Impact of Assimilation of Radiosonde and UAV Observations from the Southern Ocean in the Polar WRF Model  

作　　者：Qizhen SUN Timo VIHMA Marius OJONASSEN Zhanhai ZHANG 

机构地区：[1]College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266100,China [2]Polar Research and Forecasting Division,National Marine Environmental Forecasting Center,Beijing 100081,China [3]Finnish Meteorological Institute,PO Box 503,Helsinki FI 00101,Finland [4]Geophysical Institute,University of Bergen,PO Box 7803,Bergen NO 5020,Norway [5]The University Centre in Svalbard,PO Box 156,Longyearbyen NO 9171,Norway [6]Key Laboratory for Polar Science of the State Oceanic Administration,Polar Research Institute of China,Shanghai 200136,China

出　　处：《Advances in Atmospheric Sciences》2020年第5期441-454,共14页大气科学进展（英文版）

基　　金：the China National Key R&D Program of China(Grant No.2016YFC1402705);the Academy of Finland(contract:304345).

摘　　要：Weather forecasting in the Southern Ocean and Antarctica is a challenge above all due to the rarity of observations to be assimilated in numerical weather prediction(NWP)models.As observations are expensive and logistically challenging,it is important to evaluate the benefit that additional observations could bring to NWP.Atmospheric soundings applying unmanned aerial vehicles(UAVs)have a large potential to supplement conventional radiosonde sounding observations.Here,we applied UAV and radiosonde sounding observations from an RV Polarstern cruise in the ice-covered Weddell Sea in austral winter 2013 to evaluate the impact of their assimilation in the Polar version of the Weather Research and Forecasting(Polar WRF)model.Our experiments revealed small to moderate impacts of radiosonde and UAV data assimilation.In any case,the assimilation of sounding data from both radiosondes and UAVs improved the analyses of air temperature,wind speed,and humidity at the observation site for most of the time.Further,the impact on the results of 5-day-long Polar WRF experiments was often felt over distances of at least 300 km from the observation site.All experiments succeeded in capturing the main features of the evolution of near-surface variables,but the effects of data assimilation varied between different cases.Due to the limited vertical extent of the UAV observations,the impact of their assimilation was limited to the lowermost 1?2-km layer,and assimilation of radiosonde data was more beneficial for modeled sea level pressure and near-surface wind speed.

关 键 词：numerical weather prediction RADIOSONDE SOUNDINGS unmanned AERIAL vehicles data ASSIMILATION ANTARCTIC Southern Ocean 

分 类 号：P412.2[天文地球—大气科学及气象学]