Abstract
Antarctic Sea Ice Processes and Climate (ASPeCt) visual ship-based observations were conducted in the Bellingshausen Sea during the Sea Ice Mass Balance in the Antarctic (SIMBA) cruise in austral spring 2007. A total of 59 ASPeCt observations are compared to coincident satellite active and passive microwave data. Envisat and RADARSAT-1 C-Band HH-polarization radar backscatter values (called NRCS henceforth) are derived on km-scales for six individual ice types and ice type mixtures. C-Band HH-polarized and Ku-Band VV-polarized NRCS are extracted on several 10. km-scale areas from coincident Envisat, RADARSAT-1, and QuikSCAT radar images for areas primarily covered with multiyear, deformed first-year, and undeformed young ice, as well as ice of the marginal ice zone (MIZ). The C-Band NRCS permits distinction between first-year, MIZ, and undeformed young ice. However, NRCS of the multiyear ice zone overlaps with that of the other ice zones and types. Ku-Band NRCS obtained for the same ice types permits discrimination of the first-year ice zone only. Obtained NRCS agree with those of previous studies and suggest a high degree of deformation and considerable potential for flooding for the first-year ice case. In comparison to large scale NRCS, AMSR-E snow depth values form two clearly separated clusters, one for 0.24-0.35. m depth (first-year ice zone) and one for 0.36-0.54. m depth (multiyear ice zone). However, a comparison to ASPeCt observations suggests a remarkable underestimation of the snow depth by AMSR-E in the multiyear-first-year-ice transition zone and for first-year cake ice. Nevertheless, a fusion of the coarse AMSR-E snow depth ranges for interior pack ice regions with radar imagery at large scale, appears promising for mapping the major zones (MIZ and Pack Ice) and ice types (first-year and multiyear) of Antarctic sea ice on a circumpolar basis.
| Original language | English |
|---|---|
| Pages (from-to) | 1092-1111 |
| Number of pages | 20 |
| Journal | Deep-Sea Research Part II: Topical Studies in Oceanography |
| Volume | 58 |
| Issue number | 9-10 |
| DOIs | |
| Publication status | Published - May 2011 |
| Externally published | Yes |
Funding
We wish to acknowledge United States National Science Foundation (NSF) Grant ANT ( #AWT0703682 ) and NASA Grant ( #NNX08AQ87G ) to UTSA for support. The National Snow and Ice Data Center in Boulder, Colorado provided AMSR-E images, NASA Distributed Active Archive Center provided MODIS, and Institut Français pour l'Exploitation de la Mer (IFREMER) provided QuikSCAT images. Their support is gratefully acknowledged. ESA is thanked for providing Envisat ASAR images (© ESA, 2007), and NIC/RPSC provided RADARSAT-1 images taken by Canadian Space Agency and their purchase was supported by the National Science Foundation. Additional Envisat images provided by ESA through Category-1 project (ID #6097) to UTSA are greatly appreciated. We are also grateful to sea ice observers aboard R/V Nathaniel B. Palmer. Sincere thanks also go to editor Petra Heil for her valuable support in writing the paper. The Python code for processing and calibration of the Envisat ASAR images was kindly provided by Lars Kaleschke. The International Space Science Institute (Bern, Switzerland) is acknowledged for supporting this study via project #137, #169, and #184.
| Funders | Funder number |
|---|---|
| RPSC | |
| National Science Foundation | 0703682 |
| National Aeronautics and Space Administration | 08AQ87G |
| National Institute of Corrections | |
| Canadian Space Agency |
Keywords
- Antarctica
- Microwave remote sensing
- Scatterometer
- Sea ice type discrimination