Integrating Enhanced GRACE Terrestrial Water Storage data into the U.S. and North American Drought Monitors
M. Rodell, C. Peters-Lidard
May 14, 2013 16:46:18
Description of Problem
NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites measure time variations of the Earth’s gravity field enabling reliable detection of spatio-temporal variations in total terrestrial water storage (TWS), including groundwater. The U.S. and North American Drought Monitors are two of the premier drought monitoring products available to decision-makers for assessing and minimizing drought impacts, but they rely heavily on precipitation indices and do not currently incorporate systematic observations of deep soil moisture and groundwater storage conditions. Thus GRACE has great potential to improve the Drought Monitors by filling this observational gap. We expect that the integration of the enhanced GRACE data into the operational production of objective drought indicator blends will lead to more accurate depictions of short and long-term drought conditions, ultimately benefitting the many stakeholders who depend on these products.
Scientific Objectives and Approach
Horizontal, vertical and temporal disaggregation of the coarse-resolution GRACE TWS data has been accomplished by assimilating GRACE TWS anomalies into the Catchment Land Surface Model using an ensemble Kalman smoother. The Drought Monitors combine several short-term and long-term drought indices and indicators expressed in percentiles as a reference to their historical frequency of occurrence for the location and time of year in question. To be consistent, we are in the process of generating a climatology of estimated soil moisture and ground water based on a 60-year Catchment model simulation which will subsequently be used to convert seven years of GRACE assimilated fields into soil moisture and groundwater percentiles, for systematic incorporation into the objective blends that constitute Drought Monitor baselines.
To date, completed and ongoing objectives include:
• Terrestrial water storage anomalies have been derived from GRACE for North American basins and converted into Drought Indicator percentiles for integration into the US and NA drought monitors
• The GRACE data assimilation system (GRACE-DAS) domain was expanded from the Mississippi River basin to all of North America.
• Soil moisture and groundwater anomalies, derived by GRACE-DAS, were evaluated using independent datasets.
Refereed Journal Publications
Houborg, R., Rodell, M., Li, B., Reichle, R., & Zaitchik, B.F. (2011). Drought indicators based on model assimilated GRACE terrestrial water storage observations. Submitted to Water Resources Research.
Other Publications and Conferences
Rodell, M. & Houborg, R. (2010). New GRACE Products for Hydrology. GRACE science team meeting at GFZ Potsdam, 11-12 Nov., 2010.
Houborg, R., Rodell, M., Zaitchik, B.F., & Reichle, R. (2010). Impact of GRACE data assimilation on the simulation of hydrologic states across North America. AGU Fall Meet. 2010, abstract H23H-08.
Zaitchik, B.F., Rodell, M., Reichle, R.H., Li, B., Houborg, R., Bolten, J.D. (2010). Realizing the potential of the GRACE data assimilation system. AGU Fall Meet. 2010, abstract H34C-04.
Houborg, R., Rodell, M., Lawrimore, J., Reichle, R., Heim, R., Rosencrans, M., Tinker, R., Famiglietti, J., Svoboda, M., Wardlow, B., Zaitchik, B. (2010). Using enhanced GRACE water storage data to improve drought detection by the U.S. and North American drought monitors. Geoscience & Remote Sensing Symposium, IGARSS 2010, July 25 – 30, Hawaii, pp. 710-713.
Houborg, R., & Rodell, M. (2010). Integrating GRACE Terrestrial Water Storage Data into the U.S. and North American Drought Monitors. Opportunities for Emerging Geospatial Technologies, ASPRS 2010, San Diego, 26-30 April.
Houborg, R., M. Rodell, J. S. Famiglietti, R. Heim, J. Lawrimore, B. Li, R. H. Reichle, M. Rosencranz, M. Svoboda, B. D. Wardlow, and B. F. Zaitchik, 2010: Toward Integrating Enhanced GRACE Terrestrial Water Storage Data into the U.S. and North American Drought Monitors. 90th AMS Annual Meeting, Atlanta, GA, 17-21 January, 2010.
Houborg, R., M. Rodell, J. S. Famiglietti, R. Heim, J. Lawrimore, B. Li, R. H. Reichle, M. Rosencranz, M. Svoboda, B. D. Wardlow, and B. F. Zaitchik, 2009: Toward Integrating Enhanced GRACE Terrestrial Water Storage Data into the U.S. and North American Drought Monitors. 2nd GRACE Hydrology Workshop, Austin, TX, Nov. 4, 2009.
Rodell, M., Li, B., Bolten, J., Houborg, R., Kato, H., Zaitchik, B.., and Reichle R., 2009: Satellite Data Integration for Drought Monitoring and Water Resources Applications. Proceedings of the 6th International Scientific Conference on the Global Energy and Water Cycle, Melbourne, Australia, 24-28 August, 2009.
Rodell, M., Zaitchik, B.F., Li, B, Bolten, J.D., Houborg, R., Velicogna, I., Famiglietti, J.S., 2009: Hydrologic Applications of GRACE Terrestrial Water Storage Data. Eos Trans. AGU, 90 (52), Fall Meet. Suppl., Abstract G33E-05.