ANTARCTIC CLOUD MASS MERIDIONAL TRANSPORT
Joseph J. Nettesheim[*]1,2,Matthew A. Lazzara1,3, Linda M. Keller1,2, and Maria Tsukernik4
1Antarctic Meteorological Research Center, Space Science and Engineering Center
2Department of Atmospheric and Oceanic Sciences
University of Wisconsin-Madison, Madison, WI
3Department of Physical Sciences, School of Arts and Sciences, Madison Area Technical College, Madison, WI
4Environmental Change Initiative, Department of Geological Sciences, Brown University, Providence, RI
1. OVERVIEW
The construction of an Antarctic cloud mass meridional transport (CMMT) event climatology is presented. We define CMMT events as the poleward propagation of large, synoptic scale cloud masses for a minimum of 48 hours. The climatology represents the twenty-year period from November 1992 through October 2012 and is comprised of event counts and duration, as determined through infrared and water vapor satellite composites. By considering the meridional transport of cloud masses, we are one step closer to discovering and understanding the meteorological situations that result in Antarctic ice sheet snow accumulation. Snow accumulation is important due to the significant contribution to the mass balance, yet hard to estimate due to the lack of differentiation between precipitating snow and blowing and drifting snow. The purpose of this project is to identify regions of Antarctica that are favorable for meridional cloud transport and to quantify this analysis.
We provide temporal insight into events that occur in seven spatially defined sections: Marie Byrd Land, Ellsworth Land, Queen Maud Land, Enderby Land, Queen Mary Coast, Wilkes Land and Victoria Coast (See Figure 1). We find that October is the most active month overall for the entire continent and the summer field season (December, January and February) is the least active season. Additionally, Ellsworth Land (75°W - 120°W) and Queen Maud Land (30°E - 120°W) are the two most active sectors in terms of days affected and total number of events, respectively. The impacts of CMMT events are also easily traced by considering associated weather conditions (pressure fluctuations, winds and precipitation) observed from automated weather stations (AWS), providing a verifying timeline of events. This climatology represents the first Antarctic meridional cloud mass transport climatology, strictly constrained to the relatively rare meridional shift from the predominantly zonal flow, resulting in the advection onto the continent of cloud masses.
Figure 1. An infrared satellite composite image with a map of Antarctica and regional sectors (color-coded) of the Antarctic continent used for tracking CMMT events.
2. ACKNOWLEDGEMENTS
This material is based upon work supported by the National Science Foundation under grant #ANT-1141908, ANT-1244924, and NSF-1246178.
[*] Corresponding Author: Joseph J. Nettesheim
Antarctic Meteorological Research Center, Space Science and
Engineering Center, University of Wisconsin-Madison
E-mail: nettesheim@@wisc.edu