Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration
Seasonal frozen states in the northern terrestrial cryosphere limit vegetation photosynthetic activities and evapotranspiration (ET) through cold temperature constraints to biological processes and chemical unavailability of water as a result of being frozen. Seasonal transitions of the landscape be...
Published in: | Hydrological Processes |
---|---|
Main Authors: | , , , |
Format: | Text |
Language: | unknown |
Published: |
ScholarWorks at University of Montana
2011
|
Subjects: | |
Online Access: | https://scholarworks.umt.edu/ntsg_pubs/236 https://doi.org/10.1002/hyp.8350 |
id |
ftunivmontana:oai:scholarworks.umt.edu:ntsg_pubs-1235 |
---|---|
record_format |
openpolar |
spelling |
ftunivmontana:oai:scholarworks.umt.edu:ntsg_pubs-1235 2024-09-09T19:28:10+00:00 Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration Zhang, Ke Kimball, John S Kim, Youngwook McDonald, Kyle C. 2011-12-01T08:00:00Z application/pdf https://scholarworks.umt.edu/ntsg_pubs/236 https://doi.org/10.1002/hyp.8350 unknown ScholarWorks at University of Montana https://scholarworks.umt.edu/ntsg_pubs/236 doi:10.1002/hyp.8350 © 2011 John Wiley & Sons, Ltd. Numerical Terradynamic Simulation Group Publications Arctic Boreal cryosphere Evapotranspiration freeze thaw global warming growing season non-frozen season vegetation text 2011 ftunivmontana https://doi.org/10.1002/hyp.8350 2024-06-20T05:32:53Z Seasonal frozen states in the northern terrestrial cryosphere limit vegetation photosynthetic activities and evapotranspiration (ET) through cold temperature constraints to biological processes and chemical unavailability of water as a result of being frozen. Seasonal transitions of the landscape between predominantly frozen and thawed conditions are analogous to a biospheric and hydrological on/off switch, with marked differences in ET, vegetation productivity and other biological activity between largely dormant winter and active summer conditions. We investigated changes in freeze–thaw (FT) seasons and ET from 1983 to 2006 and their connections in the northern cryosphere by analyzing independent satellite remote sensing derived FT and ET records. Our findings show that the northern cryosphere (≥ 40°N) has experienced advancing (−2.5 days/decade; P = 0.005) and lengthening (3.5 days/decade; P = 0.007) non-frozen season trends over the 24-year period, coinciding with an upward trend (6.4 mm/year/decade; P = 0.014) in regional mean annual ET over the same period. Regional average timing of spring primary thaw and the annual non-frozen period are highly correlated with regional annual ET (|r| ≥ 0.75; P < 0.001), with corresponding impacts to annual ET of approximately 0.6 and 0.5% per day, respectively. The impact of primary fall freeze timing on ET is relatively minor compared with primary spring thaw timing. Earlier onset of the non-frozen season generally promotes annual ET in colder areas but appears to suppress summer ET by increasing drought stress in the southernmost parts of the domain where water supply is the leading constraint to ET. The cumulative effect of future freeze-thaw changes on ET in the region will largely depend on future changes of large-scale atmosphere circulations and rates of vegetation disturbance and adaptation to continued warming. Text Arctic Global warming University of Montana: ScholarWorks Arctic Hydrological Processes 25 26 4142 4151 |
institution |
Open Polar |
collection |
University of Montana: ScholarWorks |
op_collection_id |
ftunivmontana |
language |
unknown |
topic |
Arctic Boreal cryosphere Evapotranspiration freeze thaw global warming growing season non-frozen season vegetation |
spellingShingle |
Arctic Boreal cryosphere Evapotranspiration freeze thaw global warming growing season non-frozen season vegetation Zhang, Ke Kimball, John S Kim, Youngwook McDonald, Kyle C. Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
topic_facet |
Arctic Boreal cryosphere Evapotranspiration freeze thaw global warming growing season non-frozen season vegetation |
description |
Seasonal frozen states in the northern terrestrial cryosphere limit vegetation photosynthetic activities and evapotranspiration (ET) through cold temperature constraints to biological processes and chemical unavailability of water as a result of being frozen. Seasonal transitions of the landscape between predominantly frozen and thawed conditions are analogous to a biospheric and hydrological on/off switch, with marked differences in ET, vegetation productivity and other biological activity between largely dormant winter and active summer conditions. We investigated changes in freeze–thaw (FT) seasons and ET from 1983 to 2006 and their connections in the northern cryosphere by analyzing independent satellite remote sensing derived FT and ET records. Our findings show that the northern cryosphere (≥ 40°N) has experienced advancing (−2.5 days/decade; P = 0.005) and lengthening (3.5 days/decade; P = 0.007) non-frozen season trends over the 24-year period, coinciding with an upward trend (6.4 mm/year/decade; P = 0.014) in regional mean annual ET over the same period. Regional average timing of spring primary thaw and the annual non-frozen period are highly correlated with regional annual ET (|r| ≥ 0.75; P < 0.001), with corresponding impacts to annual ET of approximately 0.6 and 0.5% per day, respectively. The impact of primary fall freeze timing on ET is relatively minor compared with primary spring thaw timing. Earlier onset of the non-frozen season generally promotes annual ET in colder areas but appears to suppress summer ET by increasing drought stress in the southernmost parts of the domain where water supply is the leading constraint to ET. The cumulative effect of future freeze-thaw changes on ET in the region will largely depend on future changes of large-scale atmosphere circulations and rates of vegetation disturbance and adaptation to continued warming. |
format |
Text |
author |
Zhang, Ke Kimball, John S Kim, Youngwook McDonald, Kyle C. |
author_facet |
Zhang, Ke Kimball, John S Kim, Youngwook McDonald, Kyle C. |
author_sort |
Zhang, Ke |
title |
Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
title_short |
Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
title_full |
Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
title_fullStr |
Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
title_full_unstemmed |
Changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
title_sort |
changing freeze-thaw seasons in northern high latitudes and associated influences on evapotranspiration |
publisher |
ScholarWorks at University of Montana |
publishDate |
2011 |
url |
https://scholarworks.umt.edu/ntsg_pubs/236 https://doi.org/10.1002/hyp.8350 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Global warming |
genre_facet |
Arctic Global warming |
op_source |
Numerical Terradynamic Simulation Group Publications |
op_relation |
https://scholarworks.umt.edu/ntsg_pubs/236 doi:10.1002/hyp.8350 |
op_rights |
© 2011 John Wiley & Sons, Ltd. |
op_doi |
https://doi.org/10.1002/hyp.8350 |
container_title |
Hydrological Processes |
container_volume |
25 |
container_issue |
26 |
container_start_page |
4142 |
op_container_end_page |
4151 |
_version_ |
1809897441010384896 |