bluuebunny/crossref_metadata_2025 huggingface dataset:
Mining Large Climate Model Datasets to Make Multi-Year Initialized ENSO Forecasts with Actionable Skill
Authors: Newman Matthew , Ding Hui , Lou Jiale , Lillo Sam , Alexander Michael , Hoell Andrew , Wittenberg Andrew
Published: March 2022

Seasonal to interannual forecasts made by coupled general circulation models (CGCMs) undergo strong climate drift and initialization shock, driving the model state away from its long-term attractor. Here we explore initializing directly on a model’s own attractor, using an analog approach in which model states close to the observed initial state are drawn from a “library” obtained from prior uninitialized CGCM simulations. The subsequent evolution of those “model-analogs” yields an ensemble forecast, without additional model integration. This technique is applied to CGCMs either used operationally by NCEP or as part of the CMIP6 dataset. By selecting from these long control runs those model states whose monthly SST and SSH anomalies best resemble the observations at initialization time, hindcasts are then made for leads of 1-36 months during 1958-2019. Deterministic and probabilistic skill measures of these model-analog hindcasts are comparable to, and in some regions better than, traditionally assimilation-initialized CGCM hindcasts after 1982, for both the individual models and the multi-model ensemble.

On average, ENSO skill of AC>0.5 exists for forecast leads of 18 months for forecasts initialized in summer. More important, we find that not only were some notable ENSO events predictable two years (or more) ahead of time, but that we can both identify forecast “hits” and avoid “false alarms” -- at the time of forecast -- by using a simple forecast signal-to-noise metric (SNR; root-mean-squared ensemble mean divided by ensemble spread), determined from the large (O(100) member) model-analog ensemble. That is, our analog ensemble approach can be used to make actionable ocean predictions, where forecasts of opportunity can be identified well in advance.

Since these long-lead hindcasts do not require full-field initialization, they have also been extended back prior to 1900. We find that while there has been considerable multi-decadal variation in seasonal ENSO skill, there has been no long-term trend for leads up to about 6-9 months. However, while multi-year ENSO skill appears to have also occurred in the past for a few large ENSO events, in the past thirty years it has occurred with considerably greater frequency, raising the possibility that it is a more recent phenomenon.
Progressing the global samples community through the new partnership between IGSN and DataCite
Authors: Ramdeen Sarah , Lehnert Kerstin , Klump Jens , Buys Matt , Wimalaratne Sarala , Wyborn Lesley
Published: March 2022

In October 2021, DataCite and the IGSN e.V. signed an agreement to form a partnership to support the global adoption, implementation, and use of physical sample identifiers. Both DataCite and IGSN currently offer the ability to provide Globally Unique Persistent, Resolvable Identifiers (GUPRIs) within the overall research ecosystem, and the proposed collaboration will bring together the strengths of each organization.

DataCite is a community-led organisation that has been providing the means to create, find, cite, connect, and use research across 47 countries globally since 2009. DataCite provides persistent identifiers (DOIs) for research data and other research outputs, and supports the efforts of several identifier communities. DataCite also develops services that make it easier for researchers to connect and share their DOIs with the broader research ecosystem. 
IGSN e.V. is an international, non-profit organization with more than 20 members and has a narrower focus than DataCite. The core purpose of IGSN is to enable transparent and traceable connections between samples, instruments, grants, data, publications, people and organizations. Since 2011, IGSN has provided a central registration system that enables researchers to apply a globally unique and persistent identifier for physical samples.

The proposed partnership will enable IGSN to leverage DataCite DOI registration while allowing IGSN to focus on community efforts such as promoting and expanding the global samples ecosystem and supporting new research and best practice in methods of identifying, citing, and locating physical samples. DataCite will provide the IGSN ID registration services and support to ensure the ongoing sustainability of the IGSN PID infrastructure and its integration with the global PID ecosystem.

This partnership is an opportunity for IGSN to reenvision its governance and community engagement and to reassess how the IGSN can best serve the community in today’s open science ecosystem. This talk will focus on the developing changes to the IGSN governance and community efforts.
Different research communities have a wide range of requirements towards metadata and identification of samples. The IGSN plans to develop an international ‘Community of Communities’ which will include members from the global samples community across multiple disciplines. The community will support varying levels of skills with PIDs and metadata. It will enable cohesion around the use of IGSN thus enabling greater research discovery, innovation and advancement for samples.

The IGSN Samples Community (IGSN SC) aspires to be a collaborative space for community development that promotes the use of samples and their connections to any derived observations, images, and analytical data.
Improvements to the Stratospheric Water and OzOne Satellite Homogenized (SWOOSH) data set and implications for ozone and water vapor variability and trends
Authors: Davis Sean , Rosenlof Karen , Jia Yue
Published: March 2022

In this presentation, we summarize recent improvements to the Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) database. SWOOSH is primarily a monthly mean zonal mean merged data set of vertically resolved ozone and water vapor data from a subset of limb profiling instruments operating since the 1980s. This presentation details recent updates and improvements made to SWOOSH to include additional sources of data and improve uncertainty estimates. The improvements to SWOOSH include new efforts to better account for uncertainties related to sparse sampling and inconsistent error estimates among different satellite sensors. We also assess the impact on variability and trends of incorporating three new satellite sensors to SWOOSH (ACE-FTS, SAGE III/ISS, and OMPS-Limb Profiler), as well as from including the new Aura MLS version 5 data. With the expected loss of the Aura MLS instrument sometime in the mid 2020’s, the addition of these new instruments will help continue the SWOOSH record into the future.
Observation of spatiotemporal variability of deep near-inertial waves in the western Arctic Ocean 
Authors: Park Jae-Hun , Jeon Chanhyung , Boury Samuel , Peacock Thomas
Published: March 2022

A current- and pressure-recording inverted echo sounder (CPIES) placed on the sea floor observes physical ocean environment from months to years. Recently, a new technology was developed to collect high-resolution observational data remotely from CPIES using a popup-data-shuttle (PDS) through Iridium satellites. Remotely retrieved direct measurements of near-bottom currents in 30-minute intervals from an array of six PDS-CPIES deployed in the western Arctic Ocean reveal spatiotemporal variabilities of deep near-inertial waves (NIW). The deep NIW activity distinguishes energetic and calm NIW periods in July–December and in January–June, respectively. At the southernmost site in the Northwind Abyssal Plain, the NIW energy level during the energetic NIW period is around 10 times higher than during the calm NIW period. Comparison with the surface sea-ice changes suggests that the energetic deep NIW is significantly related with sea-ice reduction during the summer months. Site-dependent thickness of the near-bottom mixed layer causes rapid vertical decay of NIW activity close to the seabed, explaining notable differences in the observations between two of the sites. This study implies that investigating of the propagation and dissipation of NIW can help a better understanding of the evolving physical environmental changes of the Arctic Ocean interior caused by the recently accelerated decline of sea ice in the Arctic.
Towards use of extreme rainfall forecast and socio-economic data to generate Impact-based forecasts
Authors: Singhal Akshay , Raman Ashwin , Jha Sanjeev
Published: March 2022

Each year India witnesses numerous casualties, economic losses and vast displacement of people due to extreme rainfall events (EREs). One of the reasons for such losses is that the weather warnings associated with the EREs are not properly communicated to the general public. It is essential that the expected impacts are communicated well in advance so that appropriate remedial actions can be taken and losses can be minimized. Several national and regional rainfall forecasting agencies have started issuing risk-based warnings which includes the potential impacts arising due to the EREs. This framework of providing forecast information based on the potential impacts of a hazard is called Impact-Based Forecasting (IBF). In this study, we develop a framework for generating the impact-based forecasts and associated warning matrices for the districts of eastern Uttar Pradesh, India, by integrating the rainfall forecasts and the socio-economic characteristics of the region. The region is densely populated, has relatively poor socio-economic conditions and is prone to frequent EREs. We take into account various sectors such as population, economy and agriculture where maximum impacts are expected to take place. Moreover, we identify the vulnerable districts based on the frequency of the number of extreme rainfall forecasts in the past four years (2017-2020) and the nature of socio-economic conditions. The vulnerable districts are categorized in three categories (low, medium and high) based on the expected impacts. For each of the vulnerable districts, sample IBFs and warning matrices are generated. IBFs inform about the possible impacts different sectors in each district may face on a given day due to the forecasted ERE. On the other hand, warning matrices provide updated information regarding the category of risk for the district a few days in advance. The study is significant since it follows a methodological framework to generate impact-based forecasts and warnings which includes analysis of rainfall forecasts, identification of possible impacts and suggestion of appropriate mitigation actions.
On the scaling features of magnetic field fluctuations at sub-protonic scales
Authors: Consolini Giuseppe , Benella Simone , Alberti Tommaso , Stumpo Mirko
Published: March 2022

Fluctuations of magnetic field in space plasmas at sub-protonic scales have been supposed to be the result of a turbulence process involving different wave modes (EMHD, KAW, …). However, the observed spectral and scaling features seem to be non-universal. Furthermore, there is a wide evidence for the occurrence of a global scale invariance. Now, the complex nature of the fluctuations at these scales could be due to the interweaving of fluid and kinetic processes that might alter the usual scenario expected for the occurrence of strong turbulence. Here, using high-resolution data from the Parker’ Solar Probe mission we attempt an analysis of the scaling features of magnetic field fluctuations at sub-protonic scales using different approaches: i) the structure function analysis, ii) the singularity spectrum analysis and the rank-ordered multifractal analysis. The aim of these multiple approaches is to unveil the inherent complexity of fluctuation field at sub-protonic scale and to understand the controversial issues related to the occurrence of intermittency at these scales.

We acknowledge financial support by Italian MIUR-PRIN grant 2017APKP7T on Circumterrestrial Environment: Impact of Sun-Earth Interaction.
Application of a semi-automatic tool for field variability assessment on a cultivated field in Northern Italy to evaluate variable fertilization benefits
Authors: Moretto Johnny , Giomo Matteo , Fantinato Luciano , Rasera Roberto
Published: March 2022

Traditional fertilization techniques in crop production consist in a homogeneous distribution of inputs all over the cultivated field. Alternatively variable fertilization methods could minimize the environmental impact and increase economic benefits.

The objective of this study is to evaluate the capabilities of a Google Earth Engine code conceived to rapidly study the variability of cultivated fields, for a possible variable fertilization. The tool is semi-automatic as it requires just the field boundary and it gives few outputs ready to be inspected by the user. This work presents an application of this model in a corn field in Northern Italy (province of Venice).

Field variability is evaluated through NDVI index extracted from Sentinel-2 images from 2017 to 2021. For the purpose, the tool provides NDVI statistics, classified maps, classified area percentages, and punctual NDVI trends.

Results show that boundary regions of the field are systematically less vigour than other parts, thus crop production is not efficient. Otherwise, fertilization should be enhanced in internal parts, as they are steadily healthier.

The proposed model is a fast way to analyse field vigour status and Google Earth Engine capabilities permit to apply it nearly all over the world. Field variability and linked variable fertilization are crucial to reduce environmental and increase economic benefits, especially in extensive farming.
A Preliminary Assessment of the Indonesian Tsunami Ready Communities 
Authors: Anugrah Suci Dewi , Julius Admiral Musa , Daryono Daryono , Hidayanti Hidayanti , Weniza Weniza , Kriswinarso Tribowo , Simangunsong Gloria , Rahayu Resti Herdiani , Apriani Mila , Yatimantoro Tatok , Hawati Purnomo , Karnawati Dwikorita , Sadly Muhamad , Prayitno Bambang Setiyo
Published: March 2022

Tsunami risk in Indonesia is strongly real and needs serious handling. Due to the extremely dangerous, it is important for coastal communities to be prepared and responsive in responding to threats. The recent decade tsunami disaster highlighted the extraordinary gaps and challenges on the development and strengthening of the downstream component on the system. Communities need to be educated, aware and ready to respond to warnings both natural as well as official warnings. For this reason, the Indonesia Agency for Meteorology, Climatology, and Geophysics (BMKG) considers to introduce an Indonesia Tsunami Ready programme that will encourage communities to build, strengthen and develop their capacity and ability to respond to tsunami threats.

In this paper we try to analyze the community actualization on hazard assessment, preparedness, and response as the result of the Indonesian Tsunami Ready programme. The assessment is based on the 12 indicators of the tsunami ready which had been determined by the United Nations Educational, Scientific and Cultural Organization-the Intergovernmental Oceanographic Commission (UNESCO-IOC). A field survey of the 12 indicators has been carried out to assess seven communities (Penggarangan, Pangandaran, Gelagah, Kemandang, Tambakrejo, Kuta Mandalika, and Tanjung Benoa) living in the tsunami prone area.

Generally, the results showed the communities didn’t have the updated tsunami hazard map as the hazard assessment indicator. The previous hazard map was not established based on the latest seismological study and tsunami modelling. Most of communities have an emergency operation plan for earthquake and tsunami, even though it doesn’t consider the earthquake information and tsunami warning. In some villages such as Tanjung Benoa and Kuta Mandalika, local potentials are used also to empower the preparedness and response capacity.

BMKG gave an advocacy to complete and accomplish some the unavailable indicators such as tsunami hazard map, emergency operation plan, and public education materials. The result of this study is expected to be an effective way to build a community awareness, preparedness and response.

Keywords: tsunami ready, 12 indicators of tsunami ready, hazard assessment, preparedness, response
The extreme sea-level event of 14-15 October 2016 on the coasts of British Columbia and Washington State caused by Typhoon "Songda"
Authors: Rabinovich Alexander , Šepić Jadranka , Thomson Richard
Published: March 2022

From 12 to 16 October 2016, a series of three strong low-pressure systems, including typhoon “Songda”, passed over the coasts of southern British Columbia (BC) and Washington State (WA). Typhoon “Songda” was generated on 2 October about 1,000 miles to the southwest of Hawaii. After passing along the coast of Japan, it turned eastward, crossed the Pacific Ocean, arriving off the coast of North America on 12 October, where it merged with local extratropical cyclones propagating along the coast of Vancouver Island.  These three lows passed across the western coast of the island on 14-15 October, generating strong surface currents if the offshore region and significant sea level oscillations, including storm surges, seiches and infragravity waves along southern BC and northern Washington. Oceanic observations of the event included HF WERA radar data, offshore bottom sea pressure measurements from the Ocean Network Canada (ONC) observatories and sea level records from BC and WA tide gauges. Meteorological data analyzed included radar records, satellite imaginary, reanalysis synoptic data, and air pressure and wind surface measurements of remarkable spatial and temporal resolution from more than 150 school network stations. These extensive datasets allowed for a detailed tracking of atmospheric processes responsible for strong ocean surface currents and sea-level oscillations. Maximum currents of up to 50 cm/s were measured by the HF radar. The surge heights on the southern BC and northern WA coasts were higher than 80 cm, with maximum storm surge observed at La Push, WA (117 cm) and New Westminster, BC (101 cm). A particularly interesting phenomenon was observed on the west side of Vancouver Island, beginning at Tofino, where the tide gauge record indicated a sharp, knife-like 40-cm increase in sea level with a peak value at 07:01 UTC on 14 October. Slightly lower sharp sea level peaks were also observed at Bamfield, Port Alberni and Port Renfrew. The high negative correlation between sea level and atmospheric pressure is consistent with the inverted barometer (IB) effect. Sharp sea level peaks at Tofino, Bamfield and Port Alberni are shown to be related to the specific shapes of the air pressure variations at these sites (the minimum atmospheric pressure at Tofino was 971.4 hPa), but the sea level response was 1.5-2.5 times greater than the IB effect, demonstrating the topographic amplification of sea levels in the respective areas. Such oscillations at Tofino and surrounding regions, may be described as a “meteorological tsunami” that for this specific case has a character of a forced solitary wave.
How changes in compartments of water storage affect the vegetation?
Authors: Pernati Srinivas , Bharath Narayana Reddy Komali , Devaraju Balaji
Published: March 2022

The relationship between water storage and vegetation growth differs with changes in different water
compartments such as total water storage, soil moisture and groundwater. This relationship can be
established between variations in water storage and Normalized Difference Vegetation Index (NDVI)
values. The compartments of water storage anomalies were computed with Gravity Recovery and Climate
Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) data sets. NDVI data from
Global Inventory Monitoring and Modeling System (GIMMS) was used to compare with water storage
anomalies. These water storage anomalies and NDVI values were aggregated over each sub-basin of the
Ganga catchment. A correlation analysis was made between water storage components and NDVI values,
which helped to determine how vegetation growth depends on changes in different water compartments.
Initial computations of auto-correlation and cross-correlation between water storage components and
NDVI show different lags for different sub-basins. 
Youth Citizen Science and Agro-Climatology in Côte d’Ivoire
Authors: Bogie Nathaniel , Bayala Roger
Published: March 2022

Since the 1980s the number of stations reporting quality weather data across Africa has been in decline. Weather data is critical for meeting climate challenges that the world will face in the 21st century. Unfortunately, along with the paucity of climatological data, Africa faces some of the largest vulnerabilities to a changing climate, including changes to local precipitation and temperature regimes upon which farmers rely for rainfed agriculture, which makes up 98% of the agriculture in Côte d’Ivoire. In this project students and scientists in Côte d’Ivoire and the United States are leveraging the Trans African Hydrometeorology Network (TAHMO) University to University (U2U) program to build a network of youth scientists in the region of Université Jean Lorougnon Guédé de Daloa (UJLG). In order to carry out this work we have identified ten locations at primary and secondary schools where manual rainfall and temperature gauges are being installed. The partner locations are schools in Gonaté, Brizeboua, Kibouo, Tahiragué, Zahia, Bla and Zéréfla. At these sites students will learn about weather and climate measurement and read daily rainfall amounts and temperatures from manual recorders. University students at UJLG and San José State University will collect, compile, and check the weather data in order to post it to a shared website where it can be viewed publicly. In addition, we plan to install one of the automated TAHMO weather stations at UJLD which is a robust station that records air temperature, wind speed, solar radiation, relative humidity, barometric pressure, wind speed and direction, lightning strike, and lightning strike distance and communicates them directly to the TAHMO network where they are available for viewing on the web. Using the manually recorded data as well as the automated data from the TAHMO station we plan to further develop teaching materials for earth system and agro-meteorology courses at UJLG and SJSU. The objectives of this project are to (1) provide opportunities for youth to learn about climate and weather data using a hands-on approach in their local area  (2) strengthen ties between US and Ivorian students and scientists and (3) to contribute to increasing the amount and quality of climate data across the African continent.
Soil erosion under extreme rainfall events: detecting and modelling using a radar-runoff-nowcasting-system
Authors: Ciampalini Rossano , Moretti Sandro , Rosi Ascanio , Antonini Andrea , Ortolani Alberto
Published: March 2022

Soil erosion by water is one of the most widespread forms of soil degradation in Europe, where the relevant annual cost for agricultural productivity loss is estimated to be around 295 million euros. Under climate changes, soil erosion due to rainfall is dramatically increasing, for the most part because of an increasing of the frequency of extreme, localised events.

Here, we present the MSCA-Horizon2020 project, focused on understanding and quantifying extreme rainfall effects on soil erosion, by means of ground-based weather-radar observations and hydrological modelling at regional scale (namely in Tuscany, central Italy).

In critical hydrological phenomena, such as intense surface runoff, flooding and soil erosion, the spatiotemporal extent is crucial in the development of the processes. This feature significantly  affects the impact and the evolution of critical phenomena, especially during extreme events. Therefore, an approach directed to refine as much as possible the knowledge of these dynamics is recommended both at the monitoring and the modelling level.

Using an approach based on statistical analyses of rainfall data from ground-based radar and modelling, this project aims to: 1) Quantify on historical data the spatiotemporal distribution of extreme rainfalls / runoff and soil erosion over the last years, 2) Build a platform to model runoff and soil erosion during extreme events in real-time, 3) Simulate in real-time runoff and soil erosion behaviours related to extreme rainfalls, integrating the current regional-warning-system for the extreme weather events.
Estimates of total phosphorus for Amazonia based on an expanded harmonized soil database
Authors: Maia Monique Rodrigues da Silva Andrade , Anderson Liana Oighenstein , Quesada Carlos Alberto Nobre
Published: March 2022

The element phosphorus total (Pt) is considered a basic element for life on earth. It controls key processes of CO2 absorption from tropical forests to food production. For the Amazon region, estimates of Pt in the soil are scarce. In this study, we developed models through equations of pedotransfer function (PTF's) using data collected in the field (RAINFOR data). Were generated 16 regression models based on the Akaike information criteria (AIC) with R² above 65% was validated with independent RAINFOR data. The results Pt distribution were spatialized using interpolations by geostatistical method of inverse distance weights (IDW) and shown through maps.
Enernization of Alpha Particles in the Solar Wind Magnetic Reconnection
Authors: Duan Die , He Jiansen , Zhu Xingyu , Zhuo Rui , Wu Ziqi , Yang Liu
Published: March 2022

The acceleration and heating of solar wind particles by energy dissipation in the magnetic reconnection is an important problem in space physics. Although alpha particles are the second most abundant element in the solar wind, their dynamical behavior in the magnetic reconnection of the solar wind is not well understood. Using the high energy (1500~3000 eV) part of the SWA/PAS instrument on board the Solar Orbiter, we study the kinetic behavior of alpha particles in a magnetic-reconnetion exhaust region within a heliospheric current sheet. In this event, protons and alpha particles have similar bulk velocities. Alpha particles are accelerated and form a jet in the exhaust region. The counter-stream distribution of alpha particles is observed inside the exhuast region, which changes the direction from parallel to perpendicular to the magnetic field direction when the magnetic field is reversed. In addition, a pair of the slow shock/rotational discontinuity is observed in the exhuast region. The exhaust region is heated and bounded by the slow shocks , while the accelerated plasma jet is bounded by the rotational discontinuities.
Anthropogenic heat helps reduce PM2.5 pollution and related health burden in China
Authors: Liu Zehui , Zhang Lin
Published: March 2022

Large amounts of energy consumption in recent years have not only increased air pollution and greenhouse gas emissions, but have also released more anthropogenic heat into the atmosphere. However, the latter was overlooked in previous air quality and pollution-related health impacts studies. Here we use the atmospheric chemistry model coupled the exposure mortality model to investigate the effects of increased anthropogenic heat flux on PM2.5 pollution and related health burden in China. We find the ignoring anthropogenic heat leads nighttime PM2.5 concentrations to be overestimated, especially in metropolitan areas. The rising anthropogenic heat flux between 2000-2016 decreases surface PM2.5 by 4 ug·m-3 in Chinese urban region through altering microphysical processes and enhancing vertical mixing. Furthermore, the anthropogenic heat changes could avoid additional 15% (47 thousand) premature deaths, compare to anthropogenic emission reductions. Our findings indicate that anthropogenic heat should be included in air quality modeling and reveal the health benefit of energy use from a microphysical standpoint.
Long-term differential water level responses of a group of tropical maar lakes in a semi-arid basin (Cuenca Serdán Oriental, México)
Authors: Silva Aguilera Raúl Alberto , Escolero Oscar , Alcocer Javier
Published: March 2022

Global change has different effects on inland water bodies. In the case of lakes, the water level is a variable frequently affected. Lakes in semi-arid zones are susceptible to climatic and anthropic forcing. Understanding how these factors modulate changes in lakes is essential to develop forecasts and generate management and conservation programs. However, lakes evolution under external forcing may differ despite belonging to the same system. The differences highlight the importance of developing particular management plans for each lake. Therefore, it is necessary to understand the factors that modulate these peculiarities. An example in central Mexico is the six maar lakes found in the easternmost basin of the Mexican Plateau, the Serdán Oriental Basin: Alchichica, Quechulac, La Preciosa, Atexcac, Tecuitlapa, and Aljojuca. Groundwater flow is essential in the water balances of these lakes. However, intensive groundwater exploitation for agriculture has occurred since the '80s in this semi-arid basin. Several studies have revealed that these lakes' trophic states, biota, and chemical compositions differ remarkably. Both locals and researchers have noted water-level declines in all lakes in recent decades. Water level evolution also seems to be particular in each lake. Data on the lakes water levels from 1960 to 1992 and subsequent changes are analyzed. We assessed physical (e.g., climatic, geological, hydrogeological, vegetation) and anthropic (land-use changes and groundwater exploitation) factors that could modulate the water level evolution differences. Time series analysis, remote sensing, and statistical methods were applied. This work represents a conceptual framework for further studies oriented to the numerical modeling of the lake system and the exploration of future change scenarios.
Quantifying the hydrological responses of future climate changes on a large scale river basin in India
Authors: Naha Shaini , Rico Ramirez Miguel Angel , Rosolem Rafael
Published: March 2022

The serious hydrological consequences of climate change faced by developing countries like India show regional variability. Understanding these regional hydrologic impacts has a crucial role in the management of water resources. Mahanadi river basin (MRB) is a major large-scale river basin in India that is predicted to face severe floods under future climate change scenarios. Commonly, climate change impacts are simulated for a specific decade, specific scenario, or specific climate model in the future. We, however, employed an arguably more objective, approach that would identify the impacts of all possible combinations of specific change within the possible mean annual temperature and precipitation 2-dimensional scenario space (derived from thirteen CMIP6 models) on the hydrological responses. CMIP6 is the recent generation of climate models, released to overcome the drawbacks of the previous generation CMIP5 models such as under/overestimating the monsoon characteristics over the Indian subcontinent. Our methodological approach also involves using an ensemble of VIC models, representing the overall model uncertainty due to parameter value choices, in conjunction with these climate projections, instead of using a single calibrated model to predict the hydrological responses. The climate projections show an overall change in mean annual precipitation and mean annual average temperature that ranges from -5 to +105% and 0-7◦C respectively. This has resulted in significant changes in both mean annual flows and peak flows of up to 2849 and 29,776 m3s-1 respectively. Uncertainties associated with the model parameters, of up to 1211 m3s-1 are observed in the predicted peak flow magnitudes, which is considerably higher than in predicted annual flow magnitudes. Our findings indicate that precipitation mainly controls the future predicted flows in the basin. This study has provided a set of results on the likely future behavior of the MRB mean annual and peak flows under the CMIP6 climate projections. Future projections of hydrologic variables, along with the associated model parameter uncertainties can help with better hydrologic impact assessment and developing adaptation strategies for MRB in India.

Keywords: Climate change, CMIP6, VIC, Mahanadi river basin, flows
Variability of Sea-surface Magnetic Anomalies at Ultraslow Spreading Centers: Consequence of Detachment Faulting and Contrasted Magmatism?
Authors: Zhou Fei , Dyment Jérôme
Published: March 2022

The capacity of oceanic crust to record geomagnetic polarity reversals makes sea-surface magnetic anomalies an essential tool to study plate tectonics. The anomalies are usually well-defined at magmatic spreading centers, but are distorted and eventually disappear on magma-poor mid-ocean ridges such as the ultraslow Southwest Indian Ridge (SWIR), making their interpretation difficult. We attribute the variability of the SWIR sea-surface magnetic anomalies to the alternance of magmatic spreading and detachment faulting. A three-layer magnetic model is used to simulate the influence of such an alternance on the sea-surface magnetic anomalies. Conversely, observed magnetic profiles at the SWIR are modelled to unravel their off-axis crustal structure and past mode of spreading. The intruding gabbro bodies on the footwall of detachment faults play a major role in explaining the variability of sea-surface magnetic anomalies at slow and ultraslow spreading ridges.
Missing extremes in CML rainfall estimates due to total loss of signal
Authors: Chwala Christian , Polz Julius , Graf Maximilian , Kunstmann Harald
Published: March 2022

Attenuation data from commercial microwave links (CMLs) has proven to provide useful rainfall information. With their high density in urban areas, CMLs offer a great potential to estimate and study rainfall variability on small scales. Since the transmission power of CML hardware is limited, heavy rainfall can, however, lead to a complete loss of signal at the receiving end. As a consequence, very high rain rates can be missing in CML-derived rainfall information. The rain rate for which a specific CML experiences complete loss of signal depends on its length and frequency as well as on its dynamic range which is defined by transmit power, receiver noise level and antenna gain.

We analyze the occurrence and effect of such complete losses of signal, which we term “blackouts”, using two different datasets. First, a CML dataset with one minute temporal resolution consisting of 4000 CMLs in Germany is used to investigate the blackouts in real CML attenuation data over a period of three years. Second, the gauge-adjusted radar climatology RADKLIM-YW from the German Meteorological Service is used to derive synthetic rain induced attenuation data for each CMLs path with 5-minute temporal resolution for a period of 20 years.

For the real CML observations we introduce and apply a new algorithm to detect rain induced blackout gaps. This allows us to quantify the number and length of the blackout gaps stemming from heavy rainfall. Using the path-averaged RADKLIM-YW data as reference, we then quantify the rain rates and rainfall amount that is missed due to the CML blackout gaps. We find that longer CMLs are more likely to be affected by blackout gaps. This effect occurs even though the CMLs in our dataset are configured so that longer CMLs have a larger dynamic range to account for the increasing attenuation with increasing length. Using the dynamic range of each CML, we derive the long-term statistics of potential blackout occurrence from the synthetic attenuation data based on RADKLIM-YW. We find a pattern similar to the one in the real CML attenuation data, albeit with a smaller fraction of time steps affected by blackouts for all CMLs.

Our results provide a reliable basis for researchers to judge the capability of their CML dataset to capture rainfall extremes. Furthermore, it can serve as an improved basis for planning the layout and configuration and thus the dynamic range of individual CMLs.
Accounting for anisotropy in the simulation of rainfall fields with blunt extension of discrete Universal Multifractal cascades
Authors: Gires Auguste , Tchiguirinskaia Ioulia , Schertzer Daniel
Published: March 2022

Universal Multifractals have been widely used to characterize and simulate geophysical fields extremely variable over a wide range of scales such as rainfall. Despite strong limitations, notably its non-stationnarity, discrete cascades are often used to simulate such fields. Recently, blunt cascades have been introduced in 1D, 2D, and space-time to cope with this issue while remaining in the simple framework of discrete cascades. It basically consists in geometrically interpolating over moving windows the multiplicative increments at each cascade steps.

 

While being a well-known feature of rainfall fields, anisotropy is not yet addressed with blunt extensions of discrete Universal Multifractal cascades. In this paper, we suggest to extend this framework to account for anisotropy. It basically consists in using different sizes according to the direction for the moving window over which the interpolation is carried out. In a first step Multifractal expected behaviour is theoretically established. Then it is numerically confirmed with the help of ensembles of stochastic simulations. Finally, the features of simulated fields are compared with actual rainfall data ones. Data collected with help of a dual polarisation X-band radar operated by HM&Co-ENPC is used (radx.enpc.fr/).

 

Authors acknowledge the RW-Turb project (supported by the French National Research Agency - ANR-19-CE05-0022), for partial financial support.
Contribution of measurement error in calibration and validation data to the prediction accuracy of pedotransfer functions
Authors: van Leeuwen Cynthia , Mulder Titia , Batjes Niels , Heuvelink Gerard
Published: March 2022

Modelling of soil processes is dependent on the availability of high-quality soil data. Soil properties that are considered difficult to measure are frequently determined through pedotransfer functions (PTFs). Here, readily available data are translated into data that are needed. Aside from these input soil properties, a reference wet chemistry dataset of the soil property of interest is required. However, these calibration and validation data are imperfect due to measurement error caused by various sources. Until now, the uncertainty of calibration and validation data has been ignored when deriving PTFs, and uncertainty quantification remains limited to the propagation of model input, parameter and structural uncertainty. In this contribution, we aimed to take uncertainty analysis one step further by studying how measurement error in wet chemistry calibration and validation soil data affects PTF predictions and associated prediction uncertainty. We focused on PTFs to predict the soil’s cation-exchange capacity (CEC), which is an important indicator of soil fertility and nutrient retention capacity. To predict CEC through PTFs, soil properties such as clay percentage, organic carbon content and pH are commonly included. We aimed to study the effect of measurement error in CEC data on the accuracy of multiple linear regression and random forest prediction models. PTFs were developed for the entire USA, subdivided per soil taxonomic order. Here, wet chemistry data from the National Cooperative Soil Survey’s (NCSS) Soil Characterization Database were used. The PTFs were fitted with and without including measurement error. However, the majority of the samples from the NCSS Soil Characterization Database were not measured in duplicate, which was needed to quantify measurement error. Alternatively, we used data from the Wageningen Evaluating Programmes for Analytical Laboratories (WEPAL) to provide a best estimate for the measurement error. Comparison of PTFs with and without measurement error showed significant differences in model accuracy metrics.
Late Quaternary deglaciation pattern of Lancaster Sound and Barrow Strait traced by radiogenic isotope records in marine sediments
Authors: Hingst Johanna , Hillaire-Marcel Claude , Lucassen Friedrich , Okuma Emmanuel , Kasemann Simone
Published: March 2022

The retreat of the Laurentide and Innuitian Ice Sheets in the Canadian Arctic Archipelago (CAA) during the late Quaternary led to the opening of Arctic gateways and the inflow of low salinity Arctic waters into Baffin Bay. Studies on marine sediments focusing on the timing and deglaciation pattern of Canadian Archipelago straits mainly concentrated on the Holocene. Here we present two marine radiogenic isotope records from the mouth of Lancaster Sound (GeoB22336-4) and from Barrow Strait (PS72/287) that cover the last ~14.5 ka BP, thus encompass the earlier deglaciation stage. The radiogenic isotope composition (Nd, Sr, Pb) of the detrital sediment fraction serves as provenance tracer and provides information on changing position of the ice margin and oceanographic conditions. Data from both sediment cores show contributions from highly variable source areas during deglaciation in response to the dynamics of the glacier termini involved. However, a strong influence of detrital carbonates, likely eroded from carbonate outcrops of the CAA and northern Baffin Island, by retreating ice, constitutes a dominant feature. Later, the post-glacial deposits recorded more uniform radiogenic isotope signatures until the mid/late Holocene transition, indicating relatively stable environmental conditions. In addition to local sources, isotope compositions in Lancaster Sound illustrate an increasing influence of sediments from Barrow Strait and thus the setting of oceanographic conditions enabling sediment transport from the central CAA towards the NW Baffin Bay. According to these observations and based on a preliminary age model, complete deglaciation with subsequent flushing of major channels is assumed to have occurred at approximately 10 ka BP. During the late Holocene, slightly changing Sr, Pb, and Nd isotope signatures in both cores probably indicate renewed regional ice advances in response to the neoglacial cooling.
X-rays associated with the stepping of upward negative leaders at the Säntis Tower: Preliminary results
Authors: Sunjerga Antonio , Hettiarachchi Pasan , Stanley Mark , Smith David , Chaffin Jeffrey , John Ortberg , Cooray Vernon , Rubinstein Marcos , Rachidi Farhad
Published: March 2022

X-rays have been observed in downward cloud-to-ground lightning and rocket-triggered lightning for the case of negative leaders both during the leader stepping and the dart leader phase [1-3]. X-rays have also been observed during the stepping of dart leaders in upward negative lightning flashes [4,5].      

In this study, we present results from three positive upward flashes. The observations consist of the simultaneous records of X-rays, electric current and electric field at 23 m. Observations from a 2D interferometer system are available for two of the flashes while the third flash was captured by a high-speed camera operating at 24 000 frames per second.

We report X-rays recorded during the initial phase of upward negative leader propagation. To the best of our knowledge, this is the first time that such observations are reported in the literature. The observed X-rays are associated with the stepping of upward negative leaders that can be observed both in the electric field and current waveforms. X-rays associated with the very first step of the upward negative leader were observed in one of the three flashes.

These observations are important to understand the initiation of upward lightning and the mechanisms involved in the initial breakdown.          

[1] Moore, C. B., Eack, K. B., Aulich, G. D., & Rison, W. (2001). Energetic radiation associated with lightning stepped-leaders. Geophysical Research Letters, 28(11), 2141–2144. https://doi.org/10.1029/2001gl013140

[2] Dwyer, J. R. (2003). Energetic Radiation Produced During Rocket-Triggered Lightning. Science, 299(5607), 694–697. https://doi.org/10.1126/science.1078940

[3] Bowers, G. S., Smith, D. M., Martinez‐McKinney, G. F., Kamogawa, M., Cummer, S. A., Dwyer, J. R., Wang, D., Stock, M., & Kawasaki, Z. (2017). Gamma Ray Signatures of Neutrons From a Terrestrial Gamma Ray Flash. Geophysical Research Letters, 44(19). https://doi.org/10.1002/2017gl075071

[4] Hettiarachchi, P., Cooray, V., Diendorfer, G., Pichler, H., Dwyer, J., & Rahman, M. (2018). X-ray Observations at Gaisberg Tower. Atmosphere, 9(1), 20. https://doi.org/10.3390/atmos9010020

[5] Sunjerga, A., Hettiarachchi, P., Smith, D., Rubinstein, M., Cooray, V., Azadifar, M., Mostajabi, A., & Rachidi, F. (2021). X-rays observations at the Santis Tower: Preliminary results. Copernicus GmbH. https://doi.org/10.5194/egusphere-egu21-9586
The fuzzy effect of soil conservation practices on runoff and sediment yield from agricultural lands at the catchment scale
Authors: Egozi Roey , Bekin Nadav , Prois Yaakov , Laronne Jonathan
Published: March 2022

Intensive soil degradation of agricultural lands during the past decades led local authorities in the Harod Catchment, northern Israel, to implement soil and water conservation practices. Herein, for the first time in Israel, we quantified the impact of these practices on water discharge, runoff/rainfall, and sediment yields at the catchment scale. We monitored two neighboring tributaries of the Harod River: Shkedim and Shunem. Both are dominated by intensive agriculture, are similar with respect to soils and rain patterns, but differ in terms of tillage and soil conservation practices - implemented in abundance in the Shkedim catchment. Inner-catchment processes were studied at the plot scale using a structure for motion photogrammetry, utilizing an unmanned aerial vehicle. At the catchment scale, we used airborne LIDAR to provide a better understanding of the extent to which different geomorphometric characteristics might influence flood discharge, suspended sediment concentration, and yield. We monitored the impact of temporal changes in vegetation cover with remote sensing. Intense storms occurring in early winter when the soil was bare and freshly tilled generated much runoff and sediment. During three field seasons, measured mean annual sediment yields were 820 and 2,000 t km−2 y-1 for Shkedim and Shunem, respectively. The benefits of soil conservation practices applied in the Shkedim catchment are manifested by lower runoff yields and peak discharges. Conservation practices together with milder topography were identified to limit flow continuity and to promote sinks, while in the Shunem, tillage parallel to contour lines induced higher hydro-geomorphic connectivity. Still, Shkedim soil loss is high due to cultivation of riparian zones, lack of maintenance of engineered structures, and a larger area of bare soil during winter due to rotational cropping. These blur the efficiency of soil conservation practices at the catchment scale.