Natural hazards such as flashfloods and landslides occur in response to large precipitation. Flashfloods are associated with heavy rainfall rates, whereas landslides are initiated in response to large subsurface runoff, and thus may happen during the storm or long after rainfall stopped. Previous research in the Great Smoky Mountains suggests that as rain falls through fog and low level clouds, intensity of rainfall can increase by a factor of ten in a few minutes. In this project, we will collect observations to investigate rainfall enhancement processes that can be used to improve the estimation and prediction of rainfall and the response-time of subsurface runoff and streamflows. The measurements will include characterization of aerosols and CCN leading to fog and low level cloud formation, and observations of the microphysics of fog, light and heavy rainfall. Soil water and stream water samples will be collected for future tracer analysis to determine how the subsurface water moves and how the water in the streams travels within regional watersheds. Many graduate and undergraduate students from multiple universities and colleges will work side-by-side in the project. We will train the students to use a variety of novel instruments, and to collect high-quality measurements that can be used for scientific research. This project will be coordinated with the Integrated Hydrology and Precipitation Experiment (IPHEx) 2014.
Natural hazards such as flashfloods and landslides occur in response to large precipitation. Flashfloods are associated with heavy rainfall rates, whereas landslides are initiated in response to large subsurface runoff, and thus may happen during the storm or long after rainfall stopped. Previous research in the Great Smoky Mountains suggests that as rain falls through fog and low level clouds, intensity of rainfall can increase by a factor of ten in a few minutes even for nonconvective storms. In this project, we collected observations to investigate rainfall enhancement processes that can be used to improve the estimation and prediction of rainfall and the response-time of subsurface runoff and streamflows in mounatinous regions. This project was coordinated with the Integrated Hydrology and Precipitation Experiment (IPHEx) 2014. The measurements included characterization of aerosols and CCN leading to fog and low level cloud formation, and observations of the vertical structure of fog, light and heavy rainfall using a suite of radars operating at multiple frequencies. Specifically, the collective observations at the Maggie Valley supersite represent the most comprehensive concurrent high-quality ground-based data set to date tracking the life cycle of hydrometeors from cloud condensation nuclei to rainfall in the US. Because of the various multifrequency radars deployed at the site, this data set provides a first look at transient microphysical regimes and how this translates into transient precipitation regimes that lead to heavy rainfall. Water samples for tracer analysis were collected from springs located at different elevations in the inner region of the Southern Appalachians to determine how the subsurface water moves. Soil moisture samples were collected at multiple locations on the foothills of the eastern slopes of the Southern Appalachians to support operational hydrologic modeling. Many graduate and undergraduate students from multiple universities and colleges will work side-by-side in the project. Overall, more than 100 scientists including over 40 graduate and undergradaute students participated in IPHEx and were trained to use a variety of novel instruments, and to collect high-quality measurements that can be used for scientific research.
