An "island" in the stratosphere - on the enhanced annual variation of water vapour in the middle and upper stratosphere in the southern tropics and subtropics

作者：Lossow Stefan^*; Garny Hella; Joeckel Patrick

来源：Atmospheric Chemistry and Physics, 2017, 17(18): 11521-11539.

DOI：10.5194/acp-17-11521-2017

The amplitude of the annual variation in water vapour exhibits a distinct isolated maximum in the middle and upper stratosphere in the southern tropics and subtropics, peaking typically around 15 degrees S in latitude and close to 3 hPa (similar to 40.5 km) in altitude. This enhanced annual variation is primarily related to the Brewer-Dobson circulation and hence also visible in other trace gases. So far this feature has not gained much attention in the literature and the present work aims to add more prominence. Using Envisat/MIPAS (Environmental Satellite/Michelson Interferometer for Passive Atmospheric Sounding) observations and ECHAM/MESSy (European Centre for Medium-Range Weather Forecasts Hamburg/Modular Earth Submodel System) Atmospheric Chemistry (EMAC) simulations we provide a dedicated illustration and a full account of the reasons for this enhanced annual variation.

• 出版日期2017-9-27