Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 4/16/2003
Publication Date: 7/15/2002
Citation: Jackson, T. 2002. Passive microwave remote sensing soil moisture and regional drought monitoring. Interpretive Summary: Soil moisture maps, an improved index of drought, and inputs to global climate models are possible through the use of passive microwave remote sensing of soil moisture. These products could provide information on drought potential and severity. Since drought indices and GCMs do not consider actual soil moisture conditions, this approach could have major value for agriculture. The basis for measuring soil moisture using passive microwave remote sensing is presented with a description of alternative techniques for retrieving soil moisture. Current and future satellite systems are reviewed along with examples of soil moisture studies that illustrate how this information can be used in drought monitoring and assessment. Results could improve the accuracy, timing and reliability of the indices and predictions. This is a major goal identified in the National Drought Policy Commission report. As noted in that report, federal linteragency efforts to detect drought trends two-weeks in advance is a goo start. Longer-term predictions would improve services. Improved warnings of drought would benefit farmers, ranchers, water managers and the markets. These products are highly relevant to the Global Water and Energy Experiment and NRCS National Water and Climate Program. Better assessments would be of both significant economic and environmental value on a national and global basis.
Technical Abstract: Current tools to predict drought, indices and global climate models (GCMs), not include any direct observations of the soil condition, which is critica for agriculture. Soil moisture and deficit products are now feasible using new generation of microwave remote sensing satellites. These measurements c be used to measure and monitor the actual soil moisture conditions on a dai ibasis over the entire Earth. The quality of these products will continue t improve over time as new sensors are launched. These satellite products, combined with existing insitu observations and models, should be exploited drought monitoring, assessment and prediction. The basis for measuring soil moisture using passive microwave remote sensing is presented with a description of alternative techniques for retrieving soil moisture. Current and future satellite systems are reviewed along with examples of soil moist studies that illustrate how this information can be used in drought monitor rand assessment. Within the next five years a wide range of new and significantly improved satellites will be launched that will offer new opportunities. These new opportunities should help mitigating the effects o drought can be achieved through better information on the current status (monitoring), prediction of occurrence, and extent of impact.