Early in July, a divergence of 2018 surplus ice resembled a hockey stick temporarily. Though the blade later drooped downward, ice extent remained above average throughout July. The graph above shows 2018 300k km2 above the 11 year average for July (2007 to 2017 inclusive). Only 2015 and 2008 had a higher July monthly average extent. Note that SII (NOAA’s Sea Ice Index) was lower by 436k km2 in 2018, and SII 11 yr. average is lower by 264k km2.
The surprise: This is the first 2018 month above the average. Indeed March 2018 (annual maximum) was almost 500k km2 lower than March 11 yr. average. But reduced rates of melting in May, June and July have resulted in more ice extent than most other recent Julys. At end of July, 2018, 2017 and 11 yr. average are close together, with SII 600k lower and 2007 with 824k km2 less…
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