Evaluation of Southern Ocean Atmospheric Rivers in Atmospheric Reanalysis data Based on a Navigational Observation
Atmospheric rivers significantly impact the ocean-land-ice-atmosphere interaction around Antarctica.However,the shortage of in situ observations limits people's understanding,bringing considerable uncertainty in numerical simulation results and products.This study utilized ship-borne radiosonde data collected during the 37th Chinese Antarctic Expedition to evaluate four kinds of state-of-the-art atmospheric reanalysis datasets(ERA5,CFSv2,JRA-55,and MERRA-2)during an atmospheric river event in the Southern Ocean.All reanal-ysis provide acceptable descriptions of integrated water vapor transport(IVT)compared with the observation,even during the atmospheric river events.However,all reanalyses overestimated the humidity and underestimat-ed the wind speed across the entire atmospheric column(from surface to 300 hPa).Moreover,all reanalyses,ex-cept for ERA5,failed to capture the variation in the covariance term between humidity and wind speed in the ver-tical direction;the latter contributes to a considerable bias in the IVT of reanalyses.The ERA5 demonstrates su-perior performance during the observation period,especially in humidity and low-level jet profiles when the at-mospheric river arrives at the observation site.In this study,ERA5 seems to be the best atmospheric reanalysis for studying atmospheric rivers in the Southern Ocean.
万方数据
维普
