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 (Parkinson et al., 1999; Zwally et al., 2002; Parkinson, 2019).
• Thorough inter-calibration between sensors for consistency throughout the record (Cavalieri et al., 1999; Cavalieri et al., 2012)
• Manual corrections and spatial and temporal interpolation to remove errors and fill in data gaps (Cavalieri et al., 1999)
• Less sensitive to temperature variations because it uses ratios instead of differences (Comiso et al., 1997)
• Concentrations are generally reliable within the ice pack (away from the ice edge) during cold (non-melt) conditions (Comiso et al., 1997)
• Microwave observations provide surface snow and ice coverage during cloudy and night-time (including polar night) conditions (Cavalieri et al., 1999)
• 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 (Cavalieri et al., 1999)
• Underestimates sea ice concentration during melt season (Kern et al., 2020) and/or when the ice is thin (Ivanova et al., 2015)
• Higher uncertainties in Antarctica due to flooded snow and other ice characteristics (Comiso et al., 1997)
• Algorithm coefficients are fixed for a given sensor, so biases can occur if characteristic surface conditions change (Cavalieri et al., 1999)
• False coastal ice can occur due to mixed land and ocean within a sensor footprint (Cavalieri et al., 1999)