Date/Time
Date(s) - 10/02/2020
1:30 pm - 2:30 pm

TITLE:     Phase change: Understanding greenhouse gas dynamics in warming Arctic waters through repeat measurements 

Date:                        Monday, February 10^th,2020

 Time:                       1:30 p.m.  

Place:                       ABB 164

Abstract: 

The atmospheric concentrations of the greenhouse gases carbon dioxide, methane, and nitrous oxide are increasing due to human activities, causing global climate change.Rapid warming in the Arctic could potentially mobilize vast stores of greenhouse gases and organic carbon that are currently sequestered in frozen matrices, accelerating global climate change. Predicting how climate change will affect methane and nitrous oxide distributions and emissions in Arctic waters is challenging due to a lack of published data on these gases across broad spatial scales, multiple years, and multiple seasons. To address these knowledge gaps, we have collected over 4000 summertime measurements of methane and nitrous oxide across the North American Arctic Ocean from 2015–2019 and used the data to reveal the dominant source regions for these gases and their sea-air fluxes.  Additionally, we established a year-round community-based sampling program in Cambridge Bay (Iqaluktuuttiaq), Nunavut, to characterize seasonality in greenhouse gas distributions. These measurements,as well as targeted observations with a novel robotic greenhouse gas-sensing kayak during ice melt, demonstrated that river discharge at the start of the melt season contains elevated levels of methane and carbon dioxide and that these greenhouse gases are rapidly ventilated to the atmosphere once ice cover retreats. These observations will serve as a benchmark against which future changes in Arctic greenhouse gas dynamics can be detected.