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Showing posts with label jet stream. Show all posts
Showing posts with label jet stream. Show all posts

Wednesday 2 July 2014

What's wrong with the weather?

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Above map shows temperatures in NewFoundland and Labrador close to 30°C (86°F), compared to temperatures in Albuquerque, New Mexico of only 20°C (68°F), while temperatures seem to be even lower in Mexico City. What's happening with the weather?

Jet Streams are changing


World climate zones used to be kept well apart by jet streams. On the northern hemisphere, the polar jet stream was working hard to separate the Tundra and Boreal climate zones' colder air in the north from the Temperate climate and the Subtropical climate zones' warmer air in the south.

As the Arctic is warming even faster than the Equator, the falling temperature difference between the two reduces the speed at which warm air is moving from the Equator to the North Pole. This in turn slows the speed at which the jet streams are circumnavigating the globe on the Northern hemisphere and it is deforming the jet streams in other ways as well.

[ NOAA image ]
As above image shows, the polar jet stream is typically located at about 60°N and the subtropical jet stream at about 30°N. The polar jet stream's altitude typically is near the 250 hPa pressure level, or 7 to 12 kilometres (4.3 to 7.5 mi) above sea level, while the weaker subtropical jet stream's altitude is higher, between 10 and 16 kilometres (6.2 and 9.9 mi) above sea level.

NOAA image
The polar jet stream used to travel at speeds of up to 140 miles per hour, while following a relatively straight track that was meandering only slightly, i.e. with waves that go up and down only a little bit. This fast and relatively straight jet stream kept climate zones well apart. Accordingly, the Northern Temperate Zone used to experience only mild differences between summer and winter weather, rather than the extremely hot or cold temperatures that we're increasingly experiencing now.

Polar jet stream (blue) & subtropical
jet stream (red) - NOAA image
Loss of snow and ice cover in the north is accelerating warming in the Arctic. This is decreasing the difference in temperature between the Arctic and the Northern Temperate Zone, in turn causing the polar jet to slow down and become more wavy, i.e. with larger loops, as illustrated by the animation below.

Imagine a river that at first rapidly runs down a narrow and straight path when its waters fall down from the top of a high mountain. Once that river flows through flat land, though, it becomes slow and curvy.

Similarly, the polar jet stream is now circumnavigating the globe at slower speed and along a wavier tracks. Its waves are now more elongated, more stretched out vertically, making that cold air can move more easily down from the Arctic, e.g. through the middle of North America, as illustrated by the animation below.

At the same time, warm air can move up more easily from the South into the Arctic. This is creating huge temperature anomalies in many places, as also illustrated by the animation below.


[ This animation is a 1.4MB file that may take some time to fully load ]
                Diagram of Doom, Sam Carana
These changes to polar jet stream constitute a self-reinforcing feedback that is further accelerating warming in the Arctic. As the jet stream slows down and its waves become more elongated, cold air can leave the Arctic more easily and descend deep into the Northern Temperate Zone. Conversily, more warm air can at the same time move north into the Arctic. The result is a warmer Arctic.

This 'open doors' feedback further decreases the difference in temperature between the Arctic and the Northern Temperate Zone, in turn further slowing down the jet stream and making it more wavy, and thus further accelerating warming in the Arctic.

This feedback is pictured in the image below as feedback #10.


Diagram of Doom - see Feedbacks in the Arctic for links


Arctic sea ice in steep descent

Global warming and the numerous feedbacks have a devastating impact on the sea ice, which is currently showing an almost vertical fall in extent, as illustrated by the image below.



Oceans are turning red

Arctic sea ice is also under threat from very warm waters. As the image below illustrates, oceans are turning red around the globe.



The image below shows that where the sea ice disappears, sea surface temperature anomalies as high as 8°C and higher show up.


Comprehensive and Effective Climate Action

The situation is dire, as huge amounts of methane are contained in sediments underneath the seafloor of the Arctic Ocean. Loss of sea ice means that huge amounts of heat that was previously reflected back into space will be absorbed by the Arctic Ocean. Furthermore, heat that previously went into melting the ice will also be absorbed by the water. Comprehensive and effective action is needed, as discussed at the Climate Plan blog.



Post by Sam Carana.

Friday 16 May 2014

More extreme weather can be expected

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The heaviest rains and floods in 120 years have hit Serbia and Bosnia this week, Reuters and Deutsche Welle report.

The animation below shows the Jet Stream's impact on the weather. Cold temperatures have descended from the Arctic to Serbia and Bosnia in Europe and all the way down to the Gulf of Mexico in North America, while Alaska, California, and America's East Coast are hit by warm temperatures. In California, 'unprecedented' wildfires and fierce winds lead to 'firenadoes', reports CNN.



The image below shows that on May 15, 2014, the wind approaching Serbia and Bosnia at 700 hPa reached speeds of up to 120 km per hour (75 mph), as indicated by the green circle on the main image and inset.


The image below, from skeptical science, shows the cyclonic spin that can be expected in a through such as the one that hit Serbia and Bosnia recently.


As the Jet Stream changes, more extreme weather events can be expected. What makes the Jet Stream change? As the Arctic is warming up faster than the rest of the world, the temperature difference between the Arctic and the equator decreases, in turn decreasing the speed at which the Jet Stream circumnavigates the globe. This can cause 'blocking patterns', with extreme weather events hitting an area longer than before.

As the jet stream becomes wavier, cold air can more easily descend from the Arctic down to lower latitudes in a downward through of the Jet Stream, while warm air can more easily reach higher latitudes in an upward ridge of the Jet Stream.

This spells bad news for many areas across the world that can be expected to be hit by more extreme weather events such as heatwaves, wildfires fuelled by stronger winds and more intense drought, storms and floods.

Heatwaves are a huge threat in the Arctic, especially when followed by storms that can cause warm surface water to mix down to the bottom of the sea and warm up sediments under the seafloor that can contain huge amounts of methane in the form of hydrates and free gas. The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.


Related

- Extreme weather strikes around the globe - update
http://arctic-news.blogspot.com/2014/02/extreme-weather-strikes-around-the-globe-update.html

- Escalating extreme weather events to hammer humanity (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/04/escalating-extreme-weather-events-to-hammer-humanity.html

- Our New Climate and Weather (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/01/our-new-climate-and-weather.html

- Our New Climate and Weather - part 2 (by Paul Beckwith)
http://arctic-news.blogspot.com/2014/01/our-new-climate-and-weather-part-2.html

- Changes to Polar Vortex affect mile-deep ocean circulation patterns
http://arctic-news.blogspot.com/2012/09/changes-to-polar-vortex-affect-mile-deep-ocean-circulation-patterns.html

- Polar jet stream appears hugely deformed
http://arctic-news.blogspot.com/2012/12/polar-jet-stream-appears-hugely-deformed.html



Post by Sam Carana.

Saturday 5 April 2014

Escalating extreme weather events to hammer humanity

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By Paul Beckwith

Extreme weather events are rocketing upwards in their frequency of occurrence, intensity, and duration and are impacting new regions that are unprepared. These events, such as torrential rains, are causing floods and damaging crops and infrastructure like roads, rail, pipelines, and buildings. Cities, states, and entire countries are being battered and inundated resulting in disruption to many peoples lives as well as enormous economic losses. As bad as this is, it is going to get much worse by at least 10 to 20 times. Why?

Greenhouse gas emissions from humans have changed the chemistry of the atmosphere. The optical absorption of infrared heat has increased in the atmosphere which raises temperature, and thus water vapor content, and therefore fuels more intense storms. The jet streams that guide these storms are slower and wavier and more fractured and cause our weather gyrations and weird behavior. Areas far north can get very warm, while areas far south can get very cold. Some areas get persistent drought. Then, the pattern can flip. The jet streams are much wavier in the north-south direction since the Arctic temperatures have warmed 5 to 8 times faster than the global average. This reduces the temperature difference between the Arctic and equator and basic physics forces the jets to slow and get wavier.

Why is the Arctic warming greatly amplified? The region is darkening and thus absorbing more sunlight, since the land-based snow cover in spring and the Arctic sea ice cover volume are both declining exponentially. The white snow and ice is being replaced by dark surfaces like the ocean and the tundra. The most detailed computer model on sea ice decline is a U.S. Naval Graduate School model, and it shows the sea ice cover could be gone by late summer in 2016. If this happens, the Arctic warming will rocket upwards, the jets will distort much more, and the extreme weather events will rocket upwards in frequency, amplitude, and duration and civilization will be hammered.


Paul Beckwith
Paul Beckwith is part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. Paul teaches climatology/meteorology and does PhD research on 'Abrupt climate change in the past and present'. Paul holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life. Below are Paul's earlier posts at the Arctic-news blog.


Paul Beckwith with sign (arrows highlighted by 
Sam Carana, from earlier post)

Below, a recent video in which Paul Beckwith discusses how a weaker Jet Stream lets warmer air move from lower latitudes into the Arctic (feedback #10).


From December, 2013 until early April, 2014 there have been persistent and very large temperature anomalies in the northern hemisphere (+20 C = +36 F in the Arctic, -20 C = -36 F in vast parts of the US and Canada). I claim that this represents a previously unrecognized large positive feedback acting to homogenize the temperature in the northern hemisphere.



Earlier posts by Paul Beckwith

- Abrupt Climate Change

- Our New Climate and Weather - part 2

- Our New Climate and Weather

- Are Alberta’s Tar Sands prepared for a torrential rain event?

- Stop All New Fossil Fuel Megaprojects

- Toward Genuinely Improved Discussions of Methane & Climate

- The Social Tipping Point

- Arctic Cyclone July 2013

- Arctic Ocean Events - Videos by Paul Beckwith

- Climate change fighting town savaged by runaway oil train

- Extreme weather becomes the norm - what can you do?

- Thin Spots developing in Arctic Sea Ice

- The Tornado Connection to Climate Change

- Anthropogenic Arctic Volcano can calm climate

- Hold on folks… the times they are a-changin’

- Hurricane Sandy moving inland

- Open Letter to Canadian MPs

- State of Climate Change October 2012

- Is death by lead worse than death by climate? No.

- You are now entering the nonlinearity zone…

- Vanishing Arctic sea ice is rapidly changing global climate

- Storm enters Arctic region

- Update on September Arctic cyclone

- Arctic cyclone warning for September 7

- Paul Beckwith on ice speed and drift - update 1

- Paul Beckwith on ice speed and drift

- Another Arctic Cyclone brewing

- Sea ice in the Arctic - Shaken and stirred (by a powerful cyclone)

- How to part ways with a climate denier that has incredible stamina...



Post by Sam Carana.

Tuesday 1 April 2014

Earthquakes in the Arctic Ocean

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Earthquakes in the Arctic Ocean
indications of immiment catastrophic methane eruptions?

1. Methane over Greenland

The image below shows high methane concentrations over Greenland and over the Arctic Ocean.

[ Yellow areas indicate methane readings of 1950 ppb and higher - click on image to enlarge ]
The large yellow areas on this image indicate that the methane entered the atmosphere there. This is especially likely when such large yellow areas keep appearing in the same area over a few days. In the case of the large yellow areas around Novaya Zemlya, the methane is likely to have travelled there underneath the sea ice, from the Gakkel Ridge, to enter the atmosphere where the sea ice was thin or fractured enough for the methane to pass through, as discussed in earlier posts.

As described in the post High methane readings over Greenland, huge temperature swings can hit areas over Greenland over the course of a few days. Temperature anomalies may go down as low as as -20°C one day, then climb as high as 20°C a few days laters, to hit temperature anomalies as low as -20°C again some days later.

This could explain the methane over Greenland. Methane is present in the Greenland ice sheet in the form of hydrates and free gas. These huge temperature swings are causing the ice to expand and contract, thus causing difference in pressure as well as temperature. The combined shock of wild pressure and temperature swings is causing movement and fractures in the ice, and this enables methane to rise to the surface and enter the atmosphere.

To further illustrate this, the image below shows recent temperature anomaly forecasts over Greenland.

[ click on image to enlarge ]
2. What is causing these extreme weather events?

Frigid cold weather in the U.S., torrential rain and flooding in the U.K., and wild temperature swings over Greenland. What is causing these extreme weather events? 

As discussed in many previous posts, the Arctic has become warmer than it used to be and temperatures in the Arctic are rising several times faster than global temperatures. This decreases the temperature difference between the areas to the north and to the south of the Jet Stream, which in turn decreases the speed at which the Jet Stream circumnavigates the globe, making the Jet Stream more wavier and increasing opportunities for cold air to descend from the Arctic and for warm air to enter the Arctic.

3. Did temperature swings also trigger earthquakes?

[ click on image to enlarge ]
These wild temperature swings may be causing even further damage, on top of the methane eruptions from the heights of Greenland. Look at the above map, showing earthquakes that hit the Arctic in March 2014.
Topographic map of Greenland
without the Greenland Ice Sheet.

BTW, above map doesn't show all earthquakes that occured in the Arctic Ocean in March 2014. An earthquake with a magnitude of 4.5 on the Richter scale hit the Gakkel Ridge on March 6, 2014.

Importantly, above map shows a number of earthquakes that occurred far away from faultlines, including a M4.6 earthquake that hit Baffin Bay and a M4.5 earthquake that hit the Labrador Sea. These earthquakes are unlikely to have resulted from movement in tectonic plates. Instead, temperature swings over Greenland may have triggered these events, by causing a succession of compression and expansion swings of the Greenland ice mass, which in turn caused pressure changes that were felt in the crust surrounding the Greenland Ice Sheet.

Glaciers could be the key to make this happen. Glaciers typically move smoothly and gradually. It could be, however, that such wide temperature swings are causing glaciers to come to a halt, temporarily, causing pressure to build up over a day or so, to then suddenly start moving again with a shock. Intense cold can literally freeze a glacier in its track, to be shocked into moving again as temperatures rise abruptly by 40°C or so. This can send shockwaves through the ice sheet into the crust and trigger earthquakes in areas prone to destabilization. The same mechanism could explain the high methane concentrations over the heights of Greenland and Antarctica.

Ominously, patterns of earthquakes can be indicators of bigger earthquakes yet to come.

4. Situation looks set to get a lot worse

This situation looks set to get a lot worse. Extreme weather events and wild temperature swings look set to become more likely to occur and hit Greenland with ever greater ferocity. Earthquakes could reveberate around the Arctic Ocean and destabilize methane held in the form of free gas and hydrates in sediments underneath the Arctic Ocean.

Meanwhile, as pollution clouds from North America move (due to the Coriolis Effect) over the Atlantic Ocean, the Gulf Stream continues to warm up and carry warmer water into the Arctic Ocean, further increasing the likelihood of methane eruptions from the Arctic seafloor.


The above image shows the Gulf Stream off the coast of North America, while the image below shows how the Gulf Stream continues, carrying warmer water through the Atlantic Ocean into the Arctic Ocean.


Feedbacks, such as the demise of the Arctic's snow and ice cover, further contribute to speed up the unfolding catastrophe. Methane eruptions from the seafloor of the Arctic Ocean have become especially noticable over the past half year. The big danger is that this will develop into runaway global warming, as discussed in the recent post Feedbacks in the Arctic.

Furthermore, as-yet-unknown feedbacks may start to kick in. As an example, submarine earthquakes and volcanos could add nutrients into the water that feed methane-producing (methanogenic) microbes. A recent study found that expansion of such microbes could have played a large role in the end-Permian extinction, and that it was catalyzed by increased availability of nickel associated with volcanism. Authors support their hypothesis with an analysis of carbon isotopic changes leading up to the extinction, phylogenetic analysis of methanogenic archaea, and measurements of nickel concentrations in South China sediments.

5. Need for comprehensive and effective action

The situation calls for comprehensive and effective action as discussed at the Climate Plan blog.





Related

- Methane Release caused by Earthquakes
http://arctic-news.blogspot.com/2013/09/methane-release-caused-by-earthquakes.html

- Seismic activity
http://arctic-news.blogspot.com/p/seismic-activity.html

- Climate Plan
http://climateplan.blogspot.com



Post by Sam Carana.


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