NOAA@ NSIDC is pleased to announce that MASAM2: Daily 4 km Arctic Sea Ice Concentration, Version 2 is now available. MASAM2 is a blend of the 4 km Multisensor Analyzed Sea Ice Extent – Northern Hemisphere (MASIE-NH) ice extent product and a 10 km AMSR2 sea ice concentration product. With Version 2, the data set provides ice concentration values that may range between 40 percent and 100 percent everywhere that the MASIE product has detected ice.
In Version 1, where the MASIE product indicated sea ice, the corresponding MASAM2 grid cell was set to the bilinearly interpolated AMSR2 sea ice concentration if that concentration value was greater than 70 percent, else it was set to 70 percent. Based on feedback from users, we lowered this threshold. We chose 40 percent because that is the threshold used by analysts at the U.S. National Ice Center when they create the product that MASIE is based on.
This change yields data with much more spatial variability than those of Version 1, as illustrated in the figure below. The Version 2 product should be more suitable for ice forecasting and modeling applications. The User Guide has more information about how the threshold was chosen and has been used in both versions.
Note that Version 1 will continue to be processed and available through 31 December 2023 at which time it will be retired and removed from distribution.
To access the Version 2 data and view the documentation, visit the data set landing page.
Data set DOI: https://doi.org/10.7265/bqd9-vm28