92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Sunday, 22 January 2012
Satellite and Analysis Based Examination of the Warm Conveyor Belt in An Extratropical Cyclone
Hall E (New Orleans Convention Center )
Juan A. Crespo, Purdue University, West Lafayette, IN; and D. J. Posselt

Extratropical cyclones are a major factor in regulating Earth's energy balance by transporting heat and energy poleward, providing large amounts of precipitation for temperate zones. A majority of this moisture present in extratropical cyclones is transported by the Warm Conveyor Belt (WCB), an airstream of ascending moisture that rises from the boundary layer to the upper troposphere. As the WCB strengthens, previous research has shown that there has been a positive correlation with rain rate and moisture in the cyclone, as WCB's are nearly 100% efficient at precipitating all transported moisture. Extratropical cyclones and their WCBs occur more often during the winter seasons than in the summer; however, there is stronger seasonal variability in the Northern Hemisphere. With the large impact that extratropical cyclones and warm conveyor belts have on the general atmospheric circulation, it is important to conduct research to better understand their properties to lead to better forecasting and how they could be affected by climate change.

Using observations from NASA's Earth Observing System Afternoon-Train (A-Train) Satellite constellation, along with GFS Reanalysis data, allowed us to observe the various properties of a warm conveyor belt of an extratropical cyclone that occurred November 21st to the 25th in 2006. Of the current A-Train Satellites, three of Aqua's instruments were used in the analysis of the WCB. The Atmospheric Infrared Sounder (AIRS) instrument observed the amount of total cloud and precipitable water, cloud phase and effective radius. The Advanced Microwave Scanning Radiometer for EOS (AMSR-E) instrument observations of cloud water, water vapor and rain rate were used in this experiment in addition for analysis of the WCB. Finally, the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument observations of cloud top pressure and temperature, along with cloud properties like aerosol content and cloud phase were key components in understanding the overall structure of the extratropical cyclone and WCB. By plotting GFS Reanalysis data from this 5 day span, we were also able to form a synoptic view of the extratropical cyclone and its warm conveyor belt. Analysis of variables such as winds, pressure, geopotential height, temperature, potential temperature, and precipitable water at multiple vertical levels allowed us to paint a picture of the overall structure of the storm and the WCB. Our results demonstrate the value of an analysis that combines satellite and numerical model data, and provide insight into the relationships between mesoscale cloud and precipitation features and the cyclone scale dynamics and thermodynamic environment. This experiment opens the door for future research involving multivariate analysis of extratropical cyclones and WCBs, particularly with respect to how they may be affected by potential changes in the Earth's climate system.

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