Long-term coastal-polynya dynamics in the southern Weddell Sea from MODIS thermal-infrared imagery

Abstract. Based upon thermal-infrared satellite imagery in combination with ERA-Interim atmospheric reanalysis data, we derive long-term polynya characteristics such as polynya area, thin-ice thickness distribution, and ice-production rates for a 13-year investigation period (2002–2014) for the austral winter (1 April to 30 September) in the Antarctic southern Weddell Sea. All polynya parameters are derived from daily cloud-cover corrected thin-ice thickness composites. The focus lies on coastal polynyas which are important hot spots for new-ice formation, bottom-water formation, and heat/moisture release into the atmosphere. MODIS has the capability to resolve even very narrow coastal polynyas. Its major disadvantage is the sensor limitation due to cloud cover. We make use of a newly developed and adapted spatial feature reconstruction scheme to account for cloud-covered areas. We find the sea-ice areas in front of the Ronne and Brunt ice shelves to be the most active with an annual average polynya area of 3018 ± 1298 and 3516 ± 1420 km2 as well as an accumulated volume ice production of 31 ± 13 and 31 ± 12 km3, respectively. For the remaining four regions, estimates amount to 421 ± 294 km2 and 4 ± 3 km3 (Antarctic Peninsula), 1148 ± 432 km2 and 12 ± 5 km3 (iceberg A23A), 901 ± 703 km2 and 10 ± 8 km3 (Filchner Ice Shelf), as well as 499 ± 277 km2 and 5 ± 2 km3 (Coats Land). Our findings are discussed in comparison to recent studies based on coupled sea-ice/ocean models and passive-microwave satellite imagery, each investigating different parts of the southern Weddell Sea.

[1]  T. Markus,et al.  Coastal polynyas in the southern Weddell Sea: Variability of the surface energy budget , 2002 .

[2]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[3]  Stefan Kern,et al.  Wintertime Antarctic coastal polynya area: 1992–2008 , 2009 .

[4]  Sascha Willmes,et al.  Cross-validation of polynya monitoring methods from multisensor satellite and airborne data: a case study for the Laptev Sea , 2010 .

[5]  Takeshi Tamura,et al.  Mapping of sea ice production for Antarctic coastal polynyas , 2008 .

[6]  Lars Kaleschke,et al.  Investigating High-Resolution AMSR2 Sea Ice Concentrations during the February 2013 Fracture Event in the Beaufort Sea , 2014, Remote. Sens..

[7]  T. Tamura,et al.  Estimation of Surface Heat/Salt Fluxes Associated with Sea Ice Growth/Melt in the Southern Ocean , 2011 .

[8]  Dorothy K. Hall,et al.  MODIS Sea Ice Products User Guide to Collection 5 , 2007 .

[9]  G. Heinemann,et al.  Atmospheric forcing of coastal polynyas in the south-western Weddell Sea , 2015, Antarctic Science.

[10]  Naohiko Hirasawa,et al.  Estimation of Thin Ice Thickness and Detection of Fast Ice from SSM/I Data in the Antarctic Ocean , 2007 .

[11]  T. Markus.  The effect of the grounded tabular icebergs in front of Berkner Island on the Weddell Sea ice drift as seen from satellite passive microwave sensors , 1996, IGARSS '96. 1996 International Geoscience and Remote Sensing Symposium.

[12]  Dorothy K. Hall,et al.  Sea ice surface temperature product from MODIS , 2004, IEEE Transactions on Geoscience and Remote Sensing.

[13]  L. Kaleschke,et al.  Sea ice remote sensing using AMSR‐E 89‐GHz channels , 2008 .

[14]  Jeffrey R. Key,et al.  Less winter cloud aids summer 2013 Arctic sea ice return from 2012 minimum , 2014 .

[15]  Ron Kwok,et al.  Sea ice production and export from coastal polynyas in the Weddell and Ross Seas , 2011 .

[16]  R. Colony,et al.  The thickness distribution of sea ice , 1975 .

[17]  D. Barber,et al.  A new clear‐sky downward longwave radiative flux parameterization for Arctic areas based on rawinsonde data , 2006 .

[18]  W. Paul Menzel,et al.  Nighttime polar cloud detection with MODIS , 2004 .

[19]  Nicholas R. T. Biggs,et al.  Polynya Dynamics: a Review of Observations and Modeling , 2004 .

[20]  Steven A. Ackerman,et al.  Global Moderate Resolution Imaging Spectroradiometer (MODIS) cloud detection and height evaluation using CALIOP , 2008 .

[21]  Sohey Nihashi,et al.  Circumpolar Mapping of Antarctic Coastal Polynyas and Landfast Sea Ice: Relationship and Variability , 2015 .

[22]  S. Willmes,et al.  Long-term polynya dynamics from MODIS thermal-infrared imagery , 2015 .

[23]  Sascha Willmes,et al.  Spatio-temporal variability of polynya dynamics and ice production in the Laptev Sea between the winters of 1979/80 and 2007/08 , 2011 .

[24]  T. Vihma,et al.  Derivation of turbulent surface fluxes — An iterative flux-profile method allowing arbitrary observing heights , 1990 .

[25]  Ralph Timmermann,et al.  Simulated heat flux and sea ice production at coastal polynyas in the southwestern Weddell Sea , 2013 .

[26]  Seelye Martin,et al.  Observations of ice thickness and frazil ice in the St. Lawrence Island polynya from satellite imagery, upward looking sonar, and salinity/temperature moorings , 2003 .

[27]  T. Vihma,et al.  Validation of the diurnal cycles in atmospheric reanalyses over Antarctic sea ice , 2013 .

[28]  G. Maykut.  Energy exchange over young sea ice in the central Arctic , 1978 .

[29]  Richard A. Frey,et al.  Cloud Detection with MODIS. Part I: Improvements in the MODIS Cloud Mask for Collection 5 , 2008 .

[30]  Axel Schweiger,et al.  Evaluation of Seven Different Atmospheric Reanalysis Products in the Arctic , 2014 .

[31]  L. Kaleschke,et al.  Arctic clouds and surface radiation - a critical comparison of satellite retrievals and the ERA-interim reanalysis , 2011 .

[32]  Sascha Willmes,et al.  Improvement and Sensitivity Analysis of Thermal Thin-Ice Thickness Retrievals , 2013, IEEE Transactions on Geoscience and Remote Sensing.

[33]  Son V. Nghiem,et al.  Uncertainties of Temperature Measurements on Snow-Covered Land and Sea Ice from In Situ and MODIS Data during BROMEX , 2015 .

[34]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[35]  D. Rothrock,et al.  Thin ice thickness from satellite thermal imagery , 1996 .

[36]  Sascha Willmes,et al.  Thin-ice dynamics and ice production in the Storfjorden polynya for winter seasons 2002/2003-2013/2014 using MODIS thermal infrared imagery , 2014 .

[37]  Sascha Willmes,et al.  Spatial Feature Reconstruction of Cloud-Covered Areas in Daily MODIS Composites , 2015, Remote. Sens..