Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica
The McMurdo Dry Valleys (MDV), the largest ice-free region (4,500 km2) in Antarctica, are a polar desert with an average annual temperature of −18 °C. In Taylor Valley, one of the MDV, closed-basin, perennially ice-covered lakes occupy the valley floor. Their water balance is controlled by inflow fr...
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ftproquest:oai:pqdtoai.proquest.com:22620970 2023-05-15T13:54:51+02:00 Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica Cross, Julian Michael 2019-01-01 00:00:01.0 http://pqdtopen.proquest.com/#viewpdf?dispub=22620970 ENG eng Portland State University http://pqdtopen.proquest.com/#viewpdf?dispub=22620970 Physical geography|Hydrologic sciences thesis 2019 ftproquest 2021-03-13T17:37:14Z The McMurdo Dry Valleys (MDV), the largest ice-free region (4,500 km2) in Antarctica, are a polar desert with an average annual temperature of −18 °C. In Taylor Valley, one of the MDV, closed-basin, perennially ice-covered lakes occupy the valley floor. Their water balance is controlled by inflow from glacial meltwater runoff and loss due to sublimation, making them sensitive indicators of climate. In this study, a physically-based model of glacier meltwater and lake ice sublimation is adapted to explain modern (1996 to 2013) lake-level variations. Meltwater model results were improved by the inclusion of MODIS remotely-sensed albedo measurements (E = 0.47; nRMSE = 0.73). After 2008 the meltwater model significantly under-predicted streamflow and only through decreasing albedo by -30% (equivalent to a decrease of -0.18 on average) did the results match observations (E = 0.79; nRMSE = 0.45). This study provides the first estimate of direct (unmeasured) glacier inflow to the lakes, 69%, 73% and 28%, and sublimation loss rates, 0.37 m yr−1, 0.24 m yr−1 and 0.16 m yr−1, for lakes Bonney, Hoare and Fryxell, respectively. Despite similar meltwater volumes entering lakes Bonney and Fryxell, the difference in basin hypsometry results in a much faster lake rise at Bonney from 2002–13.If future climate conditions match current (1996–2013) conditions, all lakes will rise through the end of the century. Thesis Antarc* Antarctica McMurdo Dry Valleys polar desert PQDT Open: Open Access Dissertations and Theses (ProQuest) McMurdo Dry Valleys Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) Bonney ENVELOPE(162.417,162.417,-77.717,-77.717) Fryxell ENVELOPE(163.183,163.183,-77.617,-77.617) Hoare ENVELOPE(162.850,162.850,-77.633,-77.633) |
institution |
Open Polar |
collection |
PQDT Open: Open Access Dissertations and Theses (ProQuest) |
op_collection_id |
ftproquest |
language |
English |
topic |
Physical geography|Hydrologic sciences |
spellingShingle |
Physical geography|Hydrologic sciences Cross, Julian Michael Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica |
topic_facet |
Physical geography|Hydrologic sciences |
description |
The McMurdo Dry Valleys (MDV), the largest ice-free region (4,500 km2) in Antarctica, are a polar desert with an average annual temperature of −18 °C. In Taylor Valley, one of the MDV, closed-basin, perennially ice-covered lakes occupy the valley floor. Their water balance is controlled by inflow from glacial meltwater runoff and loss due to sublimation, making them sensitive indicators of climate. In this study, a physically-based model of glacier meltwater and lake ice sublimation is adapted to explain modern (1996 to 2013) lake-level variations. Meltwater model results were improved by the inclusion of MODIS remotely-sensed albedo measurements (E = 0.47; nRMSE = 0.73). After 2008 the meltwater model significantly under-predicted streamflow and only through decreasing albedo by -30% (equivalent to a decrease of -0.18 on average) did the results match observations (E = 0.79; nRMSE = 0.45). This study provides the first estimate of direct (unmeasured) glacier inflow to the lakes, 69%, 73% and 28%, and sublimation loss rates, 0.37 m yr−1, 0.24 m yr−1 and 0.16 m yr−1, for lakes Bonney, Hoare and Fryxell, respectively. Despite similar meltwater volumes entering lakes Bonney and Fryxell, the difference in basin hypsometry results in a much faster lake rise at Bonney from 2002–13.If future climate conditions match current (1996–2013) conditions, all lakes will rise through the end of the century. |
format |
Thesis |
author |
Cross, Julian Michael |
author_facet |
Cross, Julian Michael |
author_sort |
Cross, Julian Michael |
title |
Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica |
title_short |
Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica |
title_full |
Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica |
title_fullStr |
Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica |
title_full_unstemmed |
Glacial Meltwater Modeling to Simulate Lake Water Budget (1996–2013) in Taylor Valley, Antarctica |
title_sort |
glacial meltwater modeling to simulate lake water budget (1996–2013) in taylor valley, antarctica |
publisher |
Portland State University |
publishDate |
2019 |
url |
http://pqdtopen.proquest.com/#viewpdf?dispub=22620970 |
long_lat |
ENVELOPE(163.000,163.000,-77.617,-77.617) ENVELOPE(162.417,162.417,-77.717,-77.717) ENVELOPE(163.183,163.183,-77.617,-77.617) ENVELOPE(162.850,162.850,-77.633,-77.633) |
geographic |
McMurdo Dry Valleys Taylor Valley Bonney Fryxell Hoare |
geographic_facet |
McMurdo Dry Valleys Taylor Valley Bonney Fryxell Hoare |
genre |
Antarc* Antarctica McMurdo Dry Valleys polar desert |
genre_facet |
Antarc* Antarctica McMurdo Dry Valleys polar desert |
op_relation |
http://pqdtopen.proquest.com/#viewpdf?dispub=22620970 |
_version_ |
1766260993540751360 |