Arctic October Chill Continues

Extents expanded rapidly during the last 13 days of October through yesterday, already gaining back to  reach 50% of March maximum.   On the right side Laptev Sea has filled in completely, and just above it East Siberian Sea is also growing solid ice toward East Asia. Kara sea just below Laptev is growing fast ice from the shore outward. On the left, Canadian Archipelago is now full of ice, with Beaufort spreading toward shore and next to Greenland, Baffin Bay is extending southward.

The graph compares extents over the first 22 days of October.
2017 has reached 7.5 M km2, 100k km2 above the 10 year average, 800k km2 more than 2016 and more than 2012.  2007 lags 1.3M km2 lower than 2017.  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 295 in regions of the Arctic ocean. 10 year average comes from 2007 through 2016 inclusive.

Region	2017295	Day 295 Average	2017-Ave.	2007295	2017-2007
(0) Northern_Hemisphere	7543438	7431370	112068	6284693	1258745
(1) Beaufort_Sea	764794	801247	-36453	806764	-41970
(2) Chukchi_Sea	297001	378182	-81180	135321	161680
(3) East_Siberian_Sea	737817	777926	-40109	133466	604351
(4) Laptev_Sea	895187	725836	169351	690628	204559
(5) Kara_Sea	365187	292669	72518	283333	81854
(6) Barents_Sea	67973	47903	20070	25377	42597
(7) Greenland_Sea	243447	401693	-158246	446006	-202559
(8) Baffin_Bay_Gulf_of_St._Lawrence	224104	145178	78926	90620	133484
(9) Canadian_Archipelago	747134	680155	66980	576142	170992
(10) Hudson_Bay	39910	25325	14585	1954	37957
(11) Central_Arctic	3158019	3151075	6944	3093807	64212

The important deficits to average are in Chukchi and Greenland Seas, while larger surpluses appear in Laptev, Kara, Baffin Bay and Canadian Archipelago. If ice extents continue to grow at the present rate to month end, the October 2017 monthly average will exceed the 10 year October average by several 100k km2.

Halloween is Coming!

Footnote

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 can not 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 his 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 which 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 was 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 horizon.

http://www.natice.noaa.gov/ims/ims_1.html