Ethan Gutmann

Ethan Gutmann studies climate downscaling for hydrology, mountain snowpack, interception measurement, land surface atmosphere interaction, and soil hydrology.  Most recently he has been developing the Intermediate Complexity Atmospheric Research model (ICAR).

ICAR

Ethan has developed the Intermediate Complexity Atmospheric Research model (ICAR) which is capable of running hundreds to thousands of times faster than state of the art regional climate models (e.g. WRF) while still providing ~90% of the information about precipitation and temperature patterns.  ICAR will allow climate models to be downscaled based on first principles instead of statistics.  ICAR simulations can run with a high-resolution over the continental US for over a hundred years for each of one hundred differen climate model scenarios with only modest computational costs. 

Snow Measurement

Ethan has also developed novel techniques to measure snow on the ground by building a continuously  operating terrestrial scanning laser and researching the use of GPS interferometry for snow pack measurement.  The laser system was the first of its kind able to continuously map snow depth over an area nearly 50m in diameter with mm scale precision through an entire winter season at high altitudes for less than $10k.  The GPS measurement works by exploit patterns in the signal to noise ratio recorded by standard GPS installations.   

In related work, Ethan has been comparing the measurements of snow fall with high-resolution weather model predictions in complex terrain.  This furthers our understanding of how much water is available for water resource managers while teasing out the fundamental physical controls on snow fall in complex terrain.  It was work distilling these physical processes into a simpler model that lead to the creation of ICAR. 

Soil Hydrology

Ethan's soil hydrology research focuses on the role of soil hydraulic properties in land surface models.  Soil properties are traditionally defined for soil cores that are 10s of cm in diameter, while land surface models use grid cells that are often 10s of km across. This disparitiy in scale brings into question wheather the small scale properties are appriate to use in land surface models.  Ethan has been analyzing the appropriate landscape hydraulic properties by deriving them from large scale measurements such as remotely sensed surface temperature and locally observed latent and sensible heat fluxes.