bluuebunny/crossref_metadata_2025 huggingface dataset:
Single-Particle Aerosol Composition in the Asian Tropopause Aerosol Layer and in the North American Upper Troposphere/Lower Stratosphere during ACCLIP
Authors: Schill Gregory , Murphy Daniel , Lawler Michael , Abou-Ghanem Maya
Published: February 2023

The Asian Summer Monsoon Anticyclone (AMA) is known to bring ground-level pollutants up to the stratosphere. Aerosols in the AMA often form what is known as the Asian Tropopause Aerosol Layer (ATAL), with modelling studies suggesting that the ATAL can provide up to 15 % of the stratospheric aerosol in the Northern Hemisphere. In this work, we present single-particle mass spectrometry measurements of aerosol composition in the AMA outflow and in the North American upper troposphere/lower stratosphere (UTLS) during the same season. Measurements were taken by the Particle Analysis by Laser Mass Spectrometry (PALMS) instrument and made during the Asian Summer Monsoon Chemical & CLimate Impact Project (ACCLIP). We find that the dominant aerosol type found in the ATAL and those found in the UTLS over North America are chemically different. Despite high concentrations of ground-level gas phase pollutants, particles in the ATAL are dominated by secondary nitrate particles. The organic content of these particles is low, which precludes them from being organic-nitrate aerosol; thus, we believe that these particles are either nitric/sulfuric acid solutions, or they are mixtures of partially neutralized ammonium nitrate/sulfate. Finally, we present the mass concentrations of nitrate particles, dust, and sulfate-organic particles in the ATAL, and estimate each particle type’s influence on the aerosol composition over the North American continent.
Statistical analysis of a systematic review on soil water erosion assessment in Morocco
Authors: Lamane Houda , Mouhir Latifa , Moussadek Rachid , Baghdad Bouamar , Briak Hamza , Zouahri Abdelmjid , El Bilali Ali
Published: February 2023

A large effort has been devoted over the past century to assessing soil erosion using a variety of methods under a wide range of climatic conditions, soil types, land uses, topography, and others. Thus, we attempt to provide an analysis of national data of several soil erosion modeling and fingerprinting. The methodology adopted for this research is a review of scientific articles, conference papers and thesis on soil erosion, focusing more on categorization of the different soil erosion models and methods applied. Based on the statistical analysis provided by this review, the results are as follows: (i) Even though the threat of soil erosion is grave, the number of studies conducted to characterize and evaluate soil erosion in Morocco is limited. (ii) Studies on water erosion modeling are concentrated in the north of the country (Rif 32.89%, High Atlas 32.89%, Occidental Meseta 18.43% and Middle Atlas 10.53%). (iii) Water erosion models have been steadily developed and interfaced with GIS based approaches in recent decades. (iv) Although Morocco is geomorphologically and geologically varied (Rif, Middle and High Atlas, Mesetian and Saharan domain), several authors use soil erosion assessment models that ignore the unique characteristics of each study area and fail to adapt them to local conditions. (v) USLE (R) models have been widely used and modified over the past two decades and remain the most commonly used modeling tool today. (vi) The largest proportion of the erosion rate is concentrated in the Atlas and Rif mountains. (vii) Demonstration of a strong relationship between soil erosion rates with environmental factors and modeling conditions, and the lack of correlation with study area size and erosion rate. While the overall results show a relatively high variance, which cannot be explained by this combination of factors, it is partly related to the experimental conditions. This review is intended to support future soil erosion assessment and to facilitate the identification of priorities for soil erosion research in Morocco by supplying a state of the art for future targeted and comprehensive analyses to deal with the issue of soil erosion in Morocco.Keywords: Soil water erosion models, Fingerprinting methods, Literature review, Morocco.
Soil and crop monitoring in a processing tomato fertigation experiment in a reclaimed saline marsh soil in SW Spain using proximal and remote sensing.
Authors: Gómez Flores José Luis , Ramos Rodríguez Mario , Farzamian Mohammad , Salvatierra Bellido Benito , López Rodríguez Manuel , Vanderlinden Karl
Published: February 2023

Reclaimed saline marsh areas in SW Spain are characterized by a fragile balance in the rootzone between salt accumulation and leaching. Increasing climate variability and the introduction of new crops and irrigation methods can disrupt this balance, with undesirable environmental and economic consequences. In addition, the decreasing availability of irrigation water and the need to limit fertilizer use in areas vulnerable to nitrate contamination requires the implementation of more sustainable fertigation practices. A field experiment was set up in a commercial processing tomato field in the B-XII irrigation district (Lebrija, Seville) where four fertigation treatments (conventional and sustainable irrigation and fertilization) were compared in a random design with three replicates. Each elemental plot consisted of three tomato rows, each 250 m long and 1.5 m wide. Apparent electric conductivity (ECa) of each treatment was measured weekly using an electromagnetic induction sensor and multiespectral images were obtained on two dates using an UAV. ECa could be linked to the irrigation treatments and showed a strong within-treatment variability in accordance with the local soil characteristics and the depth of the underlying saline water table. The largest NDVI was observed for the sustainable irrigation and fertilization treatment, while the smallest NDVI corresponded to the sustainable fertilization and conventional irrigation treatment. Plants in the latter treatment presented chlorosis due to excessive accumulation of chloride and sodium in the leaves, as a result of root-zone salinization during the irrigation season, resulting in a strong decline in tomato yield (~60%) for this treatment. Overall, tomato yield showed a strong correlation with NDVI (R≈0.90). Our results suggest that more sustainable fertigation practices can be implemented in salinization-prone agricultural areas without increasing the risk of topsoil salinization or loss of crop productivity.AcknowledgementThis work is funded by the Spanish State Agency for Research through grant PID2019-104136RR-C21/AEI/10.13039/501100011033, and by IFAPA/FEDER through grant AVA2019.018. Additionally, this work is also funded through PhD grant PRE2020-095133 by the Spanish State Agency for Research, and co-funded by the European Social Fund. 
Mechanisms of deep earthquakes unraveled thanks to unsupervised machine learning
Authors: Li Jiaqi , Mao Gilbert , Ferrand Thomas , Zhu Brian , Xi Ziyi , Chen Min
Published: February 2023

Although transformational faulting in the rim of the metastable olivine wedge is hypothesized as a triggering mechanism of deep-focus earthquakes, there is no direct evidence of such rim. Variations of the b value – slope of the Gutenberg-Richter distribution – have been used to decipher triggering and rupture mechanisms of deep earthquakes. However, detection limits prevent full understanding of these mechanisms. Using the Japan Meteorological Agency catalog, we estimate b values of deep earthquakes in the northwestern Pacific Plate, clustered in four regions with unsupervised machine learning. The b-value analysis of Honshu and Izu deep seismicity reveals a kink at magnitude 3.7–3.8, where the b value abruptly changes from 1.4–1.7 to 0.6–0.7. The anomalously high b values for small earthquakes highlight enhanced transformational faulting, likely catalyzed by deep hydrous defects coinciding with the unstable rim of the metastable olivine wedge, the thickness of which we estimate at ∼1 km.
Assessment of ice mélange impacts on tidewater glacier dynamics using high resolution ICEYE imagery
Authors: Harcourt William D. , Stearns Leigh A. , Shahin Michael G. , Shankar Siddharth
Published: February 2023

There is growing evidence that ice mélange, the granular mixture of sea ice and icebergs at the termini of tidewater glaciers, impacts ice sheet discharge through physical buttressing forces and alterations to fjord circulation via iceberg melting. However, ice mélange is a highly dynamic, fragmented and mobile phenomenon which varies over a range of timescales (e.g. hours, days, weeks) and hence is difficult to monitor using traditional ground-based and spaceborne sensors. In this contribution, we utilise high spatio-temporal satellite imagery acquired from the ICEYE small satellite constellation to assess correlations between ice mélange characteristics and tidewater glacier dynamics. ICEYE is a growing constellation of 20+ small satellites each equipped with an X-band Synthetic Aperture Radar (SAR) and capable of mapping the entire globe at least once a day with fine spatial resolution (1-3 m). We utilised the ICEYE SAR imagery to study the perennial mélange matrix at the terminus of Helheim Glacier in southeast Greenland. ICEYE SAR imagery was acquired during summer and winter to assess how seasonal ice mélange conditions impact tidewater glacier dynamics. Sentinel-1 SAR imagery and ground-based TLS 3D data from two autonomous terrestrial laser scanners (ATLAS) were used to validate remote sensing analysis and provide additional data sources for interpretation of the glaciological processes. We will report on the following: (1) a spatial texture analysis (e.g. Grey Level Co-occurrence Matrix (GLCM), Gabor Transforms) of ice mélange at the terminus of Helheim Glacier using high resolution ICEYE SAR imagery; (2) results of hierarchical and random forest classifiers to map icebergs, sea ice and open water within the ice mélange matrix; (3) quantification of glacier and mélange flow variability at daily to weekly timescales; and (4) the development of observational models correlating ice mélange texture, iceberg distributions, mélange/glacier flow rates, and tidewater glacier stability. Our case study at Helheim Glacier aims to demonstrate a new approach to rapidly monitor ice mélange conditions and tidewater glacier stability using high resolution SAR imagery. In particular, this study pushes forward our Earth Observation capabilities and will help us better understand the complex processes operating at the ice-ocean interface which is critical for improved predictions of how the Greenland Ice Sheet will evolve under a warming climate.
Past and future changes of temperature and precipitation variability in climate model projections and transient simulations of the Last Deglaciation
Authors: Ziegler Elisa , Rehfeld Kira
Published: February 2023

Reliable projections of future climate change are vital for mitigation and adaptation efforts. Such efforts require not only projections of mean changes but of changes in variability, too, since those directly affect the occurrence of extremes. The evaluation of climate models regarding their ability to simulate expected changes in variability of temperature and precipitation relies on the comparison of observations with simulations of past and present-day climate. As such, studying past periods of warming furthers the understanding of the climate system and its projected changes. However, the response of the climate system to forcings depends on the background state. Thus, understanding how insights from studies of the past transfer to future projections and the limitations of this transfer is vital.Here, we present an analysis of temperature and precipitation variability in transient simulations of the Last Deglaciation and projected future climate. To this end, we analyze how the distributions of temperature and precipitation change as exemplified by the moments of the distribution, i.e. variance, skewness and kurtosis. We identify trends in the projections and compare them to results for the Last Deglaciation and present commonalities and differences between the responses in these climate states. We further present how these changes relate to differences in the background state, forcings, and the timescales on which these forcings act as well as the limitations imposed by these differences. Based on this analysis of the state-dependency of variability and its change with a warming mean state, we present conclusions on how past climates can inform and support studies of future climate change.
Modeling the influence of biogeochemical processes on the transport of microplastics in the Arctic Ocean
Authors: Berezina Anfisa , Yakushev Evgeniy , Wallhead Philip , Staalstrøm André
Published: February 2023

Microplastics (MPs) are plastic fragments less than 5 mm in size. At present, all natural environments, including the World Ocean, are polluted with MPs from the poles to the equator.The study tests the hypothesis that seasonality of processes in the marine ecosystem can affect the vertical transport of MPs in the water column (through changes in density due to biofouling and absorption and excretion of MP particles by zooplankton). The work used the biogeochemical model OxyDep (Yakushev et al., 2011) to reproduce the seasonality of marine ecosystem. BioPlast (Berezina et. al. 2021) considers processes of MPs degradation, biofouling, ingestion of particles by zooplankton and MPs in detritus. OxyDep biogeochemical module and MP module BioPlast were coupled with ROMS-20 (20 km resolution) 3D transport model using the FABM framework (Bruggeman & Bolding, 2014). The applied models describe the transformation of MPs and reproduce in detail the effect of ecosystem and biogeochemical processes on its vertical and horizontal transport, as well as on its burying in sediments.MPs were supplied to the Arctic Ocean from rivers flowing into the White, Barents, Kara and East Siberian Seas, as well as from the Atlantic Ocean, excluding any other sources. It was shown that within 8 years MPs spreads throughout the Arctic Ocean, except for the Canadian Basin. Several numerical experiments were conducted, MPs of Atlantic origin dominate in the western part of the Arctic Ocean. According to the upper estimate, the MPs from the North Atlantic occupies almost the entire water area of the Arctic Ocean. At the same time, the concentrations of MP covered with biofilm, MP in zooplankton, and MP in detritus are quite low compared to the virgin form of MP. A short-term purification of the surface layer from MP due to biofouling and sedimentation with detritus was observed in the estuarine zones and in the Fram Strait. This is partly due to the low productivity of the Arctic Ocean and the short period of phytoplankton blooms, and partly to the limitations of the BioPlast model. Further work will be devoted to the analysis of other sources of microplastics in the Arctic Ocean, such as the supply of MPs through the Bering Strait and local sources associated with maritime activity on the Northern Sea Route.The development of the described model is of great importance, especially for the Arctic region, where regular observations of MPs are not available, and the ecosystem is extremely vulnerable to anthropogenic impact.
Evaluation of global water, energy, and carbon fluxes in ECLand and ISBA models
Authors: Dutra Emanuel , Lopes Francisco , Calvet Jean-Christophe , Bonan Bertrand , Agusti-Panareda Anna , Boussetta Souhail , Jung Martin
Published: February 2023

Biogenic fluxes play a fundamental role in the carbon cycle and are crucial for the land-surface water and energy cycles. These three cycles, water/energy/carbon, are coupled and interact on time-scales ranging from minutes to centuries. Among different aspects of the processes involved, Land Use and Land Cover (LULC) are extremely relevant in the estimation of biogenic carbon. Moreover, the errors found in the model’s representation of LULC effects on the lower troposphere have also been shown to limit the progress in weather and climate predictability. In this work we evaluate different configurations of two land surface models: the ECMWF ECLand and Meteo-France ISBA within the SURFEX modelling platform. The evaluation is focused on the surface energy, water and carbon fluxes using FLUXCOM as reference, as well as land surface temperature using LSA SAF satellite product. The surface offline simulations evaluation identified the added value of a revised land cover and Leaf Area Index (LAI) in ECLand in terms of Gross Primary Production (GPP) when combined with a model configuration using the Farquhar photosynthesis model. The results also suggest that time-varying LAI, prescribed in ECLand and via data assimilation in SURFEX are relevant to GPP estimates during large-scale extreme events. Limitations in the evaluation of Net Ecosystem Exchanges and terrestrial respiration arising from model uncertainties, as well as in the reference data used, suggests that flux adjustments are paramount to mitigate biases in global CO2 analysis. Finally, coupled atmosphere weather forecasts with the ECMWF model show a clear improvement of the 2-meter temperature in Eurasia during spring following the revised land cover and LAI with a negative impact during summer in the tropics, which requires further developments.
This work was developed in the framework of the CoCO2 project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 958927.
Monitoring the evolution of sealed surfaces in Flanders (Belgium) with annual high-resolution soil sealing maps
Authors: Cockx Kasper , Pieters Joris , Van De Vijver Ellen , Willems Peter , Vanacker Stijn
Published: February 2023

Soil sealing results in an increased flood risk, reduced water infiltration, higher temperatures in urban areas, decreased carbon storage and biodiversity losses. As the Flanders region in Belgium has one of the highest soil sealing rates in Europe, it is especially prone to these effects. Hence, sustainable spatial management is crucial to ensure a healthy living environment and address climate change. The Flemish government therefore wants to promote de-sealing and limit additional sealing. An example of a concrete policy measure is that by 2050 sealed surfaces in open space zoning have to be reduced by 20% compared to 2015, which corresponds with a decrease of 9 000 ha.   In order to monitor the evolution of sealed surfaces, and thus the effectiveness of sealing-related policy measures, a method was developed for automatically generating annual and spatially detailed soil sealing maps of Flanders. These maps combine “known” sealing from administrative databases (buildings and transport infrastructure) with modelled sealing based on artificial intelligence. Administrative databases do not (adequately) cover parking lots, private driveways and garden terraces, which are a substantial part of the sealed area in Flanders. Hence, a machine learning model was built for deriving this remaining sealing from 25 cm resolution aerial imagery. For this purpose, an assessor manually labeled the sealed parts on a subset of the images. Based on this training set, a convolutional neural network model was used to produce a sealing probability map, which was converted to a binary modelled sealing map. Finally, a continuity correction was applied to ensure a temporally consistent result across the yearly maps.             According to this method, 1 m resolution soil sealing maps were obtained for 2013 until 2021. These maps show that an additional area of sealed surfaces of approximately 15 000 ha was constructed in Flanders between 2013 and 2020. They also reveal that de-sealing takes place in Flanders every year, but also is always over-compensated by new sealing. As a result, there is a net increase of soil sealing year after year. The annual soil sealing maps also show an upward trend in open space zoning that moves in the opposite direction to the target of decreasing by 9 000 ha.
The impact of precipitation and potential evapotranspiration on water flux partitioning and transit times at the catchment scale – a modeling study
Authors: Heidbüchel Ingo , Yang Jie , Fleckenstein Jan H.
Published: February 2023

In order to investigate how annual precipitation amount (P) and potential evapotranspiration (ETp) influence the partitioning of water fluxes into flow, evaporation and transpiration, we employed the physically-based spatially explicit 3D model HydroGeoSphere in a virtual catchment running 100 scenarios with different combinations of catchment and climate properties. In addition, we looked at the changes in the transit times of the different fluxes.Unsurprisingly, the fraction of flow increases with larger P and decreases with stronger ETp. Both transpiration and evaporation fractions generally decrease with larger P and increase with stronger ETp. However, the increase in the evaporation fraction ends for dryness indices (ETp/P) larger than 1 while the increase in the transpiration fraction continues. With regard to the transit times we found that on the one hand transpiration becomes younger in catchments with more P while it becomes older when ETp increases (vegetation has to resort to all potential water sources, also the ones deeper down and older). Evaporation and flow on the other hand become younger with larger P but become older with weaker ETp (basically, the decrease in transpiration leaves water longer in the system which is then available for older evaporation and streamflow).This also means that an acceleration of the hydrologic cycle can be caused both by an increase or decrease in the dryness index – depending on whether this change is caused by a change in P or ETp. This can have significant impacts for predicting catchment response and solute transport in light of future climate variability.
Uncertainty assessment of modeling the impact of debris cover on global glacier mass change: challenges and solutions
Authors: Mojtabavi Seyedhamidreza , Rounce David , Maussion Fabien , Marzeion Ben
Published: February 2023

It is essential to test the potential impact of processes missing in the global-scale models that are used to project on glacier mass balance in the glacier models, such as the modification of the mass balance through debris-cover. In this study, we evaluate the impact of a parameterization of debris cover on glacier mass change projections using the Open Global Glacier Model (OGGM). The assessment of uncertainties about the potential impact of debris cover on global scale modeling is complicated by the scarcity of suitable data on debris-covered glaciers for validation (e.g., mass balance measurements for individual elevation bins on debris-covered glaciers). To calibrate and validate the mass balance module, we rely on glacier-wide geodetic volume changes. Debris cover can enhance ice melting if less than a few centimeters thick, or decrease ice melting through insulation of the underlying ice by a thick layer of debris. Ice cliffs, supraglacial ponds and streams associated with debris cover may increase the absorption of heat and increase ice melting. In OGGM, the effects of debris cover are parameterized by a simple modification of the mass balance module, through introducing an elevation-dependent temperature sensitivity parameter (“degree-day factor”) and including a debris-related melt correction factor. While debris cover plays only a minor role on glacier mass change on the global scale, this becomes important on regional and individual glacier scales. Our results show the effect of debris cover could improve model performance on the mass balance gradient, not the overall mass balance. To validate our results on the mass balance gradient, we rely on the geodetic mass balance for each elevation band.
Beach ridge formation and landward migration along the isostatically rising coastlines of Hudson Bay
Authors: Ehn Jens , Gupta Kaushik , Reeves Arijit , Mukhodpadhyay Anirban
Published: February 2023

While most global coasts suffer from a loss of landmass due to sea-level rise and coastal transgression, the Arctic and Sub-Arctic coastlines of Hudson Bay and James Bay witness a reverse phenomenon due to post-glacial rebound. The carbon-rich peatlands Hudson Bay Lowland, that emerged from the retraction of the Tyrell Sea, are witnessing the highest rate of vertical upliftment on the planet. The continual reshaping of the coastline by multiple physical forcings is readily visible by the contiguous and recurrent pattern of raised beach ridges imprinted on the rising land far from the present-day coastline. These beach ridges, formed through the interplay of coastal sea ice dynamics and then preserved above sea-level by uplift, hold back terrestrial runoff and are thus critical to the extensive wetland-saltmarsh ecosystems that provide important habitats for waterfowl and wildlife. This study examines the intricate process behind the formation and modification of these geomorphological units using remote sensing techniques. The study includes the use of various remote sensing products to determine ice duration (Canadian Ice Service- Ice Charts), change detection of ridge dimensions and vectors (Landsat Images), elevation (SRTM and ICESat-2), rate of vertical upliftment (glacial isostasy models) and ice motion in the nearshore zone (GOES). Remote sensing observations reveal that the beach ridges originate offshore on mudflats due to ice scouring and gradually, pushed by sea ice, move shoreward, and often merge and build up existing ridges but sometimes initiating a new beach ridge sequence. The current study documents the impact of changing ice regime on the landward movement of beach ridges on the tidal flats. We find that the seaward point of origin on the tidal flats, and the rate at which the ridges expand and finally merge with the coastline vary greatly across the coastline. The slope of the coast and the dynamics of the sea ice in the nearshore zone are key factors leading to this variability.
EGMS data for national-scale landslides zonation
Authors: Necula Nicușor , Niculiță Mihai
Published: February 2023

European Ground Motion Service (EGMS) products are ground motion velocity and displacement measurements over the EU countries provided by the ambitious project of the Copernicus Land Monitoring Service. The products consist of processed Sentinel-1 SAR images with the Multi-temporal Differential SAR Interferometry algorithms and are available for visualization and download. They include different measurements, velocity and displacement time series for both orbits, ascending and descending, the derived displacement vectors for the vertical and horizontal E-W components, and the projected vector along the slope. In this ongoing work, we aim to use these products in the R.stat environment to identify the active landslide deformations for the national scale of Romania. Preliminary results are promising as the identified areas in the eastern part of the country reveal critical landslide hot spots interacting with the urbanized built-up area and the transport infrastructure.
Vegetation-climate coupling and vegetation sensitivity to climate extremes in growing seasons
Authors: Wu Minchao , Messori Gabriele , Vico Giulia , Manzoni Stefano , Cai Zhanzhang , Tang Jing , Tagesson Torbern , Duan Zheng
Published: February 2023

Terrestrial vegetation is largely mediated by vegetation-climate coupling. Growing conditions control vegetation growth, which in turn feeds back to climate through changes in biophysical and biogeochemical properties and processes, such as canopy structure and carbon and water exchanges. The vegetation-climate coupling is thus highly variable in space and time. However, little is known on how the large-scale vegetation-climate coupling varies within growing season, and how vegetation responds to climate extremes. In this contribution, we present some recent findings on seasonal and intra-seasonal vegetation-climate coupling and vegetation sensitivity to droughts using multiple remote sensing products including MODIS EVI, GIMMS3g NDVI and VIP EVI2. We account for the differences in phenological stages of growing seasons affected by both climate and landscape heterogeneity. Based on a novel analytical framework incorporating meteorological and vegetation conditions to locally defined vegetation growing seasons, we analyse vegetation-climate couplings using both local climate conditions and teleconnection indices (e.g., Jet Latitude Index). In addition, vegetation sensitivity to droughts and post-drought vegetation changes are assessed. Our results highlight the importance of considering vegetation phenology in understanding sub-seasonal land-atmosphere interaction and vegetation dynamics. The developed analytical framework is suggested to be an effective approach for evaluating vegetation and climate dynamics simulated by Earth System Models.
Lifetimes and timescales of tropospheric ozone
Authors: Prather Michael , Zhu Xin
Published: February 2023

It is vital and informative to understand the lifetime and timescales of tropospheric O3 so that we can predict the impact of changing O3 sources on its abundance throughout the troposphere, and thence its climate and pollution damage.  As an example, current model intercomparison projects (MIPs) diagnose the impact of stratosphere-troposphere exchange (STE) flux of O3 into the troposphere by assuming that loss of this added O3 occurs through 3 specific reactions (O(1D)+H2O, HO2+O3, OH+O3) and is linear in O3, and that production through XO2+NO reactions is a constant.  A linearization of the full chemistry with respect to O3 clearly shows these assumptions are wrong (see ATom data, shown here).  Another example is the effort made to define odd-oxygen by a chemical family grouping (e.g., O3+O+NO2+…) to better understand the timescales for O3 loss, yet the true pattern of the odd-oxygen family should be apparent from the eigenvectors of the system.  Here we define and test a new protocol for model experiments designed to understand how the coupling of O3 with the full chemistry can change the accumulation and the pattern of decay depending on the O3 source (stratosphere, surface pollution, aviation).  We take a full chemistry-transport model (UCI CTM) and generate a control run for the present day, then add direct O3 emissions (not in the control run) from (i) a large industrial region, (ii) aviation, and (iii) the mid-latitude tropopause where most STE occurs. These perturbation runs produce a seasonally varying additional O3 burden – which gives us the seasonally varying lifetime for such sources – and then we cut emissions and watch the decay pattern in terms of e-fold timescale and patterns of key species to derive the odd-oxygen family pattern.   Due to the large latitudinal and seasonal variation in reactivity rates (see ATom data: Guo et al. ACP, 23, 99–117, 2023), we expect lifetimes and timescale to vary with location and timing of O3 emissions. 
Coupled effects of soil and atmospheric drying on soil-plant hydraulics of sorghum
Authors: Sauer Anna M. , Abdalla Mohanned , Wankmüller Fabian J. P. , Ahmed Mutez A.
Published: February 2023

Transpiration response of plants during both soil drying and increasing vapor pressure deficit (VPD) have been thoroughly studied separately. However, the interactive effects of both on soil-plant hydraulics remain largely unknown. In this study, we tested the combined effects of soil and atmospheric drying on soil-plant hydraulics of sorghum.Sorghum plants were grown in sandy soil under well-watered conditions with a daily VPD increment, increasing in five steps from 0.5 to 3.7 kPa. After 30 days, the soil was dried over five days. We measured transpiration rate (E), soil water content (θ), soil and leaf water potential (ψsoil, ψleaf) both under wet soil and during soil drying. A soil-plant hydraulic model was used to reproduce the data and provide further insight to disentangle soil and atmospheric effects.Both soil drying and VPD affected the relation between transpiration rate and leaf water potential. In wet soil conditions, the E (ψleaf-x) relation was linear even at high VPD. During soil drying, this relation was linear in relatively low VPD conditions (0.5 – 2.5 kPa) but exhibited a non-linear relation under relatively high VPD (2.5 – 3.7 kPa). This response was also reflected in a breakpoint of soil-plant conductance at around 2.5 kPa VPD, resulting in a decrease in transpiration. We conclude that decreasing soil water status has a stronger impact on soil-plant conductance and water uptake than increasing VPD. Furthermore, the modeling revealed the importance of understanding how soil parameters are changed by the presence of plants, especially during soil drying. We suggest that for a holistic understanding of plant response to drought, more emphasis would need to be given to the interactions between VPD and soil drying, as the effects of VPD become increasingly important with soil drying.
Quantification of the damming and sediment trapping capacity of landslides and their dammed lakes: the example of the Hintersee landslide dam
Authors: Argentin Anne-Laure , Hauthaler Thomas , Liebl Moritz , Robl Jörg , Hergarten Stefan , Prasicek Günther , Salcher Bernhard , Hölbling Daniel , Pfalzner-Gibbon Claire , Mandl Lisa , Maroschek Michael , Abad Lorena , Dabiri Zahra
Published: February 2023

Perennial landslide dams interrupt the sediment connectivity of rivers. Although most landslide dams do not persist for more than a few days, those that do can exhibit significant sediment trapping capacity. While water can pass through or over the dam, the sediment load is trapped upstream of the dam until the dam breaks or gradually erodes, or is completely filled with deposits. The volume of sediment stored in this way can reach up to three times the volume of impounded water, as we find by back-analyzing the lake Hintersee in southeastern Germany. In this work, we reconstruct the pre-landslide topography using Petrel and then use the Gerris shallow-water flow solver with a Voellmy rheology to back-analyze this landslide-dammed lake in the Bavarian Alps. We test several landslide release scenarios and different landslide rheologies to obtain the best-fitting reconstruction of the dam topography. We then fill the landslide dam with water and sediment using simple slope algorithms and validate the results against the current topography. Finally, we compare the landslide deposit thicknesses, water depths, and trapped sediment thicknesses of our different scenarios in order to provide new insight into the damming and sediment trapping capacity of landslides.
Accumulation of labile phosphorus in sediments in the zone of influence of the trout farm (Lake Ladoga)
Authors: Lapenkov Artem , Guzeva Alina , Zaripova Ksenia , Berezina Anfisa
Published: February 2023

Fish farming, also known as aquaculture, can be a productive method for producing protein-rich food. However, it has the potential to negatively impact the environment if not properly managed. One of the crucial problems is the release of waste and chemicals into the water column, including excess amounts of nutrients.
Phosphorus is a chemical element that plays a vital role in plant and animal growth, but an excess of phosphorus can lead to the proliferation of harmful algae blooms. These blooms can deplete the oxygen in the water, harming fish and other aquatic life. The total amount of mobile phosphorus entering the ecosystem is related to organic matter. The distribution of the total content of organic matter in the sediment cores can be found in a previous study ( Lapenkov et al., 2022).
Phosphorus can be supplied from different sources, including fish metabolic products and sewage, and can accumulate in sediments. When these sediments are changed, the phosphorus can be released back into the water column and contribute to the overall phosphorus load.

The study was conducted in Jakkimvaara Bay (Lake Ladoga, Russia) to examine the temporal dynamics of the content of labile phosphorus in sediments under trout farms. 

Sampling was carried out at various points throughout the year in all seasons. The Kirsanov labile phosphate extraction method (0.2 M HCl) was used to analyze the content of labile phosphorus in the sediment cores.
In general, the content of labile phosphorus was low in winter and began to increase in spring. The highest level was observed in summer. In autumn, the content of phosphorus began to decrease. Furthermore, labile phosphorus content in the sediments decreased with a depth of the cores collected in all seasons.
The results of the study showed that the nutrient load is very local. The most significant impact on sediment was found under fish cages containing rainbow trout, with phosphorus levels ranging from 0.1% to 2% by dry weight. At control points located 150 and 600 meters away, there was no increase in phosphorus, with levels remaining at 0.1% by dry weight.

Further research is needed to understand the long-term effects of fish farming on phosphorus levels and the potential risks to aquatic ecosystems. The seasonal feeding habits of rainbow trout significantly influence the levels of phosphorus accumulation. The highest levels of feeding activity are observed during the summer and autumn seasons. In the same seasons, we observed the maximum amount of labile phosphorus. Overall, the study highlights the importance of properly managing fish farms to minimize their environmental impacts.
Overview of Juno's Results from Europa and Ganymede
Authors: Hansen Candy , Bolton Scott
Published: February 2023

The evolution of Juno's elliptical polar orbit has brought it close enough to Jupiter at the inbound equatorial plane crossing to intersect the orbits of the Galilean moons.  A close pass by Ganymede occurred 7 June 2021, at an altitude of 1046 km.  The spacecraft came within 350 km of Europa's surface on 29 September 2022.             The Juno payload, designed to probe Jupiter's magnetosphere with a comprehensive complement of fields and particles instruments, was ideal for studying Ganymede's unique mini-magnetosphere.  The spacecraft approached Ganymede from the night side, went behind Ganymede as seen from the earth (achieving an earth occultation), passed through the moon's magnetosphere, and then departed on the sunlit ~sub-jovian side.  Juno's remote sensing instruments collected new data in the visible and near-infrared, and, for the first time, mapped the surface and subsurface with 6 microwave channels.  Remote sensing of Ganymede returned new results on geology, surface composition and thermal properties of the subsurface.             Europa, with its tenuous atmosphere, has a unique interaction with the jovian environment, also investigated with Juno's fields and particles instruments.  The production of water molecules from sputtering of the surface is compared to the processing and eventual loss of molecules from the atmosphere.  Juno's remote sensing instruments returned high resolution images and spectra that are being used to expand our understanding of the tectonic history of Europa's surface.  The Microwave Radiometer probe of the subsurface ice shows Europa to be very different than Ganymede.  
Assimilating cloud-affected visible & infrared satellite observations in idealized simulations
Authors: Kugler Lukas , Weissmann Martin
Published: February 2023

Clouds are the first area-wide observable signal of convection. Although heavily used in nowcasting applications, the use of cloud-affected satellite observations in data assimilation is very limited.

This work aims to estimate the potential impact of assimilating cloud-affected satellite observations of visible (0.6 µm) and near thermal infrared wavelength (6.2 µm and 7.3 µm) relative to the impact of assimilating radar reflectivity observations. The observation types are evaluated in observing system simulation experiments (OSSE) featuring two cases: isolated and scattered supercells. In the first case, a supercell is triggered by a warm bubble (temperature perturbation) with uncertain location and strength but equal evolution in time. In the second case, random perturbations give rise to numerous supercells scattered throughout the domain, which are in different stages of their lifetime. Observations are simulated using the radiative transfer model RTTOV/MFASIS and assimilated by the Ensemble Adjustment Kalman Filter in the Data Assimilation Research Testbed (DART). The Weather Research and Forecasting (WRF) model at 2-km grid resolution was used for forecasts. 

Results show that the forecast impact is notably different in the two cases. For example, the Fractions Skill Score of precipitation and cloudiness indicates that satellite observations can be as beneficial as three-dimensional radar reflectivity observations in the first case, in which the prior contains no error in the stage of storm development but only in horizontal position and strength. Hence, the vertical structure information contained in three-dimensional radar reflectivity does not seem to add value compared to satellite observations, resulting in a similar impact of both observation types. In the second case, however, three-dimensional radar observations constrain the vertical structure and improve upon forecasts that only use satellite observations.
(Intra-event) dynamics of the total mobile inventory in soil - importance for carbon balances and coupling of subsurface ecosystems
Authors: Lehmann Katharina , Lehmann Robert , Herrmann Martina , Schroeter Simon , Totsche Kai Uwe
Published: February 2023

A diverse and broad range of sizes and materials – the total mobile inventory (TMI) – is mobile in soil (Lehmann et al., 2021). Constituting matter exchange between surface and subsurface ecosystems, it is still almost unknown how dissolved, colloidal to particulate fractions (>0.45 µm) fluctuate in seepage of undisturbed soil in both the short (intra-event scale) and long terms (seasons and multiannual periods). In the topographic groundwater recharge area of the Hainich Critical Zone Exploratory (NW-Thuringia), we monitor TMI dynamics using tension-controlled lysimeters in topsoil and subsoil under forest, pasture, and cropland. Soil seepage and precipitation were sampled on a regular (biweekly) and event-scale cycle and analyzed by physico-/hydrochemical, spectroscopic, and molecular biological methods. Within >6.5 years, fluctuations in the TMI were mainly driven by atmospheric conditions (precipitation, temperature), showing pronounced seasonality in the signature of dissolved components (e.g., sulphate) and the seepage pH. In hydrological winter, the total export of bacteria from soil was 1.5-fold higher compared to summer. However, episodic, and strong infiltration events, for instance after snowmelts or heavy rain storms, resulted in increased mobilization of particles. Noteworthy, the export of particulate organic carbon (POC) during winter infiltration events accounted for ~80% of the total annual translocation. Taking >20% of the total mobile OC on average, mobile POC, thus, must be taken into account in carbon balances and for ecosystem interactions. Against the background of increasing climate variability and extreme conditions due to climate change, we furthermore investigated intra-event dynamics of the TMI by increased temporal resolution to improve the understanding of the factors influencing the translocation. During a snow melt event (February 2021) and a simulated heavy rain event (artificial irrigation, August 2021), strong intra-event fluctuations of the TMI (e.g., nitrate, DOM, microorganisms) were also caused by effects of preferential flow. Besides improving our understanding of the soil carbon balance, our long-term monitoring identifies possible controlling factors for the coupling and supply of subsurface ecosystems (aeration zone, groundwater) and for their chemical, biological and functional fluctuations.Lehmann, K., Lehmann, R., & Totsche, K. U. (2021). Event-driven dynamics of the total mobile inventory in undisturbed soil account for significant fluxes of particulate organic carbon. Science of The Total Environment, 143774.
Precipitation observations and simulations during the LIAISE-2021 field campaign
Authors: Bech Joan , Udina Mireia , Peinó Eric , Polls Francesc , García-Benadí Albert , Balagué Marta
Published: February 2023

Within the framework of the GEWEX initiative  “Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment” (LIAISE), the WISE-PreP project was carried out to study precipitation processes aiming to characterize possible differences in precipitation induced by surface characteristics (irrigated vs non-irrigated areas) in NE Spain. Specific deployed instrumentation during the 2021 campaign included three sites equipped each with a vertical radar Doppler Micro Rain Radar (MRR) and a laser disdrometer (PARSIVEL), plus an additional PARSIVEL disdrometer, covering both irrigated and non-irrigated sites. Time series of vertical precipitation profiles and in-situ drop size distributions were recorded to study microphysical processes and related variables including precipitation intensity or convective vs stratiform rainfall regimes.First results show higher accumulated precipitation in the non-irrigated area (eastern area) than those in irrigated area (western area) in summer 2021, a feature also observed in summers for a previous reference period (2010-2019). Maximum and minimum daily temperatures were higher in irrigated areas than in non-irrigated areas. Both results are consistent with current climatology based on monthly precipitation and temperature that indicate the existence of a zonal gradient that increases semi-arid conditions (drier and warmer) from the east to the west. Disdrometer derived 1-min rainfall rate distributions presented some differences between the irrigated and non-irrigated areas during summer, unlike the other seasons when surface conditions are more similar in both areas. An overview of additional results obtained with numerical simulations using the WRF model is also provided. This research was supported by projects WISE-PreP (RTI2018-098693-B-C32) and ARTEMIS (PID2021-124253OB-I00) and the Water Research Institute (IdRA) of the University of Barcelona.
A comparison of DNDC and DayCent to evaluate GHG emissions from China’s main cropping systems
Authors: Wang Junyi , Kuhnert Matthias , Abdalla Mohamed , Smith Pete , Ding Weixin , Yan Xiaoyuan , Zou Jianwen , Guo Shiwei , Fan Jianling , Jiang Yanbin , Hu Ronggui , Li Fusheng , Guo Yanbin , Chen Zengming , Zhao Xu , Xie Yingxin
Published: February 2023

China contributes the largest share of cropland’s greenhouse gas (GHG) emissions globally. Processed-based biogeochemical models are useful tools to simulate GHG emissions from cropping systems. However, model comparisons are necessary to provide information for the application of models under different climate, soil, and crop conditions. In this study, two widely-used models (DayCent and DNDC) were evaluated and compared under four main cropping systems in China. The field observations from nine experiments were used for model calibration and validation.  The DayCent and DNDC models simulated daily and seasonal CH4 emissions from early rice-late rice and rice-wheat cropping systems reasonably well (r2≥0.49 for daily simulation and nRMSE≤52.9% for seasonal simulation). Both models were able to satisfactorily predict seasonal N2O emissions from maize-wheat fields (0.6≤d≤0.8), but overestimated most daily N2O fluxes at fertilisation and irrigation events. Significantly positive relationships were found between simulated and observed cumulative N2O fluxes in spring maize growing season (0.61≤ r2≤0.85). The DNDC showed smaller differences in simulated and observed cumulative GHG emissions for spring maize and double rice, while DayCent showed better performance on estimating N2O and CH4 for maize-wheat and rice-wheat. This study shows that both models have strengths and weaknesses under a variety of cropping systems and growing regions, which are important to consider when choosing a model for a crop/region-specific simulation.