@misc{MolinaCaretoGutierrezetal., author = {Molina, M. O. and Careto, J. M. and Guti{\´e}rrez, C. and S{\´a}nchez, E. and Goergen, K. and Sobolowski, S. and Coppola, E. and Pichelli, E. and Ban, N. and Belus̆ić, D. and Short, C. and Caillaud, C. and Dobler, A. and Hodnebrog, {\O}. and Kartsios, S. and Lenderink, G. and de Vries, H. and G{\"o}kt{\"u}rk, O. and Milovac, J. and Feldmann, H. and Truhetz, H. and Demory, M. E. and Warrach-Sagi, K. and Keuler, K. and Adinolfi, M. and Raffa, M. and T{\"o}lle, M. and Sieck, K. and Bastin, S. and Soares, P. M. M.}, title = {The added value of simulated near-surface wind speed over the Alps from a km-scale multimodel ensemble}, series = {Climate dynamics}, volume = {62}, journal = {Climate dynamics}, number = {6}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {0930-7575}, doi = {10.1007/s00382-024-07257-4}, pages = {4697 -- 4715}, abstract = {The advancement of computational resources has allowed researchers to run convection-permitting regional climate model (CPRCM) simulations. A pioneering effort promoting a multimodel ensemble of such simulations is the CORDEX Flagship Pilot Studies (FPS) on "Convective Phenomena over Europe and the Mediterranean" over an extended Alps region. In this study, the Distribution Added Value metric is used to determine the improvement of the representation of all available FPS hindcast simulations for the daily mean near-surface wind speed. The analysis is performed on normalized empirical probability distributions and considers station observation data as the reference. The use of a normalized metric allows for spatial comparison among the different regions (coast and inland), altitudes and seasons. This approach permits a direct assessment of the added value between the CPRCM simulations against their global driving reanalysis (ERA-Interim) and respective coarser resolution regional model counterparts. In general, the results show that CPRCMs add value to their global driving reanalysis or forcing regional model, due to better-resolved topography or through better representation of ocean-land contrasts. However, the nature and magnitude of the improvement in the wind speed representation vary depending on the model, the season, the altitude, or the region. Among seasons, the improvement is usually larger in summer than winter. CPRCMs generally display gains at low and medium-range altitudes. In addition, despite some shortcomings in comparison to ERA-Interim, which can be attributed to the assimilation of wind observations on the coast, the CPRCMs outperform the coarser regional climate models, both along the coast and inland.}, language = {en} } @misc{LauxFeldmannMarraetal., author = {Laux, Patrick and Feldmann, David and Marra, Francesco and Feldmann, Hendrik and Kunstmann, Harald and Trachte, Katja and Peleg, Nadav}, title = {Future precipitation extremes and urban flood risk assessment using a non-stationary and convection-permitting climate-hydrodynamic modeling framework}, series = {Journal of hydrology}, volume = {661, Part B}, journal = {Journal of hydrology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-2707}, doi = {10.1016/j.jhydrol.2025.133607}, pages = {1 -- 14}, abstract = {Urban planners and engineers rely on historical climate data to plan and design flood protection infrastructure that should withstand extreme flooding events with 1\% annual exceedance probability (the 100-year flood). Here, we examine how hourly precipitation extremes are expected to change as temperatures rise and how this will affect urban flooding. The changes to short-duration rainfall extremes, often insufficiently considered in practice, are addressed utilizing a new temperature conditional extreme precipitation scaling approach and a novel regional climate convection-permitting model ensemble for +2 °C and +3 °C global warming scenarios. Based on hydrodynamic modeling, we estimate how future precipitation extremes translate into flood risks in two pre-alpine communes in Germany. Ignoring the impacts of climate change may lead to severe underestimations of flood risks. The +3 °C global warming scenario translates into an increase of 60\% of affected buildings by the highest flood risk category (water level of 1 m and above). The increase in flow intensities will be greater in the commune characterized by steeper terrain. The results suggest that recently planned or implemented infrastructure projects may not be adequately equipped to cope with the anticipated effects of climate change in the coming decades.}, language = {en} } @misc{GrigusovaLimbergerMurkuteetal., author = {Grigusova, Paulina and Limberger, Oliver and Murkute, Charuta and Pucha-Cofrep, Franz and Gonzalez-Jaramillo, Victor Hugo and Fries, Andreas and Windhorst, David and Breuer, Lutz and Dantas de Paula, Mateus and Hickler, Thomas and Trachte, Katja and Bendix, J{\"o}rg}, title = {Radiation partitioning in a cloud-rich tropical mountain rain forest of the S-Ecuadorian Andes for use in plot-based land surface modelling}, series = {Dynamics of atmospheres and oceans : planetary fluid, climatic and biogeochemical systems}, volume = {110}, journal = {Dynamics of atmospheres and oceans : planetary fluid, climatic and biogeochemical systems}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0377-0265}, doi = {10.1016/j.dynatmoce.2025.101553}, pages = {1 -- 16}, abstract = {Understanding the partitioning of downward shortwave radiation into direct and diffuse components is essential for modeling ecosystem energy fluxes. Accurate partitioning functions are critical for land surface models (LSMs) coupled with climate models, yet these functions often depend on regional cloud and aerosol conditions. While data for developing semi-empirical partitioning functions are abundant in mid-latitudes, their performance in tropical regions, particularly in the high Andes, remains poorly understood due to scarce ground-based measurements. This study analyzed a unique dataset of shortwave radiation components from a tropical mountain rainforest (MRF) in southern Ecuador, developing and testing a locally adapted partitioning function using Random Forest Regression. The model achieved high accuracy in predicting the percentage of diffuse radiation (\%Dif; R²=0.95, RMSE = 5.33, MAE = 3.74) and absolute diffuse radiation (R²=0.99, RMSE = 5.30, MAE = 14). When applied to simulate upward shortwave radiation, the model outperformed commonly used partitioning functions achieving the lowest RMSE (8.62) and MAE (5.82) while matching the highest R² (0.97). These results underscore the importance of regionally adapted radiation partitioning functions for improving LSM performance, particularly in complex tropical environments. The adapted LSM will be further utilized for studies on heat fluxes and carbon sequestration.}, language = {en} } @misc{BendixLimburgerBreueretal., author = {Bendix, J{\"o}rg and Limburger, Oliver and Breuer, Lutz and Dantas de Paula, Mateus and Fries, Andreas and Gonzalez-Jaramillo, Victor Hugo and Grigusova, Paulina and Hickler, Thomas and Murkute, Charuta and Pucha-Cofrep, Franz and Trachte, Katja and Windhorst, David}, title = {Simulation of latent heat flux over a high altitude pasture in the tropical Andes with a coupled land surface framework}, series = {The science of the total environment}, volume = {981}, journal = {The science of the total environment}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-1026}, doi = {10.1016/j.scitotenv.2025.179510}, pages = {1 -- 21}, abstract = {Latent heat flux is a central element of land-atmosphere interactions under climate change. Knowledge is particularly poor in the biodiversity hotspot of the Andes, where heat flux measurements using eddy covariance stations are scarce and land surface models (LSMs) often oversimplify the complexity of the ecosystems. The main objective of this study is to perform latent heat flux simulations for the tropical South Eastern (SE) Ecuadorian Andes using a coupled LSM framework, and to test the performance with heat flux and soil moisture data collected from a tropical high-altitude pasture. Prior to testing, we applied multi-criteria model calibration of sensitive model parameters, focusing on improving simulated soil water conditions and radiation fluxes as a prerequisite for proper heat flux simulations. The most sensitive parameters to improve soil moisture and radiation flux simulations were soil porosity, saturated hydraulic conductivity, leaf area index, soil colour and NIR (Near Infrared) leaf optical properties. The best calibrated model run showed a very good performance for half-hourly latent heat flux simulations with an R² of 0.8 and an RMSE of 34.0 W m⁻², outperforming simulations with uncalibrated and uncoupled LSM simulations in comparable areas. The slight overall overestimation in the simulated latent heat flux can be related to (i) simulation uncertainties in the canopy heat budget, (ii) an imbalance in the observed flux data and (iii) slight overestimations in the simulated soil moisture. Although our study focuses on latent heat fluxes and their relation to simulated radiation fluxes and soil moisture, model outputs of sensible heat fluxes were also discussed. The systematic overestimation of sensible heat flux in the model seems to be mainly a result of overestimated canopy temperatures. The improved simulation for latent heat flux has a high translational potential to support land use strategies in the tropical Andes under climate change.}, language = {en} } @misc{SaraviaTrachte, author = {Saravia, Christian and Trachte, Katja}, title = {Spatiotemporal analysis of NH₃ emission sources and their relation to land use types in the Eastern German lowlands}, series = {Atmosphere}, volume = {16}, journal = {Atmosphere}, publisher = {MDPI}, address = {Basel}, issn = {2073-4433}, doi = {10.3390/atmos16030346}, pages = {1 -- 21}, abstract = {Ammonia (NH₃) emissions, which are key precursors of fine particulate matter, pose significant environmental challenges. This study investigated the spatiotemporal variations in NH₃ emissions across the eastern German lowlands from 2013 to 2022 using IASI-B satellite data. Five major Land Cover Classes (LCC) -tree, grassland, cropland, built-up areas, and water bodies- were analyzed. The results showed distinct diurnal variations, with nighttime NH₃ concentrations exceeding 2.0 × 10¹⁶ molecules cm⁻² in the peak months. Seasonal patterns indicated significant emissions in March (1.2 × 10¹⁶ molecules cm⁻²), April (1.1 × 10¹⁶ molecules cm⁻2), and August (9.6 × 10¹⁵ molecules cm⁻²), while the lowest concentrations occurred in September (0.6 × 10¹⁵ molecules cmv²). Persistent hotspots were identified in the northwestern region, where emissions peaked in spring (1.8 × 10¹⁶ molecules cm⁻²) and summer (1.3 × 10¹⁶ molecules cm⁻²), primarily due to agricultural activities. Over the study period, the annual NH₃ concentration peaked in 2015, 2018, and 2022. Using k-means clustering, three distinct emission zones were identified, with Cluster 3 showing the highest NH₃ emission values, particularly in urban centers, and agricultural zones were identified, covering less than 20\% of the study area, where cropland predominates (8\%). Meteorological factors significantly influenced NH₃ levels, with negative correlations obtained for precipitation, wind speed, and evaporation, while solar radiation, boundary layer height, and instantaneous moisture fluxes showed positive correlations. A case study from March 2022, employing the HYSPLIT trajectory model, confirmed that agricultural practices are the dominant NH₃ source, with emissions reaching 3.2 × 10¹⁶ molecules cm⁻² in hotspot regions.}, language = {en} } @misc{AhmadpourBayzidiTrachte, author = {Ahmadpour, Somayeh and Bayzidi, Yasin and Trachte, Katja}, title = {Spatio-temporal patterns of evapotranspiration in the temperate Eastern German lowlands and its response to climate and land use change}, series = {Theoretical and applied climatology}, volume = {156}, journal = {Theoretical and applied climatology}, publisher = {Springer}, issn = {1434-4483}, doi = {10.1007/s00704-025-05529-5}, pages = {1 -- 19}, abstract = {Evapotranspiration (ET) is a key factor in the water and energy cycle, playing a critical role, especially in agricultural regions. The eastern German lowlands, with their continental climate, are one of the driest regions in Germany, yet agriculture is the dominant land use. This study investigates the spatio-temporal variability of ET and its response to climate and land use/land cover change (LUCC) using MODIS remote sensing products and in-situ measurements over the period 2000-2020. The results show a slight increase in the mean annual ET, with local increases of up to 7.2\% in the southern and southeastern parts of Brandenburg. LUCC revealed a 22.2\% decrease in grassland to cropland conversion, leading to a decline in ET of 21\%, while conversion from grassland to cropland increased by 14.8\%, resulting in a 10\% increase in ET. The strongest relationship with ET was found for vapor pressure deficit (VPD), temperature (Temp), and relative humidity (RH), which contributed 25.2\%, 30.9\%, and 23.2\%, respectively, to its total variability. In addition to atmospheric factors soil moisture (SM) also contributed 17.7\% to ET, but only in grassland. LUCC played a minor role as 22\% of the study area was under conversion. Consequently, climate change, represented by the temporal change of the climatic factors, was identified as the dominant driver of ET in the study area, accounting for 97\% of its variability. Accordingly, these findings underscore the importance of Temp, RH, and SM in agricultural and water resource management.}, language = {en} } @misc{LimbergerHomeierGonzalezJaramilloetal., author = {Limberger, Oliver and Homeier, J{\"u}rgen and Gonzalez-Jaramillo, Victor and Fries, Andreas and Murkute, Charuta and Trachte, Katja and Bendix, J{\"o}rg}, title = {Foliar trait retrieval models based on hyperspectral satellite imagery perform well in a biodiversity hotspot of the SE Ecuadorian Andes}, series = {International journal of remote sensing}, journal = {International journal of remote sensing}, publisher = {Taylor \& Francis}, address = {London}, issn = {1366-5901}, doi = {10.1080/01431161.2025.2511211}, pages = {1 -- 19}, abstract = {The determination of the spatial distribution of canopy traits is crucial for understanding the spatio-temporal dynamics of ecosystem functions, such as carbon sequestration, water and energy fluxes in tropical montane forests. Especially in remote areas such as the Andes of south-east Ecuador, remote sensing using satellites has been proven to provide valuable information on canopy traits. However, the performance of the multispectral models to date is limited. Here, we analyse the potential of DESIS (DLR Earth Sensing Imaging Spectrometer) hyperspectral surface reflectance data for the prediction of specific leaf area (SLA), foliar toughness, nitrogen (N) and phosphorus (P) content by calibrating a PLSR model for each foliar trait. Model validation showed a high explanation of variance (R2 : 0.78-0.92) and a low model error (mean-normalized RMSE: 8-13\%) for all traits, showing an improved performance compared to models based on multispectral imagery and ancillary data within the same forest type. Hyperspectral models predicting foliar traits from individual tree crowns showed a lower performance for most traits, probably related to the difference in spatial resolution compared to this study. Given the high species richness of the Andean biodiversity hotspot and the complex topography, the high quality of the DESIS models is remarkable, considering that the multispectral models from the region require topographic predictors in addition to reflectances to achieve a good performance. The spatial trait maps generated by our models based on the reflectances only show clear relationships with terrain elevation. Thus, the hyperspectral trait maps from satellite orbit are capable of supporting large-scale ecological analyses between features, diversity and ecosystem functions.}, language = {en} } @misc{BhawarKumarLawandetal., author = {Bhawar, Rohini L. and Kumar, Vinay and Lawand, Divyaja and Kedia, Sumita and Naik, Mrunal and Modale, Shripriya and Reddy, P. R. C. and Islam, Sahidul and Khare, Manoj}, title = {Aerosol emission patterns from the February 2019 Karnataka fire}, series = {Fire}, volume = {7}, journal = {Fire}, number = {12}, editor = {Williamson, Grant}, publisher = {MDPI}, address = {Basel}, issn = {2571-6255}, doi = {10.3390/fire7120424}, pages = {1 -- 15}, abstract = {Forests are vital for life on Earth but are threatened by forest fires, which have significant impacts on climate change both locally and globally. This study examines a forest fire that lasted from 15 to 26 February 2019 in Karnataka, India, using the Weather Research and Forecasting model with Chemistry (WRF-Chem) model to analyze the effects and atmospheric spread of fire-emitted aerosols. Model simulations are analyzed to understand the horizontal and vertical transport and radiative effects of the fire. The results show high aerosol levels and smoke particles reaching up to 3.5 km altitude and above. The fire raised near-surface air temperatures by ~1-1.5 °C. The net atmospheric forcing due to the fire over the affected area ranged from approximately 10 to 14 W/m 2 , resulting in heating rates between about 0.002 and 0.005 K/day in the impacted region.}, language = {en} } @incollection{TrachteAhmadpour, author = {Trachte, Katja and Ahmadpour, Somayeh}, title = {Europe and the Middle East}, series = {Regional Climates}, volume = {105 (2024)}, booktitle = {Regional Climates}, number = {8}, publisher = {American Meteoroligal Society}, doi = {10.1175/2024BAMSStateoftheClimate_Chapter7.1}, pages = {371 -- 484}, language = {en} } @misc{Trachte, author = {Trachte, Katja}, title = {Recent progress in atmospheric modeling over the Andes - part II: projected changes and modeling challenges}, series = {Sec. Atmospheric Science}, volume = {12 (2024)}, journal = {Sec. Atmospheric Science}, publisher = {Frontiers in Earth Science}, doi = {10.3389/feart.2024.1427837}, pages = {1 -- 21}, language = {en} } @misc{Trachte, author = {Trachte, Katja}, title = {Recent progress in atmospheric modeling over the Andes - part I: review of atmospheric processes}, series = {Atmospheric Science}, volume = {12 (2024)}, journal = {Atmospheric Science}, publisher = {Frontiers in Earth Science}, doi = {10.3389/feart.2024.1427783}, pages = {1 -- 23}, language = {en} } @misc{TrachteRaffelsbauer, author = {Trachte, Katja and Raffelsbauer, Volker}, title = {Trees with anisohydric behavior as main drivers of nocturnal evapotranspiration in a tropical mountain rainforest}, series = {PLoS ONE}, volume = {18 (3)}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0282397}, pages = {1 -- 21}, language = {en} } @misc{MurkuteSayeedPuchaCofrepetal., author = {Murkute, Charuta and Sayeed, Mostafa and Pucha-Cofrep, Franz and Carrillo-Rojas, Galo and Homeier, J{\"u}rgen and Limberger, Oliver and Fries, Andreas and Bendix, J{\"o}rg and Trachte, Katja}, title = {Turbulent energy and carbon fluxes in an Andean Montane Forest—energy balance and heat storage}, series = {Forests}, volume = {15}, journal = {Forests}, number = {10}, publisher = {MDPI}, issn = {1999-4907}, doi = {10.3390/f15101828}, abstract = {High mountain rainforests are vital in the global energy and carbon cycle. Understanding the exchange of energy and carbon plays an important role in reflecting responses to climate change. In this study, an eddy covariance (EC) measurement system installed in the high Andean Mountains of southern Ecuador was used. As EC measurements are affected by heterogeneous topography and the vegetation height, the main objective was to estimate the effect of the sloped terrain and the forest on the turbulent energy and carbon fluxes considering the energy balance closure (EBC) and the heat storage. The results showed that the performance of the EBC was generally good and estimated it to be 79.5\%. This could be improved when the heat storage effect was considered. Based on the variability of the residuals in the diel, modifications in the imbalances were highlighted. Particularly, during daytime, the residuals were largest (56.9 W/m 2 on average), with a clear overestimation. At nighttime, mean imbalances were rather weak (6.5 W/m 2 ) and mostly positive while strongest underestimations developed in the transition period to morning hours (down to -100 W/m 2 ). With respect to the Monin-Obukhov stability parameter ((z - d)/L) and the friction velocity (u*), it was revealed that the largest overestimations evolved in weak unstable and very stable conditions associated with large u* values. In contrast, underestimation was related to very unstable conditions. The estimated carbon fluxes were independently modelled with a non-linear regression using a light-response relationship and reached a good performance value (R 2 = 0.51). All fluxes were additionally examined in the annual course to estimate whether both the energy and carbon fluxes resembled the microclimatological conditions of the study site. This unique study demonstrated that EC measurements provide valuable insights into land-surface-atmosphere interactions and contribute to our understanding of energy and carbon exchanges. Moreover, the flux data provide an important basis to validate coupled atmosphere ecosystem models.}, language = {en} } @misc{HaeusserAryalBarthetal., author = {H{\"a}usser, Martin and Aryal, Sugam and Barth, Johannes A. C. and Bendix, J{\"o}rg and Garel, Emilie and Geldern, Robert van and Huneau, Fr{\´e}d{\´e}ric and Juhlke, Tobias R. and Knerr, Isabel and Santoni, S{\´e}bastien and Szymczak, Sonja and Trachte, Katja and Br{\"a}uning, Achim}, title = {Xylem formation patterns from Mediterranean to subalpine climate conditions reveal high growth plasticity of pine species on Corsica}, series = {Trees}, volume = {37}, journal = {Trees}, number = {4}, publisher = {Springer Berlin Heidelberg}, issn = {0931-1890}, doi = {10.1007/s00468-023-02402-8}, pages = {1027 -- 1039}, abstract = {Investigating seasonal wood formation is crucial to understand tree growth responses to climate impact. The present study quantifies the variability of xylogenesis along an elevation gradient on the Mediterranean island of Corsica, where two native pine species (Pinus nigra Arnold ssp. laricio Maire and Pinus pinaster Aiton) grow from the upper tree line to sea level, partly in sympatry. We extracted microcores from 35 trees at 5 sites along an East-West transect from the coasts (10 m asl) to the island's central mountain ridge (1600 m asl) during bi-weekly sampling campaigns between 2017 and 2019. We applied generalised additive models to detect radial growth differences in elevation and species along with minimum temperatures for growth initiation. We found that trees in low elevations experienced over 2 months longer growth periods with higher maximum growth rates than in high elevations. The results show a 1-month delay for the beginning of tracheid formation between the low, mid and high-elevation belts but comparable timing for its termination. At the sites where both species co-occur, P. nigra accumulates more radial cells in a shorter time than P. pinaster. Trees at the two contrasting coastal sites have similar growth period lengths, but exhibit a time shift of over a month. Minimum temperatures around growth initiation vary between 3.1 °C for P. nigra and 9.9 °C for P. pinaster. These findings emphasise the high plasticity in the growth behaviour of one of the most widespread tree genera in Mediterranean and temperate zones.}, language = {en} } @article{AhmedZaforTrachte, author = {Ahmed, Rezwan and Zafor, Md. Abu and Trachte, Katja}, title = {Land-use and land-cover changes in Cottbus City and Spree-Neisse District, Germany, in the last two decades: a study using remote sensing data and Google Earth Engine}, series = {Remote Sensing}, volume = {16}, journal = {Remote Sensing}, number = {15}, edition = {2nd edition}, publisher = {MDPI AG}, issn = {2072-4292}, doi = {10.3390/rs16152773}, pages = {1 -- 16}, abstract = {Regular detection of land-use and land-cover (LULC) changes with high accuracy is necessary for natural resources management and sustainable urban planning. The produced LULC maps from Google Earth Engine (GEE) also illustrate the transformation of the LULC for the respective landscape over time. The selected study area, Cottbus City and the Spree-Neisse district in northeastern Germany, has undergone significant development over the past decades due to various factors, including urbanization and industrialization; also, the landscape has been converted in some areas for post-mining activities. Detection of LULC changes that have taken place over the last few decades thus plays a vital role in quantifying the impact of these factors while improving the knowledge of these developments and supporting the city planners or urban management officials before implementing further long-term development initiatives for the future. Therefore, the study aims to (i) detect LULC changes for the time slices 2002 and 2022, testing machine learning (ML) algorithms in supervised and unsupervised classification for Landsat satellite imageries, and (ii) validate the newly produced LULC maps with the available regional database (RDB) from the federal and state statistical offices, Germany, and the Dynamic World (DW) near real-time 10 m global LULC data set powered by artificial intelligence (AI). The results of the Random Forest (RF) and the Smilecart classifiers of supervised classification using Landsat 9 OLI-2/TIRS-2 in 2022 demonstrated a validation accuracy of 88\% for both, with Kappa Index (KI) of 83\% and 84\%, respectively. Moreover, the Training Overall Accuracy (TOA) was 100\% for both years. The wekaKMeans cluster of the unsupervised classification also illustrated a similar transformation pattern in the LULC maps. Overall, the produced LULC maps offered an improved representation of the selected region's various land-cover classes (i.e., vegetation, waterbodies, built areas, and bare ground) in the last two decades (20022 to 2022).}, language = {en} } @misc{FennerChristenGrimmondetal., author = {Fenner, Daniel and Christen, Andreas and Grimmond, Sue and Meier, Fred and Morrison, William and Zeeman, Matthias and Barlow, Janet and Birkmann, J{\"o}rn and Blunn, Lewis and Chrysoulakis, Nektarios and Clements, Matthew and Glazer, Russell and Hertwig, Denise and Kotthaus, Simone and K{\"o}nig, Kai and Looschelders, Dana and Mitraka, Zina and Poursanidis, Dimitris and Tsirantonakis, Dimitris and Bechtel, Benjamin and Benjamin, Kit and Beyrich, Frank and Briegel, Ferdinand and Feigel, Gregor and Gertsen, Carlotta and Iqbal, Nimra and Kittner, Jonas and Lean, Humphrey and Liu, Yiqing and Luo, Zhiwen and McGrory, Megan and Metzger, Swen and Paskin, Matthew and Ravan, Marvin and Ruhtz, Thomas and Saunders, Bethany and Scherer, Dieter and Smith, Stefan Thor and Stretton, Megan and Trachte, Katja and Van Hove, Melania}, title = {urbisphere-Berlin campaign: investigating multi-scale urban impacts on the atmospheric boundary layer}, series = {Bulletin of the American Meteorological Society}, volume = {105}, journal = {Bulletin of the American Meteorological Society}, publisher = {American Meteorological Society}, issn = {0003-0007}, doi = {10.1175/BAMS-D-23-0030.1}, pages = {64}, abstract = {For next-generation weather and climate numerical models to resolve cities, both higher spatial resolution and sub-grid parameterizations of urban canopy-atmosphere processes are required. Key is to better understand intra-urban variability and urban-rural differences in atmospheric boundary layer (ABL) dynamics. This includes upwind-downwind effects due to cities' influences on the atmosphere beyond their boundaries. To address these aspects a network of >25 ground-based remote-sensing sites was designed for the Berlin region (Germany), considering city form, function, and typical weather conditions. This allows investigation of how different urban densities and human activities impact ABL dynamics. As part of the interdisciplinary European Research Council Grant urbisphere, the network was operated from Autumn 2021 to Autumn 2022. Here we provide an overview of the scientific aims, campaign setup, and results from two days, highlighting multi-scale urban impacts on the atmosphere in combination with high-resolution numerical modeling at 100 m grid-spacing. During a spring day, the analyzes show systematic upwind-city-downwind effects in ABL heights, largely driven by urban-rural differences in surface heat fluxes. During a heatwave day, ABL height is remarkably deep, yet spatial differences in ABL heights are less pronounced due to overall dry soil conditions, resulting in similar observed surface heat fluxes. Our modeling results provide further insights into ABL characteristics not resolved by the observation network, highlighting synergies between both approaches. Our data and findings will support modeling to help deliver services to a wider community from citizens to those managing health, energy, transport, land-use and other city infrastructure and operations.}, language = {en} } @misc{LehmkuhlGerwinRaabetal., author = {Lehmkuhl, Frank and Gerwin, Werner and Raab, Thomas and Birkhofer, Klaus and Hinz, Christoph and Letmathe, Peter and Leuchner, Michael and Roß-Nickoll, Martina and R{\"u}de, Thomas R. and Trachte, Katja and W{\"a}tzold, Frank}, title = {Perspectives for the lignite post-mining landscapes of the lignite mining landscapes under changing environmental conditions - what can we learn from a comparison between the Rhenish and the Lusatian regions in Germany? : EGU General Assembly 2024, Vienna, Austria \& Online | 14-19 April 2024}, publisher = {Copernicus GmbH}, doi = {10.5194/egusphere-egu24-2791}, abstract = {The German government's decision to phase out lignite mining by 2038 or earlier, as recently 2030 has been agreed for the Rhineland, will trigger a number of transition processes in Germany's remaining lignite mining areas. The two largest lignite mining areas are located in geographically different regions: Rhineland in the west and Lusatia in the east. As the socio-economic and environmental conditions in these two mining areas are set to change dramatically, the German government has adopted extensive economic support measures. However, the environmental changes will also lead to changes in the ecosystem functions and services provided by the future post-mining landscapes. Gerwin et al. (2023) compare the two main lignite producing regions of Germany in terms of their natural and cultural environments. The economic situation and its history are reflected and differences are outlined. Part of the differences in cultural development can be explained by the natural conditions, especially the edaphic factors and the climatic situation. Because of the specific geological settings, tailored mining technologies were developed and used in the two regions, with different effects on the resulting post-mining landscapes. We conclude that the landscapes of Lusatia and the Rhineland have been radically restructured by the long and varied history of lignite mining. Both regions will change significantly as the mining industry continues to decline and is expected to cease altogether within the next decade. These changes in the post-mining landscapes and the ecosystem services will provide both challenges and opportunities. The preconditions for positive socio-economic development and for sustainable land use concepts that also consider ecological aspects are different for the two regions. The exchange of knowledge and experience between the two mining regions is crucial to the success of this major transformation process, despite, or perhaps because of, these differences. Gerwin, W., Raab, T., Birkhofer, K., Hinz, C., Letmathe, P., Leuchner, M., Ro\&\#223;-Nickoll, M., R\&\#252;de, T., Trachte, K., W\&\#228;tzold, F., Lehmkuhl, F. (2023): Perspectives of lignite post-mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany? Environmental Sciences Europe 35:36. https://doi.org/10.1186/s12302-023-00738-z}, language = {en} } @misc{GerwinRaabHinzetal., author = {Gerwin, Werner and Raab, Thomas and Hinz, Christoph and Letmathe, Peter and Leuchner, Michael and Roß-Nickoll, Martina and R{\"u}de, Thomas and Trachte, Katja and W{\"a}tzold, Frank and Lehmkuhl, Frank}, title = {Perspectives of lignite post‑mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany?}, series = {Environmental Sciences Europe}, volume = {35}, journal = {Environmental Sciences Europe}, issn = {2190-4715}, doi = {10.1186/s12302-023-00738-z}, abstract = {Background The decision of the German federal government to cease lignite mining until 2038 or—if possible— already earlier until 2030, will cause manifold transition processes in the remaining lignite mining districts of Germany. The two largest districts are located in geographically opposite regions: The Rhineland in the western part and Lusatia in the east of Germany. As particularly these two mining districts will experience severe changes in their socioeconomic as well environmental conditions, the federal government has adopted comprehensive economic support measures. However, the environmental changes will also cause altered ecosystem functions and services to be provided by the future post-mining landscapes. Results In this paper, the two main lignite-producing regions of Germany are compared with regard to their natural and cultural settings. The economic situation and its history are reflected and differences are outlined. Part of the disparities in the cultural development can be explained by very different natural conditions, especially edaphic factors and climatic situation. Because of dissimilar geological settings, different mining technologies were developed and are in use in the two regions with distinct effects on the resulting post-mining landscapes. Conclusion The long-standing and manifold lignite mining activities have radically restructured the landscapes in Lusatia and the Rhineland. With the ongoing decline of the mining industry and its complete cessation, presumably within the next decade, both regions will alter their faces significantly. These changes offer both challenges but also opportunities with respect to the post-mining landscapes and their ecosystem services they are going to provide. The prerequisites for a positive socioeconomic development and for sustainable land-use concepts that also consider ecological aspects are different for both regions. However, or especially because of these differences, the knowledge exchange and experience transfer between both mining regions are pivotal for the success of this extensive transformation process.}, language = {en} } @misc{HerrmannKeulerWoltersetal., author = {Herrmann, Frank and Keuler, Klaus and Wolters, Tim and Bergmann, Sabine and Eisele, Michael and Wendland, Frank}, title = {Mit der Modellkette RCP-GCM-RCM-mGROWA projizierte Grundwasserneubildung als Datenbasis f{\"u}r zuk{\"u}nftiges Grundwassermanagement in Nordrhein-Westfalen}, series = {Grundwasser}, volume = {26}, journal = {Grundwasser}, number = {1}, issn = {1430-483X}, doi = {10.1007/s00767-020-00471-x}, pages = {17 -- 31}, abstract = {Mit einem Multi-Modell-Ensemble wurde analysiert, wie sich der Klimawandel auf den Grundwasserhaushalt in Nordrhein-Westfalen (NRW) auswirkt. Hierzu wurden Projektionen der zuk{\"u}nftigen Grundwasserneubildung f{\"u}r insgesamt 36 Mitglieder der Modellkette RCP-GCM-RCM-mGROWA, bestehend aus 3 RCP-Szenarien zuk{\"u}nftiger globaler Erw{\"a}rmung, 6 globalen und 5 dynamischen regionalen Klimamodellen sowie dem Wasserhaushaltsmodell mGROWA, vorgenommen. Mit dem Ensemble wurden f{\"u}r die hydrogeologischen Großr{\"a}ume NRWs nur teilweise signifikante {\"A}nderungen der j{\"a}hrlichen Grundwasserneubildung in den Perioden 2011-2040, 2041-2070 und 2071-2100 projiziert. Ein Robustheitstest mit zwei Kriterien ({\"U}bereinstimmung und Signifikanz der {\"A}nderungssignale) liefert keine belastbare Begr{\"u}ndung daf{\"u}r, dass sich die Grundwasserneubildung bis 2100 systematisch und signifikant {\"a}ndern wird. Aus statistischer Perspektive wird deshalb die Schlussfolgerung gezogen, dass in NRW langfristig eine Grundwasserneubildung erwartet werden kann, die sich nicht grundlegend vom Niveau der Periode 1971-2000 unterscheidet. Hydro-meteorologisch befindet sich NRW in einer {\"U}bergangszone, in der eine Zunahme der Winterniederschl{\"a}ge die Wirkung der Erw{\"a}rmung auf die Grundwasserneubildung wahrscheinlich kompensiert.}, language = {de} } @misc{VesteGreyGottschalketal., author = {Veste, Maik and Grey, Kerry-Anne and Gottschalk, Nadine and Trachte, Katja and Midgley, Guy F.}, title = {Can shelterbelt trees reduce evapotranspiration and ecophysiological stress in irrigated vineyards and citrus orchards? A transcontinental experiment in the Western Cape, South Africa and Lower Lusatia, Germany}, series = {Landscape 2021 - Diversity for Sustainable and Resilient Agriculture}, journal = {Landscape 2021 - Diversity for Sustainable and Resilient Agriculture}, doi = {10.13140/RG.2.2.34333.03043}, pages = {1}, abstract = {In the context of ongoing climate change and increasing population, there is an urgent need to optimize the water consumption of surface and groundwater in agricultural production. In recent years, intensive irrigated viticulture and horticulture have faced increasing demand pressure in many water-limited areas including the Western Cape Province in South Africa. Shelterbelts of trees are often used to reduce wind speed and water demands as an eco-engineering measure directly influencing soil evaporation and crop transpiration. Objectives are (i) to evaluate the extent of impacts of wind speed from shelterbelts at canopy level in citrus orchards and vineyards (ii) to assess the wind effects at leaf level including leaf temperature and related ecophysiological performance in irrigated vineyards.}, language = {en} } @misc{KnerrTrachteEglietal., author = {Knerr, Isabel and Trachte, Katja and Egli, Sebastian and Barth, Johannes A. C. and Br{\"a}uning, Achim and Garel, Emilie and H{\"a}usser, Martin and Huneau, Fr{\´e}d{\´e}ric and Juhlke, Tobias R. and Santoni, S{\´e}bastien and Szymczak, Sonja and Geldern, Robert van and Bendix, J{\"o}rg}, title = {Fog - low stratus (FLS) regimes on Corsica with wind and PBLH as key drivers}, series = {Atmospheric Research}, volume = {261}, journal = {Atmospheric Research}, issn = {0169-8095}, doi = {10.1016/j.atmosres.2021.105731}, abstract = {The French Mediterranean island of Corsica is already today confronted with a clear tendency towards water shortage, leading not only to socio-economical, but also to ecological problems. A potential, but not very widespread source of water is the presence of near-ground clouds, mostly fog. In this study, we investigate fog-low stratus (FLS) frequencies in Corsica, derived from a data set of Meteosat Second Generation SEVIRI, whereby a distinction between fog and low stratus is hardly feasible using remote sensing data. The FLS frequency was studied with respect to its interaction with distinct locally-generated wind and its dependence on the planetary boundary layer height (PBLH) obtained by ERA5 reanalysis (the fifth generation of the European Centre for Medium-Range Weather Forecasts, ECMWF). Results show that radiation FLS is formed in coastal areas at sunrise, with low PBLH. On the other hand, in the interior of the island at sunset, a maximum of advection FLS is formed, fostered by locally-generated and related transport of moisture. On the east side of the island, FLS frequency is lower throughout the year due to frequent lee situations. This situation is reinforced by reduced synoptic moisture transport by westerly winds, so that westerly exposed slopes benefit from moisture input by FLS formation.}, language = {en} } @misc{LimbergerHomeierFarwigetal., author = {Limberger, Oliver and Homeier, J{\"u}rgen and Farwig, Nina and Pucha-Cofrep, Franz and Fries, Andreas and Leuschner, Christoph and Trachte, Katja and Bendix, J{\"o}rg}, title = {Classification of Tree Functional Types in a Megadiverse Tropical Mountain Forest from Leaf Optical Metrics and Functional Traits for Two Related Ecosystem Functions}, series = {Forests}, volume = {12}, journal = {Forests}, number = {5}, issn = {1999-4907}, doi = {10.3390/f12050649}, abstract = {Few plant functional types (PFTs) with fixed average traits are used in land surface models (LSMs) to consider feedback between vegetation and the changing atmosphere. It is uncertain if highly diverse vegetation requires more local PFTs. Here, we analyzed how 52 tree species of a megadiverse mountain rain forest separate into local tree functional types (TFTs) for two functions: biomass production and solar radiation partitioning. We derived optical trait indicators (OTIs) by relating leaf optical metrics and functional traits through factor analysis. We distinguished four OTIs explaining 38\%, 21\%, 15\%, and 12\% of the variance, of which two were considered important for biomass production and four for solar radiation partitioning. The clustering of species-specific OTI values resulted in seven and eight TFTs for the two functions, respectively. The first TFT ensemble (P-TFTs) represented a transition from low to high productive types. The P-TFT were separated with a fair average silhouette width of 0.41 and differed markedly in their main trait related to productivity, Specific Leaf Area (SLA), in a range between 43.6 to 128.2 (cm2/g). The second delineates low and high reflective types (E-TFTs), were subdivided by different levels of visible (VIS) and near-infrared (NIR) albedo. The E-TFTs were separated with an average silhouette width of 0.28 and primarily defined by their VIS/NIR albedo. The eight TFT revealed an especially pronounced range in NIR reflectance of 5.9\% (VIS 2.8\%), which is important for ecosystem radiation partitioning. Both TFT sets were grouped along elevation, modified by local edaphic gradients and species-specific traits. The VIS and NIR albedo were related to altitude and structural leaf traits (SLA), with NIR albedo showing more complex associations with biochemical traits and leaf water. The TFTs will support LSM simulations used to analyze the functioning of mountain rainforests under climate change.}, language = {en} }