Estimation of the thin ice thickness and heat flux for the Chukchi Sea Alaskan coast polynya from Special Sensor Microwave/Imager data, 1990–2001

Abstract

[1] One of the largest Arctic polynyas occurs along the Alaskan coast of the Chukchi Sea between Cape Lisburne and Point Barrow. For this polynya, a new thin ice thickness algorithm is described that uses the ratio of the vertically and horizontally polarized Special Sensor Microwave/Imager (SSM/I) 37-GHz channels to retrieve the distribution of thicknesses and heat fluxes at a 25-km resolution. Comparison with clear-sky advanced very high resolution radiometer data shows that the SSM/I thicknesses and heat fluxes are valid for ice thicknesses less than 10-20 cm, and comparison with several synthetic aperture radar (SAR) images shows that the 10-cm ice SSM/I ice thickness contour approximately follows the SAR polynya edge. For the twelve winters of 1990-2001, the ice thicknesses and heat fluxes within the polynya are estimated from daily SSM/I data, then compared with field data and with estimates from other investigations. The results show the following: First, our calculated heat losses are consistent with 2 years of over-winter salinity and temperature field data. Second, comparison with other numerical and satellite estimates of the ice production shows that although our ice production per unit area is smaller, our polynya areas are larger, so that our ice production estimates are of the same order. Because our salinity forcing occurs over a larger area than in the other models, the oceanic response associated with our forcing will be modified.

The Spring-Time Boundary Layer in the Central Arctic Observed during PAMARCMiP 2009

“…For ice thickness between 0.2-0.4 m, the sensible heat flux may be as large as 100 W m . This was also confirmed by satellite-derived data for ice thickness and sensible heat flux for Arctic polynyas [53]. Impacts of refreezing leads in terms of enhanced sensible and latent heat fluxes and a decrease in atmospheric stability were reported downwind of the lead up to 60 m altitude [48].…”

Halocline structure in the Canada Basin of the Arctic Ocean

“…Pacific Winter Water, centered near S = 33.1, has long been recognized as primary component of the western Arctic halocline [Coachman et al, 1975]. Pacific Winter Water through the Bering Strait [Woodgate and Aagaard, 2005] was modified in the coastal polynya between Point Barrow and Cape Lisburne (e.g., increased salinity due to ice formation) [Cavalieri and Martin, 1994;Weingartner et al, 1998;Martin et al, 2004]. However, the spatial distribution of this more saline water in the Canada Basin and its role in the formation of basin-scale oceanic structures has not yet been reported.…”

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

“…Kern et al 2006) revealed that active and passive microwave data are useful mainly through the thermodynamic processes that control both ice thickness and surface dielectric properties. Based on these results, the thickness algorithms for coastal polynyas in Arctic and Antarctic regions, combined with NOAA/AVHRR data were also developed (Martin et al 2004;Tamura et al 2007). For perennial ice, the measurement of the freeboard depth has been proved to be effective with the assumption of isostatic balance, from field observations in the Arctic (Comiso et al 1991;Wadhams et al 1992) and from satellite altimetry (Laxon et al 2003;Kwok et al 2004).…”

“…Based on these results, the thickness algorithms for coastal polynyas in Arctic and Antarctic regions, combined with NOAA/AVHRR data were also developed (Martin et al 2004;Tamura et al 2007). For perennial ice, the measurement of the freeboard depth has been proved to be effective with the assumption of isostatic balance, from field observations in the Arctic (Comiso et al 1991;Wadhams et al 1992) and from satellite altimetry (Laxon et al 2003;Kwok et al 2004). While the algorithm for stable thin ice or thick perennial ice has been explored, relatively thick sea ice in SIZ remains a big issue.…”