bluuebunny/crossref_metadata_2025 huggingface dataset:
Communicating the Uncertainty in Predictions from a GIS-Modelling Framework
Authors: Milne Alice , Oulaid Bader , el fartassi imane , Zawadzka Joanna , el Alami Rafiq , Tabiti Khouloud , Metcalfe Helen , Diarra Alhousseine , Alonso chavez Vasthi , Wayne Toby , Corstanje Ron
Published: February 2023

Policy makes and other stakeholders working to improve the sustainability of agriculture need access to information on soil spatial variation, and the impacts of management strategies that policy might promote. Models and data can provide such information but typically such products are developed in isolation and so do not allow for an integrated trade-off analysis. To overcome this limitation, we have developed a GIS- modelling framework (GIS-MF) that allows users to interrogate integrated models and data layers. This GIS-MF prototype has been developed for the Tensift watershed which is in the region of Marakesh-Safi, Morocco. The alpha version of the software contains four main components: (i) a field to watershed-scale Digital Soil Mapping viewer, (ii) a watershed scale Ecosystems Services Report viewer (iii) an Interactive Ecosystem Service and Environmental Impacts viewer that allows trade-offs to be explored and (iv) a field-scale yield prediction tool.  For each component it is essential to communicate the uncertainties associated with predictions in a way that is both informative and intuitive to the end users. We have explored several ways for communicating uncertainty that we will present. For the DSM viewer we consider both methods that show uncertainty distributions as well as the probability of exceeding agronomically relevant thresholds. We take a similar approach for the Ecosystems Services Report viewer, and the yield prediction tool. For the uncertainties related to our integrated trade-offs we consider approaches to communicate the changes in multiple objectives. We draw on previous analyses to make conclusions and we will ask the EGU audience their views on each of the methods. 
Characteristics of ice over stratiform rain: Global statistics from the Dual-frequency Precipitation Radar and the proposed retrieval scheme
Authors: Mroz Kamil , Battaglia Alessandro
Published: February 2023

The Dual-frequency Precipitation Radar (DPR) on NASA's core Global Precipitation Measurement satellite is the first space-borne instrument that offers an opportunity of a dual-wavelength radar retrieval of the size and the mass concentration of hydrometeors, i.e., two microphysical parameters that control the mass flux through the weather systems. Our focus is placed on DPR observations over the stratiform rain where the analysis revealed a sharp increase in mass flux from ice to rain phase in the official algorithm. This is inconsistent with the expectation that mass flux varies little across the bright band. The proposed algorithm imposes continuity of the precipitation rate across the bright band which additionally helps in deriving bulk ice density. It is based on Bayes' rule with riming parameterized by the “fill-in” model. The radar reflectivity are simulated using the scattering models corresponding to realistic snowflake shapes. The algorithm is validated using the co-located polarimetric radar data collected for the GPM ground validation program. In the future, this dataset will be used for multi-frequency radar studies that aim at constructing high quality training datasets for artificial intelligence algorithms that are necessary to analyse the huge volume of data that will be generated by upcoming space missions such as the one proposed by Tomorrow.io
Drought resilience of a mixed beech-spruce forest - an experimental study linking responses from the rhizosphere to the canopy, from physiology to morphology, and from hours to years
Authors: Grams Thorsten
Published: February 2023

This paper addresses the knowledge gaps on what determines tree responses to drought, their recovery, and survival following drought release, integrating physiological and morphological responses from the rhizosphere to the canopy of mature trees. I summarize 10 years of research on an experimentally induced drought and subsequent recovery in a maturing beech-spruce forest in southern Germany. Study objects 70- to 80-year-old trees that are readily accessible via canopy crane and grow in either mono-specific or mixed stands. We studied about 100 trees in 12 plots of roughly 150 m2 each. Tress were exposed to experimentally induced summer drought for five consecutive years by complete throughfall exclusion during the growing season (Kranzberg forest ROOF experiment, kroof.wzw.tum.de).During the first two drought summers, when both species were not yet acclimated, drought stress intensity peaked with pre-dawn leaf water potentials near -2.0 MPa and concomitant severe declines in physiological (e.g. leaf gas exchange, phloem transport) and morphological (e.g. growth) responses. After overcoming the critical first two years of drought, significant morphological acclimation in the following three years, e.g. by adjustment of leaf area or rooting depths, resulted in relaxation of physiological stress, as evidenced, for example, by increased stomatal conductance and pre-dawn leaf water potential. Reduced water consumption of spruce and thus higher water availability, also for neighboring beech trees, significantly alleviated drought stress in the trees.After a total of five years of experimentally induced summer drought, drought release was initiated in early summer 2019 by controlled watering. Physiological parameters such as stomatal conductance or xylem sap flow recovered with hours or days after drought release, including resilience of C allocation, e.g. sugar transport along the stems, as an important prerequisite for the recovery of tree functionality and productivity. Restored coupling between canopy and rhizosphere significantly supported spruce root growth, which recovered within a few days. In contrast, other morphological responses (e.g., leaf area recovery) took years to recover. With future increases in the frequency of drought events under ongoing climate change, tree species that recover more quickly will be favored.
Evolution of the Drivers of Stratification of the Gulf of Lion in a Changing Climate
Authors: Keller Douglas , Givon Yonatan , Sevault Florence , Somot Samuel , Pennel Romain , Raveh-Rubin Shira , Drobinski Philippe
Published: February 2023

Deep convection, or open-ocean convection, occurs in the higher latitude regions of the world and is an important ocean circulation process. It is formed when the stable density gradient along the ocean column is eroded by surface buoyancy loss, leading to an overturning that can span the entire depth of the column. In the western basin of the Mediterranean Sea (Med. Sea), this process can occur in the Gulf of Lion (GOL) and assists in the thermohaline circulation of the sea by forming the Western Mediterranean Deep Water (WMDW), which then laterally spreads throughout the western basin. Significant deep convection events occur every few years in the GOL, driven by the Mistral and Tramontane winds and the seasonal atmospheric change. However, in the future these events are expected to stop altogether due to increasing stratification. In this presentation, the changes in atmospheric forcing and stratification in the GOL are examined to determine the driving factor behind the collapse of the deep convection process in the region. This task is completed using NEMO simulations driven by the CMIP6 results of Météo France's RCSM6 regional model. The years from 2015 to 2100 are studied, under the SSP5 8.5 scenario (the worst case SSP scenario). Two sets of simulations are presented, a control and seasonal set. The seasonal set was forced with filtered atmospheric forcing to remove the effect of the Mistral and Tramontane. Comparing the two sets allows to determine the effects of the Mistral and atmospheric forcing separately. Results show an evolution in atmospheric forcing that effectively leads to no net change over time in the energy fluxes at the surface of the ocean. However, the stratification in the gulf increases, driven by advected stratification, with temperature as the primary advected quantity increasing stratification.
Vulnerability and risk assessment of debris flows close to Arctic settlements based on dendrogeomorphological methods
Authors: Owczarek Piotr
Published: February 2023

An increase in temperature and the occurrence of extreme precipitation events affect mass movement activity in the Arctic. Debris flows, the most characteristic features of depositional slopes in polar regions, are one of the most dangerous processes due to their speed and rapidity. An intensification of these phenomena has been observed in recent decades. Factors that influence the activity of the process are primarily the significant supply of water to the upper layer of slope deposits from precipitation and melting snow to an increasingly thick active layer. The expanding Arctic settlements will therefore come under increasing pressure from mass movements. The aim of the study is to investigate the possibility of using dendrogeomorphological methods for an analysis of the risk assessment of debris flows in the vicinity of Longyearbyen and the Polish Polar Station on Spitsbergen. Since the 1970s, a number of catastrophic debris flows have been observed around Longyearbyen, for example on 10–11 July 1972, 1981 and 14-15 October 2016. Investigations of debris flows in Spitsbergen have been carried out for many decades using ground-based and remote-sensing methods. The use of arctic shrubs, such as Salix polaris and Dryas octopetala, makes it possible to analyse the occurrence of debris flows with up to one year's accuracy and to identify the parts of the debris cone that are most active. The use of the age of the shrubs and their selected anatomical characteristics allows the determination of the potential risk area, especially in areas where environmental monitoring is not carried out.

The research was founded by a Polish National Science Centre project no. UMO-2021/41/B/ST10/03381

 
Modelling the distribution of intermittent magnetic field fluctuations recorded by the Swarm mission in the polar area
Authors: Kovacs Peter , Heilig Balazs , Bebesi Zsófia , Opitz Andrea
Published: February 2023

The almost one decade of operation of ESAs Swarm mission provides an unprecedented opportunity to investigate the appearance of small-scale nonlinear magnetic field irregularities in the topside ionosphere in terms of various climatological and solar-cycle conditions. Within the framework of the EPHEMERIS project supported by ESA we have developed an index for the characterization of the intermittent status of the compressional and tangential (i.e., parallel and perpendicular to the mean background field, respectively) magnetic field fluctuations along the orbits of the Swarm spacecraft triplet. The index is called intermittency index, in short IMI. IMIs are computed for consecutive overlapping segments of Swarm’s magnetic field records by evaluating the deviation of their statistical distribution from the Gaussian distribution. By portraying the global spatial distribution of IMIs, it turns out that the most intensive intermittent fluctuations appear in the polar and equatorial regions, due to auroral field-aligned currents (FAC) and equatorial spread F and plasma bubble phenomena, respectively. Making use of the Adjusted Spherical Cap Harmonic (ASHA) expansion of IMIs, we model the distribution of the intermittent transverse magnetic fluctuations in the polar region in terms of geomagnetic latitude and magnetic local time (MLT), for different geomagnetic activities. We show that the most intermittent fluctuations at high latitudes are distributed about two oval regions that adjoin in the night sector. The ovals expand towards the equator with increasing geomagnetic activity. We argue that the boundaries of the poleward oval coincide with the locations of FACs, while the equatorward oval of intermittent fluctuations (separating from the poleward oval in the noon sector) corresponds to the ionosphere footprint of the plasmasphere boundary, i.e. the plasmapause. These findings are reinforced by independent aurora oval and plasmapause models.
Relative impacts of sea ice loss and atmospheric internal variability on winter Arctic to East Asian surface air temperature based on large-ensemble simulations with NorESM2
Authors: He Shengping , Drange Helge , Furevik Tore , Wang Huijun , Fan Ke , Graff Lise Seland , Orsolini Yvan
Published: February 2023

To quantify the relative contributions of Arctic sea ice and unforced atmospheric internal variability to “warm Arctic, cold East Asia” (WACE), this study analyses three sets of large-ensemble simulations carried out by the Norwegian Earth System Model with a coupled atmosphere-land surface model, forced by seasonal sea ice conditions from preindustrial, present-day, and future periods. Each ensemble-member within the same set uses the same forcing but with small perturbations to the atmospheric initial state. Hence, the difference between the present-day (or future) ensemble-mean and the preindustrial ensemble-mean provides the ice-loss-induced response, while the difference of the individual members within the present-day (or future) set is the effect of atmospheric internal variability.Results indicate that both present-day and future sea ice loss can force a negative phase of the Arctic Oscillation with a WACE pattern in winter. The magnitude of ice-induced Arctic warming is over four times larger than the ice-induced East Asian cooling, the latter with a magnitude that is about 30% of the observed cooling. Sea ice loss contributes about 60% (80%) of Arctic winter warming for the present-day (future) climate. Atmospheric internal variability can also induce a WACE pattern with comparable magnitudes between Arctic and East Asia. Ice-loss-induced East Asian cooling can easily be masked by atmospheric internal variability effects because random atmospheric internal variability may induce warming with larger magnitude. Observed WACE pattern occurs as a result of both Arctic sea ice loss and atmospheric internal variability, with the former  dominating Arctic warming and the latter dominating  East Asian cooling.
Delayed Effects of ENSO and Indian Ocean Dipole on the ensuing-summer extreme precipitation over Yangtze River Valley
Authors: Lin Yucong , Gualdi Silvio , Scoccimarro Enrico
Published: February 2023

Yangtze River Valley (YRV) locates in Southeast China, is home to about a third of the population in China. Summer extreme precipitation in Yangtze River can lead to extensive social problems and loss of lives. Understanding the characteristics of extreme precipitation and identifying the possible driving factors can increase our ability to plan for, manage and respond to related extreme events over the YRV. This study applies ERA5 data during the period of 1950~2021 to examine the possible influence of ENSO and the sea surface temperature (SST) variability over the Indian Ocean domain on the interannual variability of the extreme precipitation over the YRV. The related physical processes that link the summer Yangtze River extreme precipitation, ENSO and Indian Ocean Dipole (IOD) are investigated.Using composites analysis and Pearson correlation method, we found that both ENSO and IOD have delayed effects on summer extreme precipitation over the YRV, warm ENSO events and positive IOD phases are in favor of increased extreme precipitation in the subsequent summers, and vice versa. The anomalous anticyclone over the western Pacific Ocean (WNPAC) is the key factor in altering the inter-annual variability of extreme precipitation over the YRV. By comparing the extreme precipitation composites with different ENSO-IOD coupling events, we found that the signals of enhanced extreme precipitation are significant when El Niño occurs with a positive phase of IOD in the previous winter. The results based on the large circulation patterns also support that IOD plays an essential role in modulating the WNPAC. Our research highlights the need for a fundamental exploration into air-sea interactions over the tropical Pacific associate to ENSO-IOD coupling modes, our understanding in learning the impacts of these modes of variability on precipitation extremes over the YRV will contribute to improve the predictability of extreme events over this region.Keywords:Yangtze River Valley, extreme precipitation, ENSO, IOD, western North Pacific anomalous anticyclone 
An update on the UK ground level neutron monitor implementation phase.
Authors: Aspinall Michael , Wild Jim , Croft Stephen , Joyce Malcolm , Alton Tilly , Packer Lee , Bradnam Steve , Turner Tony , Binnersley Cory
Published: February 2023

The global network of neutron monitors comprises predominantly of the monitor standardised by Carmichael in 1964, the NM-64.  The design of these existing monitors and their instrumentation have changed very little over the last sixty years.  For example, their neutron detectors rely on gas filled proportional counters that are either filled with highly toxic boron trifluoride (BF3) or helium-3 (3He) in an arrangement not optimised for this detector type.  We have designed a new neutron monitor optimised for fully modernised, 1” diameter, gas-filled 3He detectors.  Our new design is optimised for cost savings, compactness and efficient use of 3He.  Benchmarked against a 6-NM-64, our design has a 71% smaller footprint, 83% smaller volume, and is 55% lighter.  It is estimated to be ~50% cheaper, excluding cost reductions associated with the shipping, installation, housing, maintenance and operation of a more compact instrument.  It is suited for unattended operation in relatively remote locations and designed to produce comparable results to a 6-counter NM-64 typically used in the existing global network.  We provide a progress update and latest validation results relating to the implementation of the new design at the UK Metrological Office’s Camborne observatory near Cornwall.  Funded by UK Research & Innovation (UKRI), this research is part of the Space Weather Instrumentation, Measurement, Modelling and Risk (SWIMMR) programme.
Evaluating the generalization ability of a deep learning model trained to detect cloud-to-ground lightning on raw ERA5 data
Authors: Ehrensperger Gregor , Hell Tobias , Mayr Georg Johann , Simon Thorsten
Published: February 2023

Atmospheric conditions that are typical for lightning are commonly represented by proxies such as cloud top height, cloud ice flux, CAPE times precipitation, or the lightning potential index. While these proxies generally deliver reasonable results, they often need to be adapted for local conditions in order to perform well. This suggests that there is a need for more complex and holistic proxies. Recent research confirms that the use of machine learning (ML) approaches for describing lightning is promising.In a previous study a deep learning model was trained on single spatiotemporal (30km x 30km x 1h) cells in the summer period of the years 2010--2018 and showed good results for the unseen test year 2019 within Austria. We now improve this model by using multiple neighboring vertical atmospheric columns to also address for horizontal moisture advection. Furthermore data of successive hours is used as input data to enable the model to capture the temporal development of atmospheric conditions such as the build-up and breakdown of convections.In this work we focus on the summer months June to August and use data from parts of Central Europe. This spatial domain is thought to be representative for Continental Europe since it covers mountainous aswell as coastal regions. We take raw ERA5 parameters beyond the tropopause enriched with a small amount of meta data such as the day of the year and the hour of the day for training. The quality of the resulting paramaterized model is then evaluated on Continental Europe to examine the generalization ability.Using parts of Central Europe to train the model, we evaluate its ability to generalize on unseen parts of Continental Europe using EUCLID data. Having a model that generalizes well is a building block for a retrospective analysis back into years where the structured recording of accurate lightning observations in a unified way was not established yet.
Design of a digital infrastructure for hydrological research
Authors: Fry Matt , Old Gareth
Published: February 2023

The UK is planning to implement a £38M (€43M) Flood and Drought Research Infrastructure to facilitate the hydrological science and innovation needed to underpin the UK’s adaptation and resilience to floods and droughts. The UKRI’s intent to invest from its infrastructure fund was published following a ~2-year scoping study that determined research community requirements through reviews of comparable infrastructures across the UK, Europe and globally, community workshops and questionnaires, and direct engagement with potential beneficiaries from research, industry and government bodies. Significantly, the scoping study identified the importance of a digital infrastructure to enable a step-change in access to hydrological monitoring data.  This would complement community access to the expected physical infrastructure for monitoring all phases of the water cycle across a range of catchment types.Key requirements for the proposed digital infrastructure, to be delivered through 2023-2028, include access to UK-wide hydrological data alongside new catchment observatory data, supporting field monitoring and innovation through open digital systems, advancing the state of the art for sensor data management, linking monitoring activities more closely with research data archives and delivering support for open science. The digital infrastructure would leverage technological developments e.g. in cloud-based virtual research environments, and be delivered alongside a significant community capacity building effort to support cultural change and enable researchers to transform ways-of-working to maximise its potential benefits.
Analysis of the GeoMIP G6sulfur experiment with SOCOLv4
Authors: Wunderlin Elia , Chiodo Gabriel , Sukhodolov Timofei , Vattioni Sandro , Visioni Daniele , Tilmes Simone
Published: February 2023

Climate change and its associated risks are becoming more and more prominent. Stratospheric solar geoengineering with sulfuric acid aerosols has been put forward as a way to temporarily mitigate some of the risks of climate change and is inspired by the cooling effect of large eruptions of tropical volcanoes. To learn more about the opportunities and dangers associated with stratospheric solar geoengineering, it is important to investigate the strategy beforehand, e.g., by means of climate modelling. To better understand the sources of model uncertainties, the Geoengineering Model Intercomparison Project (GeoMIP) introduced stratospheric solar geoengineering scenarios for an easier comparison of different models. Most models participating in GeoMIP either have no interactive chemistry or simplified aerosol micro-physics. In this study we perform the G6sulfur experiment with SOCOLv4, an atmosphere-ocean-aerosol-chemistry climate model. In the G6 sulfur experiment the aim is to bring the global average temperature of the SSP5-8.5 to the levels of the SSP2-4.5 sceanrio.For the calibration we ran three different tests in order to analyse the sensitivity of the aerosol burden to the order in which the microphysical processes are simulated at each timestep - nucleation of new particles from H2SO4 vapours and condensation of H2SO4 on pre-existing particles. One experiment had nucleation first, one had condensation first and finally one had nucleation first but with an added subsubstep where coagulation is called again. For all these runs we used an injection of 5 TgS/year. In the run with nucleation first the global stratospheric aerosol burden is 25% bigger than in the run where condensation is called first and 10% bigger than in the run with 2 subsubsteps. This leads to a cooling effect over 2032-2047 which is 1.02 K for nucleation first, 0.95 K for the run with the additional substep and 0.65 K for condensation first. Based on the cooling efficiency of the 5 TgS/year injection, we then derive a time-dependent emission, to keep global mean surface temperatures close to the SSP2-4.5 scenario.For the G6sulfur experiment we chose the setup of the run with 2 subsubsteps and performed three ensemble members to get a better understanding of the uncertainties within the model. We will discuss the effects on stratospheric aerosol burden, radiative forcing, temperature, ozone and precipitation changes and compare our results to other GeoMIP models. This will work provides useful insights concerning the radiative and climatic impacts of stratospheric aerosols on climate, elucidating the impact of uncertainties in the modelling of microphysical processes.
Decreasing precipitation disproportionally influences ecosystem water yield, risking water supply and shifting limits of forests' survival.
Authors: Rotenberg Eyal , Tatarinov Fyodor , Muller Jonathan , Yakir dan
Published: February 2023

Climate change is predicted to reduce many regions' annual precipitation (P). Combined with the rise in population, this will impose substantial pressure on the water supply for vegetation, food production, and human consumption. Based on global measurements of water and energy fluxes and meteorological conditions, we find that ecosystems are efficient and conservative users of rainfall irrespective of biomes’ type, location, and climate. It results in annual ET remaining at ~450±200 mm, except in dry conditions where ET»P.  As a result, changes in the residual ecosystem water yield (WYe=P-ET)  are greatly amplified relative to changes in precipitation. For example, at a site with a mean annual P of 700 mm, a decrease to 500 mm in annual P (28% decrease, well within expected climate change scenarios) would result in WY dropping from 200 to zero (100% decrease). Such changes could drive local ecosystems to their limit of sustainability and eliminate residual water for runoff and consumption. The causality underlying the conservative nature of ET is not entirely clear at present. But we can nevertheless conclude that the unsustainable state of WY<0 will be reached in many ecosystems much faster than expected based on predictions focusing on changes in P. This must be followed by drought-related tree mortality, land cover type, and density adjustments. It will also have a significant impact on water availability
Future Changes in the early winter ENSO teleconnections to the North Atlantic European region
Authors: Abid Muhammad Adnan , Kucharski Fred
Published: February 2023

North Atlantic European (NAE) winter climate variability is strongly modulated through the stratospheric and tropospheric pathways, where El Niño-Southern Oscillation (ENSO) teleconnections play an important role. Recent studies showed intra-seasonal changes of the ENSO response in the NAE circulation anomalies from early to late winter.  One mechanism for this behavior is that the Indian Ocean (IO) dominate over the direct ENSO teleconnections in early winter favoring an in-phase North Atlantic Oscillation (NAO) response over NAE region. On the other hand, the direct ENSO response dominates in latter half of winter, where it projects onto the opposite phase of the NAO. In present study, we analyze the early to late winter ENSO-NAE teleconnections in future climate projections by adopting the sixth assessment report Coupled Model Intercomparison Project (CMIP6) model datasets. During early winter, we noted an increase in the ENSO-induced precipitation variability in the Pacific as well as over western and central Indian Ocean, while decrease is noted over the eastern IO. Moreover, a strengthening of the ENSO and Indian connections are noted in almost all models except few, where these connections are not well represented in the present climate. Interestingly, the changes in ENSO forced wave train are noted, which may lead to the negative NAO like circulation anomalies over the NAE region in future compared to the present climate. 
Near term climate change in Emilia-Romagna (Italy) using CMIP6 decadal climate predictions
Authors: Todaro Valeria , D'Oria Marco , Secci Daniele , Zanini Andrea , Tanda Maria Giovanna
Published: February 2023

Ongoing climate change makes both short- and long-term adaptation and mitigation strategies urgently needed. While many long-term climate models have been developed and investigated in recent years, little attention has been paid to short-term simulations. The first attempts to perform multi-model initialized decadal forecasts were presented in the fifth Coupled Model Intercomparison Project 5 (CMIP5). Near-term climate prediction models are new socially relevant tools to support the decision makers delivering climate adaptation solutions on an annual or decadal scale. Recent improvements in decadal models were coordinated in CMIP6 and the World Climate Research Program (WCRP) Grand Challenge on Near Term Climate Prediction, as part of the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (AR6, IPCC). The Decadal Climate Prediction Project (DCPP) provides decadal climate forecasts based on advanced techniques for the reanalysis of climate data, initialization methods, ensemble generation and data analysis. The initialization allows to consider the predictability of the internal climate variability reducing the prediction errors compared to those of the long-term projections, whose simulations do not take into account the phasing between the internal variability of the model and the observations. The aim of this work is to assess the near-future climate change in the Emilia-Romagna region in northern Italy until 2031. The hydrological variables analyzed are the daily precipitation and maximum and minimum temperature. An ensemble of models, with the highest resolution available, is used to handle the uncertainty in the predictions. Initially, to assess the reliability of the selected climate models, the hindcast data of the DCPP are checked against observations. Then, the DCPP predictions are used to investigate the variability of precipitation and temperature in the near future over the investigated area. Some climate features that are referenced to have an important impact on human health and activities are evaluated, such as drought indices and heat waves.
One Martian Year of data assimilation with the Emirates Mars Mission
Authors: Young Roland , Millour Ehouarn , Forget François , Edwards Christopher , Smith Nathan , Smith Michael , Anwar Saadat , Christensen Philip , Montabone Luca
Published: February 2023

The Emirates Mars Mission (EMM) will have spent just over one Martian Year (MY) of science operations by the time the EGU General Assembly begins in late April 2023, having begun its primary science phase in May 2021 or MY36 Ls = 49o. Over this primary phase of the mission, we have been assimilating observations from EMM into the Mars Planetary Climate Model (PCM), using the Local Ensemble Transform Kalman Filter (LETKF), to understand various aspects of Mars' climate. EMM's unique high orbit and viewing geometry make it an extremely valuable source of data for assimilation, as it can observe nearly a whole hemisphere at once, monitor synoptic-scale features for several hours, and sample the whole diurnal cycle over 10 sols. This presentation will focus on the assimilation of atmospheric temperature profiles and column dust optical depth measurements, retrieved from spectral observations made by the Emirates Mars InfraRed Spectrometer (EMIRS), a thermal infrared spectrometer sensitive to 6-50 μm wavelengths on board EMM. We may also include EMIRS surface temperature measurements, and observations from Mars Climate Sounder (MCS) on board Mars Reconnaissance Orbiter (MRO) to fill in gaps in the data record. The assimilation combines EMIRS observations with a climate model in a statistically rigorous way to produce a data product consistent with the uncertainties in both. By measuring the quality of these analyses against assimilated and independent observations, we will highlight how assimilation can be used to inform the future development of our climate simulations.
Ephemeral aeolian activity and harsh paleoenvironments in North China related to the late Guadalupian extinction event on land
Authors: Zhu Zhicai , Liu Yongqing , Kuang Hongwei , Farnworth Alex , Newell Andrew J. , Benton Michael J.
Published: February 2023

The patterns and causes for the Guadalupian-Lopingian extinctions on land remain puzzling. Here, we reconstruct palaeoenvironments based mainly on the sedimentary environments from the eastern Ordos Basin, North China. Ephemeral aeolian activity in alluvial plains, as a critical marker of intermittent drought conditions, has been identified from the middle Sunjiagou Formation and can be well correlated between the Baode and Liulin areas in the eastern Ordos Basin. Thick dark red siltstones/mudstones with intercalated fine-grained sandstones rest above the aeolian sandstones, and were deposited on floodplains or oxbows adjacent to meandering channel belts. They can also be correlated by comparable mass burials of key tetrapod fossils including the pareiasaurs Shihtienfenia from Baode and Shansisaurus xuecunensis and Huanghesaurus liulinensis from Liulin, respectively. Notably, the fossil horizon at Baode shows a synchronous sharp carbon isotope negative excursion, decreased CIA, and a mercury peak, suggesting that the harsh paleoenvironment (reduced weathering intensity, arid and cool conditions) and potential influence of volcanism might have been important causes. A sandstone sample from the fossil horizon at Baode yields youngest detrital zircon ages of 266 ± 4 Ma, suggesting the maximum depositional age as late Guadalupian. Here, for the first time, we have identified late Guadalupian aeolian activity in North China based on field observations. We demonstrate that the harsh palaeoenvironment in North China may have caused the late Guadalupian tetrapod extinction events on land, before an event of sharp global warming related to the massive Emeishan large igneous province.
Fault instability and slipping in thermally unstable rock
Authors: Huang Jianhua , Zhang Bo , Zou Junjie , He Honglin
Published: February 2023

Faults that cut carbonate rocks are the most important seismogenic sources worldwide, while the fault weakening and recovery mechanism in carbonate fault rock still remains controversial. In this study, the structures of an exposed normal fault zone hosted in dolostones with chert bands from the Yuguang basin southern marginal fault (YBSMF), northeast of the Shanxi graben system, North China, was studied by field-based structural analysis, microstructural and fabric investigations. The microstructural observations show that the fault slip surface exhibits a range of slip-related structures including slickenlines, truncated clasts and nano-scale amorphous materials/fragments. On the fault slip surface, the carbonate fault rock contains a large number of nanoparticles. These nanoparticles were shaped into two forms, single spherulitic nanoparticle and agglomerated nanoparticles. The slip zone, under the slip surface, is characterized by cataclasite, with various foliatization in red injection band. EBSD analysis results show weak CPOs, with the (0001) planes of the dolomite fragments nearly parallel to the slip surface. Our microstructural investigations in the dolomite fault rocks, combined with previous publications, suggest the single spherulitic nanoparticles can be the result of thermal decomposition of dolomite along the major slip surface of the normal fault. Nano powder lubrication caused by the rolling of single spherulitic nanoparticle plays a key role during carbonate fault slipping. The thermal pressurization of pore fluid leads to laminar grain flow along the fracture and finally forms foliations in the red injection layers. The transformation from single spherulitic nanoparticles to agglomerated nanoparticles by superplastic diffusive mass transfer results in the recovery of friction strength at the fault plane. After the coseismic slip (or during afterslip), a relatively thick portion in the principal slip zone suffers a temperature increase, leading to the plastic deformation and formation of CPOs of dolomite in the principal slip zone. We inferred that nanoparticles can be produced by thermal decomposition transformation, which facilitate and inhibit earthquake behavior on fault surfaces. The postseismic strength recovery can be generated partly by agglomerated nanoparticles. We consider that nanoparticles produced by thermal decomposition of dolomite play a key role in carbonate fault instability during coseismic slip.
Analysis of Spatio-temporal variability and atmospheric drivers of the flash drought over Godavari river basin.
Authors: Remesan Renji , Pachore Akshay
Published: February 2023

Flash droughts are generally considered a subset of seasonal drought events. In the present study, we have characterized the flash drought events based on soil moisture index (SMI) using daily ERA5 reanalysis data having a spatial resolution of 0.250 * 0.250 from 1960 till 2021. Flash drought events were identified when SMI drops below the 20th percentile within less than 3 next pentads, and it terminates when SMI goes above the 20th percentile and stays there for the next 2 pentads. Flash drought time series was prepared and the Mann-Kendall trend test was applied to investigate the evidence of the statistically significant trends. To assess the atmospheric drivers (precipitation, PET) of flash drought, standardized precipitation index (SPI), and standardized precipitation evapotranspiration index (SPEI) were calculated during the occurrence of each flash drought event at each grid pixel. For calculating SPI and SPEI, ERA5 reanalysis data of precipitation and PET (potential evapotranspiration) was used. Seasonal analysis of results showed that the flash drought frequency observed during the pre-monsoon season (March-April-May) shows considerable variation when compared to the monsoon (July-August-September) and post-monsoon (October-November-December) seasons. Results of Mann-Kendall statistics show the increasing trend of flash drought over semi-arid regions like Marathwada and Vidarbha. Both SPI and SPEI shows spatially varying similarity with the flash drought events. When observed on a seasonal scale, it is observed that SPEI shows a higher degree of similarity with flash drought events during pre-monsoon season as compared to SPI as evaporative demand is high during this period.  
Aviation-induced changes of atmospheric composition in the UTLS in the multi-scale Earth system model MECO(1)
Authors: Matthes Sigrun , Nickl Anna-Leah , Peter Patrick , Mertens Mariano , Jöckel Patrick , Ziereis Helmut , Harlaß Theresa , Zahn Andreas
Published: February 2023

Aviation is concerned by its climate effects which results from CO2 and non-CO2 effects, comprising NOx-induced changes of atmospheric ozone and methane. Here climate-chemistry models are required to advance our understanding on induced changes of reactive species and the associated radiative forcing associated to aviation emissions. Evaluation of such comprehensive models is key in order to be able to investigate associated uncertainties can use observational datasets from research infrastructures like IAGOS and DLR aircraft measurement campaign data.We use the MECO(n) system which is a “MESSy-ﬁed ECHAM and COSMO nested n-times”, relying on the Modular Earth Submodel System (MESSy) framework. For this purpose, both models have been equipped with the MESSy infrastructure, implying that the same process formulations (MESSy submodels) are available for both models. Modelled atmospheric distributions from the multi-scale model system MECO(n) are systematically compared to observational data from aircraft measurements in the upper troposphere and lower stratosphere. Nudging of meteorology to reanalysis data, and special diagnostics available within the modular MESSy infrastructure are implemented in the numerical simulations. Online sampling along aircraft trajectories allows to extract model data with a high temporal resolution (MESSy submodel S4D), in order to evaluate model representation and key processes. Beyond systematic evaluation with IAGOS scheduled aircraft measurements, particular focus on those episodes where dedicated measurements from aircraft campaigns are available. We present an analysis of reactive species, NOy and ozone, which also identifies those weather pattern and synoptic situations where aviation contributes strong signals. We evaluate model representation of the NOx-induces effect on radiatively active species ozone and hydroxyl radical in both model instances, ECHAM5 and COSMO. This is key for advancing the scientific understanding of NOx-induced effects from aviation non-CO2 effects required in order to quantify potential compensation and trade-offs and eventually in order to identify robust mitigation options for sustainable aviation.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 875036 (ACACIA, Advancing the Science for Aviation and Climate) and has been supported by the DLR-Projekt Eco2Fly. This work uses measurement data from the European Research Infrastructure CARIBIC/IAGOS. High-Performance Super Computing simulations have been performed by the Deutsches Klima-Rechenzentrum (DKRZ, Hamburg) and the Leibniz-Rechenzentrum (LRZ, München).
Two-Phase Flow Simulations of Surface Waves in Wind-Forced Conditions
Authors: Loft Malte , Rung Thomas , Kühl Niklas , Buckley Marc , Carpenter Jeff , Veron Fabrice , Hinze Michael
Published: February 2023

The paper is devoted to two-phase flow simulations and investigates the ability of a diffusive interface Cahn-Hilliard Volume-of-Fluid model to capture the dynamics of the air-sea interface at geophysically relevant Reynolds numbers. It employs a hybrid filtered/averaging Improved Detached Eddy Simulation method to model turbulence, and utilizes a continuum model to account for surface tension if the diffuse interface is under-resolved by the grid. A numerical wind-wave tank is introduced to limit computational costs and results obtained for two wind-wave conditions are analyzed in comparison to experimental data at matched Reynolds numbers. The focus of the comparison is on both time-averaged and wave-coherent quantities, and includes pressure, velocity as well as modeled and resolved Reynolds stresses. In general, numerical predictions agree well with the experimental measurements and reproduce many wave-dependent flow features. Reynolds stresses near the water surface are found to be especially important in modulating the critical layer height. It is concluded that the diffusive interface approach proves to be a promising method for future studies of air-sea interface dynamics in geophysically relevant flows.
High resolution dissolved methane data using a new response time correction technique on slow response methane sensor measurements
Authors: Dølven Knut Ola , Vierinen Juha , Grilli Roberto , Triest Jack , Férre Bénédicte
Published: February 2023

To improve our understanding of critical environmental processes, high resolution measurements with acceptable accuracy are essential. Unfortunately, the high spatiotemporal variability often associated with seabed seepage environments is prone to mischaracterization due to limitations in contemporary measurement techniques. This is particularly true for dissolved methane, which are often measured by labor- and time-intensive discrete water sampling and subsequent laboratory analysis. This often yields data with inadequate spatiotemporal resolution. A potential solution to this issue is using in-situ sensors in towing, profiling, mooring/observatory or glider operations. However, typical off-the-shelf sensors with adequate payload and power requirements currently lack the response time necessary for these applications. We offer a new, easy-to-implement, laboratory and field-tested post-processing tool for retrieving fast response data from commercially available methane sensors with slow response times. The tool is based on the framework of statistical inverse theory which in practice enables the user to obtain data with quantified, explicit (modeled) measurement uncertainty and at the resolution (i.e. response time) where the sensor can provide data with a respectable level of accuracy. The user needs no input besides the raw data, sensor accuracy, and response time. In our field experiment, we successfully retrieved data corresponding to a response time of 55 s using a sensor with a stated response time of 29 minutes. Being able to obtain high-resolution data from these types of sensors can considerably enhance the capacity to properly resolve the variability within methane seep sites and comprehend associated environmental processes.
Using Satellite Column Observations with a Bayesian Inversion System for constraining the GHG budget over India
Authors: Subramanian Rakesh , Thompson Rona , Vojta Martin , Stohl Andreas
Published: February 2023

The source-sink estimation of greenhouse gases and the accurate quantification of their flux distributions are a major scientific challenge of our times. Although statistically developed inventory-based carbon emissions improve understanding of emissions, they are uncertain and occasionally, they do not reflect actual emissions, especially at finer scales. By using GHG observations in conjunction with numerical atmospheric models, GHG budgets can be constrained. However, the sparseness in the in-situ observation networks of GHGs, makes this a challenging problem, especially in certain regions like India. However, satellite remote sensing can fill this data gap. This study applies the Bayesian inversion system, FLEXINVERT (Thompson and Stohl 2014), coupled with a Lagrangian Particle Dispersion Model, FLEXPART (Stohl et al 1998), to assimilate TROPOMI satellite observations of CH4 and constrains the CH4 fluxes over India domain. This inverse modeling system uses the Source-Receptor Relationship derived from Flexpart as the Transport operator while minimizing the cost function for optimization.  The system will use various prior fluxes and initial concentration fields to test the set-up over Indian domain, which have strong fluxes of CH4 and are not well constrained by the existing ground-based measurement networks. The results will be compared with the limited in-situ observations available for the region.