Sondersammlungen

Permanent URI for this communityhttps://hohpublica.uni-hohenheim.de/handle/123456789/7011

Browse

Browsing Sondersammlungen by Classification "550"

Type the first few letters and click on the Browse button
Now showing 1 - 3 of 3
  • Thumbnail Image
    Publication
    Improved method for temporally interpolating radiosonde profiles in the convective boundary layer
    (2026) von Klitzing, Linus; Turner, David D.; Lange, Diego; Wulfmeyer, Volker; von Klitzing, Linus; Institute of Physics and Meteorology, University of Hohenheim, Stuttgart, Germany; Turner, David D.; NOAA Global Systems Laboratory, Boulder, CO, USA; Lange, Diego; Institute of Physics and Meteorology, University of Hohenheim, Stuttgart, Germany; Wulfmeyer, Volker; Institute of Physics and Meteorology, University of Hohenheim, Stuttgart, Germany
    A significantly improved technique for temporally interpolating radiosonde (RS) profiles of potential temperature and water vapor mixing ratio in the planetary boundary layer during daytime is introduced. The key innovation of this technique is its operation on a height grid normalized with the planetary boundary layer height. This study utilized a three-month dataset of three-hourly soundings from the Atmospheric Radiation Measurement Facility's Southern Great Plains site. The technique was evaluated for convective boundary layer cases, with the necessary boundary layer height data obtained from a ground-based infrared spectrometer. A total of 79 comparisons were conducted between reference soundings and interpolated profiles that did and did not employ height normalization. The results demonstrated a substantial improvement in the representation of interpolated profiles using the new technique, characterized by enhanced correlation, improved amplitude representation, and reduced bias for potential temperature, as well as improved correlation and reduced bias for water vapor mixing ratio.
  • Thumbnail Image
    Publication
    A multivariate approach to drought monitoring: Improving robustness and accuracy through a new drought index in regions with high climate variability, applied to the drought-prone region of Ethiopia
    (2026) Kebede, Abebe; Warrach-Sagi, Kirsten; Schwitalla, Thomas; Wulfmeyer, Volker; Abebe, Tesfaye; Tadesse, Tsegaye
    Study focus: Assessing, monitoring, and quantifying drought characteristics to develop early warning systems is crucial for identifying the spatial extent and severity of droughts at regional and local scales especially in regions of vulnerable societies relying on local agriculture. Observations and reanalysis from 1981 to 2022 are analyzed for spatiotemporal droughts in Ethiopia. While standard drought indices like Standardized Precipitation Index and Standardized Soil Moisture Index are based solely on precipitation or soil moisture, a new drought index based on precipitation, potential evaporation, surface temperature, soil temperature, and soil moisture is developed, making the index more robust to climate and land use changes. This new Multivariate Standardized Drought Index (MvrSDI) is evaluated focusing on the severity and duration of 2015 and 2022 droughts in Ethiopia. Results show that spatiotemporal comparisons of MvrSDI at 3-, 6-, and 12-month time scales detect drought severity and duration in each drought-prone region of Ethiopia. Further,Mann-Kendall statistic test identifiy a drought trend between 1981 and 2022 an increasing drought severity. New hydrological insight for the region: The MvrSDI effectively assesses and monitors drought impacts on agriculture, proving beneficial for stakeholders focused on environmental sustainability and food security. Its multivariate character makes MvrSDI more robust and therefore a valuable tool for drought monitoring and decision-making in regions with high climate variability and land use changes in drought-prone regions like Ethiopia.
  • Thumbnail Image
    Publication
    Soil moisture–atmosphere coupling strength over central Europe in the recent warming climate
    (2025) Schwitalla, Thomas; Jach, Lisa; Wulfmeyer, Volker; Warrach-Sagi, Kirsten
    In recent decades Europe has experienced severe droughts and heatwaves. Notably, precipitation in central Europe exhibited strong dry anomalies during the summers of 2003, 2018, and 2022. This phenomenon has significant implications for agriculture, ecosystems, and human societies, highlighting the need to understand the underlying mechanisms driving these events. Despite significant advancements in understanding land–atmosphere (LA) coupling, the temporal variability in LA coupling strength and its associated impacts remain poorly understood. This study aims to quantify the variability in LA coupling strength over central Europe during the summer seasons from 1991 to 2022, with a focus on the relationships between temperature, soil moisture, precipitation, and large-scale weather patterns. Our results reveal that interannual variability occurs in different coupling relationships throughout the summer seasons, with significant implications for climate extremes, agriculture, and ecosystems. The increasing frequency of warm and dry summers from 2015 onwards hints at extended periods of reduced soil moisture available for evapotranspiration and the likelihood of locally triggered convection. This study provides new insights into the dynamics of LA coupling, highlighting the importance of considering the interannual variability in LA coupling strength in climate modeling and prediction, particularly in the context of a warming climate.