NSIDC 2023 Arctic SIE Sept. Monthly Avg. - August 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

[oren]

Keeping my 4.25-4.75 vote for a 3rd time. We are not in 2012, 2020 territory, but I also think not in 2021, 2022 territory and not even 2017, 2018. Much depends on the trajectory within September, this poll is harder to pinpoint correctly.

[Juan C. García]

I changed my vote one bin up, to 4.50-5.00 million km2. I think it is getting too late to have a change in the current trend.

[Stephan]

I did not change my mind (4.25-4.75 M km²) compared to the previous polls.

[gerontocrat]

Here is some one day NSIDC Exent data & graphs.

AS for JAXA extent data, July was another very average melt month. Nearly 80% of average sea ice extent losses from max to min is done, and average daily losses are now in swift decline. (1st image)

The arithmetical projection of the daily minimum is currently 4.71 million km2, while the graph (image 2) is slighty higher at 4.75 million (due to the plume of projections graph being influenced by the timing of each year's minimum). The range of the last 10 years outcomes (which now excludes 2012) is from around  4.25 to 5.15 million km2.

The current projection of the September average extent is 4.92 million km2 (3rd graph and Table).

I am plumping for a last minute modest increase in daily sea ice extent losses resulting in a September average of around 4.5 million km2, i.e. bin 4.25 to 4.75.

[gerontocrat]

 Some data for the pollwatchers..

September average current estimate 4.46 million km2, 5th lowest in the satellite record.

[gerontocrat]

And the result is.....

September average daily extent 4.37 million km2, 5th lowest in the 45 year satellite record, 0.09 million km2 above the longterm linear trend, and 0.53 million km2 below the 2022 September average.

[oren]

Thanks, Gero.
Turns out 10 out of 19 voters got the result, >50%, though there was a definite upward bias in voting - or rather a downward surprise in the results.

[jdallen]

Thanks, Gero.
Turns out 10 out of 19 voters got the result, >50%, though there was a definite upward bias in voting - or rather a downward surprise in the results.

It would appear our collective understanding has improved with time.