Peak-summer energy and carbon fluxes on a thawing permafrost site
We present measurements of surface fluxes taken between 7 July and 6 August 2017, on a palsa mire near the Iškoras mountain in Finnmark, northern Norway. Palsa mires are a particular landform found at the edge of the discontinuous permafrost zone, where mean annual temperatures are close to 0 °C and...
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Language: | English |
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The University of Bergen
2018
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ftunivbergen:oai:bora.uib.no:1956/18762 2023-05-15T15:19:02+02:00 Peak-summer energy and carbon fluxes on a thawing permafrost site Slettebø, Isak Haldorsson 2018-12-12T23:00:06Z application/pdf https://hdl.handle.net/1956/18762 eng eng The University of Bergen https://hdl.handle.net/1956/18762 Copyright the Author. All rights reserved ground heat flux Permafrost eddy covariance surface energy balance micrometeorology Atmosfærisk karbondioksid Klimavariasjoner Mikrometeorologi Overflatetemperatur Temperaturendringer Temperaturmåling https://data.ub.uio.no/realfagstermer/c012705 https://data.ub.uio.no/realfagstermer/c013883 https://data.ub.uio.no/realfagstermer/c007293 https://data.ub.uio.no/realfagstermer/c011425 https://data.ub.uio.no/realfagstermer/c001133 https://data.ub.uio.no/realfagstermer/c004291 756213 Master thesis 2018 ftunivbergen 2023-03-14T17:44:21Z We present measurements of surface fluxes taken between 7 July and 6 August 2017, on a palsa mire near the Iškoras mountain in Finnmark, northern Norway. Palsa mires are a particular landform found at the edge of the discontinuous permafrost zone, where mean annual temperatures are close to 0 °C and climate change is expected to have a high impact. Turbulent fluxes of sensible heat, latent heat and carbon dioxide were measured with the eddy-covariance (EC) method, while complementary energy balance data was provided by a net radiometer and two soil heat flux plates. The raw turbulence data was processed by the validated TK3 software package, which applies the plausability tests, corrections and quality controls needed for reliable flux calculations. Through a footprint analysis we found the average turbulent fetch area to overlap well with our ecosystem of interest, in that only 20 % of the footprint climatology was outside the palsa mire. However, a greater carbon uptake was observed during northerly winds than otherwise, which suggests that the more vegetated area to the north of the palsa mire also influenced our flux measurements. Overall, our results are similar to those of other studies from the growing season at sub-Arctic sites. The mean daytime Bowen ratio was 74 %, which is typical for high-latitude wetlands in summertime. The soil heat flux was positive most of the time, and from our cumulative flux estimates we found a large soil heat uptake during the campaign, which is characteristic for permafrost regions during the warm season. However, the average flux from the upper sensor at 10 cm was only 8 % of the net radiation. This is in general less than what other permafrost studies have found for the ground heat flux, likely due to a change in heat storage above the 10 cm level. The average net ecosystem exchange of carbon dioxide during the campaign was –1.1 μmol/m2s, which indicates carbon uptake and compares well to what has been reported in other studies from similar sites in summertime. ... Master Thesis Arctic Climate change Finnmark Northern Norway palsa permafrost Finnmark University of Bergen: Bergen Open Research Archive (BORA-UiB) Arctic Iškoras ENVELOPE(25.369,25.369,69.297,69.297) Norway |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
ground heat flux Permafrost eddy covariance surface energy balance micrometeorology Atmosfærisk karbondioksid Klimavariasjoner Mikrometeorologi Overflatetemperatur Temperaturendringer Temperaturmåling https://data.ub.uio.no/realfagstermer/c012705 https://data.ub.uio.no/realfagstermer/c013883 https://data.ub.uio.no/realfagstermer/c007293 https://data.ub.uio.no/realfagstermer/c011425 https://data.ub.uio.no/realfagstermer/c001133 https://data.ub.uio.no/realfagstermer/c004291 756213 |
spellingShingle |
ground heat flux Permafrost eddy covariance surface energy balance micrometeorology Atmosfærisk karbondioksid Klimavariasjoner Mikrometeorologi Overflatetemperatur Temperaturendringer Temperaturmåling https://data.ub.uio.no/realfagstermer/c012705 https://data.ub.uio.no/realfagstermer/c013883 https://data.ub.uio.no/realfagstermer/c007293 https://data.ub.uio.no/realfagstermer/c011425 https://data.ub.uio.no/realfagstermer/c001133 https://data.ub.uio.no/realfagstermer/c004291 756213 Slettebø, Isak Haldorsson Peak-summer energy and carbon fluxes on a thawing permafrost site |
topic_facet |
ground heat flux Permafrost eddy covariance surface energy balance micrometeorology Atmosfærisk karbondioksid Klimavariasjoner Mikrometeorologi Overflatetemperatur Temperaturendringer Temperaturmåling https://data.ub.uio.no/realfagstermer/c012705 https://data.ub.uio.no/realfagstermer/c013883 https://data.ub.uio.no/realfagstermer/c007293 https://data.ub.uio.no/realfagstermer/c011425 https://data.ub.uio.no/realfagstermer/c001133 https://data.ub.uio.no/realfagstermer/c004291 756213 |
description |
We present measurements of surface fluxes taken between 7 July and 6 August 2017, on a palsa mire near the Iškoras mountain in Finnmark, northern Norway. Palsa mires are a particular landform found at the edge of the discontinuous permafrost zone, where mean annual temperatures are close to 0 °C and climate change is expected to have a high impact. Turbulent fluxes of sensible heat, latent heat and carbon dioxide were measured with the eddy-covariance (EC) method, while complementary energy balance data was provided by a net radiometer and two soil heat flux plates. The raw turbulence data was processed by the validated TK3 software package, which applies the plausability tests, corrections and quality controls needed for reliable flux calculations. Through a footprint analysis we found the average turbulent fetch area to overlap well with our ecosystem of interest, in that only 20 % of the footprint climatology was outside the palsa mire. However, a greater carbon uptake was observed during northerly winds than otherwise, which suggests that the more vegetated area to the north of the palsa mire also influenced our flux measurements. Overall, our results are similar to those of other studies from the growing season at sub-Arctic sites. The mean daytime Bowen ratio was 74 %, which is typical for high-latitude wetlands in summertime. The soil heat flux was positive most of the time, and from our cumulative flux estimates we found a large soil heat uptake during the campaign, which is characteristic for permafrost regions during the warm season. However, the average flux from the upper sensor at 10 cm was only 8 % of the net radiation. This is in general less than what other permafrost studies have found for the ground heat flux, likely due to a change in heat storage above the 10 cm level. The average net ecosystem exchange of carbon dioxide during the campaign was –1.1 μmol/m2s, which indicates carbon uptake and compares well to what has been reported in other studies from similar sites in summertime. ... |
format |
Master Thesis |
author |
Slettebø, Isak Haldorsson |
author_facet |
Slettebø, Isak Haldorsson |
author_sort |
Slettebø, Isak Haldorsson |
title |
Peak-summer energy and carbon fluxes on a thawing permafrost site |
title_short |
Peak-summer energy and carbon fluxes on a thawing permafrost site |
title_full |
Peak-summer energy and carbon fluxes on a thawing permafrost site |
title_fullStr |
Peak-summer energy and carbon fluxes on a thawing permafrost site |
title_full_unstemmed |
Peak-summer energy and carbon fluxes on a thawing permafrost site |
title_sort |
peak-summer energy and carbon fluxes on a thawing permafrost site |
publisher |
The University of Bergen |
publishDate |
2018 |
url |
https://hdl.handle.net/1956/18762 |
long_lat |
ENVELOPE(25.369,25.369,69.297,69.297) |
geographic |
Arctic Iškoras Norway |
geographic_facet |
Arctic Iškoras Norway |
genre |
Arctic Climate change Finnmark Northern Norway palsa permafrost Finnmark |
genre_facet |
Arctic Climate change Finnmark Northern Norway palsa permafrost Finnmark |
op_relation |
https://hdl.handle.net/1956/18762 |
op_rights |
Copyright the Author. All rights reserved |
_version_ |
1766349220902600704 |