Location
East-West Center, University of Hawai'i at Manoa (Honolulu, Hawai'i)
Start Date
16-10-2012 5:30 PM
End Date
16-10-2012 7:30 PM
Document Type
Poster
Description
In simulations of tropical-tropopause-layer (TTL) cirrus forced by a large-scale equatorial Kelvin wave, we show that the radiatively induced mesoscale dynamics in these clouds actively contributes to vertical transport of water vapor. In a typical TTL cirrus, the heating that results from absorption of radiation by ice crystals induces a mesoscale circulation. Advection of water vapor by the radiatively induced circulation leads to upward advection of the cloudy air. Upward advection of the cloudy air is equivalent to upward transport of water vapor when the air above the cloud is drier than the cloudy air. On the other hand, ice nucleation and depositional growth, followed by sedimentation and sublimation lead to downward transport of water vapor. The net direction of transport is determined by the relative magnitudes of the upward advection of water vapor and the downward transport associated with microphysical processes.
Cirrus and water vapor transport in the tropical tropopause layer: A modeling study
East-West Center, University of Hawai'i at Manoa (Honolulu, Hawai'i)
In simulations of tropical-tropopause-layer (TTL) cirrus forced by a large-scale equatorial Kelvin wave, we show that the radiatively induced mesoscale dynamics in these clouds actively contributes to vertical transport of water vapor. In a typical TTL cirrus, the heating that results from absorption of radiation by ice crystals induces a mesoscale circulation. Advection of water vapor by the radiatively induced circulation leads to upward advection of the cloudy air. Upward advection of the cloudy air is equivalent to upward transport of water vapor when the air above the cloud is drier than the cloudy air. On the other hand, ice nucleation and depositional growth, followed by sedimentation and sublimation lead to downward transport of water vapor. The net direction of transport is determined by the relative magnitudes of the upward advection of water vapor and the downward transport associated with microphysical processes.
