With a volume of 21.9 [1000 km3], 2018 is still second lowest.
Average Arctic sea ice VOLUME for April 1, for the period 1980-89, was ~30,200 cubic kilometers. April 1, 2018 Arctic sea ice VOLUME is ~21,900 cubic kilometers, ~ 8300 cubic kilometers LESS than the 1980-89 average for April 1.
Like 2015, 2016 & 2017, 2018 Arctic sea waters(which used to be ice & reflected solar energy to space) have set themselves up to absorb much excess AGW predicted solar energy, while the sun is at its approaching maximum elevations in the sky. Any downwellings in those .5+ million square kilometers excess AGW generated waters, will transport excess AGW solar absorbed energy directly downward to Arctic continental shelves or into deeper Arctic waters, for storage.... energies that had not been available previously to the Earth. It has also been determined that excess solar energy can be absorbed through thin AGW generated ice when the sun is at its highest elevations in the Arctic....even more energy stored in Arctic waters.
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For half a century(+?), the solar TSI has been languid. For 11+ years the solar TSI has been well below average(including a 3+ year low period setting a 100 year record). For many years, due to the low solar TSI, AGW deniers have declared an ice age.
But Earth has NOT even returned to early 20th century low temperatures. For 395+ STRAIGHT months Earth temperatures have been over the 20th century average. AGW deniers should be happy there are no gay activities.
The first decade of the 21st century has been the hottest recorded decade, also including the 20th & 19th century recorded temperatures. The last five years have been the hottest 5 year recorded period, including the 21st, 20th, & 19th centuries. 2014, 2015, 2016, & 2017 has been the hottest recorded successive years, including the 21st, 20th, & 19th centuries. All this while solar TSI is low, which science says is only a blip low. For billions of years, the sun has continued to warm & WILL continue to warm. Once solar TSI becomes its normal, higher(& higher, still) self, Earth temperatures (already escalating), will take a faster elevator, upward!
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On January 1, average Arctic sea ice extent for the 1980's was 14.52 million KM2. Like 2015, 2016, 2017 & now 2018, MAXIMUM Arctic sea ice extent did not reach 14 million square kilometers. Indeed, 3 months of Arctic sea ice freezing has disappeared!!