Retrieving Soil Moisture from Satellite Microwave Sensors for Fire Danger Assessment in Boreal and Arctic Regions

Laura Louise Bourgeau-Chavez, Michigan Tech Research Institute, lchavez@mtu.edu (Presenter)
Michael Battaglia, Michigan Technological University, mjbattag@mtu.edu
William Buller, Michigan Tech Research Institute, wtbuller@mtu.edu
Michael Billmire, Michigan Tech Research Institute (MTRI), mgbillmi@mtu.edu
Kyle McDonald, The City College of New York, kmcdonald2@ccny.cuny.edu
Chele Hanes, Canadian Forest Service, chelene.hanes@canada.ca
Liza K Jenkins, Michigan Tech Research Institute (MTRI), lliverse@mtu.edu
John S Kimball, University of Montana, john.kimball@mso.umt.edu
Randi Jandt, University of Alaska, rjandt@alaska.edu
Joseph Buckley, Royal Military College of Canada, buckley-j@rmc.ca

In Alaska and Canada, the Canadian Forest Fire Danger Rating System (CFFDRS) is used to estimate moisture in the organic soil layers of the ground from the surface (nominally 1.2 cm) down to deeper, more compact organic layers of the duff horizons (10-20 cm depth). The moisture status of the organic soil is a key driver of the potential for wildfire and C- and L-band Polarimetric SAR as well as NASA’s Soil Moisture Active Passive (SMAP) satellite sensor have potential to provide complementary data to CFFDRS. As a weather-based point source system, CFFDRS has inherent limitations that could be greatly improved with synoptic moisture information from a satellite sensor at high repeat frequency but low spatial resolution, such as SMAP, as well as complementary high spatial resolution but low repeat frequency SAR data. Research is underway to assess the utility of the L-band 9 & 36 km resolution SMAP moisture products for organic layer fuel moisture monitoring in boreal and Arctic ecosystems for fire danger prediction including: a) comparison to the broadscale network of weather-based CFFDRS fuel moisture estimates; b) soil moisture databases; and d) the actual occurrence of wildfire. At the same time, algorithm development is underway to use PolSAR data to predict organic layer fuel moisture in a variety of boreal and arctic ecosystems. Using polarimetric data has been shown to improve moisture retrieval by more than 35% over using only the backscatter information from multiple bands. In addition, a comparison of the passive SMAP data with high-resolution SAR imagery is being evaluated to: a) address the impact of scene heterogeneity and surface water on SMAP results; and b) investigate methods for downscaling SMAP to a finer resolution (0.2 to 3 km) soil moisture product through development of hydrological modeling and integration of high resolution SAR data from Sentinel-1 and/or PalSAR-2. The overall investigation will yield a more complete understanding of the relationship between field measurements, the CFFDRS Fire Weather Index, SAR and SMAP soil moisture. A key goal of this project is the development of a refined assessment of fire danger for boreal and Arctic regions. The outcomes of this project will be valuable for fire management and prediction across the vast region where weather-based information is scarce. While the research is focused on improving modeling of fire danger to understand spatial and temporal patterns of organic soil moisture in high northern latitude ecosystems, something that has not been able to be monitored synoptically before now, the impact of this research extends beyond fire decision-making into needs for ecosystem modeling and monitoring climate change vulnerability.

Associated Project(s): 

• Bourgeau-Chavez-04

Poster Location ID: 42

Session Assigned: Permafrost and Hydrology