Geog 5100, Spring 2013 Advanced Methods In Snow Measurement: Introduction Noah Molotch Co-Instructors: Mike Durand, James McPhee, Adrian Harpold, Gannet Hallar

Importance of Snowmelt Runoff Snowfall / Runoff Ratio 1/6 th of the population and 1/4 th of GDP Barnett et al., Nature

Snowpack Trends: Service, 2004 Percent change in April 1 snow water equivalent Percent change in snowfall to rainfall Knowles et al., % % -100% -50% 0 50%

Uncertainty in Future Climate Snow albedo feedbacks an important source of uncertainty.

Outline 1.Motivations 2.Example Ground Campaigns 3.Our Objectives

Future Satellite Missions

Integrated Framework Things are inferred from satellite – NOT measured. All Models are wrong – some are useful. Data assimilation provides a framework to integrate models and measurements. Need to field measurements to improve both satellite measurements and models.

Effect of Vegetation

Ground-Based Validation: Snowpack and Microwave Emission 20 -Snowpack attenuates microwave emission from soil. -Attenuation increases with increasing mass and for larger snow grains.

Snowpack Model

Summary 1.Motivations 2.Example Ground Campaigns 3.Our Objectives