Showing posts with label weather. Show all posts
Showing posts with label weather. Show all posts

Saturday, November 22, 2014

How melting Arctic ice is driving harsh winters

by Nick Breeze

The very least 'global warming' could do for us is to give us warmer winters, right? Wrong, writes Nick Breeze, who met climate scientist and meteorologist Jennifer Francis in his attempt to understand the complex interactions of jet stream, polar vortex, the melting Arctic, and the extreme snowfall that's hitting the northeast US right now.

"Historic" snowfalls have the US northeast this week, with Buffalo, New York under an astonishing 2.4m (8ft) of snow - enough to cause some roofs to cave in under the pressure.

It's just the latest chapter in 2014 unprecedented range of weather extremes - from persistent storms that battered, and flooded much of the UK at the beginning of the year, before going on to record the hottest October since records began.

And in the US, extremes have ranged from California's record drought, to the early snows now under way in the northeast - and let's not forget the 'polar vortex' that hit much of the US in January, bringing Arctic conditions as far south as Texas and Florida, causing flights to be cancelled in Chicago as aviation fuel froze in the -38.3C (-37F) temperatures.



Scientists now have evidence that these persistent extreme weather patterns are increasing in their frequency, due to the rapid heating up of the Arctic that is changing the behaviour of the jet stream, and in turn, the polar vortex.

And Jennifer Francis of Rutgers University, one of the leading US scientists studying the relationship between Arctic warming and changes in the jet stream, believes that it's thanks to 'global warming' that northern hemisphere weather is becoming more extreme - and it's not about to get any better.

Screenshot from Youtube video further below

The 'vast river of wind' that makes our weather

"The Arctic is generally very cold", she told me, "and the areas farther south are warm, and that difference in temperature between those two areas is really what fuels that vast river of wind moving high over our head that we call the jet stream."

"The jet stream in turn creates most of the weather that we feel all around the northern hemisphere and the middle latitudes, so anything that affects this jet stream is going to affect weather patterns. So as the Arctic warms up much faster than the areas farther south, we're seeing this temperature difference between these two regions get smaller."

The result of that, she explains, is that the atmospheric forces driving the jet stream's circular motion are getting smaller - and that means the winds themselves in the jet stream are getting weaker, and moving more slowly.

"When that happens, the jet stream tends to take a wavier path as it travels around the northern hemisphere and those waves are actually what create the stormy patterns and the nice weather patterns. As those waves get larger because of this weakening of those winds of the jet stream, they tend to move more slowly from west to east."

"That means it feels like the weather patterns are sticking around longer, because those patterns are moving much more slowly and this then makes it more likely to have the kind of extreme events that are related to persistent weather patterns."



Are critical findings influencing policy?

These changes in climate have huge implications. As Dr Francis points out, there are "people who worry about whether there is enough fresh water to supply cities, whether there is enough snowpack on mountains to supply reservoirs, and for agriculture ..."

"Drought and agriculture is a big problem. Storminess in certain areas is another big problem. Yes, it has a huge impact for a whole range of issues that affect the way we live."

It's no wonder then that Dr Francis and her colleagues have attracted the attention of President Obama's chief science advisor, Dr John Holdren.

Dr Holdren has been reporting directly to the President on the real time effects of climate change and is keen to understand what this new research tells us about the future impact of changes to the jet stream.

Asked about this sudden interest in her work from the US Presidency, Francis muses thoughtfully. "Yes, we've had a lot of interest from policy makers", she acknowledges.

"I think we're starting to make a lot of progress now in getting policymakers to understand that this is a big problem they have to face ... I think decision makers and the policymakers at the local level get it much better because they're already seeing effects on their local areas.

"Sea level rise is an obvious one. They're already seeing changes in drought and agricultural problems and dealing with fresh water issues. It is really at the local level that we're having more success."

New research supports the case that Arctic sea ice loss is driving climate changes

So to understand the changes in the jet stream it's important to research how the vast atmospheric river of weather above our heads is connected to other climate mechanisms.

"It appears that over the north Atlantic, and towards Asia, there's a mechanism that appears to be quite robust, and several groups have found this mechanism using completely different analysis techniques", says Francis referring to new research by colleagues at the University of Alaska that has emerged in the last couple of months.

"So what we're finding is that there's an area, north of Scandinavia in the Arctic, where the ice has been disappearing particularly rapidly. When that ice disappears ... there is unfrozen ocean underneath, and that ocean absorbs a lot more energy from the sun through the summertime. So it becomes very warm there."

"Then as the fall comes around, all that heat that's been absorbed all summer long, where the ice has retreated, is put back in the atmosphere and that creates a big bubble of hot air ... over that region where the ice was lost."

And in turn, that goes on to disrupt the circumpolar winds whose behaviour determines much the weather across the northern hemisphere.

The gigantic bubble of warm air "tends to create a northward bulge in the jet stream", and in turn, "that creates a surface high pressure area that circulates in the clockwise direction. That sucks cold air down from the Arctic over northern Eurasia, and that creates a southward dip in the jet stream."



The bulging jet stream disrupts the polar vortex

"So what we're getting is this big northward bulge up over Scandinavia and a southward dip over Asia ... creating, first the tendency for a larger wave in the jet stream, which tends to move more slowly, but also we're seeing this mechanism that creates these colder winters that have been observed over Central Asia."

"Once the jet stream gets into this wavier pattern, it sends wave energy up into the highest levels of the atmosphere, which is called the stratosphere, where we have the polar vortex, which is kind of similar to the jet stream but it's much higher up in the atmosphere and it travels much faster."

"So as that wave energy gets sent up from this larger wave below, up into the stratosphere, it breaks down that polar vortex so that it becomes wavier as well. That wavier polar vortex sends energy back down to the lower atmosphere and it creates an even wavier jet stream in February."

"So we're seeing this connection of mechanisms that starts with Arctic sea ice loss and it makes a wavier jet stream for different reasons all the way through winter."

Will the jet stream continue to cause changes in climate?

By identifying these mechanisms and linking them back directly to loss of the Arctic sea ice, Dr Francis and her colleagues are demonstrating how man-made global warming is creating feedbacks that are changing the climate conditions in the northern hemisphere - and not for the better.

It may be counterintuitive, and it when it first happened it took scientists by surprise - but now it looks like this is one of the most important ways in which 'global warming' is hitting North America. Melting ice in the Arctic Ocean is indirectly pushing frigid Arctic air south across the continent, creating the perfect conditions for massive snowfall.

Which is all very well ... but what's coming next? "We are using these climate models, or computer simulations ... to try and project what we're expecting to see happen in the future, as greenhouse gases continue to increase.

"The early indications are that these large wavy patterns in the jet stream are going to become more frequent in the future, as far as we can tell. It is preliminary research that I haven't published yet but it does look as if they are going to increase."



Nick Breeze is a film maker and writer on climate change and other environmental topics. He has been interviewing a range of experts relating to the field of climate change and science for over four years. These include interviews with Dr James Hansen, Professor Martin Rees, Professor James Lovelock, Dr Rowan Williams, Dr Natalia Shakhova, Dr Michael Mann, Dr Hugh Hunt, among others.

Additional articles can also be read on his blog Envisionation.

Jennifer Francis is a research professor at the Institute of Marine and Coastal Sciences at Rutgers University, where she studies Arctic climate change and the link between Arctic and global climates. She has authored more than 40 peer-reviewed publications on these topics. She was also the co-founder of the Rutgers Climate and Environmental Change Initiative.

Article earlier posted at TheEcologist.org




Related





Wednesday, July 2, 2014

What's wrong with the weather?


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.

Friday, May 16, 2014

More extreme weather can be expected



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.

Saturday, February 15, 2014

Extreme weather strikes around the globe - update

As the weather gets more extreme, disaster strikes around the globe. The Guardian reports three people killed as storms continue to batter southern UK. The Vancouver Sun reports that a U.S. Northeast snowstorm kills 25. And the Sacramento Bee reports Six dead and 1,000 injured in fresh Japan snow storm.

What is the story behind these extreme weather events? The image below tells the story. The Arctic has been much warmer than it used to be, due to numerous feedbacks that accelerate warming in the Arctic. This reduces the temperature differential between the Arctic and lower latitudes, which changes the Jet Stream and Polar Vortex, in turn making the weather at many places ever more extreme.

 earlier forecasts by cci-reanalyzer.org
Above image illustrates the situation, showing an Arctic Ocean that is warmer than the higher latitudes of the Asian and North American continents.

Arctic sea ice has meanwhile reached record lows, as illustrated by the image below.


The situation can be expected to get even worse. The image below shows sea ice extent, as measured by the NSIDC, which is one day ahead compared to above image.


Below, two regular contributors to the Arctic-news blog comment on the situation.

Monday, February 10, 2014

Extreme weather strikes around the globe

  Editorial note: this post has meanwhile been updated as
Extreme weather strikes around the globe update.


As the weather gets more extreme, disaster strikes around the globe.

Here's a snapsnot from today's news. In London, the BBC reports, flooded homes along the River Thames are being evacuated and thousands more are at risk. In Japan, reports Reuters, eleven people died, more than a thousand were injured and tens of thousands lost power when the worst snowstorm in decades hit Tokyo and areas around the Japanese capital before heading north to blanket the tsunami-hit Pacific coast. Many countries in the Middle East were hit by snow. The BBC reports that heavy snow in northern Iran has left around 480,000 homes without power and some towns and villages cut off.

What is causing these extreme weather events? The image below tells the story. While at times it has been cold at many places around the world, when averaged over the past 30 days, temperatures around the globe have actually been several degrees higher than they used to be. The Arctic has been hit hardest, with anomalies as high as 21°C over this 30 day period. This affects the Jet Stream and Polar Vortex, which in turn is making the weather ever more extreme.



The situation is further illustrated by the cci-reanalyzer.org forecasts below.



And while the sea ice didn't look too bad at the start of the year, growth has meanwhile stopped, as illustrated by the image below.


Added below are two videos by Paul Beckwith, further discussing the situation.





Editor's note: Reanalysis of temperature anomaly Jan 12 - Feb 10, 2014.
Meanwhile, I've added another image (above), created with NOAA's reanalysis, which compares temperatures to a larger dataset, and the colors look a lot different, so NOAA may indeed have mixed the colors up somewhat in the initial image, as Albert suggested at the Facebook discussion (click on image below).

Anyway, the point made in the post remains, i.e. that as global warming continues, warming in the Arctic accelerates more rapidly than at lower latitudes, which weakens the polar vortex and jet stream in a self-reinforcing feedback that causes the Arctic to warm up even further compared with lower latitudes.

As said, the situation calls for comprehensive and effective action, as discussed at the Climate Plan blog.

Thursday, January 30, 2014

Forecast: America to be hit by temperatures as low as minus 40 degrees

The image on the right shows that large parts of North America, the Arctic Ocean and Siberia are experiencing low temperatures.

What many people may not realize is that temperatures in the Arctic are actually a lot higher than they used to be around this time of year.

Temperatures in the Arctic have risen due to feedbacks as described in the post The Biggest Story of 2013.

As a result, temperature anomalies above 20 degrees Celsius now feature in the Arctic. As the image on the right illustrates, the once-common temperature difference between the Arctic and lower latitudes has been shattered, and this is weakening the Jet Stream and the Polar Vortex, in turn making it easier for cold air to flow down to lower latitudes and for warmer air to enter the Arctic, as described in posts at this blog for years, e.g. this post.

This is illustrated by the image below, showing that the Arctic is hit by an overall temperature anomaly of 6.55 degrees Celsius, while some areas in the Arctic feature anomalies above 20 degrees Celsius.


Forecasts show that on February 2nd, 2014, 1200 UTC, the Arctic will be hit by a temperature anomaly of 7.85 degrees Celsius, while on February 6th, 2014, 1200 UTC, the U.S. will be hit by temperatures as low as -40 degrees, as illustrated by the image below.


The video below shows temperature forecasts from February 1to February 8, 2014.


The video below shows temperatire anomalies from February 2 to February 9, 2014.


Meanwhile, the Gulf Stream keeps pushing warm water into the Arctic Ocean, as illustrated by the image below.

Click on image to enlarge - view updated animation at earth.nullschool.net 
The image below shows how high sea surface temperature anomalies stretch out from the point where the Gulf Stream travels at high speeds, off the coast of North America, all the way into the Arctic Ocean.


This has already resulted in methane eruptions from the seafloor of the Arctic Ocean that started several months ago and are continuing to date - ominous signs of more to come. The image below, which compares peak methane levels at two altitudes between January 2013 and January 2014, suggests that January 2014 peak levels have increased strongly, compared to January 2013 peak levels. Furthermore, that the rise in average peak readings has been most dramatic at the higher altitude.


This suggests that huge quantities of methane have indeed been released from hydrates under the Arctic ocean, and that much of the methane is rising and building up at higher altitudes. The increasing appearance of noctilucent clouds further confirms indications that methane concentrations are rising at higher altitudes.

Of course, the above analysis uses a limited dataset, but if verified by further analysis, it would confirm a dramatic rise in the presence of methane in the atmosphere due to releases from hydrates. Moreover, it would confirm the immensity of threat that releases from the Arctic Ocean will escalate and trigger runaway warming, as high methane concentrations over the Arctic are contributing to the anomalously high temperatures there. The risk that this will eventuate is unacceptable, which calls for comprehensive and effective action such as discussed at the ClimatePlan blog.

Monday, January 27, 2014

Our New Climate and Weather - part 2



by Paul Beckwith

continued from part 1

In North America we are about to experience a late January, 2014 weather event that will likely go down in the record books, at least for a few weeks until the next event. Such is life on our rapidly changing planet in Climate 2.0, or perhaps this would better be called the great abrupt climate change transition between Climate 1.0 (our old climate) and the new, much warmer Climate 2.0.

In any event, the jet stream is configuring into that two crest/two trough mode that I discussed above. An enormous plug of cold Arctic air is descending southward across North America with temperature anomalies 20 degrees C below normal (36 degrees F below normal). It likely reaches far enough south to enter into northern Mexico and to cover large parts of Florida and extend out into the Gulf of Mexico and the Atlantic, resulting in northern Florida dropping below freezing (see my YouTube video below).

For more commentary on above video, see the post Deep Freeze and Abrupt Climate Change

Meanwhile, in turn, almost the entire Arctic region is seeing huge positive temperature anomalies that are 20 degrees C above normal (36 degrees F above normal). This air is changing the Arctic circulation patterns, and although the Arctic air temperature is still below zero, it is so much warmer than normal that the thickening and area growth of sea ice is being severely curtailed. There is strong ice motion out of the Fram Strait between Greenland and Svalbard which is carrying some of the thickest ridged ice just north of the Canadian archipelago out to warmer water and destruction. In the Bering Strait the ice motion is switching between transport of warm Pacific Ocean water into the Arctic Ocean and export of cold Arctic Ocean water out into the Pacific, leading to less ice formation outside the strait.


The easternmost and westernmost edges of North America are outside the jet stream trough, and being in the ridge on either side of the trough are experiencing record warm temperatures. Snow is minimal there, and lakes that would normally have frozen long ago are open water. Further south on the west coast, California is undergoing a record drought and the Sierra Nevada snow pack which feeds the rivers and reservoirs in the state is only at 15 to 20% of normal levels. And this is the normal rainy season for California, which is the breadbasket of the nation. If this drought continues, as it has for almost 3 years, it is very likely that food prices will increase substantially across North America.

Putting on my Engineering hat, it is very clear to me that the large temperature swings over short periods of time that occur as the jet stream troughs and ridges sweep past a fixed region such as a city are wreaking havoc on infrastructure. We have commonly been getting temperature swings of 40 degrees Celsius (72 degrees F) within a day or two. These swings usually cross zero, and result in torrential rain events followed by flash freezing and then large amounts of snow, or the inverse process occurs, often in a cycle over a week. Clearly buildings, roads, railroad tracks, and pipelines are under siege from these temperature swings, precipitation changes and repeated freeze/thaw cycles.

Consider a railroad track. The rails are basically two ribbons of steel of length L separated by width w that are held in place by spikes onto wooden railroad ties. Each section L is joined to adjacent sections with spacers. The tracks are designed for a nominal temperature range. At the high end temperature, the steel expands to its maximum length, and adjacent sections butt together at the join. At the low end temperature, the steel contracts and the gap between adjacent rails is at a maximum. As the daily temperature varies between the lows and highs, the rail expands and contracts. Similarly, for seasonal changes. All within design tolerances. What we are seeing now is a higher frequency of extreme temperature swings of 40 degrees C or larger (72 degrees F), which is greatly stressing the rail infrastructure. These large swings are stretching the limits of the design tolerances since they exceed the usual daily temperature ranges, and occur way faster than any seasonal change. In combination with the explosion of rail traffic from oil trains, the risk of derailment accidents has greatly increased, and we are seeing an enormous increase in derailments. We have also seen a large increase in the frequency, amplitude, duration, and spatial area of torrential rainfall events which have led to floods and extreme river flow rates which undercuts bridges and also leads to more rail derailments. Especially when the rail is submerged for extended periods of time, as occurred, for example in Colorado in late summer 2013.

Ditto with pipelines. Pipeline sections are attached to each other via welds or sleeves and during extreme temperature swings the expansion and contraction of concern is in the longitudinal direction of the pipe. The pipelines are usually buried a few meters under the ground, which can reduce the temperature variation during the atmospheric temperature swings, however where they cross rivers and streams they are exposed to the changing elements and river flows. They are also susceptible to flash freeze events in which large sections of the ground contract and lead to cracking and soil displacement. Water saturation levels in the soils has a large effect on pipeline stresses, and can undergo rapid changes from rapidly changing precipitation cycles.

We are all familiar with how roads fare under extensive freeze/thaw cycles. Even worse, the ice melting salt corrodes guardrails, signs, and posts and as cracks open up in the asphalt salty water percolates in and the freeze thaw cycles widen the cracks leading to potholes and road breakup. And that is in northern latitude regions that have a regular snow in winter climate. In more southern regions that are unaccustomed to snow, there is widespread use of concrete for road surfaces. When there are large temperature swings the concrete is more prone to cracking and it is more difficult to remove snow and ice from these roads, since there is a lack of snow removal equipment and salt in these regions, and the concrete is lighter in color and thus absorbs less solar energy than asphalt and thus stays colder.

The biggest problem that homeowners face in more southern latitudes from these deep freeze situations, apart from personal discomfort in poorly insulated homes, is water pipe freezing and rupturing. Leaving the water taps all partially open to ensure a trickle of water flow through the pipes alleviates a lot of this problem.

In summary, climate change caused extreme weather events are severely stressing infrastructure like roads, bridges, rail, pipelines, and buildings. Much of this infrastructure was built many years ago and upgrading and maintenance has been neglected due to postponed and reduced budgets; while traffic on rail, for example has exploded in volume and weight. We are now facing the consequences of accelerated climate change and the years of neglect of our aging infrastructure.

In the video below, Paul says more about the damage to railway tracks and pipelines.



Southern Hemisphere Climate Changes

In the video below, Paul Beckwith explains how declining Arctic sea ice is causing Australia to bake and Antarctic sea ice to grow.


to be continued

Saturday, January 18, 2014

Our New Climate and Weather


by Paul Beckwith

The familiar global weather patterns that we, our parents, and our grandparents (and most of our distant ancestors, at least as far back as the last ice age remnants) have always experienced are no more. We have entered an abrupt climate change phase in which an energized water primed atmosphere and disrupted circulation patterns give rise to unfamiliar, massive and powerfully destructive storms, torrential rains, widespread heat waves and droughts, and less commonly but occasionally widespread cold spells.

Why is this happening now? Sophisticated Earth System computer Models (ESMs), summaries of state-of-the-art peer reviewed climate science (Intergovernmental Panel on Climate Change IPCC), and mainstream science have generally put the climate change threat out to the latter part of the century. Global data from all parts of the world, but most noticeably the Arctic shows that reality is quite different from these models and mainstream thinking.

Just by looking out the window much of humanity now senses that something is very different, and uncomfortably wrong in their particular region.

Depending on location, vegetation is drying out and burning, or being toppled by very high wind events, or oceans are invading upon coastlines, or rivers are overrunning banks or drying up or both, while rainfall deluges are inundating other regions. In fact some regions are vacillating between massive floods and massive droughts, or record high temperatures and record low temperatures, even on a weekly basis.

As crazy as things are now, clearly they are not bad enough to wake up the general population enough to vote down denier politicians and demand extensive governmental action on the problem. Not to worry, that action is a sure bet in the near future, the only question is will it happen next year, or in 3 years?

In the meantime, many of us are doing as much as we can to educate people on the dangers we face and speed up the understanding of climate reality process. As much as we do, ultimately it is the hammer of extreme weather, causing, for example global crop failures or taking out a few more cities in rich countries that will take the final credit for an abrupt tipping point in human behavior.

The key to the disruption in the climate system is the Arctic.

Human emissions have inexorably increased levels of carbon dioxide and methane (Greenhouse gases GHGs) in the atmosphere sufficiently to cause an incremental overall increase of global mean surface temperature by 0.8 degrees C over the last century. Over the last 3 decades, the GHGs have caused sufficient warming in the Arctic to melt enough land-covered snow and ocean covered ice such that the highly reflective surfaces have been replaced by dark underlying land and ocean greatly increasing sunlight absorption causing Arctic temperature amplification of 3x to 5x and higher.

This has melted permafrost on the land and on the shallow continental shelves and has increased Arctic methane emissions, which on a molecule-to-molecule basis cause warming >150x compared to carbon dioxide on a short timescale. Arctic temperature amplification has reduced the equator-to-Arctic temperature difference, which is responsible for setting up global circulation patterns on the rotating Earth. Thus, the high speed jet stream winds which circumvent the globe become slower, and wavier, and weather patterns change.

Extreme weather events become stronger, more frequent, of longer duration, and act on new regions. In effect, the climate background has changed, so the statistics of all weather events changes. When the ocean tide comes in all boats rise, when the climate system changes all weather events change.

So how does the North American freeze of early January, 2014 and the upcoming late January, 2014 freeze fit into this picture? In our familiar climate, the polar jet stream flowed mostly west to east (with small north-south deviations or waves, with typically 4 to 7 crests and troughs around the globe) separating cold dry Arctic air from lower latitude warmer moist air. The latitude of the jet moves southward in our winter and northward in our summer.

In our present climate the jet stream waviness has greatly increased and eastward average speed has decreased. Not only that, but in early January there were only two troughs (over North America and central Asia) and two crests (over Europe and the Pacific up through Alaska and the Bering Strait).

The troughs had temperatures 20 degrees C cooler than normal, while the crests had temperatures 20 degrees C warmer than normal. These large waves and slowing of the jet stream is directly responsible for the changes we have been experiencing in weather extremes. Cold or warm, depending on your location.

continued at part 2

Thursday, June 20, 2013

Extreme weather becomes the norm - what can you do?

. . a sky that has turned red due to greenhouse gases, while the land is flooded. The handful of
people who survived are standing by helplessly on higher grounds, in despair and without hope,
while one figure turns to me in panic and pain, uttering nothing but a silent scream . . .
(comment by Sam Carana, March 8, 2012, on auction of the Scream, by Edvard Munch)

Symptoms

Torrential rains in some regions are causing massive floods while in other locales record droughts are occurring with higher frequency and severity and areal extent around the globe. Global food production is being hit hard, leading to large price increases and political instability. Areas under drought are experiencing numerous massive forest fires of incredible ferocity.

Causes

The statistics of extreme weather events have changed for the worst due to changes in the location, speed, and waviness of the jet streams which guide weather patterns and separate cold and dry northern air from warm and moist southern air. The jet streams have changed since the equator to north-pole temperature difference has decreased due to the huge temperature rise in the Arctic.

The huge temperature rise in the Arctic is due to a collapse in the area of highly reflective snow and ice, which is caused by melting. The melting is from warming from the increase of greenhouse gases from fossil fuel burning. The Arctic sea ice and spring snow cover will vanish within a few years and the weather extremes will increase at least 10x.

What can you do?

Go talk to you politicians and friends about climate change and the need to slash fossil fuel emissions. Immediately. Cut and paste my comments above and post them on facebook, send them to newspapers, and educate yourself on the science behind all the above linkages. Leave my name on or take it off and plagiarize all you want, just get this knowledge out there...

From an unmuzzled climate scientist...
Paul Beckwith, B.Eng, M.Sc. (Physics),
Ph.D. student (Climatology) and Part-time Professor,
University of Ottawa

originally posted as a comment under the CBCnews post:
Calgary braces for flooding, orders communities evacuated 

Related

- The Tornado Connection to Climate Change
- President Obama, here's a climate plan!
- Diagram of Doom
- Polar jet stream appears hugely deformed
Ten Dangers of Global Warming (originally posted March 8, 2007)

Friday, December 21, 2012

Methane contributes to accelerated warming in the Arctic


Above combination image featured earlier in the post Striking increase of methane in the Arctic. The images were produced by Dr. Leonid Yurganov, Senior Research Scientist, JCET, UMBC, who presented his findings at the AGU Fall Meeting 2012. The image below gives an update for 2012, showing an image with methane levels at 600 hPa.


Temperature anomalies on the inset on above image are averages for the full month November, whereas the methane levels displayed on the left are for the first ten days of November only. Using temperature maps for the same periods in such comparisons may result in even more striking simularities between methane levels and temperatures. For a more complete picture, further comparisons between November 2008 and November 2012 are added, for days 11-20 (below),


and for days 21-30 (below).


The images show that the highest methane levels show up above the water, as opposed to above land, indicating that methane is being released from the seabed across the Arctic.

Temperatures have meanwhile changed. In November 2012, there were high temperature anomalies in east Siberia. There now are very low temperatures throughout Siberia, as illustrated by the Wunderground map below, which shows high temperatures. Temperatures as low as -60.5°F (-51.4°C) were recorded in Susuman, east Siberia, both on December 13th and 17th, 2012.


The now hugely deformed polar jet stream and high levels of methane in the Arctic are only two out of numerous feedbacks that contribute to accelerate warming in the Arctic. Without rapid action, we can expect such wild swings in temperature to get even worse, making more extreme weather the new norm.