A model study on the influence of overshooting convection on TTL water vapour
MEE Hassim, TP Lane
ATMOSPHERIC CHEMISTRY AND PHYSICS | COPERNICUS GESELLSCHAFT MBH | Published : 2010
Overshooting deep convection that penetrates into the Tropical Tropopause Layer (TTL) is thought to have an important role in regulating the water vapour content of this region. Yet, the net effect of such convection and the dominant mechanisms remain unclear. This study uses two idealised three-dimensional cloud-resolving model simulations to examine the influence of overshooting convection on water vapour when it penetrates into two different TTL environments, one supersaturated and the other subsaturated with respect to ice. These simulations show that the overshooting convection plays a direct role in driving the ambient environment towards ice saturation through either net moistening (s..View full abstract
Awarded by Australian Research Council
This research has been partially funded by the Australian Postgraduate Award, Australian Research Council's Discovery Projects (DP0770381) and Future Fellowships (FT0990892) schemes. The authors wish to thank Tim Hume (Australian Bureau of Meteorology) for providing the corrected TWP-ICE radiosonde data and Jason Knievel (NCAR) for supplying the code and instructions for the implementation of passive scalars in the WRF model. Thank you also to Andy Heymsfield (NCAR), Andrew Gettelman (NCAR), Greg Thompson (NCAR), Peter May (Centre for Australian Weather and Climate Research, CAWCR) and Kathrin Wapler (Deutscher Wetterdienst, DWD) for helpful discussions. Computing facilities were provided by the Victorian Partnership for Advanced Computing (VPAC). Finally, we would like to thank the two anonymous reviewers who helped improve the paper.