Regional climate simulations in the Weddell Sea region (Antarctic): Model verification and evaluation of low-level jets

• Main Author: Zentek, Rolf
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2023
• Subjects: Weddellmeer; 4064942-8; Atmosphärische Grenzschicht; 4192517-8; Strahlstrom Meteorologie; 4183524-4; Modellierung; 4170297-9; Geowissenschaften; ddc:550; Antarctic; The Antarctic; Weddell Sea; Weddell; Antarc*; Antarktis*
• Online Access: https://ubt.opus.hbz-nrw.de/frontdoor/index/index/docId/2055; https://nbn-resolving.org/urn:nbn:de:hbz:385-1-20553; https://doi.org/10.25353/ubtr-xxxx-89b8-d4a1; https://ubt.opus.hbz-nrw.de/files/2055/Dissertation_Zentek.pdf

This cumulative thesis encompass three studies focusing on the Weddell Sea region in the Antarctic. The first study produces and evaluates a high quality data set of wind measurements for this region. The second study produces and evaluates a 15 year regional climate simulation for the Weddell Sea region. And the third study produces and evaluates a climatology of low level jets (LLJs) from the simulation data set. The evaluations were done in the attached three publications and the produced data sets are published online. In 2015/2016, the RV Polarstern undertook an Antarctic expedition in the Weddell Sea. We operated a Doppler wind lidar on board during that time running different scan patterns. The resulting data was evaluated, corrected, processed and we derived horizontal wind speed and directions for vertical profiles with up to 2 km height. The measurements cover 38 days with a temporal resolution of 10-15 minutes. A comparisons with other radio sounding data showed only minor differences. The resulting data set was used alongside other measurements to evaluate temperature and wind of simulation data. The simulation data was produced with the regional climate model CCLM for the period of 2002 to 2016 for the Weddell Sea region. Only smaller biases were found except for a strong warm bias during winter near the surface of the Antarctic Plateau. Thus we adapted the model setup and were able to remove the bias in a second simulation. This new simulation data was then used to derive a climatology of low level jets (LLJs). Statistics of occurrence frequency, height and wind speed of LLJs for the Weddell Sea region are presented along other parameters. Another evaluation with measurements was also performed in the last study. Diese kumulative Dissertation umfasst drei Studien mit Fokus auf die Weddellmeer-Region in der Antarktis. Im Rahmen der ersten Studie wurde ein qualitativ hochwertigen Datensatz von Wind Messungen aus der Region erzeugt und evaluiert. Im Rahmen der zweiten Studie wurde eine 15 Jahre ...