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dc.contributor.authorThunberg, Sarah M.
dc.date.accessioned2021-12-17T20:24:52Z
dc.date.available2021-12-17T20:24:52Z
dc.date.issued2021-08
dc.identifier.urihttp://hdl.handle.net/11122/12635
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2021en_US
dc.description.abstractArctic soil moisture is one of the most impactful and unknown aspects of the Arctic climate system. As the climate changes, surface soil moisture can impact water supplies, wildfire risk, and vegetation stress, all of which have consequences for terrestrial ecosystems and human activities. The present analysis is intended to (1) document seasonal and interannual variations of surface moisture fluxes in the Arctic region and (2) clarify the drivers of variations of net Precipitation minus Evapotranspiration (P-ET) across Arctic tundra and boreal vegetation and permafrost status. Forty-five flux tower sites were examined across boreal and tundra ecosystems across the Arctic and sub-arctic. The surface moisture budget at boreal forest sites in permafrost areas generally shows a moisture deficit in late spring and early summer, followed by a moisture surplus from late summer into autumn. The annual net P-ET is generally positive but can vary interannually by more than an order of magnitude. A factor analysis found the primary drivers of variations in evapotranspiration to be radiative fluxes, air temperature, and relative humidity, while a path analysis found windspeed to have the largest independent influence on evapotranspiration. Overall, the ET at boreal forest sites shows a stronger dependence on relative humidity, and ET at tundra sites shows the stronger dependence on air temperature. These differences imply that tundra sites are more temperature-limited and boreal sites are more humidity-dependent. Relative to nearby unburned sites, the recovery time of ET after disturbance by wildfire was found to vary from several years on the Alaska tundra to nearly a decade in the Alaska boreal forest.en_US
dc.description.sponsorshipNational Science Foundation, Office of Polar Programs Grant ARC-1830131en_US
dc.language.isoen_USen_US
dc.subjectEvapotranspirationen_US
dc.subjectSoil moistureen_US
dc.subjectArctic regionsen_US
dc.subjectSoil and climateen_US
dc.subjectPermafrosten_US
dc.subjectWildfiresen_US
dc.subjectTaigasen_US
dc.subject.otherMaster of Science in Atmospheric Sciencesen_US
dc.titleA comparison of surface moisture budget and structural equation models in high latitudes: evapotranspiration and atmospheric driversen_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentDepartment of Atmospheric Sciencesen_US
dc.contributor.chairWalsh, John
dc.contributor.chairEuskirchen, Eugenie
dc.contributor.committeeBhatt, Uma S.
refterms.dateFOA2021-12-17T20:24:53Z


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