Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica
Abstract Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in th...
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Online Access: | http://dx.doi.org/10.1017/s0954102021000341 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102021000341 |
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crcambridgeupr:10.1017/s0954102021000341 2024-09-30T14:26:03+00:00 Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica Levy, Joseph Division of Antarctic Sciences 2021 http://dx.doi.org/10.1017/s0954102021000341 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102021000341 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Antarctic Science volume 33, issue 5, page 533-547 ISSN 0954-1020 1365-2079 journal-article 2021 crcambridgeupr https://doi.org/10.1017/s0954102021000341 2024-09-04T04:03:15Z Abstract Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in the absence of snowmelt occurs during high humidity conditions. Here, I analyse long-term meteorological station data to determine whether soil-darkening episodes are present in the instrumental record and whether they are, in fact, correlated with relative humidity. A strong linear correlation is found between relative humidity and soil reflectance at the Lake Bonney long-term autonomous weather station. Soil reflectance is found to decrease annually by a median of 27.7% in response to high humidity conditions. This magnitude of darkening is consistent with soil moisture rising from typical background values of < 0.5 wt.% to 2–3 wt.%, suggesting that regional atmospheric processes may result in widespread soil moisture generation in otherwise dry surface soils. Temperature and relative humidity conditions under which darkening is observed occur for hundreds of hours per year, but are dominated by episodes occurring between midnight and 07h00 local time, suggesting that wetting events may be common, but are not widely observed during typical diel science operations. Article in Journal/Newspaper Antarc* Antarctic Science Antarctica McMurdo Dry Valleys Cambridge University Press McMurdo Dry Valleys Bonney ENVELOPE(162.417,162.417,-77.717,-77.717) Lake Bonney ENVELOPE(-25.588,-25.588,-80.361,-80.361) Antarctic Science 1 15 |
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Open Polar |
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Cambridge University Press |
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English |
description |
Abstract Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in the absence of snowmelt occurs during high humidity conditions. Here, I analyse long-term meteorological station data to determine whether soil-darkening episodes are present in the instrumental record and whether they are, in fact, correlated with relative humidity. A strong linear correlation is found between relative humidity and soil reflectance at the Lake Bonney long-term autonomous weather station. Soil reflectance is found to decrease annually by a median of 27.7% in response to high humidity conditions. This magnitude of darkening is consistent with soil moisture rising from typical background values of < 0.5 wt.% to 2–3 wt.%, suggesting that regional atmospheric processes may result in widespread soil moisture generation in otherwise dry surface soils. Temperature and relative humidity conditions under which darkening is observed occur for hundreds of hours per year, but are dominated by episodes occurring between midnight and 07h00 local time, suggesting that wetting events may be common, but are not widely observed during typical diel science operations. |
author2 |
Division of Antarctic Sciences |
format |
Article in Journal/Newspaper |
author |
Levy, Joseph |
spellingShingle |
Levy, Joseph Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica |
author_facet |
Levy, Joseph |
author_sort |
Levy, Joseph |
title |
Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica |
title_short |
Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica |
title_full |
Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica |
title_fullStr |
Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica |
title_full_unstemmed |
Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica |
title_sort |
episodic basin-scale soil moisture anomalies associated with high relative humidity events in the mcmurdo dry valleys, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
2021 |
url |
http://dx.doi.org/10.1017/s0954102021000341 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102021000341 |
long_lat |
ENVELOPE(162.417,162.417,-77.717,-77.717) ENVELOPE(-25.588,-25.588,-80.361,-80.361) |
geographic |
McMurdo Dry Valleys Bonney Lake Bonney |
geographic_facet |
McMurdo Dry Valleys Bonney Lake Bonney |
genre |
Antarc* Antarctic Science Antarctica McMurdo Dry Valleys |
genre_facet |
Antarc* Antarctic Science Antarctica McMurdo Dry Valleys |
op_source |
Antarctic Science volume 33, issue 5, page 533-547 ISSN 0954-1020 1365-2079 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0954102021000341 |
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Antarctic Science |
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15 |
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1811646563821289472 |