Extents expanded rapidly during the last 12 days of October through yesterday, especially on the Eurasian side. At the top center the Laptev Sea fills in completely, and to the left East Siberian Sea is also growing solid ice toward East Asia. Kara sea on the right is growing fast ice from the shore outward, while the Barents Sea fills in from the central Arctic.
The graph compares extents over the 28 days of October.
2017 has surpassed 8.1M km2, close to the 10-year average, and 700k km2 more than 2012. 2007 lags 925k km2 lower than 2017, while 2016 is 1M km2 behind. At this point MASIE and SII are showing similar ice gains in October, tracking the 10-year average.
The Table below shows where ice is located on day 301 in regions of the Arctic ocean. The 10-year average comes from 2007 through 2016 inclusive.
The deficits to average are mainly in Chukchi and Greenland Seas, while surpluses are large on the Eurasian side from East Siberian, through Laptev, Kara, and Barents. The Baffin Bay is also ahead of average.
Some people unhappy with the higher amounts of ice extent shown by MASIE continue to claim that Sea Ice Index is the only dataset that can be used. This is false in fact and in logic.
Why should anyone accept that the highest quality picture of ice day to day has no shelf life, that one year’s charts cannot be compared with another year?
Researchers do this analysis, including Walt Meier in charge of Sea Ice Index. That said, I understand his interest in directing people to use this product rather than one he does not control. As I have said before:
MASIE is rigorous, reliable, serves as calibration for satellite products, and uses modern technologies to continue the long and honorable tradition of naval ice charting.
More on this at my post Support MASIE Arctic Ice Dataset
Note: Sea Ice Index (SII) is reporting extents according to version 3.0 as of October 20, 2017. Details at: Sea Ice Index Updates to v.3.0
Footnote on MASIE Data Sources:
National Ice Center (NIC) produces ice charts using the Interactive Multisensor Snow and Ice Mapping System (IMS). From the documentation, the multiple sources feeding IMS are:
Platform(s) AQUA, DMSP, DMSP 5D-3/F17, GOES-10, GOES-11, GOES-13, GOES-9, METEOSAT, MSG, MTSAT-1R, MTSAT-2, NOAA-14, NOAA-15, NOAA-16, NOAA-17, NOAA-18, NOAA-N, RADARSAT-2, SUOMI-NPP, TERRA
Sensor(s): AMSU-A, ATMS, AVHRR, GOES I-M IMAGER, MODIS, MTSAT 1R Imager, MTSAT 2 Imager, MVIRI, SAR, SEVIRI, SSM/I, SSMIS, VIIRS
Historical Summary: IMS Daily Northern Hemisphere Snow and Ice Analysis
The National Oceanic and Atmospheric Administration / National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) has an extensive history of monitoring snow and ice coverage.
Accurate monitoring of global snow/ice cover is a key component in the study of climate and global change as well as daily weather forecasting.
The Polar and Geostationary Operational Environmental Satellite programs (POES/GOES) operated by NESDIS provide invaluable visible and infrared spectral data in support of these efforts.
Clear-sky imagery from both the POES and the GOES sensors show snow/ice boundaries very well; however, the visible and infrared techniques may suffer from persistent cloud cover near the snowline, making observations difficult (Ramsay, 1995).
The microwave products (DMSP and AMSR-E) are unobstructed by clouds and thus can be used as another observational platform in most regions. Synthetic Aperture Radar (SAR) imagery also provides all-weather, near-daily capacities to discriminate sea and lake ice.
With several other derived snow/ice products of varying accuracy, such as those from NCEP and the NWS NOHRSC, it is highly desirable for analysts to be able to interactively compare and contrast the products so that a more accurate composite map can be produced.
The Satellite Analysis Branch (SAB) of NESDIS first began generating Northern Hemisphere Weekly Snow and Ice Cover analysis charts derived from the visible satellite imagery in November 1966. The spatial and temporal resolutions of the analysis (190 km and 7 days, respectively) remained unchanged for the product’s 33-year lifespan.
As a result of increasing customer needs and expectations, it was decided that an efficient, interactive workstation application should be constructed that would enable SAB to produce snow/ice analyses at a higher resolution and on a daily basis (~25 km / 1024 x 1024 grid and once per day) using a consolidated array of new as well as existing satellite and surface imagery products.
The Daily Northern Hemisphere Snow and Ice Cover chart has been produced since February 1997 by SAB meteorologists on the IMS.
Another large resolution improvement began in early 2004 when improved technology allowed the SAB to begin creation of a daily ~4 km (6144×6144) grid. At this time, both the ~4 km and ~24 km products are available from NSIDC with a slight delay. Near real-time gridded data is available in ASCII format by request.
In March 2008, the product was migrated from SAB to the National Ice Center (NIC) of NESDIS. The production system and methodology were preserved during the migration.
Improved access to DMSP, SAR, and modeled data sources is expected as a short-term from the migration, with longer-term plans of twice daily production, GRIB2 output format, a Southern Hemisphere analysis, and an expanded suite of integrated snow and ice variable on the horizon.
Read more at Science Matters