Retrieval of sea ice thickness distribution in the seasonal ice zone from airborne L‐band SAR

Abstract

Although it is known that satellite data are useful for obtaining ice thickness distribution for perennial sea ice or in stable thin sea ice areas, it is still an unresolved issue for the seasonal sea ice zone (SIZ). In this study, we approach the problem of ice thickness retrieval by using L-band Synthetic Aperture Radar (SAR). In the SIZ, ice thickness growth is closely related to the ridging activity and therefore surface roughness is expected to be correlated with ice thickness. L-band SAR is suitable for detecting such surface roughness, and therefore is expected to be a good tool for obtaining thickness

Properties of snow overlying the sea ice off East Antarctica in late winter, 2007

“…As discussed by Dierking and Busche (2006), L-band SAR (wavelength = 24 cm) appears to be more sensitive to ice surface roughness than C-band (6 cm), because the wavelength more closely approximates the scale of surface roughness. This supports the result of Toyota et al (2009).…”

“…A conclusion is that mean ice thickness is best correlated with ice surface roughness, which indicates the potential usefulness of satellite L-band SAR as a means of estimating the ice thickness distribution in the Antarctic SSIZ from satellite -as is the case in the Sea of Okhotsk (Toyota et al, 2009). …”

“…Although L-band SAR was shown to be a candidate for the remote measurement of seasonal sea ice thickness in the Sea of Okhotsk (Japan) because of the relationship between surface roughness and ice thickness (Toyota et al, 2009), validation in various other regions is still required. The detailed transect measurement provide a good opportunity for this.…”

Retrieval of the thickness of undeformed sea ice from simulated C-band compact polarimetric SAR images

“…13). The investigation was further extended to other sensors, e.g., to the airborne Pi-SAR (X-and L-band data from the Sea of Okhotsk; Nakamura et al, 2009a;Toyota et al, 2009) and to Envisat ASAR, using radar intensity and ice thickness data from 0.2 to 2.5 m, the latter acquired from a research vessel in Lützow-Holm Bay, Antarctica (Nakamura et al, 2009b). The good correlations were attributed to the fact that the co-polarized ratio values are sensitive to the dielectric constants of the ice surface layer which change due to the process of desalination during ice growth.…”

“…This means that the co-polarized ratio (Wakabayashi et al, 2004;Nakamura et al, 2009a;Toyota et al, 2009) and the cross-polarized ratio (Kim et al, 2012) which are often used as an ice thickness proxy cannot be directly calculated from CP-mode SAR data. Although CP SAR images have been used to distinguish sea ice types (Dabboor and Geldsetzer, 2014;Charbonneau et al, 2010;Geldsetzer et al, 2015), to our knowledge there have been no published studies on its use for ice thickness detection in the open literature until now.…”