Atmosphere Ocean Science Colloquium

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Radiative constraints on the large-scale atmospheric circulation

Speaker: David Thompson, Colorado State

Location: Warren Weaver Hall 1302

Date: Wednesday, September 11, 2019, 3:30 p.m.

Synopsis:

In this talk I will present three novel ways in which clouds and water vapor influence the large-scale atmospheric circulation. One: I will argue that thermodynamic constraints placed on water vapor concentrations provide a robust constraint on the depth of mixing by large-scale extratropical eddies. As such, extratropical clouds, the level of largest extratropical wave driving, and the extratropical tropopause all remain at roughly the same temperature - and thus shift upwards - under climate change. Two: I will argue that the resulting lifting of clouds across the globe contributes to poleward shifts in the extratropical circulation as the temperature of the atmosphere increases. And three: I will present evidence that the inclusion of cloud radiative effects in numerical simulations lead to ~two-fold increases in the variance of tropical climate on decadal timescales. Implications for decadal climate variability and change will be discussed.