Global ice trends

[Simon]

Unable to find a sub forum for global ice, so I will put this very important review paper here. Moderators may like to move it elsewhere

https://www.the-cryosphere.net/about/news_and_press/2021-01-25_review-article-earths-ice-imbalance.html


Slater, T., Lawrence, I. R., Otosaka, I. N., Shepherd, A., Gourmelen, N., Jakob, L., Tepes, P., Gilbert, L., and Nienow, P.: Review article: Earth's ice imbalance, The Cryosphere, 15, 233–246, https://doi.org/10.5194/tc-15-233-2021, 2021

[kassy]

I think we should rename this Global ice trends and collect those papers here for an overview.

They get posted. This had also been posted in the SLR thread where it will be buried in other subjects soon. It is also in What is new in the Arctic.

In this thread we could collect the links to such reports.

This one is new in methodology but there is at least one other long running series we could add.

[oren]

Changed subject as requested.

[gerontocrat]

Hot from the press here are some graphs from the GRACE / GRACE-FO satellite series on the Greenland (GIS) and Antarctic (AIS) Ice sheets. Data is to mid-December.

They come from the JPL's PO.DACC system @
https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

You have to register with PO.DACC system but that is no problem.

As usual - click to enlarge images

[gerontocrat]

Jan 2021 data from the JPL @
https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI
(you have to register to det the data.)

Large Antarctic Ice Sheet mass loss exceeds Greenland Ice Sheet mass gain.

[nukefix]

Here's a link to an interactive portal in TU-Dresden, includes GRACE/GRACE-FO graphs per basin and whole ice sheets:

https://data1.geo.tu-dresden.de/

[gerontocrat]

Here's a link to an interactive portal in TU-Dresden, includes GRACE/GRACE-FO graphs per basin and whole ice sheets:

https://data1.geo.tu-dresden.de/

Thanks nukefix.

Unfortunately the data ends in Dec 2017 when the original GRACE satellites started to fail.
It has not been kept going to include the new GRACE-FO data - which is a great pity.

But I get data every month or so from GTZ by basin - always a month or two after I get the JPL summary data (i.e. AIS total only). The January and Feb 21 basin data could be really interesting.

[gerontocrat]

Here is the latest Ice Sheet graphs generated from GRACE + GRACE-FO processed by

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

To mid March '21

[gerontocrat]

Here is the latest Ice Sheet graphs generated from GRACE + GRACE-FO processed by

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

To mid April '21

[gerontocrat]

Here is the latest Ice Sheet graphs generated from GRACE + GRACE-FO data processed by the JPL.

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

To mid June '21

[gerontocrat]

And here are the long-term 365 day trailing avergaes of global SEA ICE EXTENT derived from from JAXA data

Both Arctic and Antarctic averages have been consistently increasing this year. As at the 31st August, the global average is 1.31 million km2 above the all time record low in September 2017, and 215k km2 above the long-term linear trend.

The current rate of increase is well over 3,000km2 per day, i.e. well over 1 million km2 per year.

[The Walrus]

And here are the long-term 365 day trailing avergaes of global SEA ICE EXTENT derived from from JAXA data

Both Arctic and Antarctic averages have been consistently increasing this year. As at the 31st August, the global average is 1.31 million km2 above the all time record low in September 2017, and 215k km2 above the long-term linear trend.

The current rate of increase is well over 3,000km2 per day, i.e. well over 1 million km2 per year.

If we assume that the variation is not random, but a natural response to decreasing sea ice and that the linear trend is the correct interpretation, then it is likely that the increase will continue to increase for at least another year to compensate for the drop, before continuing its downward trend.

[gerontocrat]

Here are some graphs from the GRACE / GRACE-FO satellite series on the Greenland (GIS) and Antarctic (AIS) Ice sheets. Data is to mid-August 2021.

They come from the JPL's PO.DACC system @
https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

You have to register with PO.DACC system but that is no problem.

click to enlarge images

[gerontocrat]

A look at sea ice highs and lows in the Arctic, Antarctic & Global

https://www.sciencedirect.com/science/article/pii/S0034425721004739?dgcid=rss_sd_all
Sea ice extents continue to set new records: Arctic, Antarctic, and global results

Highlights
• Arctic sea ice extents set 93 monthly 11 yearly record lows post-1986, 0 record highs.
• Highs dominated Antarctic sea ice extent records until 2016, followed by lows.
• Since 2015, global sea ice extents have set new monthly record lows for all 12 months.
• During 1979–2020, Arctic September sea ice extents varied 53%, March extents only 12%.
• #During 1979–2020, global yearly average sea ice extents varied by only 12%.

Abstract
The multi-channel satellite passive-microwave record of Earth's sea ice coverage, extending back to the late 1970s, has long revealed declining sea ice coverage in the Arctic but through 2015 revealed an overall increase rather than decrease in Antarctic sea ice coverage.

Following major decreases in Antarctic sea ice since 2015, the 42-year 1979–2020 satellite dataset now shows recent losses in sea ice coverage in both hemispheres, and this is convincingly demonstrated by the enumeration of monthly and yearly record high and record low sea ice extents experienced over the course of the 42 years.

In fact, one of the most convincing statistics on the declining Arctic sea ice cover is the fact that since 1986 the Arctic has not experienced a single monthly record high sea ice extent in any month but has experienced 93 monthly record lows. In contrast, all 12 calendar months have their 42-year Antarctic monthly record high sea ice extents in the period 2007–2015, while 8 of the 12 calendar months have had Antarctic record lows since 2015.

Globally, every calendar month has registered a new monthly record low within the past 5 years. These results are complemented (and somewhat tempered) by quantification of the range of monthly and yearly sea ice extent values over the 42 years. For instance, although the Arctic's lowest September monthly average sea ice extent (in 2012) is 53% lower than its highest September monthly average sea ice extent (in 1980), the other months have far smaller percent differences between their lowest and highest Arctic values. For yearly average sea ice extents, the Arctic's lowest value (in 2020) is 18% lower than its highest value (in 1982), the Antarctic's lowest value (in 2017) is 16% lower than its highest value (in 2014), and the global lowest value (in 2019) is only 12% lower than its highest value (in 1982).

Results
Results are presented for the Arctic, Antarctic, and global datasets through 3-D and flat visualizations, tabulations of the monthly and yearly rankings, and graphics of the occurrence of each record high and each record low (Fig. 1, Fig. 2, Fig. 3).

click images to enlarge, click maximise for full screen

[Shared Humanity]

I find the global 3D chart noisy but the other two are fascinating. This is amazing work. Visualizations can show definitively trends that can be obscured in data tables.

[gerontocrat]

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

JPL / PO.DACC have published GRACE/GRACE-FO Greenland and Antractic ice sheet mass data to October 21.

Graphs attached - no dramatic changes.

[gerontocrat]

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

JPL / PO.DACC have published GRACE/GRACE-FO Greenland and Antractic ice sheet mass data to November 21.

Graph attached - no dramatic changes. 8 Trillion tons of ice loss since 2002

[gerontocrat]

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

JPL / PO.DACC have published GRACE/GRACE-FO Greenland and Antractic ice sheet mass data to January 21.

Graph attached - no dramatic changes. 8 Trillion tons of ice loss since 2002, i.e. about 400 GT per year.

[WildFit]

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

JPL / PO.DACC have published GRACE/GRACE-FO Greenland and Antractic ice sheet mass data to January 21.

Graph attached - no dramatic changes. 8 Trillion tons of ice loss since 2002, i.e. about 400 GT per year.

That is dramatic IMO or was it sarcasm ?

[gerontocrat]

https://podaac-tools.jpl.nasa.gov/drive/files/allData/tellus/L4/ice_mass/RL06/v02/mascon_CRI

JPL / PO.DACC have published GRACE/GRACE-FO Greenland and Antractic ice sheet mass data to January 21.

Graph attached - no dramatic changes. 8 Trillion tons of ice loss since 2002, i.e. about 400 GT per year.

That is dramatic IMO or was it sarcasm ?

Depends how you look at it.

8,000 GT, 400 GT  / 400 Km3 p.a. is definitely a lot of ice.

On the other hand...

400 km3  of ice raises sea level by 1.1 millimetre.
With total ice of the GIS+AIS being just under 30 mllion GT, losing 8,000 GT is just 0.03 percent.
At 400 GT per annum it would take about 73 thousand years to melt the ice sheets.

Drama for me is when I see some acceleration in the rate of loss of ice on the ice sheets - currently seems confined to the Antarctic.

[mitch]

Global sea level is rising currently at 3.3 mm/yr.  1.1 mm/yr from the ice sheets is 1/3 of that total, so is very significant:
https://sealevel.colorado.edu/

[gerontocrat]

For a change - here is a look at Global sea ice trends using Jaxa sea ice extent data

Two graphs - total Arctic + Antarctic
and shown separately

It is Antarctic that is leading the current drop (at the moment).

click images to enlarge

[gerontocrat]

Attached is a graph showing ice sheet mass loss GRACE / GRACE-FO from data to mid-Jan 22 provided by JPL.

[gerontocrat]

And here is an analysis of Global sea ice area from NSIDC data.

NSIDC 5 Day trailing Average -  GLOBAL SEA ICE AREA:  17,555,496 KM2 as at 29-Apr-2022

- Extent gain on this day 27k, 21 k less than the average gain on this day (of the last 10 years) of 48k,
- Extent gain from minimum on this date is 3.56 million km2, 0.05 million km2, 1.3% less than the 10 year average gain of 3.61 million km2.

- Extent is 8th lowest in the satellite record

- Extent is  -0.95 million km2 LESS than 1980's Average
- Extent is  -0.56 million km2 LESS than 2010's Average
- Extent is  -0.20 million km2 LESS than 2016
- Extent is  0.61 million km2 MORE than 2017
- Extent is  0.62 million km2 MORE than 2018
- Extent is  0.25 million km2 MORE than 2020
- Extent is  -0.68 million km2 LESS than 2021

On average 61.6% of sea ice gain from minimum to maximum done, and 188 days to maximum

Projections of the Unknown Quantity.

Average remaining sea ice gain (of the last 10 years) would produce a maximum in November 2022 of 19.80 million km2, 0.73 million km2 above the 2016 record low maximum of 19.07 million km2.
___________________________________________________
After passing the  the false maximum in late June/ early July and the false minimum in early September, sea ice extent then makes the final run to the maximum in late October /early November .

N.B. In 2016 the maximum  for the year was reached in mid June. i.e. the November maximum was less than the “false” maximum.
___________________________________________________
Click an image to enlarge

[gerontocrat]

And here is an analysis of Global sea ice area 365 day trailing average from NSIDC data.


After the 2017 record low minimum the 365 day global average has been on a generally upward trend. Perhaps a change is in place. Global area is back below the long-term linear trend since 12 March 22 - by 145k, mainly due to low Antarctic sea ice area.

click images to enlarge

[gerontocrat]

Attached is a graph showing ice sheet mass loss GRACE / GRACE-FO from data to mid-May 22 provided by JPL.

click to enlarge

[gerontocrat]

Attached is a graph showing ice sheet mass loss GRACE / GRACE-FO to mid-Jun 22 provided by JPL.

[gerontocrat]

Attached is a graph showing ice sheet mass loss GRACE / GRACE-FO to mid-July 22 provided by JPL.

Also attached is the 365 day trailing avaege graph of total sea ice extent , which obscures the completely different trend in the 365 day average in the Arctic compared with the Antarctic over the last year or two (graph also attached).

click images to enlarge

[gerontocrat]

GFZ - Helmholtz Cenre, Potsdam has also produced Greenland & Antarctic Ice Sheet Mass Loss Data from GRACE/GRACE-FO data to August 22.

Overall, in the last 2+ years mass loss has been relatively slow.

click image to enlarge