Development and Analysis of Satellite-Based Aerodynamic Roughness Fields For Regional And Global Modeling Applications Using MODIS Data
J. Borak (ESSIC/UMD)
October 26, 2012 15:26:18
Description of Problem
The primary purpose of this task is to develop aerodynamic roughness fields at regional to global scales from MODIS data for improving models of land-atmosphere exchanges. The theory and algorithms have been developed by the task sponsor, Michael Jasinski, while the PI is primarily responsible for application of the algorithms. The sponsor and PI intend to develop and analyze other large modeled data fields from remote sensing products in the near future.
Scientific Objectives and Approach
The sponsor has expanded on earlier aerodynamic momentum roughness theory of M. Raupach, and extended it to produce parameters that are specific to vegetation type. The PI then employs these parameterizations with MODIS data products to generate a global time series of 1-km roughness fields. Also, the PI performs ongoing data reconnaissance in order to acquire validation data, as well as ancillary information about vegetation canopy height (e.g., from ICESat). In addition to the roughness research, the PI works with the GSFC sponsor on a statistical analysis of modeled snow water equivalent (SWE) data as part of the sponsor’s involvement with the collaborative National Climate Assessment (NCA) project being carried out within the Hydrological Sciences Laboratory at NASA/GSFC. The sponsor and PI are currently participating in the NCA effort by planning how they will analyze the modeled SWE data – once they have become available – including performing some proof-of-concept type research with remotely sensed estimates of SWE.
The key accomplishment for this task during the reporting period is the generation of a preliminary global roughness time series dataset. Some issues remain, so the data are still unreleased, but the initial goal of producing global databases of a) zero-plane displacement height (d0) and b) roughness length (z0) has been achieved. Each field is mapped to a 1-km grid, on an 8-day time step. The current version of the product covers the ten-year period from 2001-2010, and it is expected that additional temporal coverage will be added in the near future. Other anticipated enhancements include improved vegetation canopy height information available from recently published datasets.
Other Publications and Conferences
Borak, J.S. and M.F. Jasinski, A dynamic vegetation aerodynamic roughness length database developed from MODIS imagery for improved modeling of global land-atmosphere exchanges, AGU Chapman Conference on Remote Sensing of the Terrestrial Water Cycle, Kona, HI, February 19-22, 2012.