During the Cinese Arctic Cruise in 2018 frequent radiosoundings were launched in support of YOPP Special Observation Period along the path of XUELONG ice breaker. The radiosoundes were launched 2-3 times per day from July 28th to September 3rd in the Arctic Ocean and a total of 76 soundings data were shared through WMO GTS in BUFR format. These BUFR files are now available for download at:

http://data.wis.cma.cn/GTS/open/BUFR/Upper_air/Arctic_Xuelong

Data from the Yopp-endorsed project KPOPS are now available.

The radiosonde balloon sounding observations were performed from 5 August 2019 to 17 September 2019 to obtain the Arctic Ocean high-resolution atmospheric vertical profiles along the IBRV Araon cruise track at four times daily intervals (00, 06, 12, 18UTC). The data include vertical profiles of temperature, humidity, pressure, wind speed and wind direction up to about 30km. The data have been used for the data assimilation of the KOPRI Arctic weather forecast system.

Radiosonde and SYNOPs for Baranova and Tiksi stations for the YOPP SOP NH1 and NH2 are now available at

• http://www.aari.ru/main.php?lg=1&id=407 (Baranova)
• http://www.aari.ru/main.php?lg=1&id=273 (Tiksi)

Data are yet not indexed in the YOPP catalogue. Work is in progress to index these datasets.

ECMWF IFS for YOPP supersites are now available at http://thredds.met.no/thredds/catalog/alertness/YOPP_supersite/ifs-ecmwf.... Preparation of discovery metadata for inclusion in the YOPP Data Portal is in progress. ECMWF is not responsible for any use that may be made of the YOPPsiteMIP dataset.