- When Arctic temperatures spike, extreme winter weather is 2 to 4 times more likely in Boston and New York, while the West tends to be warmer, a new study shows.
- Heavy snowfalls are generally more frequent since 1990, and in many cities the most extreme snowfalls have occurred primarily during recent decades.
- Declining temperature contrast between the Arctic and the mid-latitudes leads to a wavier jet stream that disrupts normal weather patterns.
Tag Archive: arctic
Leave a Comment
Leave a Comment
- The Arctic was 5.1 degrees Celsius warmer than normal on February 27, following several days of unusually hot weather.
by Andrew Freedman, Mashable, Feb 26, 2018 read full article here
A study published in 2017 found that these types of warming events have been increasing in frequency and duration during winter as the Arctic continues to warm at more than twice the rate of the rest of the globe.
The Arctic was 5.1 degrees Celsius warmer than normal on February 27, following several days of unusually hot weather. Climate Reanalyzer
“What’s exactly driving these changes is not clear, but having storm tracks move further north (i.e. the North Atlantic storm track) may be tied to the northward retreat of the ice edge,” said Julienne Stroeve, a senior research scientist at the National Snow and Ice Data Center in Boulder, Colorado, in an email.
“Thus, while having temperatures exceed freezing during winter is not uncommon, but it may be becoming more common as the climate changes and the ice edge continues to retreat.”
Stroeve said that it’s not just summer and fall sea ice showing steep declines, but that this is occurring year round now. “What it shows us too is that the winter sea ice is now also starting to respond as every winter now for the past 4 winters has been more extreme than the year before in terms of record low sea ice,” she said….
Leave a Comment
2018 brought the warmest first half of winter on record to most of the American Southwest, including Southern California.
- Despite the still 24-hour darkness near the pole, the amplified jet steam has allowed plumes of subtropical moisture to penetrate very far poleward over the Pacific and Atlantic Oceans–yielding temperatures on the order of 55-65 degrees F above average and actually bringing *above freezing* conditions to northern Greenland and over the adjacent sea ice pack. Incredibly, sea ice in the Bering Sea near Alaska has been actively retreating in recent days
Feb 25 2018 Daniel Swain Read full CA Weather Blog here
Long absent, cold temperatures finally return to California
The 2017-2018 “rainy season” has been a pretty unusual one over much of California. The season to date has been nearly the driest on record to date over much of Southern California, and conditions have also become increasingly dry across the north as the season has progressed. Until mid-February, California had suffered through one of its warmest starts to the winter on record (in Southern California, and across most of the interior American Southwest, it was the warmest first half of winter on record)….
….Most extraordinary of all, though, is the almost unbelievable warmth that has pervaded the highest latitudes of the Earth in recent days. As of this writing (today), the Arctic (including the North Pole itself) is experiencing temperatures warmer than have previously been recorded at any point during the winter season. Despite the still 24-hour darkness near the pole, the amplified jet steam pattern noted above has allowed plumes of subtropical moisture to penetrate very far poleward over the Pacific and Atlantic Oceans–yielding temperatures on the order of 55-65 degrees F above average and actually bringing *above freezing* conditions to northern Greenland and over the adjacent sea ice pack. Incredibly, sea ice in the Bering Sea near Alaska has been actively retreating in recent days…..
Leave a Comment
- the dipole pattern – abnormally high temperatures over much of the West along with chilly conditions in the East – has dominated North American weather in four of the past five winters
- When ocean temperatures off the West Coast of North America are warmer than normal, as they have been most of the time since winter 2013, the jet stream tends to form a ridge of high pressure along the West Coast, causing storms to be diverted away from California and leaving much of the West high and dry…
- The combination of natural and climate change-related effects– “It Takes Two to Tango–” is a concept that may help explain the Ridiculously Resilient Ridge observed frequently since 2013. Several new studies support this human-caused boost of a natural pattern, though controversy still exists regarding the mechanisms linking rapid Arctic warming with weather patterns farther south in the mid-latitudes
- It’s hard to nail down whether this weather pattern – overall warmer winters in North America but longer cold snaps – will persist
by Jennifer Francis, PhD Rutgers University January 11 2018 Read full article here in theconservation
Damage from extreme weather events during 2017 racked up the biggest-ever bills for the U.S. Most of these events involved conditions that align intuitively with global warming: heat records, drought, wildfires, coastal flooding, hurricane damage and heavy rainfall.
Paradoxical, though, are possible ties between climate change and the recent spate of frigid weeks in eastern North America. A very new and “hot topic” in climate change research is the notion that rapid warming and wholesale melting of the Arctic may be playing a role in causing persistent cold spells.
It doesn’t take a stretch of the imagination to suppose that losing half the Arctic sea-ice cover in only 30 years might be wreaking havoc with the weather, but exactly how is not yet clear. As a research atmospheric scientist, I study how warming in the Arctic is affecting temperature regions around the world. Can we say changes to the Arctic driven by global warming have had a role in the freakish winter weather North America has experienced?
A ‘dipole’ of abnormal temperatures
Weird and destructive weather was in the news almost constantly during 2017, and 2018 seems to be following the same script. Most U.S. Easterners shivered their way through the end of 2017 into the New Year, while Westerners longed for rain to dampen parched soils and extinguish wildfires. Blizzards have plagued the Eastern Seaboard – notably the “bomb cyclone” storm on Jan. 4, 2018 – while California’s Sierra Nevada stand nearly bare of snow….
….Regardless what it’s called, this dipole pattern – abnormally high temperatures over much of the West along with chilly conditions in the East – has dominated North American weather in four of the past five winters. January 2017 was a stark exception, when a strong El Niño flipped the ridge-trough pattern, dumping record-breaking rain and snowpack on California while the east enjoyed a mild month.
Two other important features are conspicuous in the dipole temperature pattern: extremely warm temperatures in the Arctic near Alaska and warm ocean temperatures in the eastern Pacific. Several new studies point to these “ingredients” as key to the recent years with a persistent dipole.
…Pacific Ocean temperatures fluctuate naturally owing to short-lived phenomena such as El Niño/La Niña and longer, decades-length patterns. Scientists have long recognized that those variations affect weather patterns across North America and beyond.
The new twist in this story is that the Arctic has been warming at at least double the pace of the rest of the globe, meaning that the difference in temperature between the Arctic and areas farther south has been shrinking. This matters because the north/south temperature difference is one of the main drivers of the jet stream. The jet stream creates the high- and low-pressure systems that dictate our blue skies and storminess while also steering them. Anything that affects the jet stream will also affect our weather.
When ocean temperatures off the West Coast of North America are warmer than normal, as they have been most of the time since winter 2013, the jet stream tends to form a ridge of high pressure along the West Coast, causing storms to be diverted away from California and leaving much of the West high and dry.
If these warm ocean temperatures occur in combination with abnormally warm conditions near Alaska, the extra heat from the Arctic can intensify the ridge, causing it to reach farther northward, become more persistent, and pump even more heat into the region near Alaska. And in recent years, Alaska has experienced periods of record warm temperatures, owing in part to reduced sea ice…
….It is widely expected that global warming will produce fewer low-temperature records, a tendency already observed. But it may also be true that cold spells will become more persistent as dipole patterns intensify, a tendency that also seems to be occurring.
It’s hard to nail down whether this weather pattern – overall warmer winters in North America but longer cold snaps – will persist. Understanding the mechanisms behind these complex interactions between natural influences and human-caused changes is challenging.
Scientists find surprising evidence of rapid changes in the Arctic: radium-228 levels doubled in last decadeLeave a Comment
January 3, 2018 Woods Hole Oceanographic Institution read ScienceDaily article here
Scientists have found surprising evidence of rapid climate change in the Arctic: In the middle of the Arctic Ocean near the North Pole, they discovered that the levels of radium-228 have almost doubled over the last decade.
The finding indicates that large-scale changes are happening along the coast — because the source of the radium is the land and shallow continental shelves surrounding the ocean. These coastal changes, in turn, could also be delivering more nutrients, carbon, and other chemicals into the Arctic Ocean and lead to dramatic impacts on Arctic food webs and animal populations….
Lauren E. Kipp, Matthew A. Charette, Willard S. Moore, Paul B. Henderson, Ignatius G. Rigor. Increased fluxes of shelf-derived materials to the central Arctic Ocean. Science Advances, 2018; 4 (1): eaao1302 DOI: 10.1126/sciadv.aao1302
Leave a Comment
- first study to show that changes in winds high up in the stratosphere substantially contributed to the observed winter cooling trend in northern Eurasia.
- study lends further support that a changing Arctic impacts the weather across large swaths of the Northern Hemisphere population centers.
- changes in the jet stream that drives our weather can lead to more abrupt and surprising disturbances-potentially disastrous extremes- to which society has to adapt…
September 22, 2017 Potsdam Institute for Climate Impact Research read full sciencedaily article here
When the strong winds that circle the Arctic slacken, cold polar air can escape and cause extreme winter chills in parts of the Northern hemisphere. A new study finds that these weak states have become more persistent over the past four decades and can be linked to cold winters in Russia and Europe.
…[This study is the] first to show that changes in winds high up in the stratosphere substantially contributed to the observed winter cooling trend in northern Eurasia. While it is still a subject of research how the Arctic under climate change impacts the rest of the world, this study lends further support that a changing Arctic impacts the weather across large swaths of the Northern Hemisphere population centers….
…Despite global warming, recent winters in the Northeastern US, Europe and especially Asia were anomalously cold — some regions like Western Siberia even show a downward temperature trend in winter. In stark contrast, the Arctic has been warming rapidly. Paradoxically, both phenomena are likely linked: When sea-ice North of Scandinavia and Russia melts, the uncovered ocean releases more warmth into the atmosphere and this can impact the atmosphere up to about 30 kilometers height in the stratosphere disturbing the polar vortex. Weak states of the high-altitude wind circling the Arctic then favors the occurrence of cold spells in the mid-latitudes.
….”Jet Stream changes can lead to more abrupt and surprising disturbances to which society has to adapt. The uncertainties are quite large, but global warming provides a clear risk given its potential to disturb circulation patterns driving our weather — including potentially disastrous extremes.”
Marlene Kretschmer, Dim Coumou, Laurie Agel, Mathew Barlow, Eli Tziperman, Judah Cohen. More-Persistent Weak Stratospheric Polar Vortex States Linked to Cold Extremes. Bulletin of the American Meteorological Society, 2017; DOI: 10.1175/BAMS-D-16-0259.1
Leave a Comment
Arctic and Antarctic sea ice extents remain near-record lows
September 18, 2017
The globally averaged temperature over land and ocean surfaces for August 2017 was the third highest for the month of August in the NOAA global temperature dataset record, which dates back to 1880. The June-August seasonal global temperature was also third highest on record, while the year-to-date global temperature was second warmest in the 138-year record….
Leave a Comment
- Heat escaping from the ocean through openings in sea ice impact sea and atmospheric temperatures and wind patterns around the globe and even rainfall around the tropics.
September 11, 2017 University of Pennsylvania Read full ScienceDaily article here
- In a new analysis of climate models, researchers reveal the significant global effects that seemingly anomalous polynyas, or openings in sea ice, can have. Their findings indicate that heat escaping from the ocean through these openings impacts sea and atmospheric temperatures and wind patterns around the globe and even rainfall around the tropics.…Though this process is part of a natural pattern of climate variability, it has implications for how the global climate will respond to future anthropogenic warming.
…The work raises many new questions, such as how a decreasing sea ice extent, including the recent breaking off of a massive chunk of the Antarctic peninsula, will affect the frequency of polynyas and how the presence or absence of polynyas will affect how much atmospheric temperatures warm in response to anthropogenic climate change.
….Their model indicated that polynyas and accompanying open-ocean convection occur roughly every 75 years. When they occur, the researchers observed, they act as a release valve for the ocean’s heat. Not only does the immediate area warm, but there are also increases in overall sea-surface and atmospheric temperatures of the entire Southern Hemisphere and, to a lesser extent, the Northern Hemisphere, as well….
Anna Cabré, Irina Marinov, Anand Gnanadesikan. Global Atmospheric Teleconnections and Multidecadal Climate Oscillations Driven by Southern Ocean Convection. Journal of Climate, 2017; 30 (20): 8107 DOI: 10.1175/JCLI-D-16-0741.1
Leave a Comment
- Measurements over Canada’s Mackenzie River Basin suggest that thawing permafrost is starting to free greenhouse gases long trapped in oil and gas deposits.
- The conclusion of the authors: The warming climate triggers not only the natural production of biogenic methane, it can also lead to stronger emissions of fossil gas. This contributes significantly to the permafrost-carbon-climate feedback
Thawing permafrost releases old greenhouse gas July 19, 2017 ScienceDaily
- Study in the Mackenzie Delta in Canada shows high amount of geological methane emission
- The thawing permafrost soils in the Arctic regions might contribute to the greenhouse effect in two respects: on the one hand rising temperatures lead to higher microbial methane production close to the surface. On the other hand thawing subsurface opens increasingly pathways for old, geologic methane…
- Katrin Kohnert, Andrei Serafimovich, Stefan Metzger, Jörg Hartmann, Torsten Sachs. Strong geologic methane emissions from discontinuous terrestrial permafrost in the Mackenzie Delta, Canada. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-05783-2
Leave a Comment
Posted: 11 Jul 2017 06:43 AM PDT read full ScienceDaily article here
The warmer Arctic has triggered cooler winters and springs in North America, which has in turn weakened vegetation growth and lowered carbon uptake capacity in its ecosystems, research shows.
The team analyzed an index of sea surface temperatures from the Bering Sea and found that in years with higher than average Arctic temperatures, changes in atmospheric circulation resulted in the aforementioned anomalous climates throughout North America. In those years of intense cold and low precipitation, the team found that the unfavorable conditions adversely affected vegetation growth — including crop yields — which in turn decreased carbon uptake capacity by about 14%. In other words, although Arctic warming has increased carbon uptake in the Northern Hemisphere, this research has shown that the resulting interannual variability in Arctic temperatures can affect regions further away in North America and may counteract the initially observed increases in carbon uptake…
Jin-Soo Kim, Jong-Seong Kug, Su-Jong Jeong, Deborah N. Huntzinger, Anna M. Michalak, Christopher R. Schwalm, Yaxing Wei, Kevin Schaefer. Reduced North American terrestrial primary productivity linked to anomalous Arctic warming. Nature Geoscience, 2017; DOI: 10.1038/ngeo2986