Case, Jonathan L., ENSCO Inc./National Aeronautics
and Space Administration SPoRT, Frank J. LaFontaine, Raytheon/NASA SPoRT
Center, Sujay V. Kumar, SAIC/NASA GSFC, Christa D. Peters-Lidard, NASA GSFC
The NASA Short-term
Prediction Research and Transition (SPoRT) Center has developed a real-time
Greenness Vegetation Fraction (GVF) dataset, updated daily using swaths of
Normalized Difference Vegetation Index data from the Moderate Resolution
Imaging Spectroradiometer (MODIS) data aboard the NASA-EOS Aqua and Terra
satellites. SPoRT began generating
real-time GVF composites at 1-km resolution over the Continental United States
beginning 1 June 2010 for incorporation into the Land Information System (LIS)
within the NASA-Unified WRF (NU-WRF) modeling system. This paper will focus on individual case studies of severe
weather events at a convection-allowing resolution to determine the impacts of
incorporating real-time, high-resolution MODIS GVF in place of the Advanced
Very High Resolution Radiometer (AVHRR)-based climatology GVF.
The NU-WRF modeling
system is employed to conduct sensitivity simulations of individual
events. The NU-WRF is an
integrated modeling system based on the Advanced Research WRF (ARW) that is
designed to represent aerosol, cloud, precipitation, and land surface processes
at satellite-resolved scales in a coupled simulation environment. For this experiment, the coupling
between the LIS and the ARW model is utilized to measure the impacts of the
real-time SPoRT/MODIS versus the monthly AVHRR climatology GVF. Snapshots of LIS-Noah land surface
fields from spin-up runs are used to initialize two different coupled
simulations of the NU-WRF: one running with climatology AVHRR-based GVF, and
the other running with the real-time MODIS-based GVF. Results are highlighted in regions with substantial
differences in GVF between the AVHRR climatology and SPoRT/MODIS product during
severe weather episodes. While
many events examined had relatively minor impacts on the resulting simulations,
a few severe-weather episodes experienced improved evolution of simulated
precipitation by incorporating the real-time SPoRT/MODIS GVF, including the
Upper Midwest severe outbreak of 17 July 2010 and the Joplin, MO tornado day of
22 May 2011.