
Version Summary
- Intercalbration techniques between SMMR and F08, as well as F08 and F11 were changed to match sea ice area rather than sea ice extent.
- Ocean tie points now change each day (similar to the ice tie points) based on brightness temperatures for that day.
- The threshold for the lower limit for ice was relaxed to allow retrieval of ice at 10 percent ice concentration.
Overview
- 1 November 1978 to 31 December 2022
- 1 day
- 1 month
- 25 km
- 25 km
- NSIDC Sea Ice Polar Stereographic NorthEPSG:3411
- NSIDC Sea Ice Polar Stereographic SouthEPSG:3412
- N:90S:30E:180W:-180
- N:-39S:-90E:180W:-180
Strengths
- Long-term continuous record, with complete daily coverage of the Antarctic and the Arctic (excluding the “pole-hole”) since August 1987, preceded by every-other-day coverage since late October 1978. This makes it useful for tracking climate trends and variability and as a large-scale climate indicator (Comiso and Nishio, 2008)
- Thorough inter-calibration between sensors for consistency throughout record (Comiso and Nishio, 2008)
- Dynamic algorithm coefficients that adjust daily to account for changing surface characteristics (Comiso et al., 2017)
- Manual corrections and spatial and temporal interpolation to remove errors and fill in data gaps (Comiso and Nishio, 2008)
- Concentrations are generally reliable within the ice pack (away from the ice edge) during cold (non-melt) conditions (Comiso and Nishio, 2008)
- Microwave observations provide surface snow and ice coverage during cloudy and night-time (including polar night) conditions (Comiso and Nishio, 2008)
- Useful input/validation of climate model simulations (National Center for Atmospheric Research Staff, 2017)
Limitations
- Low spatial resolution (25 km gridded) limits detail on concentration and precision of ice edge; is unsuitable for detailed mapping of ice concentration (Comiso et al., 1997)
- Underestimates sea ice concentration during melt season (Kern et al., 2020) and/or when the ice is thin (Ivanova et al., 2015)
- Potential errors due to physical temperature variations, particularly for extreme cold temperatures (Comiso et al., 1997)
- False coastal ice can occur due to mixed land and ocean within a sensor footprint (Comiso and Nishio, 2008)