Black Carbon Deposition on Snow and Glaciers in Washington State: Implications for Accelerated Snowmelt

Ian Delaney
May 2012

Objective of Study

Black carbon, also called soot, is a dark aerosol emitted by the incomplete combustion of fossil and biofuels. In the atmosphere, black carbon absorbs radiation, causing atmospheric heating. Black carbon deposition on snow and ice darkens the surface of glaciers and snowpack, reducing albedo or reflectivity. In sufficient concentrations, black carbon can accelerate snowmelt and change the timing of runoff (Hansen and Nazarenko, 2004; Ramanathan and Carmicheal, 2008). However, there is a lack of field measurements about the spatial distribution of black carbon and the degree to which the albedo change caused by BC can result in changes to runoff.

Glaciers and seasonal snowpack in Washington State have shrunk considerably in recent years, potentially disturbing the availability of water resources throughout the year (Elsner, 2010; Pelto, 2008; Riedel and Larrabee, 2011). I hypothesize that black carbon deposition is a contributing factor in snowmelt, glacial retreat and decreased snowpack in Washington, along with documented decreases in precipitation and warmer temperatures (Mote et al., 2005). The objective of this study is to determine the distribution and amount of black carbon being deposited on snow and glacier ice in Washington State, which could affect the timing of snowmelt and contribute to glacier retreat.

Full Thesis Proposal (PDF format)