In situ observed relationships between snow and ice surface skin temperatures and 2 m air temperatures in the Arctic

Pia Nielsen-Englyst*, Jacob L. Høyer, Kristine S. Madsen, Rasmus Tonboe, Gorm Dybkjær, Emy Alerskans

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

To facilitate the construction of a satellite-derived 2 m air temperature(T2 m) product for the snow- and ice-covered regions in theArctic, observations from weather stations are used to quantify therelationship between the T2 m and skin temperature(Tskin). Multiyear data records of simultaneous Tskinand T2 m from 29 different in situ sites have been analysed forfive regions, covering the lower and upper ablation zone and the accumulationzone of the Greenland Ice Sheet (GrIS), sea ice in the Arctic Ocean, andseasonal snow-covered land in northern Alaska. The diurnal and seasonaltemperature variabilities and the impacts from clouds and wind on theT2 mTskin differences are quantified.Tskin is often (85 % of the time, all sites weighted equally)lower than T2 m, with the largest differences occurring when thetemperatures are well below 0 C or when the surface is melting.Considering all regions, T2 m is on average0.65–2.65 C higher than Tskin, with the largestdifferences for the lower ablation area and smallest differences forthe seasonal snow-covered sites. A negative net surface radiation balance generally coolsthe surface with respect to the atmosphere, resulting in a surface-drivensurface air temperature inversion. However, Tskin andT2 m are often highly correlated, and the two temperatures canbe almost identical (<0.5 C difference), with the smallestT2Tskin differences around noon and early afternoon duringspring, autumn and summer during non-melting conditions. In general, theinversion strength increases with decreasing wind speeds, but for the siteson the GrIS the maximum inversion occurs at wind speeds of about5 m s−1 due to the katabatic winds. Clouds tend to reduce the verticaltemperature gradient, by warming the surface, resulting in a mean overcastT2 mTskin difference ranging from −0.08 to1.63 C, with the largest differences for the sites in thelow-ablation zone and the smallest differences for the seasonal snow-coveredsites. To assess the effect of using cloud-limited infrared satelliteobservations, the influence of clouds on temporally averagedTskin has been studied by comparing averaged clear-skyTskin with averaged all-sky Tskin. To this end, wetest three different temporal averaging windows: 24 h, 72 h and 1 month.The largest clear-sky biases are generally found when 1-month averages areused and the smallest clear-sky biases are found for 24 h. In most cases,all-sky averages are warmer than clear-sky averages, with the smallest biasduring summer when the Tskin range is smallest.

Original languageEnglish
JournalCryosphere
Volume13
Issue number3
Pages (from-to)1005-1024
ISSN1994-0416
DOIs
Publication statusPublished - 2019

Cite this

Nielsen-Englyst, Pia ; Høyer, Jacob L. ; Madsen, Kristine S. ; Tonboe, Rasmus ; Dybkjær, Gorm ; Alerskans, Emy. / In situ observed relationships between snow and ice surface skin temperatures and 2&thinsp;m air temperatures in the Arctic. In: Cryosphere. 2019 ; Vol. 13, No. 3. pp. 1005-1024.
@article{fa3c11337ae945b3b217098dc4e947ae,
title = "In situ observed relationships between snow and ice surface skin temperatures and 2&thinsp;m air temperatures in the Arctic",
abstract = "To facilitate the construction of a satellite-derived 2 m air temperature(T2 m) product for the snow- and ice-covered regions in theArctic, observations from weather stations are used to quantify therelationship between the T2 m and skin temperature(Tskin). Multiyear data records of simultaneous Tskinand T2 m from 29 different in situ sites have been analysed forfive regions, covering the lower and upper ablation zone and the accumulationzone of the Greenland Ice Sheet (GrIS), sea ice in the Arctic Ocean, andseasonal snow-covered land in northern Alaska. The diurnal and seasonaltemperature variabilities and the impacts from clouds and wind on theT2 m–Tskin differences are quantified.Tskin is often (85 {\%} of the time, all sites weighted equally)lower than T2 m, with the largest differences occurring when thetemperatures are well below 0 ∘C or when the surface is melting.Considering all regions, T2 m is on average0.65–2.65 ∘C higher than Tskin, with the largestdifferences for the lower ablation area and smallest differences forthe seasonal snow-covered sites. A negative net surface radiation balance generally coolsthe surface with respect to the atmosphere, resulting in a surface-drivensurface air temperature inversion. However, Tskin andT2 m are often highly correlated, and the two temperatures canbe almost identical (<0.5 ∘C difference), with the smallestT2–Tskin differences around noon and early afternoon duringspring, autumn and summer during non-melting conditions. In general, theinversion strength increases with decreasing wind speeds, but for the siteson the GrIS the maximum inversion occurs at wind speeds of about5 m s−1 due to the katabatic winds. Clouds tend to reduce the verticaltemperature gradient, by warming the surface, resulting in a mean overcastT2 m–Tskin difference ranging from −0.08 to1.63 ∘C, with the largest differences for the sites in thelow-ablation zone and the smallest differences for the seasonal snow-coveredsites. To assess the effect of using cloud-limited infrared satelliteobservations, the influence of clouds on temporally averagedTskin has been studied by comparing averaged clear-skyTskin with averaged all-sky Tskin. To this end, wetest three different temporal averaging windows: 24 h, 72 h and 1 month.The largest clear-sky biases are generally found when 1-month averages areused and the smallest clear-sky biases are found for 24 h. In most cases,all-sky averages are warmer than clear-sky averages, with the smallest biasduring summer when the Tskin range is smallest.",
author = "Pia Nielsen-Englyst and H{\o}yer, {Jacob L.} and Madsen, {Kristine S.} and Rasmus Tonboe and Gorm Dybkj{\ae}r and Emy Alerskans",
year = "2019",
doi = "10.5194/tc-13-1005-2019",
language = "English",
volume = "13",
pages = "1005--1024",
journal = "Cryosphere",
issn = "1994-0416",
publisher = "Copernicus GmbH",
number = "3",

}

In situ observed relationships between snow and ice surface skin temperatures and 2&thinsp;m air temperatures in the Arctic. / Nielsen-Englyst, Pia; Høyer, Jacob L.; Madsen, Kristine S.; Tonboe, Rasmus; Dybkjær, Gorm; Alerskans, Emy.

In: Cryosphere, Vol. 13, No. 3, 2019, p. 1005-1024.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - In situ observed relationships between snow and ice surface skin temperatures and 2&thinsp;m air temperatures in the Arctic

AU - Nielsen-Englyst, Pia

AU - Høyer, Jacob L.

AU - Madsen, Kristine S.

AU - Tonboe, Rasmus

AU - Dybkjær, Gorm

AU - Alerskans, Emy

PY - 2019

Y1 - 2019

N2 - To facilitate the construction of a satellite-derived 2 m air temperature(T2 m) product for the snow- and ice-covered regions in theArctic, observations from weather stations are used to quantify therelationship between the T2 m and skin temperature(Tskin). Multiyear data records of simultaneous Tskinand T2 m from 29 different in situ sites have been analysed forfive regions, covering the lower and upper ablation zone and the accumulationzone of the Greenland Ice Sheet (GrIS), sea ice in the Arctic Ocean, andseasonal snow-covered land in northern Alaska. The diurnal and seasonaltemperature variabilities and the impacts from clouds and wind on theT2 m–Tskin differences are quantified.Tskin is often (85 % of the time, all sites weighted equally)lower than T2 m, with the largest differences occurring when thetemperatures are well below 0 ∘C or when the surface is melting.Considering all regions, T2 m is on average0.65–2.65 ∘C higher than Tskin, with the largestdifferences for the lower ablation area and smallest differences forthe seasonal snow-covered sites. A negative net surface radiation balance generally coolsthe surface with respect to the atmosphere, resulting in a surface-drivensurface air temperature inversion. However, Tskin andT2 m are often highly correlated, and the two temperatures canbe almost identical (<0.5 ∘C difference), with the smallestT2–Tskin differences around noon and early afternoon duringspring, autumn and summer during non-melting conditions. In general, theinversion strength increases with decreasing wind speeds, but for the siteson the GrIS the maximum inversion occurs at wind speeds of about5 m s−1 due to the katabatic winds. Clouds tend to reduce the verticaltemperature gradient, by warming the surface, resulting in a mean overcastT2 m–Tskin difference ranging from −0.08 to1.63 ∘C, with the largest differences for the sites in thelow-ablation zone and the smallest differences for the seasonal snow-coveredsites. To assess the effect of using cloud-limited infrared satelliteobservations, the influence of clouds on temporally averagedTskin has been studied by comparing averaged clear-skyTskin with averaged all-sky Tskin. To this end, wetest three different temporal averaging windows: 24 h, 72 h and 1 month.The largest clear-sky biases are generally found when 1-month averages areused and the smallest clear-sky biases are found for 24 h. In most cases,all-sky averages are warmer than clear-sky averages, with the smallest biasduring summer when the Tskin range is smallest.

AB - To facilitate the construction of a satellite-derived 2 m air temperature(T2 m) product for the snow- and ice-covered regions in theArctic, observations from weather stations are used to quantify therelationship between the T2 m and skin temperature(Tskin). Multiyear data records of simultaneous Tskinand T2 m from 29 different in situ sites have been analysed forfive regions, covering the lower and upper ablation zone and the accumulationzone of the Greenland Ice Sheet (GrIS), sea ice in the Arctic Ocean, andseasonal snow-covered land in northern Alaska. The diurnal and seasonaltemperature variabilities and the impacts from clouds and wind on theT2 m–Tskin differences are quantified.Tskin is often (85 % of the time, all sites weighted equally)lower than T2 m, with the largest differences occurring when thetemperatures are well below 0 ∘C or when the surface is melting.Considering all regions, T2 m is on average0.65–2.65 ∘C higher than Tskin, with the largestdifferences for the lower ablation area and smallest differences forthe seasonal snow-covered sites. A negative net surface radiation balance generally coolsthe surface with respect to the atmosphere, resulting in a surface-drivensurface air temperature inversion. However, Tskin andT2 m are often highly correlated, and the two temperatures canbe almost identical (<0.5 ∘C difference), with the smallestT2–Tskin differences around noon and early afternoon duringspring, autumn and summer during non-melting conditions. In general, theinversion strength increases with decreasing wind speeds, but for the siteson the GrIS the maximum inversion occurs at wind speeds of about5 m s−1 due to the katabatic winds. Clouds tend to reduce the verticaltemperature gradient, by warming the surface, resulting in a mean overcastT2 m–Tskin difference ranging from −0.08 to1.63 ∘C, with the largest differences for the sites in thelow-ablation zone and the smallest differences for the seasonal snow-coveredsites. To assess the effect of using cloud-limited infrared satelliteobservations, the influence of clouds on temporally averagedTskin has been studied by comparing averaged clear-skyTskin with averaged all-sky Tskin. To this end, wetest three different temporal averaging windows: 24 h, 72 h and 1 month.The largest clear-sky biases are generally found when 1-month averages areused and the smallest clear-sky biases are found for 24 h. In most cases,all-sky averages are warmer than clear-sky averages, with the smallest biasduring summer when the Tskin range is smallest.

U2 - 10.5194/tc-13-1005-2019

DO - 10.5194/tc-13-1005-2019

M3 - Journal article

VL - 13

SP - 1005

EP - 1024

JO - Cryosphere

JF - Cryosphere

SN - 1994-0416

IS - 3

ER -