Semiarid ecosystems dominated by summer rainfall can have a dramatic seasonal greening that affects land-atmosphere interactions and rainfall-runoff dynamics. Little is known about these interactions in semiarid monsoon regions throughout the world, primarily due to a paucity of ground observations and limitations in the remote sensing and numerical modeling of these complex systems. The North American Monsoon System (NAMS) provides an ideal opportunity to investigate the processes by which the land surface interacts and modulates a monsoon system. NAMS controls the distribution of rainfall, vegetation, streamflow and recharge in the southwestern US and northern Mexico and can account for 40 to 70% of the annual precipitation. Its strong geographic variation provides an organizing principle to study the influence of summer conditions on the climate, hydrology and ecology of southwestern North America. There is an urgent need for integrative studies that characterize land surface conditions and their influence on hydrologic and atmospheric processes. We argue that significant advances can be made through efforts that synthesize ground observation networks, remote sensing data and hydrometeorological models in these environments. We seek to address an identified gap in understanding land surface interactions with NAMS through comparative studies along gradients spanning across four selected Army Installations (Yuma Proving Grounds, Fort Huachuca, Fort Bliss and Fort Carson). Our scientific objectives are to: (1) Characterize the spatiotemporal variability of hydrometeorological processes in the NAMS region; (2) Analyze the seasonal evolution and linkages in meteorological forcing and land surface characteristics; (3) Conduct hydrometeorological model experiments to quantify the effects of seasonal variations in land surface conditions; and (4) Synthesize process studies and numerical modeling efforts to obtain regional spatiotemporal estimates. For each objective, we seek to gain process understanding that will be useful for improving predictive hydrometeorological models. To do so, we propose to use a portable instrumentation network, remote sensing data and hydrometeorological modeling in the Army Installations and over the broader NAMS domain. The sites have significant differences in land surface seasonality, spanning aridity and monsoonal gradients, and thus are ideal for our scientific questions. Our proposal focuses on transforming hydrometeorological data obtained at well instrumented sites into prediction capabilities useful for Army Installations. We approach the problem of improving hydrometeorological predictions by selecting sites arranged along a gradient in monsoon conditions. In order to deliver new capabilities for NAMS forecasting, we seek to acquire process understanding via field measurements and remote sensing data. Based on these observations, we will apply, test and analyze the predictions of a hydrometerological forecasting system accounting for seasonal variations in land surface characteristics. Our efforts are aimed towards improved understanding of the seasonal variability in land surface and atmospheric processes. Further, the proposed work will have a direct impact on our understanding of hydrometeorological processes in a region with significant social, economic and political issues related to water resources.
|Effective start/end date||3/1/09 → 2/28/15|
- US Department of Defense (DOD): $999,288.00