Snow and Ice
Remote sensing of snow cover and ice extent using the visible instruments of MODIS and VIIRS to monitor global snow cover extent and duration of snow cover. Combining the visible snow cover products with snow water equivalent (SWE) products derived from microwave instruments, e.g. AMSR-E, SMMR and SSM/I.
MODIS Snow Products
Revise and maintain the MODIS snow cover extent algorithms and data products for both the Terra and Aqua missions. Provide documentation of the algorithms and data products, primarily the User Guides. Provide detailed quality assessment (QA) regarding the accuracy and error of snow cover detection across all landscapes and viewing conditions.
Collection 6 (C6) production of the MODIS snow cover algorithms and products, with significant revisions to improve snow cover detection and increased QA information content will begin about September 2014.
VIIRS Snow Cover Evaluation
NPP VIIRS science team member evaluating the VIIRS snow cover Environmental Data Records (EDRs) and contributor to the NASA Suomi-NPP Land Team evaluation report of VIIRS EDRs.
Adapting the MODIS fractional snow cover extent algorithm to run with VIIRS data inputs and evaluating that new VIIRS fractional snow cover extent product to the standard VIIRS EDRs and MODIS standard data products.
MODIS Sea Ice Products
Revise and maintain the MODIS sea ice extent and ice surface temperature (IST) algorithms and data products for both the Terra and Aqua missions. Provide documentation of the algorithms and data products, primarily the User Guides. Provide detailed quality assessment (QA) regarding the accuracy and error of sea ice extent and temperature.
Collection 6 (C6) production of the MODIS sea ice extent algorithms and products will begin about September 2014.
Lead Support Scientist
SSAI - NASA GSFC
2000 - Present
RDC - NASA GSFC and RDC Greenbelt, MD
November 1989 - December 2000
MS, Forestry, Fisheries, and Wildlife, University of Nebraska, 1985
BS, Biology, Nebraska Wesleyan University, 1979
American Geophysical Union
1994 - Present
ASPRS The Imaging & Geospatial Information Society
1994 - Present
NASA GSFC Hydrospheric and Biospheric Sciences Laboratory HOBI Award for outstanding scientific and technical support, August 2012.
NASA GSFC Hydrospheric and Biospheric Sciences Laboratory Peer Award for Outstanding Support Service Contractor, September 2007.
NASA Goddard Technology Transfer Program, Certificate of Recognition for Software technology titled, “MODIS Snow and Sea Ice Maps”, 2003
NASA Goddard Technology Transfer Program, Certificate of Recognition for Software technology titled, “MODIS Snow and Sea Ice Maps – Level 2 Sea Ice, Level 3 Sea Ice Daily”, 2003
Justice, C., M. O. Roman, I. Csiszar, et al. E. Vermote, R. E. Wolfe, S. J. Hook, M. Friedl, Z. Wang, C. B. Schaaf, T. Miura, M. Tschudi, G. Riggs, D. K. Hall, A. I. Lyapustin, S. Devadiga, C. C. Davidson, and E. J. Masuoka. 2013. Land and cryosphere products from Suomi NPP VIIRS: Overview and status J. Geophys. Res. Atmos. 118 (17): 9753-9765 [10.1002/jgrd.50771]
Foster, J., G. S. Jackson, H. Meng, et al. J.-J. Wang, G. Riggs, P. J. Kocin, B. T. Johnson, J. Cohen, D. K. Hall, S. V. Nghiem, and J.-J. Wang. 2012. Passive microwave remote sensing of the historic February 2010 snowstorms in the Middle Atlantic region of the USA Hydrol. Processes 26 (22): 3459-3471 [10.1002/hyp.8418]
Foster, J. L., D. K. Hall, J. B. Eylander, et al. G. A. Riggs, S. V. Nghiem, M. Tedesco, E. J. Kim, P. M. Montesano, R. E. Kelly, K. A. Casey, and B. J. Choudhury. 2011. A blended global snow product using visible, passive microwave and scatterometer satellite data International Journal of Remote Sensing 32 (5): 1371-1395 [10.1080/01431160903548013]
Akyurek, Z., D. K. Hall, G. A. Riggs, and A. Sensoy. 2010. Evaluating the utility of the ANSA blended snow cover product in the mountains of eastern Turkey International Journal of Remote Sensing 31 (14): 3727-3744 [10.1080/01431161.2010.483484]
Hall, D. K., G. A. Riggs, J. L. Foster, and S. V. Kumar. 2010. Development and evaluation of a cloud-gap-filled MODIS daily snow-cover product Remote Sens Environ 114 (3): 496-503 [10.1016/j.rse.2009.10.007]
Hall, D. K., J. Key, K. A. Casey, G. A. Riggs, and D. J. Cavalieri. 2004. Sea ice surface temperature product from the Moderate Resolution Imaging Spectroradiometer (MODIS) IEEE Trans Geosci Remote Sensing 42 1076-1087
Talks, Presentations and Posters
Suomi NPP Snow Cover EDR Evaluation.
February 23, 2013
Oral presentation regarding evaluation of the VIIRS Snow Cover EDRs given at the NASA NPP Science Team Review, 23-25 January 2013, at GSFC. Purpose of review was to evaluate current status of the VIIRS products and use that information to develop plans for direction of the NPP program.
Tracking Seasonal Mountain Snow Cover with MODIS Snow Products
July 4, 2014
Oral presentation given an the Eastern Snow Conference, 3-5 June 2014, Boone NC. Demonstrated a technique using the daily MODIS snow cover product (MOD10A1) that can be used to track seasonal snow cover in a mountains region, allowing the user to determine the duration of seasonal snow cover extent.
Riggs, G. & Hall, D. 2012. Suomi NPP VIIRS Snow Cover Products Initial Evaluation, poster presentation at the NASA NPP Science Team Meeting, Greenbelt, MD, 10-11 May 2012
June 10, 2012
Initial evaluation of the accuracy and error of the VIIRS Snow Cover Environmental Data Records (EDRs). Evaluation was based on analysis of the algorithms and the comparative analysis of snow cover extent maps to ground station data and corresponding MODIS snow cover extent maps.