NSIDC 2023 Arctic SIE September Monthly Average - July Poll

[Juan C. García]

This is the NSIDC Poll for September Monthly Average. Not to be confused with the JAXA Daily Minimum Poll.

These are the NSIDC September Arctic Sea Ice Extent averages in 2000-2022 (in million km²):

Year      NSIDC ASIE
            (10^6 km2)
2000         6.25
2001         6.73
2002         5.83
2003         6.12
2004         5.98
2005         5.50
2006         5.86
2007         4.27
2008         4.69
2009         5.26
2010         4.87
2011         4.56
2012         3.57
2013         5.21
2014         5.22
2015         4.62
2016         4.53
2017         4.82
2018         4.79
2019         4.36
2020         4.00
2021         4.95
2022         4.90

[Richard Rathbone]

I'm sticking with my June guess 4.5-5.

The June predictions from SIPN have some fairly extreme values from the dynamic models but the statistical ones are also mainly predicting a mid-range post 2012 outcome.
https://www.arcus.org/sipn/sea-ice-outlook/2023/june

The June 2023 Outlook received 38 pan-Arctic contributions (Figure 1). This year's median forecasted value for pan-Arctic September sea-ice extent is 4.54 million square kilometers with an interquartile ranges of 4.34 to 4.90 million square kilometers. This is nearly the same as last year's June median forecast for September, but higher than the three previous years (2019–2021). The lowest sea-ice extent forecast is 2.95 million square kilometers, from UC Louvain, which would be a new record low for the satellite period (1979-present); the highest sea-ice extent forecast is 5.60 million square kilometers, from the HEU Group, which would be the highest September extent since 2006. Only one Outlook forecasts a new record minimum September extent, though two others (Met Office, NCEP-EMC) forecast an extent that is essentially the same as the record low September (3.57 million square kilometers)

.

A few selected predictions:
CPOM (May melt pond correlation) predicts 4.2
Nico Sun (Tealight) predicts 4.57
Uni Washington (PIOMAS in prediction mode) predicts 3.99, arranged much like last year but with rather more melt on the Siberian side.

[oren]

Keeping 4.25-4.75 from last month.

[gerontocrat]

At June 30th NSIDC Arctic SIE at 9.65 million km2 is 34k above the 2010's average and sea ice loss from maximum to date is 124k, 2.4%, below the last 10 years average, i.e. a slow melting season so far with on average 50% of sea ice extent loss completed.

If sea ice losses are at the 10 year average from now to end September, the September monthly average woud be 4.71 million km2, 9th lowest in the satellite record, and 0.39 million km2 above the longterm linear trend.

However, I still lean to above average sea ice extent losses in the 2nd half of the melting season. This is reinforced by the Northward movement of +ve temperature anomalies from the Atlantic to the Arctic Ocean, and after a very slow start up to late June, the extreme melt on the Greenland ice sheet sustained over the last 4 days  that includes a large part of the far North.

So I am going for the range 4.00 to 4.5 million km2 for the September average, maybe in the top 6 lowest minima since 1979.

another hostage to fortune nailed to the mast

[Paddy]

I’m going 4.25 - 4.75; reckoning on slightly above average melting ahead with the heat and other conditions but hedging against a top 3 finish.

[nadir]

4-4.5 warm year. Widespread melting in the entire Pacific Half already, including the Western CAB and CAA which all together is not so common.

[Stephan]

I kept with my June Poll value (4.25-4.75 M km² bin)

[The Walrus]

Not changing from 4.5 - 5.0.  While ice melt sped up during the latter part of June, it has slowed during the first part of July.  The ice has been tracking 2022 quite closely since the winter maximum, and the September average last year was 4.90.  Could possibly be above 5.0, but I think that is less likely.

[nadir]

Not changing from 4.5 - 5.0.  While ice melt sped up during the latter part of June, it has slowed during the first part of July.  The ice has been tracking 2022 quite closely since the winter maximum, and the September average last year was 4.90.  Could possibly be above 5.0, but I think that is less likely.

Curiously my perception is almost the opposite, but it’s about actual ongoing melting. Extent losses will come if present weather persists, but everything could be halted by a shift to colder conditions.

I think it’s going to be around 4.5 m km2, potentially below it.

[The Walrus]

Not changing from 4.5 - 5.0.  While ice melt sped up during the latter part of June, it has slowed during the first part of July.  The ice has been tracking 2022 quite closely since the winter maximum, and the September average last year was 4.90.  Could possibly be above 5.0, but I think that is less likely.

Curiously my perception is almost the opposite, but it’s about actual ongoing melting. Extent losses will come if present weather persists, but everything could be halted by a shift to colder conditions.

I think it’s going to be around 4.5 m km2, potentially below it.

I thought that also, when the melt started increasing towards the end of May.  It looked as if the ice was going to continue its fall, based on temperture, weather, and other factors.  However, once the calendar turned over to July, the melt has eased (compared to recent years).  The extent is currently 250k above the 10-year average, and third highest since 2010 for this date.

[gerontocrat]

I am not changing my guess of 4 to 4.5 million km2 even though recent data says "no chance".

That recent data as at 9th July includes:
- current extent is 260k km2 above the 2010's average,
- in July to date the 7 day average of daily extent losses is well below the average,
- Average daily exent losses of the last 10 years from now to September 30th would produce a September monthly average of 5.01 million km2, 14th lowest in the satellite record an 0.68 million km2 above the longterm linear trend,
- The plume of projected sea ice extent shows that none of the last 10 years producing even a daily minimum below 4 million km2.
- on average by now 60% of area loss from max to min has been completed

I am still looking for a (very) late crash.

[be cause]

Mine remains unchanged too .

[echoughton]

Between 4.75 and 5,25. Looking much like last two seasons. And I always tend to be optimistic. 

[oren]

Final result was 4.37 Mkm2, as calculated by Gero.
Amazingly, 20 out of 31 voters (nearly 65%) got the correct bins. Well done.