Tag: Arctic amplification

Climate scientists track young, thin Arctic ice

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Sea ice mingles with icebergs off the coast of Greenland during the peak of the 2015 melt season. @bberwyn photo.

Remarkable changes with huge planetary implications

Staff Report

Earth’s climate control system — the Arctic — is changing so fast that researchers are having a hard time keeping up. In an effort to understand how the region is shifting toward a new state, a team of scientists spent nearly six months examining the younger and thinner sea ice that’s become ubiquitous in the past few years. They discussed their findings this week at the fall meeting of the American Geophysical Union in San Francisco.

“Many things we experienced took us by surprise,” said Mats Granskog, a research scientist at the Norwegian Polar Institute and chief scientist of the Norwegian young sea ICE, or N-ICE2015 project. “We saw that the new Arctic, with much thinner sea ice only three to four feet thick, functions much differently from the Arctic we knew only 20 years ago, when the ice was much thicker.”

One of the biggest concerns is that the reduced sea-ice coverage and thickness will lead to even more melting, the so-called Arctic amplification. Most of the solar energy that reaches Arctic snow and sea ice gets reflected back into space. But when the snow and ice is replaced by darker, open water, most of the energy gets absorbed and in turn helps melt more ice. Continue reading “Climate scientists track young, thin Arctic ice”

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Global hot streak continues in October

No let up in global warming spiral, especially in the Arctic

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Surface air temperature anomaly for October 2016 relative to the October average for the period 1981-2010. Source: ERA-Interim. (Credit: ECMWF, Copernicus Climate Change Service)

Staff Report

The average global temperature for October 2016 was 0.57 degrees Celsius above the 1981 to 2010 average, continuing a spell of “exceptional global warmth that has now lasted more than a year, according to the European Climate Change Service.

Global temperature anomalies topped out in February with the peak of El Niño, then declined in spring and rose again in summer, declining only slightly in September. The October departure from normal was only slightly lower in October,  just 0.07 degrees Celsius under the all-time record for the month, set just last year.

With the exception of June, each month from October 2015 to October 2016 has been more extreme than January 2007, which was previously the month with the warmest anomaly. Each month from August 2015 to September 2016 successively became the warmest on record for that particular month.

October 2016 was cooler than the 1981-2010 average over much of Europe, but warmer than average in the far north of the continent and over the Iberian Peninsula and Mediterranean.  Well-above normal temperatures also occurred over the USA and parts of Africa. Temperatures were most above normal over much of the Arctic and Antarctic, with record-low sea extent in both regions.

Temperatures were below average along the equator over the eastern Pacific Ocean, indicating weak La Niña conditions, over some oceanic regions of the southern hemisphere and over part of the North Atlantic. Other land areas with below-average temperatures include most of Australia, western and north-eastern Canada and much of the southern half of South America. The zone of below-average temperatures bounded north and south by above-average temperatures extended eastwards across Asia.

Averaging over twelve-month periods smooths out the shorter-term variations. Globally, the warmest twelve-month period on record is from October 2015 to September 2016, with a temperature 0.64 degrees Celsius above the 1981-2010 average.

Uncertainty in the global value is relatively high for the year 2005, but there is agreement between various datasets regarding:

  • the exceptional warmth of 2016, and to a lesser extent 2015;
  • the overall rate of warming since the late 1970s;
  • the sustained period of above-average values from 2001 onwards.

There is more variability in average European temperatures, but values are less uncertain because observational coverage of the continent is relatively dense. Twelve-month averages for Europe have been at a persistently high level for the last three years or so. They are nevertheless lower than the averages from around the middle of 2006 to the middle of 2007.

Climate: USGS measures Alaska land carbon stock

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How will Arctic tundra respond to climate change? @bberwyn photo.

New assessment finds increased plant growth will absorb more carbon through end of the century

Staff Report

With temperatures in the Arctic warming far faster than the global average, scientists have been trying to quantify how climate change will affect the carbon cycle.

A new study led by U.S. Geological Survey and University of Alaska at Fairbanks scientists took a close look at the question in Alaska — an effort to get some baseline data on the carbon cycle against which to measure future changes.

Alaska makes up about 18 percent of the total U.S. land area but accounts for about 35 percent of the total carbon stock. The future of that carbon has big implications for global climate. If it’s released quickly, it could drive up global temperatures more than expected. And the carbon stored in high latitude ecosystems is considered to be vulnerable to climate change because of global warming. Continue reading “Climate: USGS measures Alaska land carbon stock”

Global warming: New NOAA study eyes link between Arctic meltdown and extreme weather in mid-latitudes

A warming Arctic is changing the configuration of the jet stream, which affects mid-latitude weather. GRAPHIC COURTESY NOAA.
A warming Arctic is changing the configuration of the jet stream, which affects mid-latitude weather. GRAPHIC COURTESY NOAA.

‘Too soon to tell …’

Staff Report

*More Summit Voice stories on this subject are here

FRISCO — There’s been lots of speculation and some early research on a possible link between soaring temperatures in the Arctic and extreme weather in North America and Europe, but the jury is still out, according to scientists with the National Oceanic and Atmospheric Administration.

NOAA’s James Overland was part of an international team that took a close look at possible connections and concluded that more research is needed.

“We are in the pre-consensus stage of a theory that there are links between the rapid warming of the Arctic and some severe weather events since 2007,” said Overland, lead author of the new study, “The melting Arctic and Mid-latitude weather patterns: Are they connected?” Continue reading “Global warming: New NOAA study eyes link between Arctic meltdown and extreme weather in mid-latitudes”

Can massive plankton blooms speed global warming?

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Biological feedback loop may accelerate global warming.

‘The increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating …’

Staff Report

FRISCO — Scientists already know that melting sea ice in the Arctic is speeding up global warming in the region because darker-colored water absorbs more heat than reflective ice.

But a new study says there’s another factor to consider. Increasing amounts of open water for longer periods of time means there’s more plankton, and that may amplify Arctic warming by another 20 percent. Continue reading “Can massive plankton blooms speed global warming?”

Climate: Arctic sea ice extent peaks at record low level

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The polar ice cap is smaller than ever. bberwyn photo.

Loopy jet stream keeps much of Arctic warm

Staff Report

FRISCO — Federal ice researchers say this year’s maximum Arctic sea ice extent, reached Feb. 25, is the lowest on record during the satellite era, about 50,000 square miles smaller than the previous record set in 2011. While a shift in wind patterns could result in some additional growth, it’s unlikely the sea ice will expand past the extent reached on that date. Continue reading “Climate: Arctic sea ice extent peaks at record low level”

Climate study says Arctic sea ice meltdown could pause for years due to natural variability

Researchers are trying to identify the consequences of dwindling sea ice. Photo courtesy University of Alaska Fairbanks.
Researchers are trying to identify the consequences of dwindling sea ice. Photo courtesy University of Alaska Fairbanks.

‘It is quite conceivable that the current period of near zero sea-ice trend could extend for a decade or more …’

Staff Report

FRISCO — Even with a strong human-caused global warming signal in the Arctic, natural climate variability will be a big factor in the pace of the sea ice meltdown in the next few decades.

A new modeling study that included scientists with the CU-Boulder Boulder-based Cooperative Institute for Research in Environmental Sciences shows that sea ice could remain relatively stable for 10 years or more due to natural factors. Continue reading “Climate study says Arctic sea ice meltdown could pause for years due to natural variability”