About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice
Knowledge about Antarctic sea-ice volume and its changes over the past decades has been sparse due to the lack of systematic sea-ice thickness measurements in this remote area. Recently, first attempts have been made to develop a sea-ice thickness product over the Southern Ocean from space-borne rad...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-07-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/10/1415/2016/tc-10-1415-2016.pdf |
| _version_ | 1818209505637302272 |
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| author | S. Schwegmann E. Rinne R. Ricker S. Hendricks V. Helm |
| author_facet | S. Schwegmann E. Rinne R. Ricker S. Hendricks V. Helm |
| author_sort | S. Schwegmann |
| collection | DOAJ |
| description | Knowledge about Antarctic sea-ice volume and its changes over the past
decades has been sparse due to the lack of systematic sea-ice thickness
measurements in this remote area. Recently, first attempts have been made to
develop a sea-ice thickness product over the Southern Ocean from space-borne
radar altimetry and results look promising. Today, more than 20 years of
radar altimeter data are potentially available for such products. However,
the characteristics of individual radar types differ for the available
altimeter missions. Hence, it is important and our goal to study the
consistency between single sensors in order to develop long and consistent
time series. Here, the consistency between freeboard measurements of the
Radar Altimeter 2 on board Envisat and freeboard measurements from the
Synthetic-Aperture Interferometric Radar Altimeter on board CryoSat-2 is
tested for their overlap period in 2011. Results indicate that mean and
modal values are in reasonable agreement over the sea-ice growth season
(May–October) and partly also beyond. In general, Envisat data show higher
freeboards in the first-year ice zone while CryoSat-2 freeboards are higher
in the multiyear ice zone and near the coasts. This has consequences for the
agreement in individual sectors of the Southern Ocean, where one or the
other ice class may dominate. Nevertheless, over the growth season, mean
freeboard for the entire (regionally separated) Southern Ocean differs
generally by not more than 3 cm (8 cm, with few exceptions) between Envisat
and CryoSat-2, and the differences between modal freeboards lie generally
within ±10 cm and often even below. |
| first_indexed | 2024-12-12T05:01:47Z |
| format | Article |
| id | doaj.art-3e2f270285ea480d88d9e55095a6770b |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-12T05:01:47Z |
| publishDate | 2016-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-3e2f270285ea480d88d9e55095a6770b2022-12-22T00:37:12ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242016-07-011041415142510.5194/tc-10-1415-2016About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea iceS. Schwegmann0E. Rinne1R. Ricker2S. Hendricks3V. Helm4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, GermanyFinnish Meteorological Institute, Marine Research, Erik Palménin aukio 1, 00560 Helsinki, FinlandAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, GermanyKnowledge about Antarctic sea-ice volume and its changes over the past decades has been sparse due to the lack of systematic sea-ice thickness measurements in this remote area. Recently, first attempts have been made to develop a sea-ice thickness product over the Southern Ocean from space-borne radar altimetry and results look promising. Today, more than 20 years of radar altimeter data are potentially available for such products. However, the characteristics of individual radar types differ for the available altimeter missions. Hence, it is important and our goal to study the consistency between single sensors in order to develop long and consistent time series. Here, the consistency between freeboard measurements of the Radar Altimeter 2 on board Envisat and freeboard measurements from the Synthetic-Aperture Interferometric Radar Altimeter on board CryoSat-2 is tested for their overlap period in 2011. Results indicate that mean and modal values are in reasonable agreement over the sea-ice growth season (May–October) and partly also beyond. In general, Envisat data show higher freeboards in the first-year ice zone while CryoSat-2 freeboards are higher in the multiyear ice zone and near the coasts. This has consequences for the agreement in individual sectors of the Southern Ocean, where one or the other ice class may dominate. Nevertheless, over the growth season, mean freeboard for the entire (regionally separated) Southern Ocean differs generally by not more than 3 cm (8 cm, with few exceptions) between Envisat and CryoSat-2, and the differences between modal freeboards lie generally within ±10 cm and often even below.http://www.the-cryosphere.net/10/1415/2016/tc-10-1415-2016.pdf |
| spellingShingle | S. Schwegmann E. Rinne R. Ricker S. Hendricks V. Helm About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice The Cryosphere |
| title | About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice |
| title_full | About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice |
| title_fullStr | About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice |
| title_full_unstemmed | About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice |
| title_short | About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice |
| title_sort | about the consistency between envisat and cryosat 2 radar freeboard retrieval over antarctic sea ice |
| url | http://www.the-cryosphere.net/10/1415/2016/tc-10-1415-2016.pdf |
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