Antarctic Sea Ice Hits New All-Time Record Low

During late February, Antarctic sea ice breached the previous all-time record low for extent coverage since measurements began in 1978. And in the following days, sea ice extent measures near the South Pole have continued to creep lower, gradually extending into unprecedented ranges.

Record Melt During a Period of Considerable Global Heat

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(This February, according to JAXA, the Antarctic sea ice extent measure hit a new all time record low. Image source: JAXA.)

Hitherto unseen global heat — driven primarily by human fossil fuel emissions — appears to be the chief contributor to this melting. During 2016, global average surface temperatures rose to 1.2 degrees Celsius above 1880s ranges. This global reading likely represents the warmest surface temperatures the world has experienced in the last 115,000 years. At the same time, the global ocean system has been rapidly accumulating warmth and transferring it through the surface and deep layers of the world’s waters.

Such pervasive heat is producing an ongoing trend of considerable sea ice melt in the Arctic — a trend that has been in place since record-keeping began in 1978. One that, all by itself, is strong enough to drag global sea ice measures lower and lower. The warmth is also producing land ice melt around the world — including glaciers in Antarctica, Greenland and across numerous mountain ranges.

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(Global warming produced an identifiable global sea ice melt trend during the post year 2000 period. By 2016, that trend had become glaringly obvious. See final paragraph for further discussion. Image source: Wipneus.)

Mild Antarctic Ice Growth Trend Reversed

Sea ice melt in the Antarctic, however, is a possible new feature. In the past, it is thought that fresh water outflow from glaciers in Antarctica and strong winds encircling the Southern Hemisphere sea ice helped to protect it from the initial pulse of human-forced warming. And as recently as 2014 and 2015, Antarctic sea ice experienced new record high readings even as the long-term trend hinted at a possible slow expansion of sea ice near the South Pole. Researchers had indicated that the protection for Southern Hemisphere sea ice might only last as long as fragile wind patterns around the South Pole remained.

For 2016 and 2017, however, that thin veil of protection appears to have fallen. Previous record lows for Antarctic sea ice extent set in 1997 at 2.26 million square kilometers sea ice coverage during the austral summer month of February have now been exceeded by 100,000 square kilometers. As of yesterday, according to JAXA, the new record low stood at 2.16 million square kilometers.

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(More above average temperatures predicted this week for Antarctica may extend sea ice record lows somewhat before refreeze sets in. Image source: Climate Reanalyzer.)

Antarctic refreeze typically starts during mid-February as seasonal cooling sets in. However, 2017’s warmth has driven an extension of late season melt with Antarctic sea ice continuing to decline through the end of February. At some point during the next week or two, however, refreeze is likely to finally kick in. But this return to rising ice coverage may be still be delayed somewhat by very warm Antarctic temperatures predicted to range as high as 2.9 C above average through the next five days.

Global Sea Ice Coverage Falling Rapidly

This year’s all time record low for Antarctic sea ice extent also comes at a time when the Arctic has been experiencing daily, monthly and seasonal record lows. Highly unseasonable temperatures have dominated Arctic Fall and Winter during 2016 and 2017 — producing never before see low extent coverage during the period. As a result of record lows occurring at the same time in the north and in the south, overall global sea ice coverage has taken a considerable beating and the larger global sea ice trend is now strongly negative.

Links:

JAXA

Climate Reanalyzer

Wipneus

NASA GISS

IPCC Ocean Heat Gain

Global Sea Ice Diminishing Despite Antarctic Gains

What’s Going on With Antarctic Sea Ice?

Atlantic Tropical Storm Bonnie May Become Second 2016 Cyclone to Form Before Hurricane Season Start

Ocean temperatures off the East Coast of the US are extraordinarily warm for this time of year. A region of water in the Gulf Stream 100 miles off Virginia Beach now features sea surface temperatures of 81 degrees Fahrenheit or 10 degrees (F) above average. To the south and east, in a stormy zone between Bermuda and the Bahamas, temperatures are around 77 degrees Fahrenheit or 4 degrees above average. Readings more typical of July and not at all usual for May in this region of the world ocean.

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(Extremely warm sea surface temperatures ranging from 75 to 82 Fahrenheit off the US East Coast contain enough heat potential energy to support tropical storm and hurricane development during late May. Image source: Earth Nullschool.)

Ocean heat is a primary driver of tropical cyclone formation. And record warm 2016 land and ocean surfaces contributed to the January formation of hurricane Alex in the Northeastern Atlantic this year. An unprecedented January-forming hurricane that organized five months before the typical start of hurricane season on June 1.  Now, a low pressure center swirling between the Bahamas and Bermuda on Thursday appears to be developing tropical or subtropical characteristics in what may become Bonnie — the second named tropical cyclone of 2016 — over the next few days.

Weather statements from the National Hurricane Center (NHC) at 2:55 PM Eastern Standard Time noted that conditions would become more favorable for tropical cyclone development over the next 24-48 hours. And the Center predicted that a tropical cyclone was 60 percent likely to form over the next two days and 70 percent likely to form over the coming five. The NHC also warned that all coastal interests from Georgia to North Carolina should monitor the progress of this developing low.

Bonnie Begins to Organize

(An area of disturbed weather in the lower right hand portion of this image may form into tropical storm Bonnie over the next two to five days. Image source: The National Hurricane Center.)

Current satellite imagery indicates high, cold cloud tops associated with thunderstorm formation north of the low’s center of circulation. Forecast models indicate a west-northwest storm track that ultimately brings the low on shore near the North Carolina – South Carolina border on early Sunday morning. Models then predict that the low will stall out, hovering over the coastal Carolinas for the next 3-4 days.

If Bonnie does reach tropical storm strength it will only be the fifth time two tropical storm or hurricane strength cyclones have ever formed before June 1 since record keeping began in 1794. It’s also worth noting that the January formation of Hurricane Alex already makes the 2016 season one for the record books. Increasing ocean surface temperatures across almost all basins due to a fossil-fuel emissions based warming of the world is likely to result in a higher likelihood of such out-of-season storms all while increasing the potential maximum strength of the strongest storms. And recent events in the Pacific, Atlantic, and Indian oceans seem to bear out these predicted trends.

Links:

The National Hurricane Center

Earth Nullschool

Alex Now an Unprecedented Atlantic Hurricane in January

List of Off-Season Atlantic Hurricanes

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