced Microwave Sounding Unit) on board meteorological satellites. These sounders are very useful to provide the global overview but may suffer from biases and orbital drifts and have a poor vertical resolution in the upper stratosphere. Since 2000 radio-occultation sensors, among them the US-Taiwan COSMIC constellation, provide well-resolved and accurate temperature profiles but limited to the upper troposphere-lower stratosphere. Rayleigh lidars implemented within the NDACX (Network for the Detection of Atmospheric Composition Change) international network measure accurately the temperature profile from the middle stratosphere to the upper mesosphere but in a very few locations. They are used climate change monitoring, dynamics studies and satellite validation.

In this presentation we will present an update of the interannual variability and trends in the stratospheric temperature from AMSU, Rayleigh lidar and radio-occultation measurements. Similarities and differences in the temperature evolution captured by these various sensors will be evaluated. The contribution of anthropogenic and natural forcings to the observed changes will be discussed. A particular focus will be given to the role of SSW events to the stratospheric temperature evolution as a function of latitude and season.

## O-1108-04

### Role of the middle atmosphere for low-frequency climate variability

T. Reichler (1); Z. Bowen (1)

(1) University of Utah, Atmospheric Sciences, Salt Lake City, Utah, United States of America

It is commonly believed that the ocean represents the dominant source for climate variability on longer, interdecadal time scales and that this drives the low-frequency variability of the atmosphere. Here, we provide evidence for the existence of opposite pathways. Investigating long control simulations with coupled and uncoupled climate models we find considerable multi-decadal variability in the atmosphere that is independent of the ocean and that influences climate. The middle atmosphere represents one source for such low-frequency variability. The variability is related to relatively long-

lived fluctuations in the strength of the stratospheric polar vortex, which in turn project on the state of the North Atlantic Oscillation. This creates signals in ocean temperatures over the deep convective region to the south of Greenland, which, over the course of several years, propagate into the deep ocean. These events modulate and drive intrinsic low-frequency variability in the Atlantic Multidecadal Overturning Circulation (AMOC) and explain about 20% of the natural AMOC variability. Our findings support the view that trends and low-frequency variations in the middle atmosphere extend their influence beyond the troposphere into the ocean and that this constitutes an important source of climate variability. We discuss natural and anthropogenic sources for such low-frequency stratospheric variability.

## O-1108-05

### The millennium water vapour drop in the stratosphere in chemistry-climate model simulations

S. Brinkop (1); M. Dameris (1); P. Joeckel, (1); H. Garny, (1) S. Lossow, (2); G. Stiller (2)

(1) DLR-Deutsches Zentrum fuer Luft- und Raumfahrt, Institut fuer physik der atmosphäre, Oberpfaffenhofen, Germany; (2) KIT - Karlsruher Institut fur Technologie, Imk- asf, Karlsruhe, Germany

This study investigates the millennium water vapour drop, the abrupt and severe water vapour decline in the stratosphere beginning in year 2000, by means of various simulations using the Chemistry-Climate Model (CCM)EMAC. Since the beginning 1980s, balloon borne stratospheric water vapour measurements and correspondingsatellite measurements starting in the early 1990s indicated a long-term steady increase of water vapour concentrations. However, the multi-year data sets also show significant fluctuations on different time scales. In the year 2000, an extraordinary sudden drop of stratospheric water vapour concentration has been observed followed by persistent low values for several years. Solomon et al., (2010) showed that this drop slowed down the rate of increase in global surface temperature over the following decade by about 25%. So far, the stratospheric water vapour variations observed by satellite from 1992 to 2012 are not reproduced by CCM simulations forced by observed changes in sea surface temperatures, greenhouse gases and ozone-depleting substances (Gettelman et al., 2010, Randel and Jensen, 2013). However, the CCM EMAC is able to reproduce the signature and pattern of the water vapour disturbances inagreement with those derived from observations. In this paper we present results of a hierarchy of simulationswith the CCM EMAC, demonstrating that it is possible to retrace the observed water vapour fluctuations in thestratosphere (incl. the millennium drop), if suitable inner and outer boundary conditions are applied.

## 1108-POSTER PRESENTATIONS

### P-1108-01

#### The ARISE project: dynamics of the atmosphere and climate

E. Blanc (1); A. Charlton-Perez (2); P. Keckhut (3); L. Evers (4); P. Heinrich (1); A. Le Pichon (1); A. Hauchecorne (5)

(1) CEA, Arpajon, France; (2) University of Reading, Department of meteorology, Reading, United Kingdom; (3) LATMOS-IPSL, Guyancourt, France; (4) Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands; (5) CNRS, Latmos, Guyancourt, France

It has been robustly demonstrated that variations in the circulation of the middle atmosphere influence weather and climate throughout the troposphere all the way to the Earth's surface. A key part of the coupling between the troposphere and stratosphere occurs through the propagation and breaking of planetary waves and gravity waves. Limited observations of the middle atmosphere and these waves in particular hamper our ability to faithfully reproduce the dynamics of the middle atmosphere in numerical weather prediction and climate models.

An exciting scientific development in recent years has been the potential for a number of novel ground-
based measurement techniques to give new and complementary measurements of the middle atmosphere. The main challenge of the ARISE (Atmospheric dynamics Infrastructure in Europe) project[1] is to combine for the first time existing national and international observation networks which observe the middle atmosphere including: the International infrasound monitoring system developed for the CTBT (Comprehensive nuclear-Test-Ban Treaty) verification, the NDACC (Network for the Detection of Atmospheric Composition-Changes) lidar network, localized European observation infrastructures at mid latitudes (OHP observatory, tropics (Maido observatory), high latitudes (ALOMAR and EISCAT), infrasound stations developed at national level in European countries and satellite measurements. This joint network provided advanced data products, with the scope to assemble the derived upper atmospheric wind and temperatures into NWP models.

The ARISE infrastructure is unique because of its coverage (from polar to equatorial and tropical regions in the European longitude sector and adjacent regions), its ability to sense a wide range of altitudes (including stratosphere, mesosphere, lower thermosphere, ionosphere) and the involved scales both in time (from seconds to tens of years) and space (from tens of meters to thousands of kilometers). We are about to embark upon a new phase of development to allow the network be improved by i) including innovative instrumentation for measurements in the middle atmosphere between 40 and 80 km where temperature and wind measurements are especially rare, ii) adding measurements in low latitude African stations where only infrasound observations are currently available, iii) and by automating lidar and radar measurements for routine observations.

The major ARISE objective is to provide a full description of gravity and planetary waves in the stratosphere and mesosphere for wave parameterization and assimilation in the models. This could lead to a better prediction of extreme events such as Sudden Stratospheric Warming and improvement of the tropospheric weather forecasts on weekly time scales. The societal impact is potentially very large, including for sectors such as agriculture, industry, energy consumption, transport, insurance and risk quantification.

The ARISE objectives are also i) to better characterize the coupling between atmospheric layers and effects on the global atmospheric circulation and climate, ii) to quantify the trends in extreme events relate to climate, iii) to determine the impact of the Earth's geo-space.

The project is multidisciplinary and includes European groups with complementary expertise in weather forecasting, climate, extreme events monitoring. It has partners in a number of international organizations including the ECMWF (European Centre for Medium-Range Weather Forecasts), WMO (World Meteorological Organization), SPARC (Stratospheric Processes and Their Role in Climate), ROSMIC (Role Of the Sun and the Middle atmosphere-thermosphere-ionosphere (In Climate), IRGGEA (International Research Group in Geophysics Europe Africa).

This presentation will review recent advances in this topic especially obtained in the framework of the ARISE project. It will also discuss perspectives and future project challenges related to climate.

[1] ARISE is an infrastructure Design Study project funded by the European Commission under the H2020 program.

## P-1108-02

# Stratospheric chemistry-climate interactions and their importance for the surface climate in Antarctica

P. Braesicke (1) ; J. Keeble (2) ; L. Abraham (3) ; S. Kellmann (1) ; J. Pyle (2) ; G. Stiller (1) ; X. Yang (4)

(1) KIT, IMK-ASF, Eisenberg-Geodaufahrten, Germany; (2) University of Cambridge, Cas, Cambridge, United Kingdom; (3) University of Cambridge, Ncas, Cambridge, United Kingdom; (4) BAS, British antarctic survey, Cambridge, United Kingdom

One prominent example of anthropogenic environmental change is the annually recurring ozone hole in the Southern Hemisphere (SH). This systematic change in stratospheric composition affects circulation and tropospheric climate. To improve our understanding of

how a stratospheric change induces shifts in tropospheric climate, we investigate model integrations run with the fully coupled chemistry climate model UM-UKCA. Results are confronted, where appropriate, with satellite observed changes from the MIPAS instrument on ENVIAT.

Comparing two climate-equilibrium runs with and without an ozone hole we find statistically significant changes in the models thermal structure and circulation. Polar lower stratospheric cooling, in conjunction with the elevation of the high latitude tropopause and followed by an increase in the vertical component of the EP flux from November to December are consistent with a surface warming of the Antarctic Peninsula in December. The seasonal change of circulation is accompanied by an apparently descending anomaly of the EP flux divergence in the stratosphere, thus suggesting an active role of stratospheric dynamics in the surface response.

The robustness of such a circulation response to ozone changes can be studied diagnosing differences of long-lived trace gas distributions as an indicator for large-scale circulation changes. Here, we contrast the MIPAS observed year-to-year variability in N2O to changes in the seasonal evolution of N2O in different modelled climate equilibrium states with different ozone amounts. We conclude that the climate system can respond sensitively (but coherently) in its seasonal evolution to small chemical perturbations and the circulation adjustments modelled are consistent with observed interannual variability. This finding supports the applicability of the UM-UKCA climate equilibrium runs to the interpretation of the Antarctic Peninsula warming.

## P-1108-03

# Stochastic parameterizations of the gravity waves emitted from convection and fronts: theory, validation, and impacts of the middle atmospheric circulation

A. De La Camara (1) ; F. Lott, (1) ; L. Guez, (1) ; A. Hertzog, (1)

(1) Laboratoire de Meteorologie Dynamique, Paris, France

Internal gravity waves (GWs) propagating vertically from their tropospheric sources impact the circulation of the middle atmosphere, and are crucial for the reversal of the mesospheric jet and the maintenance of the quasi-biennial oscillation. Their spatial scales being too small to be represented in current Earth System models, they need to be parameterized. Neither Earth systems nor mechanisms of GW emission by fronts and jets remain largely elusive nowadays. As a result, non-orographic GW parameterizations have traditionally assumed an arbitrarily uniform source of waves, which makes them insensitive to the annual cycle of the GW sources or to a changing climate. For these reasons, much effort has been made over the last decade to develop schemes that relate the GWs to their sources.

A recently developed stochastic parameterization of gravity waves is used and adapted to represent the gravity waves produced by convection and mid-latitude fronts. For the fronts, the parameterization uses a theory of the spontaneous adjustment that relates directly the gravity waves field to potential vorticity anomalies. With relatively little modification to the theory, we show that the spontaneous adjustments occurring in the troposphere are sufficient to produce a right amount of waves in the mesosphere. We also predict the gravity wave field present during the Concordiasi long-duration ballon campaign in the lower stratosphere, and show that the gravity waves predicted by the parameterization are quite realistic. The impacts on the climate are also addressed with the General Circulation Model LMDz, with a particular emphasis on the annual cycle in the stratosphere. We also address the significance of including the GWs sources on the middle atmosphere response to a changing climate. Preliminary results show that when GW sources are included, the middle atmosphere response to climate change is stronger than without the sources, the impacts even reaching the surface at least in the Southern Hemisphere.

de la Cámara, A., and F. Lott, 2015: A parameterization of gravity waves emitted by fronts and jets, Geophys. Res. Lett., doi: 10.1002/2015GL063298.

de la Cámara, A., F. Lott, and A. Hertzog, 2014: Intermittency in a stochastic parameterization of non-orographic gravity waves, J. Geophys. Res. Atmos., 119, 11,905-11,919, doi:10.1002/2014JD022002.
Lott, F., and L. Guez: 2013: A stochastic parameterization of the gravity waves due to convection and impact on the equatorial stratosphere, J. Geophys. Res., 118 (16), 8897–8909.

P-1108-04

On the coupling between polar and tropi-
cal regions during springtime: variability of
tropical intrusion and Frozen in Anticy-
clones

N. Huret (1) ; R. Thiéblement (2) ; A. Hauchecorne (3) ; YJ. Orlowski (4) ; K. Mathes (2)

(1) LPC2E/CNRS and Orléans University, Orléans, France;
(2) GEOMAR, Kiel, Germany; (3) CNRS, Latmos, Guyancourt, France; (4) NILU, Kjeller, Norway

Recent observational and modeling transport studies of Arctic stratospheric final warming have shown that tropical/subtropical air masses can be transported to high latitudes and remain confined within a long-lived 'frozen-in' anticyclone (FrIAC), embedded in the summer easterlies for several months.

We first present a climatology of these sporadic events over the period 1960–2011 using ERA–40 and ERA Interim reanalyses. This study highlights stratospheric favorable preconditioning for FrIACs occurrence, that is: i) early and abrupt final warming, ii) no stratospheric major warming during the previous winter, and iii) East phase of the Quasi–Biennial Oscillation. We will present in detail the FrIAC in spring 2011, which was the largest ever recorded. Our climatology further suggests that the frequency of occurrence of FrIACs has increased over the last decade (among the nine cases detected over the period 2060–2011, five occurred between 2002 and 2011).

A chemistry climate model is then used for the first time to investigate FrIACs characteristics and variability. Simulations were performed with the NCAR's Community Earth System Model (CESM, version 1.0.2), a coupled model system including the Whole Atmosphere Community Climate Model (WACCM). FrIACs characteristics (i.e. spatial extent and duration), are overall consistent by comparing with FrIACs detected ERA–40 meteorological reanalyses. Dynamical analysis reveals that FrIACs are associated with an abrupt and early winter-to-summer stratospheric circulation transition, characterized by an amplification of protostatic wave activity. Furthermore, our model results confirm that FrIACs occur feedback when the easterly phase of the QBO and in absence of MSW during the preceding winter. Finally, we notice that extreme climate change conditions (RCP8.5 scenario) do not influence FrIACs frequency.

P-1108-05

Stratospheric ozone causes a negative
feedback in CO2-driven climate change
simulations

M. Ponater (1) ; S. Dietmüller, (1) ; M. Dameris (2) ; R. Sausen, (1)

(1) DLR-Institut für Physik der Atmosphäre, Earth System Modelling, Oberpfaffenhofen, Germany; (2) DLR, Institut für physik der atmosphäre, Oberpfaffenhofen, Germany

Ozone has been considered mainly as a contributor to climate change in terms of radiative forcing. However, it is also providing a radiative feedback when climate change is induced by, for example, a radiative forcing from CO2 increase. Interactively coupled chemistry-climate models can be used to identify and confirm this feedback. In a set of simulations forced by CO2 increase of different strength we find a negative ozone radiative feedback, which reduces the climate sensitivity compared to a model system where the ozone distribution is prescribed. Stratospheric ozone is more important than tropospheric ozone for this chemical feedback. The feedback, mechanism mainly works through intensification of the Brewer–Dobson circulation as sea surface temperature increases. The stratospheric water vapour feedback is modified by interaction with the ozone feedback, becoming less positive than in simulations with fixed ozone. Hence, a negative ozone feedback and a reduced water vapour feedback overlap constructively in CO2-driven simulations with interactive ozone, giving a global sea surface temperature response

that is 4 to 10% smaller than in a corresponding simulation
without interactive chemistry.

P-1108-06

Evidence by remote sensing and com-
bined-model approaches for the role of
gravity waves in sudden stratospheric
warmings

P. Preusse (1) ; M. Ern, (1) ; BG. Song, (2) ; T. Trinh, (1) ; F. Friedl–Vallon, (3) ; P. Bechtold, (4) ; HY. Chun, (2) ; J. Orphal, (3) ; M. Riese, (1)

(1) Forschungszentrum Juelich GmbH, IEK-7, Juelich, Germany; (2) Yonsei University, Seoul, Republic of Korea; (3) Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany; (4) ECMWF, Reading, United Kingdom

Observations of absolute values of gravity wave momentum flux (GWMF) from the satellite instruments SABER ad HIRDLS in conjunction with global stratospheric and mid streric winds are used to investigate the role of GWs in the different phases of the sudden stratospheric warmings (SSWs) during the recent decade. Both GWMF and its vertical gradient as a proxy for drag are enhanced before the central date of major SSWs. After the central date of the SSW, GWMF and gravity wave drag in the stratosphere are strongly reduced. However, GWs contribute to the downward propagation of newly formed polar jets and of elevated stratospheric to their climatological» altitude. This is likely at least in part due to poleward propagation of GWs. In order to shed light on the sources, propagation direction and phase speed spectra of the waves we complement the observations by high-resolution global model fields of ECMWF. We use these fields to infer the characteristics of GWs in the lower stratosphere and couple the results to global ray-tracing. This allows us to a) infer sources of GWMF by backward ray-tracing and b) to study the interaction of GWs in the stratosphere and mesosphere by forward ray-tracing in the background of geostrophic winds inferred from MLS and SABER. The current satellite observations can not reveal the propagation direction of the waves and model data need still to be proven to be fully realistic: the advantages of both approaches would be combined in limb-imaging measurements of a future mission. A concept for such an instrument is presented.

P-1108-07

The impact of biogenic bromine emissions
from the oceans on the middle atmosphere
in a changing climate

BM. Sinnhuber (1) ; G. Krysztofiak (2) ; S. Meul (3)

(1) Karlsruhe Institute of Technology, Institute for Meteorology and Climate Research, Eggenstein-Leopoldshafen, Germany; (2) University of Orléans, LPC2E, CNRS, Orléans, France; (3) Freie Universität Berlin, Berlin, Germany

Bromine from very short-lived substances, primarily from natural oceanic sources, contribute substantially to the halogen loading of the free troposphere and stratosphere with an important impact on atmospheric chemistry. This source of atmospheric bromine has so far been ignored in most chemistry-climate model simulations of tropospheric and stratospheric ozone trends. Here we will present chemistry climate model simulations over the past decades including the biogenic emissions of bromine from the oceans and their impact on atmospheric chemistry and ozone trends. We will discuss possible interactions between oceanic emissions, atmospheric chemistry and climate change.

P-1108-08

Network for the Detection of Mesopausal
Change (NDMC): What can we learn from
airflow measurements in terms of better
understanding atmospheric dynamics?

S. Wüst (1) ; M. Bittner (1) ; C. Schmidt, (1) ; PJ. Espy (2) ; J. French (3) ; F. Mulligan, (4) ; J. Scheer (5) ; M. Taylor, (6)

(1) DLR Oberpfaffenhofen, DFD-ATM, Wessling, Germany; (2) Norwegian University of Science and Technology, Trondheim,