Microwave remote sensing of snow water equivalent and melt
Snow extent, depth, and melt status have implications for energy balance, hydrology, wildlife, hazards, and human systems. Passive microwave sensors have a long, multi-decadal record of global daily observations. These observations work in darkness and cloud cover so they have importance for high latitude and stormy regions. We are using Calibrated Enhanced-resolution brightness temperatures (CETB) from the suite of SSMI, SSMIS, and AMSR sensors to measure snow water equivalent for the entire period of record, and improving tools for measuring snow melt timing over that time period and in near real time.
Snow Properties and Caribou Migration
Caribou (Rangifer tarandus) make major migrations in the spring, moving from southern wintering grounds to northerly calving areas. Some herds seem to have a close association in time between the spring migration departure and the onset of snow melt. We are currently working to understand how widespread this is and what factors impact the caribou timing.
Hyper- and Multi- Spectral Analysis of Subarctic Wetland Flora/Plant Functional Type
At northern latitudes where the effects of arctic amplification drive warming at twice the rates seen in lower latitudes, climate patterns drive complex feedback loops in wetland ecosystems. Reserves of ancient carbon locked into northern latitude soils are at risk of release under a rapidly changing climate. A key driver in soil carbon dynamics may be the shift from non-vascular to vascular plants; rates of carbon sequestration have been shown to be related to the distribution of vegetation type. We use remote sensing to map floristic gradients in high latitude peatlands in order to use vegetation characteristics to develop a baseline vegetation map of vulnerable peatlands. Monitoring detailed vegetation coverage and change can be a tool to understand change in the carbon storage in these remote landscapes. We used a variety of computational methods to combine field and remote sensing data into a sophisticated interpretation of the wetland characteristics in this region. We developed remote-sensing methods to scale from ground to airborne, and up to satellite resolution, to enable mapping and monitoring the changing patterns of northern wetland vegetation.
