Showing posts with label weakening. Show all posts
Showing posts with label weakening. Show all posts

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

Wednesday, January 30, 2013

Extreme Weather Warning

Above image is from NOAA Storm Prediction Center, with Convective Watches in red. 

Below, storm reports, from the same site. 

For an update on the current situation in your area, see:

Meanwhile, in Canada, Paul Beckwith gives more background on 'Our rapidly changing climate and weather'.

Paul Beckwith
Part-time professor, PhD student (abrupt climate change), Department of Geography
Location: University of Ottawa, in the hub next to the university bookstore
Not a typical January in Ottawa. 10 degrees C for several days one week; -30 the next; followed by 10 the one after that. Why?

Normally the high altitude jet streams that circle the planet are predominantly from west to east with little waviness. Weather is cold and dry northward of the jets (Arctic air sourced) and warm and wet southward (moist tropics and ocean sourced). Now, and moving forward, the jets are extremely wavy and as the crests and troughs of the waves sweep by us each week we experience the massive swings in temperature. The extreme jet waviness is due to a very large reduction in the equator-to-Arctic temperature gradient caused by an exponentially declining Arctic reflectivity from sea-ice and snow cover collapses (which causes great amplification of Arctic temperatures). Additional amplification is occurring due to rapidly rising methane concentrations sourced from sea-floor sediments and terrestrial permafrost.

Observed changes will accelerate as late summer sea-ice completely vanishes from Arctic within a few years. Largest human impacts will be food supply shortages and increases in severity, frequency, and duration of extreme weather events.

In the video below, by Gzowski Films, Paul Beckwith speaks on our radical weather patterns.