Gretchen Keppel-Aleks (Postdoctoral Scholar) uses observations and models to understand carbon exchange between the atmosphere, the land biosphere, and the oceans.  A member of Jim Randerson’s Research Group, Gretchen works to improve flux estimates of CO₂ in two ways.  First, by comparing observed to modeled CO₂ levels, she can determine how well the model captures reality.  This information informs improved models of CO₂ patterns of variability.  Second, Gretchen uses flux data and satellite observations to improve models of gross photosynthesis and respiration for global ecosystems. Prior to starting her postdoc, Gretchen spent five weeks biking and hiking through the Cascades and Rocky Mountains.  She biked from Seattle up to Jasper before hopping on a Greyhound back to the LA area. 

Global Passages of Scientists (GPS)

While completing her studies at Caltech, Gretchen visited Park Falls in northern Wisconsin.  They used a Fourier transform spectrometer inside a converted shipping container (see picture), sitting in the middle of a field, that made remote sensing observations of atmospheric CO₂.  Generally, the measurements were automated, but sometimes things broke, and when they did it was usually during cold, icy winters.  Gretchen would head out there in the snow to fix things – this was a pretty good reality check for a grad student living in southern California.