bluuebunny/crossref_metadata_2025 huggingface dataset:
Releasing global forests from management: how much more carbon could be stored?
Authors: Roebroek Caspar , Duveiller Gregory , Seneviratne Sonia , Davin Edouard , Cescatti Alessandro
Published: February 2023

Global forests play a key role in the global carbon cycle and are a cornerstone in international policy-making to prevent global warming from exceeding 1.5°C and reach carbon neutrality. In line with recent climate science, the actions taken in the current decade are crucial for obtaining the goals laid out in international agreements. One forest-based strategy with high short-term climate benefits is the return of global forests to their carbon storage potential, by ceasing forest management, but the ecological boundaries of increasing biomass in existing forests remain poorly quantified. Recent studies preferentially focus on the mitigation potential of reforestation, without explicitly accounting for the carbon dynamics in existing forests, thus providing an incomplete evaluation of the possible expansion of the forest carbon stock. Here we integrate satellite remote sensing estimates of current forest biomass with a machine learning framework to show that existing global forests could increase their above-ground biomass by 44.1 PgC at most (an increase of 16% over current levels) if allowed to reach their natural equilibrium state. In total, the maximum carbon storage potential in this hypothetical scenario equates to just about 4 years of global anthropogenic CO2 emissions (at the 2019 rate). This maximum potential would require the complete stop of forest management and harvesting for decades. Therefore, without first strongly reducing CO2 emissions, this strategy holds low climate change mitigation potential. This urges to view storing additional carbon in existing forests as an effective strategy to offset carbon emission from sectors that will be hard to decarbonise, rather than as a tool to compensate all business-as-usual emissions.
Estimating the Offshore Wind Energy potential of the North Sea considering exclusion zones and the efficiency of large wind farms clusters
Authors: Hahmann Andrea , Mitsakou Aikaterini , Alonso De Linaje Nicolás G. , García-Santiago Oscar , Badger Jake , van Uden Jelle , Rennuit-Mortensen Anders , den Haan Michiel
Published: February 2023

The European Union has set ambitious greenhouse gas reduction targets, stimulating renewable energy production and accelerating the deployment of offshore wind energy in northern European waters, mainly the North Sea. We investigate if the set targets are achievable given the wind climate of the North Sea and efficiency loss resulting from large-scale extraction of kinetic energy.We utilise the wind climate of the North Sea estimated from ERA5 and the New European Wind Atlas (NEWA) to evaluate the offshore energy potential of this region. We consider three scenarios of wind turbine technologies: wind farms in operation today, existing plus wind farms in the construction and planning stage, and all wind farms, which include all possible areas where offshore wind farms could be built in the future, which are determined from current exclusions zones in the North Sea. We estimate the annual energy production and capacity factors per country for the various scenarios under free-stream conditions, considering wind farm wakes from engineering models and the loss of efficiency of huge wind farms. We study the sensitivity of the energy potential to the source of wind climate (ERA5 versus NEWA), whether the data is bias-corrected or not, and the method used to apply the wake losses to the wind farm considered. We also evaluate the possible year-to-year variability of these estimates.
The Dashboard of the EU Soil Observatory – making soil data speak to policy-makers and society
Authors: Marechal Anne
Published: February 2023

Life on Earth depends on healthy soils. Soil provides food, clean water and habitats for biodiversity while contributing to climate resilience. They are at the centre of many of the most pressing societal challenges of this century. Knowing the state of soil health, its current pressures and its trends is essential for the soil community (e.g. policy makers, researchers or practitioners) to know about where, when and how to better protect, improve or restore soils. The Dashboard of the EU Soil Observatory (JRC Unit D3) aims to do just this. Tapping into the wealth of soil data produced by the JRC and other international research institutions, it provides a clear picture of the state and trend of soil health in the EU. It will also report on the state of implementation of EU soil policy. A focus in the Dashboard is to present soil data spatially. In particular, the EUSO Dashboard uses the ‘convergence of evidence’ methodology to map the likely occurrence of soil degradation processes in the EU and the UK. Through visuals (graphs, maps, infographics, etc.) the EUSO Dashboard aims to be the reference point providing a clear up-to-date assessment of the state of soil health and the policy actions taken at EU level to improve it.
Heterogeneity and C dynamics in soil
Authors: Nunan Naoise , Schmidt Hannes , Chenu Claire , Pouteau Valerie , Raynaud Xavier
Published: February 2023

Heterogeneity (spatial, temporal chemical and biological) is a fundamental property of soils. Although it is rarely explicitly accounted for in models of soil microbial functioning, it is a determinant of microbial access to substrate and therefore of microbial activity. Microbial adaptation to heterogeneity is also likely to play a significant role in determining microbial activity and therefore C persistence in soil. A more developed understanding of heterogeneity and how microbial communities interact with their heterogenous environment can help us better understand the mechanisms that regulate microbial activity and soil C dynamics, as well as offer potential avenues for upscaling. In this presentation I will show how microbial communities have adapted to spatial and molecular heterogeneity at the microbial scale and, through the use of a spatial explicit model, how spatial and molecular heterogeneity interact to reduce decomposition. Pore scale heterogeneity affects the distribution of both decomposers and organic matter. Using a stable isotope approach, I will show that, although there does not appear to be a clear relationship between microbial decomposer composition and pore size, a simple relationship emerges between pore size and microbial decomposition of organic substrate. As the pore size distribution of soils can be deduced from pedo-transfer functions, this relationship may provide a more mechanistic basis for the representation of moisture effects on C dynamics in larger scale models.
MultilayerPy: a tool for creating and optimising multi-layer models of aerosol and film processes
Authors: Milsom Adam , Lees Amy , Squires Adam , Pfrang Christian
Published: February 2023

Heterogeneous processes such as aerosol-gas chemical reactions and vapour uptake are key to understanding the behaviour of aerosols in our environment. They contribute to their ability to take up water to form cloud droplets and determine the persistence of harmful particle-bound compounds, impacting the climate and human health.Kinetic multi-layer models such as the kinetic multi-layer model for aerosol surface and bulk chemistry (KM-SUB) and gas-particle interactions (KM-GAP) are state-of-the-art models used to describe these processes on the particle and film level (Shiraiwa et al., 2010, 2012). KM-SUB and KM-GAP-based models have been used to determine the oxidative potential of particulate matter, the impact of surfactant self-organisation on aerosol chemical lifetimes, and the impact of aerosol phase state on the long-range transport of toxic chemicals. These models are useful but cumbersome to write and there is a need for an open-source tool to assist researchers in creating and optimising them.We have developed MultilayerPy (Milsom et al., 2022), an open-source Python package which facilitates the creation and optimisation of kinetic multi-layer models. This software is written such that the user uses building blocks (i.e. reaction scheme, bulk diffusion parameterisations, and model components) to automatically generate model code which can then be ran and the output presented in a reproducible manner. This reduces the time needed to develop model descriptions of aerosol processes and allows the user to focus on the scientific issues rather than coding the models. I will present recent use cases of the software looking at the chemical lifetime of real aerosol material in the atmosphere, along with ongoing work extending the base package.References:Milsom, A., Lees, A., Squires, A. M. and Pfrang, C.: MultilayerPy (v1.0): a Python-based framework for building, running and optimising kinetic multi-layer models of aerosols and films, Geosci. Model Dev., 15(18), 7139–7151, doi:10.5194/gmd-15-7139-2022, 2022.Shiraiwa, M., Pfrang, C. and Pöschl, U.: Kinetic multi-layer model of aerosol surface and bulk chemistry (KM-SUB): The influence of interfacial transport and bulk diffusion on the oxidation of oleic acid by ozone, Atmos. Chem. Phys., 10, 3673–3691, doi:10.5194/acp-10-3673-2010, 2010.Shiraiwa, M., Pfrang, C., Koop, T. and Pöschl, U.: Kinetic multi-layer model of gas-particle interactions in aerosols and clouds (KM-GAP): Linking condensation, evaporation and chemical reactions of organics, oxidants and water, Atmos. Chem. Phys., 12(5), 2777–2794, doi:10.5194/acp-12-2777-2012, 2012.
A portable, ground-based FTS for reflected sunlight: Performance evaluation for mapping CO2 and CH4 above Los Angeles
Authors: Hemmer Benedikt , Enders Vincent , Hase Frank , Kleinschek Ralph , Kostinek Julian , Pongetti Thomas , Sander Stanley , Zeng Zhao-Cheng , Butz André
Published: February 2023

Precise knowledge of sources and sinks in the carbon cycle is desired to understand its sensitivity to climate change and to account and verify man-made emissions. In this context, extended sources like urban areas play an important role. While in-situ measurements of carbon dioxide (CO2) and methane (CH4) are highly accurate but localized, satellites measure column-integrated concentrations over an extended footprint. The CLARS-FTS [1, 2] stationed at the Mt. Wilson observatory looking downward into the Los Angeles basin has pioneered an innovative measurement technique that fills the sensitivity gap between in-situ and satellite measurements. The technique enables mapping the urban greenhouse gas concentration fields by collecting spectra of ground scattered sunlight and scanning through the region.
We develop a similar but portable instrument using a CLARS-FTS-like measurement geometry. It is based on the EM27/SUN FTS with a modified pointing system, increased throughput and a more sensitive detector than the standard type. The compact setup enables campaign-based observations in various source regions of interest, utilizing the increased sensitivity to boundary layer concentration by the horizontal light path component.
Here, we present the portable instrument setup and its performance. Throughout April 2022, we observed the Los Angeles basin with both the portable setup and the CLARS-FTS simultaneously. The retrieval algorithm is based on the RemoTeC software, previously employed for solar backscatter satellite measurements. From this, we evaluate the XCO2 and XCH4 precision of our setup under field conditions, and compare our instrument to the concurrent CLARS-FTS measurements.
 
References:[1] Fu, D. et al., 2014: Near-infrared remote sensing of Los Angeles trace gas distributions from a mountaintop site, Atmos. Meas. Tech., 7, 713–729, https://doi.org/10.5194/amt-7-713-2014[2] Wong, K. W. et al., 2015: Mapping CH4 : CO2 ratios in Los Angeles with CLARS-FTS from Mount Wilson, California, Atmos. Chem. Phys., 15, 241–252, https://doi.org/10.5194/acp-15-241-2015
Significance of sources and size distribution on calibration of low-cost particle sensors: Evidence from a field sampling campaign
Authors: Malyan Vasudev , Kumar Vikas , Sahu Manoranjan
Published: February 2023

Low-cost sensors (LCS) are gathering the interest of researchers and monitoring agencies worldwide due to their compact size and economic feasibility. However, the data recorded by LCS is often of low quality owing to its calibration dependencies and biases. An intensive field sampling campaign was conducted at five sites inside the IIT Bombay campus to understand the fundamental issues associated with LCS. PA-II and OPC-N2 LCS were collocated with BAM-1020 and OPS- 3330 at the sampling locations for inter-comparison. LCS shows a good correlation with BAM-1020 at sites where the contributing sources produce more particles in the 1–2.5 μm size range than particles in below 1 μm (PM1) and 2.5–10 μm size range. The performance decreased with an increase in mass fractions of PM1 and PM10. The overall performance of both PA-II (R2 = 0.72) and OPC-N2 (R2 = 0.73) are comparable. Both PA-II and OPC-N2 have substandard performance with R2 in the range of 0.30–0.39 and 0.42–0.53 at the construction and main gate site respectively. Comparing the two calibration approaches used in this study indicates the importance of including size distribution parameters in the calibration of LCS. The calibration models were developed for each site and were compared with the general model developed for PA-II and OPC-N2. Results indicate that the site-specific models are in better agreement with the reference instrument than the general calibration model. The number concentration recorded by PA-II was poorly correlated with OPS-3330, especially for particles >1 μm and vice versa for OPC-N2. The particle count for PM > 2.5 μm recorded by PA-II is predominantly zero, which is inconsistent with the mass concentration data recorded by the sensor. The size distribution results indicate that LCS assumes a universal monotonically decreasing function of number concentration with respect to the particle diameter. It is one of the critical problems with LCS measurements as any error in the number measurement is increased 3-fold in the mass conversion. This study shows the need for site-specific robust calibration of LCS based on the particle size distribution and provides a direction in their development.
Improving active faults monitoring leveraging submarine telecom fiber optic cables : first results from central Chile
Authors: Rivet Diane , Baillet Marie , Trabattoni Alister , van den Ende Martijn , Vernet Clara , Lior Itzhak , Barrientos Sergio , Sladen Anthony , Ampuero Jean-Paul
Published: February 2023

Subduction zones host some of the greatest diversity in seismic and aseismic fault slip behaviors, such as recurrent slow slip, non-volcanic tremors and repeating earthquakes, that are large enough to be measurable at the surface. Our understanding of the mechanisms leading to fault rupture, especially the role of aseismic slip is limited by the sparsity of instrumentation near the nucleation zone, which is predominantly located offshore away from permanent onland seismic networks.Fiber-optic Distributed Acoustic Sensing (DAS) offers a new opportunity for long-term seismic observation of off-shore active faults by turning existing fiber-optic seafloor telecom cables into dense arrays of seismic and acoustic sensors. We conducted a one-month long DAS experiment on the northern leg of the Concón landing site of the Prat cable belonging to the GTD company. The longitudinal strain rate was recorded every 4m over a 150km-long fiber section at a temporal sampling rate of 125 Hz, which enabled us to measure low magnitude earthquakes and to locate them precisely. The earthquake catalog generated from the DAS data comprises more than 900 seismic events, which greatly extends the existing regional catalog. A preliminary analysis indicates that several seismic sequences are clustered in time and space, which include numerous events that cannot be detected by the onland seismological network. The ABYSS project will deploy this new observation tool continuously over several years, which will offer a new opportunity to better characterize the distribution of the seismicity in time and space, and will provide new constraints to the models of fault behavior during the seismic cycle. Combined with other types of analysis, such as seismic wave velocity changes monitoring at depth, these data will also provide additional constraints on the aseismic deformation of the fault zone.
Exhumation history of the Northern Apennines (Italy) recorded by low temperature thermochronology of Epiligurian wedge-top basins
Authors: Stendardi Francesca , Viola Giulio , Carrapa Barbara , Vignaroli Gianluca
Published: February 2023

The Northern Apennines accretionary wedge has been extensively investigated by means of thermochronological studies to constrain its thermal history with respect to burial and exhumation. However, the Epiligurian wedge-top basins, which represent the shallowest portions of the orogenic wedge, have received less attention. These basins exhibit an internal complex structural architecture formed in response to the progressive growth of the Northern Apennines accretionary wedge during its progressive involvement in the fold-and-thrust belt. In this study, we combine a new structural characterisation of the Epiligurian stratigraphic succession with preliminary thermochronological data, with the aim to constrain the low-temperature thermal history of the Epiligurian system formation. We investigated the coarser arenaceous components of different middle Eocene to the upper Miocene Epiligurian formations (Loiano, Antognola, Pantano and Cigarello formations). We use both apatite fission-track (AFT) and (U-Th)/He (AHe) analyses. The majority of the AFT central ages cluster between 53 and 65 Ma (Paleocene-Lower Eocene). None of the samples passed the χ2 test, indicating the presence of different population of grains. For all but one sample three to four detrital populations are characterised by the same range of ages, which varies from 140 to 41 Ma (Early Cretaceous-upper Eocene). The fact that these detrital populations are older than the depositional age of the hosting strata suggests minimal resetting of the AFT system and T generally lower than 120°C post deposition. We interpret the AFT detrital populations consistent throughout the stratigraphic features as representative of cooling ages of the sediment source (alpine derivation source) that fed the Epiligurian basins. AHe ages show a more variable single grain age distribution ranging from 104 to 13 Ma (Late Cretaceous-middle Miocene) suggesting a significant degree of thermal resetting for the AHe system post deposition. AHe ages for the lowest part of the Epiligurian Units (Loiano and Antognola Fms) suggest a possible cooling/exhumation event of the basin at around 30-20 Ma. These preliminary results suggest that the Epiligurian basins experienced T ranging between >120 to 80°C post deposition. AFT data suggest rapid exhumation of the sediment source in the middle to late Eocene recorded by relatively short lag time of the youngest detrital population (~41 Ma). AHe data suggest subsequent Oligocene-Miocene exhumation consistent with deformation of the Northern Apennine.
What future for pollinators in the understorey vegetation under the impact of climate change ?
Authors: Lanssens Benjamin , François Louis , Hambuckers Alain , Moens Merijn , Anders Tim , Tölle Merja , Verma Arpita , Remy Laura
Published: February 2023

Although understorey biomass is negligible in comparison to overstorey biomass, understorey vegetation supports the majority of biodiversity within forests. The diversity of  plant species in the understorey is important for pollinators, such as bees and butterflies, which use the available resources for food and shelter. However, the future of understorey vegetation is uncertain due to the impact of climate change and human activities.  Climate change and forest management are known to be among the most important factors affecting the diversity and abundance of understorey plant species. Most studies on understorey vegetation has often been limited in scope, either focusing on a small number of specific plant species or large-scale studies of plant functional types. In this study, we take a more comprehensive approach by combining the results of a species distribution model with a dynamic vegetation model to simulate the evolution of understorey vegetation at the species level. We select a set of 30 species important for pollinators. In order to cover a large climatic gradient, simulations are performed over the Walloon region in Belgium and the Eisenwurzen region in Austria. The climate dataset is provided by the regional climate model COSMO-CLM, which has a 3 km spatial resolution and covers the period from 1980 to 2070 under different greenhouse gas concentration scenarios (RCP 2.6 and RCP 8.5). Additionally, we investigate the effect of different forest management practices (thinning and clear-cutting) on overstorey and how they impact understorey vegetation. Overall, the study aims to provide new insights into the current and future state of understorey vegetation with a focus on the impact of climate change and forest management on key pollinator resources.
Improved monitoring and prediction of permafrost climate change related landsliding in the Arctic
Authors: Jonassen Marius Opsanger , Christiansen Hanne Hvidtfeldt , Shestov Aleksey , Tveit Knut Ivar Lindland
Published: February 2023

The Arctic plays a key role in understanding and mitigating the challenge of climate adaptation. Indeed, the observed Arctic warming is more than twice the global mean, implying that the Arctic may serve as an ‘early warning region’ in terms of climate change impacts. Longyearbyen, the Arctic capital settlement situated at 78°N in the archipelago of Svalbard, is located in a geographical hotspot affected by extreme Arctic climate change. Reports show that both experienced changes from 1971-2000 and projected 2071-2100 changes for Svalbard include increased air temperature, increased precipitation (especially in summer and autumn) and more frequent and intense events with heavy rainfall. Immediate and potentially detrimental impacts of these climate changes are seen in the widespread permafrost of the Arctic, which is particularly sensitive to climate change. These impacts include increases in active-layer thickness and melting of ground ice, resulting in increased risk of landslides.Based in Longyearbyen, Svalbard, the PermaMeteoCommunity project develops a permafrost and meteorological response system that consists of (1) instrumented boreholes for direct observations of ground temperature and pore water pressure in the active layer and top meters of permafrost, (2) a network of meteorological stations, which records key standard parameters such as air temperature and precipitation with high spatial and temporal resolution. Using IoT technology, the observations are to be connected with an open online platform that receives and displays all data in near real-time. The data can thereby be used for local authorities and decision makers, during operational evaluations and extreme weather events such as large amounts of rain, potentially inducing permafrost-related landslides. The platform will also give access to historical data and the system will be highly relevant for use in research, for education, and in outreach as well as for long-term societal infrastructure and overall land area planning. Furthermore, work is being done to include more elements in the response system, among others (1) remote sensing data for monitoring of ground movement (2) high-resolution numerical weather simulations to be employed in preparedness situations on an on-demand basis and (3) a machine learning component for enhanced predictions of landslides.
Opportunities and Challenges in the Efficient Exploiting of Land, Energy and Water Resources within the Volta and Tana Basins in Africa
Authors: Annor Frank Ohene , Martin Viktoria , Ofosu Eric Antwi , Lucendo Carlos Guerrero , Akuku Boniface , Fofana Rafatou , van de Giesen Nick , Abraham Edo
Published: February 2023

The design of strategic investments in water, energy and food (WEF) infrastructures is challenging because the size, location, technology mix and pace of development is made uncertain by multiple factors. For example, the return on investment, which comes long after building a hydropower dam, is made uncertain by local, regional and global climate and socio-economic factors. This is exacerbated by the challenges associated with the impacts of climate change, especially in sub-Saharan Africa (SSA) where it is difficult to model these impacts, hence leading to high levels of uncertainty in future scenarios (2050 and beyond).Long-term investment planning and system operations for energy, depend on and compete with other sectors for, the availability of water (for hydropower and cooling thermal plants) and land resources (e.g. for biofuel production and arability). The efficient exploitation of land, energy and water resources and their synergised use for economic development therefore require an multidimensional integrated optimisation approach co-created with stakeholders in dialogue. This starts with planning followed by prioritised investments based on local, national and regional needs in the energy, agricultural and water sectors. This is mostly lacking in SSA at the moment. We gathered a selected group of experts in Accra, Ghana in November 2022 with a broad mix of experiences and expertise in the energy, water and agricultural sectors, who shared deeper insights and values of the need for integrated WEF planning to begin tackling challenges and opportunities identified in the Volta Basin in West Africa (starting with Ghana) and the Tana basin in Kenya. The main challenge identified was the disjointed planning of WEF infrastructures due to different financing mechanisms and siloed sectoral thinking; and participants raised emerging opportunities for planning infrastructure through transnational and regional cooperation  as well as the need to build on existing and new initiatives devoid of entrenched political goals.In this contribution, we will present some of the main findings from the meeting in Accra and share knowledge on how transparent WEF modelling can be contextualised for local operational relevance, and through co-creation, how interactive engagement tools can be used for planning, policy- and decision-making.Keywords: WEF modelling, sub-Saharan Africa, WEF Infrastructures, Investment Planning, OptimisationThe work leading to these results has received funding from the European Horizon Europe Programme (2021-2027) under grant agreement No.101083763 (EPIC Africa). The opinions expressed in the document are of the authors only and in no way reflect the European Commission’s opinions. The European Union is not liable for any use that may be made of the information.
Submarine melting of glaciers in Greenland amplified by atmospheric warming
Authors: Slater Donald , Straneo Fiamma
Published: February 2023

The retreat and acceleration of Greenland's marine-terminating glaciers since the 1990s is responsible for approximately half of Greenland's sea level contribution over the same period. A warming ocean, and the associated increase in submarine melting of calving fronts, is understood to be the most likely driver of this retreat. Yet atmospheric variability can also affect submarine melting by modulating subglacial discharge, which plays a role in driving fjord circulation and enhancing the transfer of heat from ocean to ice. The relative importance of atmospheric and oceanic sources of variability in submarine melting have, however, not been quantified.We use atmospheric and oceanic reanalyses to estimate submarine melt rate at Greenland's marine-terminating glaciers since 1979, finding that in southeast Greenland the ocean has driven the majority of variability in submarine melt, while in northwest Greenland it is the atmosphere that has played the greater role. A simple two-stage glacier model is then used to map submarine melting onto dynamic mass loss, suggesting that although submarine melting is intuitively an ocean process, a warming atmosphere has amplified the impact of the ocean on the Greenland ice sheet.
ESA CCI and C3S Soil Moisture - New developments and recent applications
Authors: Preimesberger Wolfgang , Stradiotti Pietro , Madelon Remi , van der Schalie Robin , Rodriguez-Fernandez Nemesio , Hirschi Martin , Pasik Adam , Gruber Alexander , Dorigo Wouter , de Jeu Richard , Kidd Richard , Albergel Clement
Published: February 2023

ESA CCI Soil Moisture (SM) is a long-term global Climate Data Record of soil water content stored in the surface soil layer, derived from satellite observations in the microwave domain. To make it suitable for long-term analyses of the climate system, ESA CCI SM merges observations from a total of 19 satellite radiometers and scatterometers (active and passive systems) into harmonized records covering a period of more than 40 years (from 1978 onwards). ESA CCI SM is currently in its 8th development cycle. Following every development cycle, the CCI algorithm is adopted to create the Copernicus Climate Change (C3S) soil moisture data records. These operational records are extended on a regular basis to provide input data for time-critical applications such as monitoring systems. The data sets have been widely used (100+ scientific publications per year) in studying the water, energy and carbon cycles over land, understanding land surface-atmosphere hydrological feedbacks, assessing the impact of climate change on the occurrence of climatic extremes, assimilation into and evaluation of climate models. ESA CCI SM has been the main input for assessing global soil moisture conditions as presented in the BAMS “State of the Climate” reports for more than 10 years, while C3S has been used in the yearly “European State of the Climate” reports for several years nowIn this presentation we give an overview over the algorithm underlying the ESA CCI SM product with a focus on new scientific developments included in the latest version. These comprise an improvement in the estimation of intra-annual uncertainties and two additional, experimental versions of the COMBINED product: 1) a gap-filled version in which data points between satellite overpasses are interpolated using statistical methods without the use of ancillary data; and 2) a model-independent version in which all merged sensors are scaled to L-band observations, as opposed to model values in previous versions. We show how both ESA CCI and C3S have been used in recent years to monitor droughts and floods globally and in Europe, respectively.The development of ESA CCI and C3S SM has been supported by ESA’s Climate Change Initiative for Soil Moisture (Contract No. 4000104814/11/I-NB & 4000112226/14/I-NB) and the Copernicus Climate Change Service implemented by ECMWF through C3S 312a Lot 7 & C3S2 312a Lot 4 Soil Moisture.
A systematic exploration of biodiversity-ecosystem function relationship using remote sensing and eddy covariance networks
Authors: Gomarasca Ulisse , Duveiller Gregory , Ceccherini Guido , Cescatti Alessandro , Girardello Marco , Pacheco-Labrador Javier , Reichstein Markus , Wirth Christian , Migliavacca Mirco
Published: February 2023

Biodiversity positively affects vegetation productivity and the ability of ecosystems to withstand disturbance events and invasions of alien species (ecosystem stability). However, the relationship between biodiversity and ecosystem functioning remains understudied at the landscape or whole ecosystem scales.In particular, biodiversity can not be easily monitored at large spatial scales or frequent intervals. Therefore, confronting measurements of biodiversity and ecosystem functioning at the same spatial and temporal scales remains challenging. In this work, we present new methods to systematically bridge these scale gaps. We focus on collecting ecosystem data and developing metrics able to decypher the effect of plant biodiversity on ecosystem functioning. Based on eddy covariance fluxes from 78 NEON and ICOS sites, we compute key ecosystem functional properties related to ecosystem productivity and stability. Moreover, we calculate biodiversity indices from field surveys of species abundances, functional traits, and structural properties at these sites. Finally, we compute remote sensing metrics of biodiversity based on Sentinel 2 measurements. These metrics exploit the fine scale multispectral information from different and complementary perspectives, and are adapted to match the footprint of typical eddy covariance sites.We investigate the relationship between ground- and satellite-based biodiversity metrics to understand the capability of remote sensing to contribute to biodiveristy-ecosystem function analyses that may one day be scaled globally. Despite dominant environmental and climatic constraints, we hypothesize that ecosystem functional properties covary with biodiversity metrics. To elucidate this point, we analyze the multivariate relationship between the different biodiversity estimates, ecosystem functional properties related to water, carbon, and energy fluxes, structural variables of the vegetation, and climate.Assessing whether biodiversity effects apply to the functioning and stability of ecosystems is pivotal to understanding ecosystem processes and developing appropriate forecast models and climate change mitigation strategies.
Evaluating the effects of climate warming and precursor emission changes on surface ozone air quality over coming decades: a case study for Austria
Authors: Schmidt Christian , Mayer Monika , Stähle Christoph , Kult-Herdin Jessica , Huszár Peter , Karlický Jan , Moshammer Hanns , Rieder Harald
Published: February 2023

Ozone production and loss in surface air is determined by ambient temperature,  chemical conditions and precursor emissions. Despite efforts to abate surface ozone air pollution, the daily maximum 8-hour average ozone target value for the protection of human health  is regularly exceeded at several monitoring sites in Austria especially during the warm seasons. Here we investigate projected changes in the surface ozone burden and effects of climate warming and changes in precursor emissions over the next decades in a series of tailored chemistry-transport model (CTM) experiments, performed with WRF-Chem and CAMx. Specifically we contrast changes in ozone air quality in decadal time slices for 2026-2035 and 2046-2055 with the recent past (2007-2016). Our CTM ensemble comprises simulations following the Representative Concentration Pathways (RCPs) 2.6, 4.5 and 8.5. Our results show a persistent large variability in ozone abundances driven by the large intra- and interannual  variability in meteorological conditions. Overall we find general improvements in the surface ozone burden for low emission scenarios (RCP2.6 and RCP4.5) driven by ambitious NOx controls. In contrast under RCP8.5 we find, on the one hand an increase in the frequency of non-attainment days and on the other a shift in the prime ozone season from summer towards spring. These increases are driven by both a climate penalty and changes in the chemical production regime (NOx vs. VOC limitation) and increasing methane and ozone backgrounds. Furthermore, we investigate impacts of projected ozone changes on human health at the municipal level in Austria.
Policy and practice relevant climate change impact assessments: Case study, Western Nepal
Authors: Bharati Luna , Chapagain Dipesh
Published: February 2023

Most existing climate impact assessments in Nepal only consider a limited number of generic climate indices such as means. Few studies have explored climate extremes and their sectoral implications, which in turn are key for informing policy and practice. This study evaluates future scenarios of extreme climate indices from the list of the Expert Team on Sector-specific Climate Indices (ET-SCI) and their sectoral implications in the Karnali Basin in western Nepal. First, future projections of 26 climate indices relevant to six climate-sensitive sectors in Karnali are made for the near (2021–2045), mid (2046–2070), and far (2071–2095) future for low- and high-emission scenarios (RCP4.5 and RCP8.5, respectively) using bias-corrected ensembles of 19 regional climate models from the COordinated Regional Downscaling EXperiment for South Asia (CORDEX-SA). Second, a qualitative analysis based on expert interviews and a literature review on the impact of the projected climate extremes on the climate-sensitive sectors is undertaken. We also used widely available global data sets such as DesInventar and national census data and disaster-specific mixed-effects regression models to assess the impact of precipitation extremes on landslide and flood mortality.  Both the temperature and precipitation patterns are projected to deviate significantly from the historical reference already from the near future with increased occurrences of extreme events. Results show winter in the highlands is expected to become warmer and dryer. The hot and wet tropical summer in the lowlands will become hotter with longer warm spells and fewer cold days. Low-intensity precipitation events will decline, but the magnitude and frequency of extreme precipitation events will increase. Furthermore, an increase in one standardized unit in maximum one-day precipitation increases flood mortality by 33%, and heavy rain days increase landslide mortality by 45%.
25 years of infrasound monitoring: achievements and challenges
Authors: Blanc Elisabeth , Le Pichon Alexis , Farges Thomas , Listowski Constantino , Mialle Pierrick
Published: February 2023

The infrasound International Monitoring System (IMS, ) is a unique tool for atmospheric observations due to its high capacity for long-range detection and localisation. Its development, starting in the nineties, motivated technological innovations in sensors, array stations, network configuration and automatic detection algorithms. The rapidly increasing number of certified stations detected a large diversity of anthropic and natural infrasound events, well identified thanks to their accurate description. Numerical simulations, based on propagation laws and atmospheric models, determined the IMS specifications for infrasound monitoring. They were revisited at the end of the 2000s, integrating an improved representation of the variable atmospheric environment, showing the high performances of the network. Data analyses clearly demonstrated that most uncertainties originate from the middle atmosphere disturbances, which control the infrasound waveguides and are under-represented in models. Unexpectedly, relevant atmospheric parameters were identified in infrasound signals from well-known sources such as volcanoes, opening new infrasound remote sensing possibilities. The association of the infrasound IMS to complementary multi-instrument platforms provided new middle atmosphere data, needed for the determination of uncertainties in atmospheric models and infrasound simulations for more precise event analyses. New methods are developed for middle atmospheric remote sensing from IMS infrasound ocean swell noise observations. Such global observations could be relevant for future data assimilation systems used in numerical weather prediction models. A remote volcano information system is developed to provide in the future notification to civil aviation in case of large eruptions of non-instrumented volcanoes. Large-scale climatology systems, such as the inter-tropical convergence zone (ITCZ) of the winds and the semi-annual oscillation (SAO) of stratospheric winds were recently identified. They can provide relevant information about the evolution of climate related parameters. This shows the high IMS potential for weather, climate and civil safety applications.
The role connectivity in soil for stability of soil organic matter degradation: a biophysical model
Authors: Otten Wilfred , Portell-Canal Xavier , Falconer Ruth
Published: February 2023

Soils contain the largest terrestrial reservoir of organic carbon, and dynamics in soil organic carbon turnover will drive carbon-climate feedbacks over the coming century. To date, most SOC dynamics have been simulated with pool-based models, which assume homogeneous physical properties in soil. However, there is increasing evidence which suggests that soil carbon turnover is not just determined by carbon inputs, but by restrictions on microbial access to organic matter in a spatially heterogeneous soil environment. Pore geometry is a critical factor in affecting the accessibility of organic matter for microorganisms, but this accessibility has not been explicitly considered in models. Therefore, we have a challenge to mechanistically predict how environmental change will impact on the balance between soil stored in soil and in the atmosphere.We will exemplify the impact of pore-connectivity on organic matter turn-over by modelling fungal mediated processes in soil. The fungal model includes important fungal processes such as growth, death and spread, secretion of enzymes to degrade soil organic matter, and translocation of dissolved organic matter through its hyphal structure. For such a complex system the question of what constitutes a connected habitat and how this affects soil processes may not be as easy to address and needs to consider more than the pore connectivity often highlighted. For example, for these fungal mediated processes, habitat connectivity may be determined by various characteristics, namely: (i) the total volume of the connected pore space; (ii) the connected air-filled pore volume, through which fungal spread predominantly occurs and gasses diffuse, (iii) the connected water phase volume, through which dissolved C diffuses, (iv) the distribution of particulate organic matter that fuels fungal growth, and (v) biological traits such as those enabling translocation through for example fungal hyphal networks. We demonstrate how various aspects of habitat connectivity differentially impact on two contrasting fungal species, representing e.g. R and K strategists. The results suggest that: i) connectivity of the water phase is critical as it regulates diffusion of dissolved organic matter; this is even so for fungi that preferentially spread through air-filled pores, and ii) whether fungi behave as R or K strategists is not just determined by fungal traits but to a large extend depends on the physical environment. Consequently, selective pressures can be exerted by physical conditions. It was however not possible to identify a key physical driver as the dynamics were mostly determined by interactions between the various types of connectivity. These different pathways tend to compensate each other, enhancing stability of the function. We argue that the fact that multiple connected pathways underpin a soil function leads to resilience of soils to perturbations and underpins soil health. 
Stomatal optimization modelling in JSBACH: an in-depth case study on a boreal forest measurement site
Authors: Mauranen Aleksanteri , Mäkelä Jarmo , Hölttä Teemu , Salmon Yann , Vesala Timo
Published: February 2023

The stomata on the leaves of terrestrial plants are a crucial pathway both in the soil-plant-atmosphere hydrological continuum and in the global carbon cycle. Stomatal optimization approaches have proven to be relevant in modelling the trade-off between carbon assimilation and water stress avoidance. In this in-depth case study, we use new optimization-based stomatal models in modelling vegetation gas exchange with the land surface model JSBACH.The theoretical framework presented in Dewar et al. (2018) combines different optimization hypotheses and photosynthesis models to provide analytical solutions for various leaf-level state variables such as stomatal conductance and photosynthesis rate. The most successful combinations assume that plants regulate stomata as if to maximize photosynthesis at all times, and that photosynthesis is restricted by non-stomatal limitations related to water stress. In this study, we further develop the framework, which yields several promising stomatal conductance models.We implement these stomatal models in the land surface model JSBACH, which we run for a single boreal forest site, the SMEAR II measurement station in southern Finland. The model runs are constrained with meteorological and soil moisture data and parametrized with plant properties previously measured at the site, such as xylem hydraulic conductance and photosynthetic parameters. Gross primary production and transpiration rates predicted by JSBACH under different stomatal and photosynthesis models are compared to eddy covariance measurements from SMEAR II, covering the years 2006 through 2012. The model results are also compared to each other and to those obtained using the Unified Stomatal Optimization model by Medlyn et al. (2011). The comparison is restricted to dry daytime hours in the growing season. References:Dewar et al. 2018, New Phytol. 217: 571–581Medlyn et al. 2011, Glob. Change Biol. 17: 2134–2144
A parametrization scheme accounting for non-hydrostatic effects on vertically propagating orographic gravity waves and implementation in the Model for Prediction Across Scales (MPAS)
Authors: Xu Xin , Zhang Rongrong , Teixeira Miguel , van Niekerk Annelize , Li Runqiu
Published: February 2023

 The momentum transport by orographic gravity waves (OGWs) plays an important role in driving the large-scale circulation throughout the atmosphere, which is subject to parameterization in numerical models. Current parameterization schemes commonly assume that the unresolved OGWs are hydrostatic, typically only valid for waves with large horizontal scale, weak winds and high stability. These schemes were originally developed for coarse-resolution numerical models and, as a result, captured the first-order effects of unresolved OWGs. With the increase in the horizontal resolution of state-of-the-art numerical models, unresolved OGWs are of smaller horizontal scales and may be more influenced by nonhydrostatic effects (NHE), thus challenging use of the hydrostatic assumption. Based on the analytical formulae of nonhydrostatic OGWs derived in our recent study, this work revises the orographic gravity wave drag (OGWD) parameterization scheme employed in the Model for Prediction Across Scales (MPAS) by accounting for NHE. Global simulations are conducted to investigate NHE on the momentum transport of parameterized OGWs and their impact on the simulated large-scale circulation. NHE are found to be the most evident in regions of complex terrain where the subgrid-scale orography is narrow. As NHE act to reduce the surface wave momentum flux (WMF) of OGWs, the revised scheme tends to inhibit wave breaking in the lower troposphere and transport more WMF upward, leading to an enhancement of OGWD in the upper troposphere and lower stratosphere. Over Antarctica, where the largest zonal-mean NHE occur, the OGWD-induced meridional circulation is strengthened, which helps reduce the cold pole and westerly wind biases associated with a too strong polar vortex, thereby alleviating the delayed breakdown of the Antarctic polar vortex in late spring and early summer, a bias commonly found in climate models.