Special Seminar: Tamlin Pavelsky
Quantifying Surface Water and Mountain Snowpack at Large Scales
Physical, biological, and human systems are impacted by the storage and transport of water at scales from a single leaf to the entire globe. Despite this fact, our ability to quantify the mean state and temporal changes in the reservoirs, states, and fluxes of the water cycle remains limited. While ground-based hydrologic measurements form the basis for much of our current knowledge, except at a few highly instrumented sites they are insufficiently dense to provide an accurate picture of the entire water cycle. Spatially distributed information from physics-based models and satellite remote sensing can fill in many gaps, but only after rigorous validation. In this talk, we will explore new ways of combining models, remote sensing, and in situ data to track two components of the water cycle: mountain snowpack and surface water in rivers and lakes.
Ground-based and space-based measurements produce highly uncertain estimates of mountain snowpack at large scales, but comparison with ground data suggests that high-resolution regional climate models show increasing promise for accurate estimates of snowpack magnitude and extent. We will examine one such model and its potential applications to understanding the magnitude and geographic distribution of mountain precipitation. Meanwhile, satellite remote sensing products are contributing to new advances in tracking spatial and temporal variations in surface water extent, and we will discuss the first global, high-resolution dataset of river widths from remotely sensed imagery. In addition, we will explore upcoming space-based technologies such as the NASA Surface Water and Ocean Topography (SWOT) Mission, which will provide new global estimates of variations in lake water storage and river discharge. In combination, continued advances in modeling, remote sensing, and field measurements will contribute to an improved understanding of the water cycle and how it is changing.
Bio: Tamlin Pavelsky is an assistant professor of global hydrology in the Department of Geological Sciences at UNC Chapel Hill. He received his BA from Middlebury College and an MA and PhD from UCLA, all in geography. Tamlin grew up outside of Fairbanks, Alaska in a cabin without electricity or running water. Exploring remote Arctic rivers motivated him to study the impacts of climate change on the water cycle and how we can observe the water cycle from space. Tamlin is a 2012 recipient of the Presidential Early Career Award for Scientists and Engineers (PECASE).