Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS05] Stratosphere-troposphere Processes And their Role in Climate

Wed. May 29, 2019 10:45 AM - 12:15 PM 201B (2F)

convener:Yoshio Kawatani(Japan Agency for Marine-Earth Science and Technology), Shingo Watanabe(Japan Agency for Marine-Earth Science and Technology), Takashi Sekiya(Japan Agency for Marine-Earth Science and Technology), Kaoru Sato(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Chairperson:Takashi Sekiya

11:45 AM - 12:00 PM

[AAS05-08] Inter-comparison of Upper Air Temperature in China between Satellite MSU and Radiosonde Datasts

*Yanjun GUO1, Cheng-zhi Zou2, Panmao Zhai3, Guofu Wang1 (1.National Climate Center(NCC), China Meteorological Administration(CMA) , 2.Center for Satellite Applications and Research, NOAA/NESDIS, 3.Chinese Academy of Meteorolgical Sciences (CAMS), China Meteorological Administration (CMA))

Keywords: upper air, temperature, satellite, radiosonde, China, trend

Reconciling upper-air temperature trends derived from radiosonde and satellite observations is a necessary step to confidently determine the global warming rate. This study examines the raw and homogenized radiosonde observations over China and compares them with layer-mean atmospheric temperatures derived from satellite microwave observations for the lower-troposphere (TLT), mid-troposphere (TMT), upper troposphere (TUT), and lower stratosphere (TLS) by three research groups. The comparisons are for averages over China, excluding Tibetan Plateau, and at individual stations where metadata contain information on radiosonde instrument changes. It is found that major differences between the satellite and radiosonde observations are related to artificial systematic changes. The radiosonde system updates in early 2000s over China caused significant discontinuities and led the radiosonde temperature trends to exhibit less warming in the middle and upper troposphere and more cooling in the lower stratosphere than the satellite temperatures. Homogenized radiosonde data have been further adjusted using shift-point adjustment approaches to match with satellite products for China average. The obtained trends during 1979-2015 from the re-adjusted radiosonde observation are respectively 0.203±0.066, 0.128±0.044, 0.034±0.039, and -0.329±0.135 K Decade-1 for TLT, TMT, TUT, and TLS equivalents. Compared to satellite trends, the re-adjusted radiosonde trends are within 0.01 K Decade-1 for TMT and TUT, and 0.054 K Decade-1 warmer for TLT and 0.051 K Decade-1 cooler for TLS. The results suggest that the use of satellite data as a reference are helpful in identifying and removing inhomogeneities of radiosonde temperatures over China and reconciling their trends to satellite microwave observations. Future efforts are to homogenize radiosonde temperatures at individual stations over China using similar approaches.