Remote Sensing

We are undertaking biophysical remote sensing investigations that seek to improve satellite image interpretations and to develop environmental monitoring capacity in the Arctic.  We are also using unmanned aerial vehicles (UAV) to carry out precision mapping and permafrost research.

Summer temperatures play a primary role in determining dominant vegetation communities/functional types, phytomass, abundance and richness in regional floras. Summer temperatures also impact phenology, photosynthesis and ecosystem respiration (ER) differentially across vegetation communities in the High Arctic. Given that temperatures are warming at high latitudes, the focus of our research is on the estimation of biophysical variables and modeling of ecosystem processes at multiple scales across a ten degree latitudinal gradient (~65º-75ºN). Whereas there have been studies examining biophysical variables at high latitudes, they have generally been limited to coarse (i.e., 1-8 km²) and to a lesser extent, intermediate spatial resolutions. Also, there is some uncertainty as to the optimal spectral indices for estimating biophysical variables.

There has been very little research directly linking field measures of biophysical variables to high spatial resolution data (<10 m), particularly with the goal of linking satellite reflectance to field measures of net ecosystem exchange (NEE). For instance, our research indicates that spectral indices are affected by seasonal moisture regimes. In addition, vegetation is variable with respect to chlorophyll expression, meaning that individual plants express green phytomass as well as senesced components throughout their phenological cycle. Hence, our research examines, develops and tests spectral VIs and models that optimally characterize dominant vegetation communities/functional types, phenology, aboveground phytomass (AGP), percent vegetation cover (PVC) fraction of absorbed photosynthetically active radiation (FAPAR) and NEE for heterogeneous tundra ecosystems (vegetated versus non-vegetated, green versus senesced, variable mineral substrates, organic content) across moisture regimes and at multiple scales.