Solar influence on mesospheric water vapor with impact on NLCs

摘要: Abstract On the basis of our global 3d-model dynamics and chemistry middle atmosphere COMMA-IAP we investigate influence variation solar activity on composition mesosphere/lower thermosphere. In mesosphere, unlike thermosphere, almost only marked results from change Lyman- α irradiance varying maximum by a factor about two over cycle. The radiation has strongest impact water vapor distribution above upper mesosphere. Water is key compound entire mesosphere determining all other chemically active species due to hydrogen radical production this source constituent. As result, thermally feedback dynamics. also constituent for formation NLCs PMSEs in high latitude summer. Above all, consider mixing ratio. Special attention given chemical NLC region at latitudes. expected find an increasing relative response ratio with height. Due strongly absorption below 70 km, variations become increasingly smaller are irrelevant non-definable 60 km. normally anti-phase activity, usually without distinct phase delay. Other such as ozone OH varies more irregularly, but coarse agrees photolysis highest values around maximum.