%0 Journal Article
%A Ploeger, Felix
%A Birner, Thomas
%A Charlesworth, Edward
%A Konopka, Paul
%A Müller, Rolf
%T Moist bias in the Pacific upper troposphere and lower stratosphere (UTLS) in climate models affects regional circulation patterns
%J Atmospheric chemistry and physics
%V 24
%N 3
%@ 1680-7316
%C Katlenburg-Lindau
%I EGU
%M FZJ-2024-01693
%P 2033 - 2043
%D 2024
%X Water vapour in the upper troposphere and lower stratosphere (UTLS) is a key radiative agent and a crucial factor in the Earth's climate system. Here, we investigate a common regional moist bias in the Pacific UTLS during Northern Hemisphere summer in state-of-the-art climate models. We demonstrate, through a combination of climate model experiments and satellite observations, that the Pacific moist bias amplifies local long-wave cooling, which ultimately impacts regional circulation systems in the UTLS. Related impacts involve a strengthening of isentropic potential vorticity gradients, strengthened westerlies in the Pacific westerly duct region, and a zonally displaced anticyclonic monsoon circulation. Furthermore, we show that the regional Pacific moist bias can be significantly reduced by applying a Lagrangian, less-diffusive transport scheme and that such a model improvement could be important for improving the simulation of regional circulation systems, in particular in the Asian monsoon and Pacific region.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001190484800001
%R 10.5194/acp-24-2033-2024
%U https://juser.fz-juelich.de/record/1023129