Real-time SPoRT/LIS upgraded on September 10th

Effective 10 September, the real-time SPoRT-LIS running over much of the southern and eastern U.S. was upgraded with several improvements.

The upgrade is transparent to Environmental Modeling System (EMS) end-users, since file and data formats are the same and the EMS processing with the “lis” land surface model (LSM) option operates the same as before.  However, it is highly recommended that EMS end-users currently running the “lis” option consider changing to the land-use database described in the 2nd bullet below.

The most noteworthy modifications and improvements are:

  • Updated LIS software to support an upgrade from Noah LSM version 2.7.1 to version 3.2.  This upgrade includes an improved look-up table methodology for some static fields and improved handling of heat fluxes over snow-covered regions.
  • Changed land-use classification (vegetation type) from the U.S. Geological Survey (USGS) 24-class database to the newer International Geosphere Biosphere Programme (IGBP)/MODIS 20-class database.  The IGBP/MODIS database is more up-to-date than the USGS database, especially with urban classifications.
  • Switched from a coarse-resolution surface albedo climatology to a look-up table methodology for surface albedo based on (a) input Green Vegetation Fraction (GVF) data from the high-resolution SPoRT-MODIS real-time product and (b) the newer IGBP/MODIS land-use database.  A sample real-time SPoRT-MODIS GVF map projected onto the 3-km LIS domain is given in Figure 1, showing a comparison between the monthly climatological GVF and the real-time MODIS GVF data from 30 August.  An example comparison between the original climatological specification of surface albedo and the newer look-up table methodology using real-time SPoRT-MODIS vegetation data is given in Figure 2 from the same day.  Both of these upgrades will improve the surface energy budget in the real-time LIS.
  • Modified the long-term atmospheric forcing (excluding precipitation) that drives the LIS-Noah LSM integration from the North American Land Data Assimilation System (NLDAS) to NLDAS phase 2 (NLDAS-2).

Contact SPoRT for the official upgrade documentation for further details.

Figure 1. Comparison between the default monthly climatological Green Vegetation Fraction (GVF, in percent) time-interpolated to 30 August (left), and real-time SPoRT-MODIS GVF on 30 August 2012 (right). Note the much lower GVF over the Midwest in the SPoRT-MODIS dataset corresponding to the substantial drought. (Click image twice for full size)

Figure 2. Comparison between climatological surface albedo (%) time-interpolated to 30 August in the former LIS configuration (left), and surface albedo as a function of the real-time SPoRT-MODIS GVF in the upgraded LIS configuration (right). Note the higher surface albedo corresponding to lower SPoRT-MODIS GVF in the Plains and Midwest regions. (Click image twice for full size)

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