Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002
In boreal and tundra ecosystems the freeze state of soils limits rates of photosynthesis and respiration. Here we develop a technique to identify the timing of freeze and thaw transitions of high northern latitude land areas using satellite data from the Scanning Multichannel Microwave Radiometer (S...
Published in: | Journal of Geophysical Research: Atmospheres |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Geophysical Union
2004
|
Subjects: | |
Online Access: | https://doi.org/10.1029/2003jd004472 |
id |
ftcaltechauth:oai:authors.library.caltech.edu:8qzzt-evf32 |
---|---|
record_format |
openpolar |
spelling |
ftcaltechauth:oai:authors.library.caltech.edu:8qzzt-evf32 2024-10-13T14:11:11+00:00 Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 Smith, Nicole V. Saatchi, Sassan S. Randerson, James T. 2004-06-27 https://doi.org/10.1029/2003jd004472 unknown American Geophysical Union https://doi.org/10.1029/2003jd004472 eprintid:91308 info:eu-repo/semantics/openAccess Other Journal of Geophysical Research. Atmospheres, 109(D12), Art. No. D12101, (2004-06-27) remote sensing soil freezeâ€thaw northern latitudes info:eu-repo/semantics/article 2004 ftcaltechauth https://doi.org/10.1029/2003jd004472 2024-09-25T18:46:39Z In boreal and tundra ecosystems the freeze state of soils limits rates of photosynthesis and respiration. Here we develop a technique to identify the timing of freeze and thaw transitions of high northern latitude land areas using satellite data from the Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I). Our results indicate that in Eurasia there was a trend toward earlier thaw dates in tundra (−3.3 ± 1.8 days/decade) and larch biomes (−4.5 ± 1.8 days/decade) over the period 1988–2002. In North America there was a trend toward later freeze dates in evergreen conifer forests by 3.1 ± 1.2 days/decade that led, in part, to a lengthening of the growing season by 5.1 ± 2.9 days/decade. The growing season length in North American tundra increased by 5.4 ± 3.1 days/decade. Despite the trend toward earlier thaw dates in Eurasian larch forests, the growing season length did not increase because of parallel changes in timing of the fall freeze (−5.4 ± 2.1 days/decade), which led to a forward shift of the growing season. Thaw timing was negatively correlated with surface air temperatures in the spring, whereas freeze timing was positively correlated with surface air temperatures in the fall, suggesting that surface air temperature is one of several factors that determines the timing of soil thaw and freeze. The high spatial resolution, frequent temporal coverage, and duration of the SMMR and SSM/I satellite records makes them suitable for rigorous time series analysis and change detection in northern terrestrial ecosystems. © 2004 American Geophysical Union. Received 19 December 2003; revised 2 April 2004; accepted 14 April 2004; published 19 June 2004. The authors thank W. Chapman and J. Walsh for providing them with surface air temperature data. We also thank S. Wofsy and A. Dunn for soil temperature data at the BOREAS North Study Area. N.V.S. thanks L. Caspar, J. D. Godchaux, and N. Downey for their helpful comments on the manuscript. This work was supported ... Article in Journal/Newspaper Tundra Caltech Authors (California Institute of Technology) Boreas ENVELOPE(-3.933,-3.933,-71.300,-71.300) Journal of Geophysical Research: Atmospheres 109 D12 |
institution |
Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
unknown |
topic |
remote sensing soil freezeâ€thaw northern latitudes |
spellingShingle |
remote sensing soil freezeâ€thaw northern latitudes Smith, Nicole V. Saatchi, Sassan S. Randerson, James T. Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
topic_facet |
remote sensing soil freezeâ€thaw northern latitudes |
description |
In boreal and tundra ecosystems the freeze state of soils limits rates of photosynthesis and respiration. Here we develop a technique to identify the timing of freeze and thaw transitions of high northern latitude land areas using satellite data from the Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I). Our results indicate that in Eurasia there was a trend toward earlier thaw dates in tundra (−3.3 ± 1.8 days/decade) and larch biomes (−4.5 ± 1.8 days/decade) over the period 1988–2002. In North America there was a trend toward later freeze dates in evergreen conifer forests by 3.1 ± 1.2 days/decade that led, in part, to a lengthening of the growing season by 5.1 ± 2.9 days/decade. The growing season length in North American tundra increased by 5.4 ± 3.1 days/decade. Despite the trend toward earlier thaw dates in Eurasian larch forests, the growing season length did not increase because of parallel changes in timing of the fall freeze (−5.4 ± 2.1 days/decade), which led to a forward shift of the growing season. Thaw timing was negatively correlated with surface air temperatures in the spring, whereas freeze timing was positively correlated with surface air temperatures in the fall, suggesting that surface air temperature is one of several factors that determines the timing of soil thaw and freeze. The high spatial resolution, frequent temporal coverage, and duration of the SMMR and SSM/I satellite records makes them suitable for rigorous time series analysis and change detection in northern terrestrial ecosystems. © 2004 American Geophysical Union. Received 19 December 2003; revised 2 April 2004; accepted 14 April 2004; published 19 June 2004. The authors thank W. Chapman and J. Walsh for providing them with surface air temperature data. We also thank S. Wofsy and A. Dunn for soil temperature data at the BOREAS North Study Area. N.V.S. thanks L. Caspar, J. D. Godchaux, and N. Downey for their helpful comments on the manuscript. This work was supported ... |
format |
Article in Journal/Newspaper |
author |
Smith, Nicole V. Saatchi, Sassan S. Randerson, James T. |
author_facet |
Smith, Nicole V. Saatchi, Sassan S. Randerson, James T. |
author_sort |
Smith, Nicole V. |
title |
Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
title_short |
Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
title_full |
Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
title_fullStr |
Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
title_full_unstemmed |
Trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
title_sort |
trends in high northern latitude soil freeze and thaw cycles from 1988 to 2002 |
publisher |
American Geophysical Union |
publishDate |
2004 |
url |
https://doi.org/10.1029/2003jd004472 |
long_lat |
ENVELOPE(-3.933,-3.933,-71.300,-71.300) |
geographic |
Boreas |
geographic_facet |
Boreas |
genre |
Tundra |
genre_facet |
Tundra |
op_source |
Journal of Geophysical Research. Atmospheres, 109(D12), Art. No. D12101, (2004-06-27) |
op_relation |
https://doi.org/10.1029/2003jd004472 eprintid:91308 |
op_rights |
info:eu-repo/semantics/openAccess Other |
op_doi |
https://doi.org/10.1029/2003jd004472 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
109 |
container_issue |
D12 |
_version_ |
1812818822274482176 |