2023: August Report from Sea Ice Prediction Network

The August median forecasted value for pan-Arctic September sea-ice extent is 4.60 million square kilometers with interquartile values of 4.35 and 4.80 million square kilometers, while individual forecasts range from 2.88 to 5.47 million square kilometers. We note that the lowest two forecasts predict a new record September sea-ice extent value (current record is September 2012, with a sea-ice extent of 3.57 million square kilometers), but these forecasts are outliers relative to the other contributions.

These are predictions for the September 2023 monthly average ice extent as reported by NOAA Sea Ice Index (SII). This post provides a look at the 2023 Year To Date (YTD) based on monthly averages comparing MASIE and SII datasets. (17 year average is 2006 to 2022 inclusive).

The graph puts 2023 into recent historical perspective. Note how 2023 was slightly below the 17-year average for the first 5 months, then recovered to match average in May and has maintained or exceeded average through August. The outlier 2012 provided the highest March maximum as well as the lowest September minimum, coinciding with the Great Arctic Cyclone that year.  2007 began the period with the lowest minimum except for 2012.  SII 2023 was running below MASIE except for May/Juneand is currently just below MASIE 2007 and 2012.

The table below provides the numbers for comparisons (all are M km2)

The first two columns are the 2023 YTD shown by MASIE and SII, with the MASIE surpluses in column three.  Column four shows MASIE 2023 compared to MASIE 17 year average, while column five shows SII 2023 compared to SII 17 year average.  YTD August both MASIE and SII are very slightly below average. The last column shows MASIE 2017 holding an August surplus of 241k km2 over 2007.

Summary

The experts involved in SIPN are expecting SII 2023 September to be higher than 2007 and somewhat lower than 2022.  The way MASIE is going, this September looks to be nearly average unless some bad weather intervenes.  While the daily minimum for the year occurs mid September, ice extent on September 30 is typically slightly higher than on September 1.

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, 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 continues the long and honorable tradition of naval ice charting using modern technologies. More on this at my post Support MASIE Arctic Ice Dataset

MASIE: “high-resolution, accurate charts of ice conditions”
Walt Meier, NSIDC, October 2015 article in Annals of Glaciology.

The animation shows Arctic ice extents on day 151 (end of May) through yesterday June 30, 2023  As usual, the Pacific basins Bering and Okhotsk (far left) became ice-free and are no longer included in these updates. Years vary as to which regions retain more or less ice.  For example, this year Hudson Bay (bottom right) lost half its ice by June 30, earlier than average.  That is a shallow basin and can quickly lose its ice in coming days.  Despite this early melting, the NH Ice extent remains greater than the 17 year average.

The graph below compares the June monthly ice extents 2007 to 2023 and compared to the 17 year average.

Clearly June ice appears as a plateau, and most years MASIE shows greater extents than SII, with differences of only a few 100k km2.  Previously 2019-20 were in deficit to average, but June 2022-3 have returned to surplus years.  More on MASIE dataset at the end.

The graph shows the melting pattern during June 2023 remained above average all month, and greatly exceeded 2007 and 2020, especially in the last 2 weeks.  June 30, 2023 was 322k km2 in surplus, and exceeded 2007 by 0.4 Wadhams (M km2).

The table below shows ice extents by regions comparing 2023 with 17-year average (2006 to 2022 inclusive) and 2007.

2023 is 322k km2 above average (3.3%). The main deficit is in Hudson Bay, more than offset by large  surpluses in Baffin Bay and Greenland Sea, along with additonal ice elsewhere.

Footnote on MASIE Data Sources:

MASIE reports are based on data primarily from NIC’s 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

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. Source:  Interactive Multisensor Snow and Ice Mapping System (IMS)

Apparently someone posted on Facebook that Arctic ice extent is presently surplus to average, which triggered the fact checking agency employed by the platform.  The content below is from The Cable Fact Check No, short time data can’t determine overall decline of arctic sea ice.  In italics with my bolds and comments in parentheses.

Facebook post has claimed that arctic ice is neither declining nor disappearing.

Attached to the post was an article showing a graph for arctic ice for mid-April through mid-May in 2007, 2018, 2021 and 2023. 

The article was titled: “Arctic Ice Plentiful Mid May 2023”.

The graph indicated that the area of the ocean covered by a certain percentage of ice is higher in 2023 than in the other listed years and similar to the 17-year average.

“The ice is not disappearing,” says the Facebook post, which claimed that data for the month of April and May 2023 shows that the arctic sea ice is not declining. [consistent with “similar to the 17-year average”]

RECORDS SHOW THAT SEA ICE IS DECREASING

According to the National Aeronautics and Space Administration (NASA), a US agency responsible for aeronautics and space research, the volume of ice has significantly reduced. [Note the switch to the volume metric which is model estimated with considerable uncertainty]

The US agency has also reported that the average age of sea ice is becoming shorter.

Citing far back as the late 1970s, when satellite recording commenced, NASA says most of the ice covering the arctic ocean at that time was greater than 4 years old.

Presently, most of the ice covering the ocean is first-year ice, formed during winter, and very unlikely to withstand a single melt season during summer.  [Really, how about this:

Also, data released by the National Snow and Ice Data Centre, explains that the size of the arctic sea has declined since the 1970s. [size of the sea itself?]

Although the 2023 sea ice extents were slightly higher for the period under review – mid-April through mid-May than in 2007, 2018 and 2021 – just like the Facebook post stated. However, the sea ice varies by year and season despite that it is experiencing an overall decline. [Varies, yes, but the decline stopped in 2007:

Sea ice extent is the area of ice that covers the arctic ocean at a given time.

Climate experts have also reported that compiling or analysing short-term data is inadequate for making accurate climatological inferences.

Olusola Ayantobo, a hydro-climatologist and research associate at China’s Tsinghua University, had told TheCable that “station data shouldn’t be used to predict climate change conditions over a particular region”.

The climate expert added that: “Short-term datasets can only be used for weather prediction while a long dataset is appropriate for climate change predictions.” [Note that both their preferred Sea Ice Index (SII) and MASIE the best current condition dataset, validated from 2006 forward, show the same lack of decline in sea ice extent]

Experts say that though two decades might look quite long, however, it is short when studying long-term climate trends.  [True, but the same people predicted an ice-free arctic based on the decline from 1997 to 2007.]

MELTING SEA ICE AGGRAVATES GLOBAL WARMING

The albedo effect explains why the rapid melting of sea ice aggravates climate change. The theory says that the bright surface of the ice reflects solar energy, which has a cooling effect. Also, ocean water, which is darker, absorbs more solar energy, causing more warming. 

The loss of sea ice warms the arctic, hence, contributing to a phenomenon referred to as arctic amplification, a process through which the arctic warms at a faster rate than lower latitudes.

VERDICT

The claim that the sea ice is neither melting nor disappearing is false.

Long-term studies dating back to 1970 show that arctic sea ice has declined significantly. Climate experts have also warned that only long-term data analysis can provide accurate inferences when studying climate trends. [Note: Does that mean ignoring the last 17 years of ice stability?]

This fact check was produced by TheCable with support from Code for Africa’s PesaCheck, International Fact-Checking Network, and African Fact Checking Alliance network. [Code For Africa is funded by 2 investors. Omidyar Network and Bill & Melinda Gates Foundation are the most recent investors.]

[Comment:  As usual, they are checking a narrative, rather than facts.  And then cherry-pick other facts or statements favoring their preferred narrative.]

Regarding Arctic “Amplification”

An artifact of using anomalies, which are highly variable at higher latitudes:

The Original Post:  Arctic Ice Plentiful Mid May 2023

The image above shows 2023 Arctic ice extents from Mid April (day 106) to Mid May (day 135). As usual, the LIFO pattern is observed: ice that is Last In is the First Out.  The Pacific basins of Okhotsk (top left) and Bering (bottom left) rapidly turn to open water.  Baffin Bay (lower right) melts more slowly. Barents Sea (top center loses ice extent steadily.  Note Hudson Bay (bottom) keeps its ice, and Canadian Archipelago (lower center) retains most of its ice. On the left center, the Eurasian coastline remains frozen.

The graph below shows 2023 compared to 17 year average and some recent years for this time period.

Firstly, on average this period shows ice declining 1.44 M km2 down to 12.68M km2,  Note that  2023 matched the average in April, then retained more ice than usual during first two weeks of May. Sea Ice Index (SII) was close to MASIE throughout..  The other years, including 2007, were ~300k km2 lower than average.

The table shows the distribution of ice in the Arctic basins.  The main deficits to average are Baffin and Hudson Bays, more than offset by surpluses in Kara and Greenland Seas. Most other regions are surplus with a few slightly negative.

Resources:  Climate Compilation II Arctic Sea Ice

The image above shows 2023 Arctic ice extents from May 1 (day 121) to May end (day 151).  The Pacific basins of Okhotsk (center left) and Bering (bottom left) rapidly turn to open water.  Baffin Bay (center right) melts more slowly. Barents Sea (top center steadily loses ~200k km2 ice extent.  Note Hudson Bay (bottom) mostly keeps its ice, ending the month with 86% of its March max.  And Canadian Archipelago (lower center) retains 97% of its ice. On the left center, the Eurasian coastline remains mostly frozen.

The graph below shows 2023 compared to 17 year average and some recent years for this time period.

Firstly, on average this period shows ice declining 1.73 M km2 down to 11.72 M km2,  Note that  2023 matched the average May 1,  then retained more ice than usual during May, ending with a decline of 1.24 M km2.  Most of May Sea Ice Index (SII) tracked higher than MASIE, an average 100 km2 extra ice extent..  The other years, including 2006, were 200 to 300k km2 lower than average.

The table shows the distribution of ice in the Arctic basins.  The main deficits to average are Kara and Barents Seas, more than offset by surpluses in Beaufort, Chukchi, and Greenland Seas, along with Baffin Bay. Most other regions are surplus with a few slightly negative.  Note that 2023 exceeds May 2006 by  more than half a Wadham (1M km2 ice extent).

Resources:  Climate Compilation II Arctic Sea Ice

The image above shows 2023 Arctic ice extents from Mid April (day 106) to Mid May (day 135). As usual, the LIFO pattern is observed: ice that is Last In is the First Out.  The Pacific basins of Okhotsk (top left) and Bering (bottom left) rapidly turn to open water.  Baffin Bay (lower right) melts more slowly. Barents Sea (top center loses ice extent steadily.  Note Hudson Bay (bottom) keeps its ice, and Canadian Archipelago (lower center) retains most of its ice. On the left center, the Eurasian coastline remains frozen.

The graph below shows 2023 compared to 17 year average and some recent years for this time period.

Firstly, on average this period shows ice declining 1.44 M km2 down to 12.68M km2,  Note that  2023 matched the average in April, then retained more ice than usual during first two weeks of May. Sea Ice Index (SII) was close to MASIE throughout..  The other years, including 2007, were ~300k km2 lower than average.

The table shows the distribution of ice in the Arctic basins.  The main deficits to average are Baffin and Hudson Bays, more than offset by surpluses in Kara and Greenland Seas. Most other regions are surplus with a few slightly negative.

Resources:  Climate Compilation II Arctic Sea Ice