Natural Aerosol Feedback Effects During Extreme Weather Events For North East U.S.

Abstract:

The predictability of extreme weather events associated with high wind speed and precipitation is significant due to the impacts in human lives and the environment. As storm occurrences of various types and intensities have become more frequent in the Northeastern part of the United States, the need for improving the numerical prediction of those storms has emerged. In this work, we investigate the role of natural aerosols in the atmospheric conditions during extreme weather events, using regional atmospheric modeling systems. We explore how natural aerosols (dust, sea salt) influence the accuracy of the numerical prediction in real-time as well as in hind-cast mode by including the radiative feedback and the explicit treatment of cloud condensation nuclei. Two research activities are associated with the objectives described herein that will be presented and discussed. Real-time operational forecasts for NE U.S. are produced using two atmospheric modeling systems: WRF and RAMS/ICLAMS. The use of two modeling systems was chosen in the view of assessing the uncertainty of atmospheric variables by implementing two different and, at the same time, similarly configured modeling systems. Past storm cases that affected the region have been analyzed covering the period from 2001 to 2013 ranging from thunderstorms, snow/ice storms to typical winter storms and hurricanes. To accomplish that, we used the two models to create an ensemble that informs other research activities related to infrastructure resiliency and adaptation. In addition, we analyzed several past storm cases including the natural aerosol feedback effects and measure the responsiveness of the prediction as well as the differences in the storm intensity. The second activity that relates to the objectives of this work is the participation in the Integrated Precipitation and Hydrology EXperiment (IPHEx) that supports the Global Precipitation Measurement (GPM) mission. We performed daily weather forecasts for the hydrological forecasting as well as post-experiment simulations for the complex terrain of the Southern Appalachians including the natural aerosol feedback effects (Intense Observing Period (IOP): May-June 2014). Results from both activities will be presented and discussed.