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  • Structure of an Atmospheric River Over Australia and the Southern Ocean. Part I: Tropical and Midlatitude Water Vapor Fluxes
Title: Structure of an Atmospheric River Over Australia and the Southern Ocean. Part I: Tropical and Midlatitude Water Vapor Fluxes
Abstract An atmospheric river (AR) impacting Tasmania, Australia, and the Southern Ocean during the austral summer on 28–29 January 2018 during the Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study campaign is analyzed using a modeling and observational approach. Gulfstream‐V dropsonde measurements and Global Precipitation Measurement radar analyses were used in conjunction with Weather Research and Forecasting model simulations with water vapor tracers to investigate the relative contributions of tropical and midlatitude moisture sources to the AR. Moisture associated with a monsoonal tropical depression became entrained into a midlatitude frontal system that extended to 60°S, reaching the associated low‐pressure system 850 km off the coast of Antarctica—effectively connecting the tropics and the polar region. Tropical moisture contributed to about 50% of the precipitable water within the AR as the flow moved over the Southern Ocean near Tasmania. The tropical contribution to precipitation decreased with latitude, from >70% over Australia, to ~50% off the Australian coast, to less than 5% poleward of 55°S. The integrated vapor transport (IVT) through the core of the AR reached above 500 kg m−1 s−1during 1200 UTC 28 January to 0600 UTC 29 January, 1.29 times the average amount of water carried by the world's largest terrestrial river, the Amazon. The high IVT strength might be attributed to the higher water vapor content associated with the warmer temperatures across Australia and the Southern Ocean in austral summer.  more » « less
Award ID(s):
1762096
PAR ID:
10374915
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  
Publisher / Repository:
DOI PREFIX: 10.1029
Date Published:
Journal Name:
Journal of Geophysical Research: Atmospheres
Volume:
125
Issue:
18
ISSN:
2169-897X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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