Four projects with contributions from the German institutes Alfred-Wegener-Institut (AWI), the Leibniz Institute for Tropospheric Research (TROPOS) and the University of Trier support the YOPP mission by intensifying observations and advancing understanding of polar processes. During the Special Observing Period (SOP) for YOPP-SH AWI will increase radiosoundings at the Antarctic research station Neumayer and onboard the icebreaker Polarstern to four sondes per day (00, 06, 12, 18 UTC, project AWImet). AWI will also ensure continued operation of two automatic weather stations in Antarctica at least until the end of the SOP. Some 20 autonomous buoys measuring sea-ice parameters such as sea-ice and snow thickness as well as ice-drift velocity will be deployed in the eastern Wedell Sea around Feb./Mar. 2018 (project IPAB) by AWI. Additional buoys will be deployed on the fast-ice area in front of Neumayer Station in May/June 2018. Intentionally, these buoys will drift with the Weddell Gyre and still deliver data during the SOP. Buoys for ocean surface drift velocity could also be deployed on the Polarstern cruise in January 2019, but funding is still required. During the Antarctic season 2016/17 the Swiss-lead Antarctic Circumnavigation Expedition was conducted. As partner of the “Study of Preindustrial-like-Aerosol Climate Effects” (SPACE) project TROPOS carried out various aerosol measurements with special focus on particles able to act as cloud condensation nuclei and on particles able to nucleate ice. The overall aim of this project is to improve the understanding of aerosol-cloud interactions in the pristine Antarctic atmosphere. Quality assured measurement data shall be made available through GASSP and EBAS databases. During Polarstern cruise PS111 from Jan. till March 2018 wind lidar measurements will be carried out in the Weddell sea by the University of Trier. Measurements include horizontal and vertical scan programs to deduce wind profiles. Depending on weather conditions, data up to 1 km (and in single cases up to 2 km) can be collected, with a spatial resolution of 10m and temporal resolution of 15 min. The data, along with other Antarctic atmospheric measurements during YOPP, will be used in high-resolution atmospheric simulations (5km) for model verification and improvement of parameterizations.