Impact of ice temperature on microwave emissivity of thin newly formed sea ice

B Hwang, Jens K. Ehn, David G. Barber

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

This study examines the impact of ice temperature on microwave emissivity over thin, newly formed sea ice at 6, 19, and 37 GHz during October 2003 in the southern Beaufort Sea, where the physical properties of newly formed sea ice were coincidently measured with microwave emissions. Six ice stations with distinct properties were selected and divided according to ice surface temperature into warm (above -3°C) or cold (below -3°C) stations. The warm stations had a lower emissivity at the vertical polarization by 0.1 than the cold stations and a corresponding difference in brine volume and dielectric properties. Significant correlations were observed between brine volume and ice emissivity (R2 = 0.8, p value < 0.05). A sensitivity study showed that decreasing ice temperatures from -2.1° to -5.0°C explained the observed difference of 0.1 in ice emissivity between warm and cold stations. The results suggest that the temperature of thin bare ice could be the critical factor in determining ice emissivity near the melting point (about -2°C). Furthermore, a slight decrease in ice temperature (i.e., from -2° to -5°C) significantly reduces the brine volume, thus resulting in high ice emissivity. Finally, we demonstrate the potential of newly formed ice to cause errors in estimating sea ice concentrations using Advanced Microwave Scanning Radiometer-E data.

Original languageEnglish
Article numberC02021
JournalJournal of Geophysical Research: Oceans
Volume113
Issue number2
DOIs
Publication statusPublished - 29 Feb 2008
Externally publishedYes

Fingerprint

Sea ice
sea ice
Ice
emissivity
ice
Microwaves
microwaves
temperature
stations
Temperature
brine
microwave
Beaufort Sea (North America)
microwave emission
dielectric property
Radiometers
Beaufort Sea
radiometers
dielectric properties
radiometer

Cite this

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title = "Impact of ice temperature on microwave emissivity of thin newly formed sea ice",
abstract = "This study examines the impact of ice temperature on microwave emissivity over thin, newly formed sea ice at 6, 19, and 37 GHz during October 2003 in the southern Beaufort Sea, where the physical properties of newly formed sea ice were coincidently measured with microwave emissions. Six ice stations with distinct properties were selected and divided according to ice surface temperature into warm (above -3°C) or cold (below -3°C) stations. The warm stations had a lower emissivity at the vertical polarization by 0.1 than the cold stations and a corresponding difference in brine volume and dielectric properties. Significant correlations were observed between brine volume and ice emissivity (R2 = 0.8, p value < 0.05). A sensitivity study showed that decreasing ice temperatures from -2.1° to -5.0°C explained the observed difference of 0.1 in ice emissivity between warm and cold stations. The results suggest that the temperature of thin bare ice could be the critical factor in determining ice emissivity near the melting point (about -2°C). Furthermore, a slight decrease in ice temperature (i.e., from -2° to -5°C) significantly reduces the brine volume, thus resulting in high ice emissivity. Finally, we demonstrate the potential of newly formed ice to cause errors in estimating sea ice concentrations using Advanced Microwave Scanning Radiometer-E data.",
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Impact of ice temperature on microwave emissivity of thin newly formed sea ice. / Hwang, B; Ehn, Jens K.; Barber, David G.

In: Journal of Geophysical Research: Oceans, Vol. 113, No. 2, C02021, 29.02.2008.

Research output: Contribution to journalArticle

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