Date of Award

Fall 2016

Project Type

Thesis

Program or Major

Earth Sciences

Degree Name

Master of Science

First Advisor

Jack E Dibb

Second Advisor

Cameron P Wake

Third Advisor

Madeleine M Mineau

Abstract

Seasonal snowpacks accumulate soluble impurities derived from atmospheric aerosols and trace gases throughout the winter and release them quickly early during snow melt. Previous field and laboratory studies have shown that a snowpack can lose up to 80% of the ion burden in the first 20% of the melt, an event commonly known as an ionic pulse. Other studies have concluded that particulate impurities (e.g. black carbon (BC)) concentrate in surface layers during melt which can have important implications for snowpack albedo. To characterize snow chemistry, quantify the release of impurities, and qualify enhancement effects, we collected and analyzed near daily chemical profiles in the snowpack at three sites during two winters in New Hampshire, United States of America. We observe an ionic pulse of major ions and a pulse of BC from the snowpack at the onset of melt, with up to 62% of BC leaving with the first 24% of the melt. Surface concentrations of BC are higher than seasonal medians at the end of the winter season, but enhancements do not appear to be closely linked to decreases in snow-water equivalence.

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