DANCING NEBULA

DANCING NEBULA
When the gods dance...

Monday, October 29, 2012

Why Hurricane Sandy Has Morphed into a 'Frankenstorm'

Environment 

Why Hurricane Sandy Has Morphed into a 'Frankenstorm' -- And Why We Should Get Used to Catastrophic Weather

Here's how manmade carbon pollution is making many of the most destructive kinds of extreme weather events -- Frankenstorms -- more frequent and more intense.

This GOES-13 satellite image provided by the US Naval Research Laboratory shows the eye of Hurricane Sandy it churns just off the eastern coast of the US.
Photo Credit: AFP

What would you call an “unprecedented and bizarre“ storm that is:

  • The “largest hurricane in Atlantic history measured by diameter of gale force winds (1,040mi)” [Capital Weather Gang]
  • “A Storm Like No Other” [National Weather Service via AP]. NWS“I cannot recall ever seeing model forecasts of such an expansive areal wind field with values so high for so long a time. We are breaking new ground here.”
  • “Transitioning from a warm-core (ocean-powered) hurricane into an extra-tropical low pressure system, a classic Nor’easter, fed by powerful temperature extremes and swirling jet stream winds aloft to amplify and focus the storm’s fury” [meteorologist Paul Douglas]
  • Being fueled in part by “ocean temperatures along the Northeast U.S. coast [] about 5°F above average,” so “there will be an unusually large amount of water vapor available to make heavy rain” [former Hurricane Hunter Jeff Masters]
  • Also being driven by a high pressure blocking pattern near Greenland “forecast to be three standard deviations from the average” [Climate Central and CWG]
  • “Stitched together from some spooky combination of the natural and the unnatural.” [Bill McKibben]

McKibben explains “Our relationship to the world around us is shifting as fast as that world is shifting. ‘Frankenstorm’ is the right name for Sandy, and indeed for many other storms and droughts and heat waves now.”

CBS News offered another coincidental reason for the name in its headline, “Hurricane Sandy may slam into U.S. East Coast as Halloween week ‘Frankenstorm’.”

Readers of my book, “Language Intelligence: Lessons on Persuasion from Jesus, Shakespeare, Lincoln, and Lady Gaga,” know the unique power of metaphors. As one review article put it, “Studies reveal that virtually all of our abstract conceptualization and reasoning is structured by metaphor.”

Frankenstein — and his monster — have become a metaphor for the unintentional consequences of scientific and technological advances.

Humans are changing the climate in dangerous and unprecedented ways. At first it was unintentional, but no one in the public arena can possibly claim today they haven’t been warned — repeatedly — by climate scientists and others (see, for instance Lonnie Thompson on why climatologists are speaking out: “Virtually all of us are now convinced that global warming poses a clear and present danger to civilization.”)

Dr. Kevin Trenberth, former head of the Climate Analysis Section at the U.S. National Center for Atmospheric Research, explained in a must-read 2012 review article in Climatic Change:

The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be….

We can even make a stronger statement today in the case of hurricanes thanks to a brand new study, “Homogeneous record of Atlantic hurricane surge threat since 1923

We demonstrate that the major events in our surge index record can be attributed to landfalling tropical cyclones; these events also correspond with the most economically damaging Atlantic cyclones. We find that warm years in general were more active in all cyclone size ranges than cold yearsThe largest cyclones are most affected by warmer conditions and we detect a statistically significant trend in the frequency of large surge events (roughly corresponding to tropical storm size) since 1923. In particular, we estimate that Katrina-magnitude events have been twice as frequent in warm years compared with cold years.

The name “Frankenstorm” fits. The unique severity of the storm is the point! Manmade warming has consequences. The time to act is now.

For those who aren’t regular readers of Climate Progress, here’s more of the literature on how manmade carbon pollution is making many of the most destructive kinds of extreme weather events — Frankenstorms – more frequent and more intense.

Let’s start with a quote from Jennifer Francis of Rutgers (via DotEarth) on the link between Sandy and the record-smashing Arctic sea ice loss:

The jet stream pattern — particularly the strongly negative NAO [North Atlantic Oscillation] and associated blocking — that has been in place for the last 2 weeks and is projected to be with us into next week is exactly the sort of highly amplified (i.e., wavy) pattern that I’d expect to see more of in response to ice loss and enhanced Arctic warming. Blocking happens naturally, of course, but it’s very possible that this block may have been boosted in intensity and/or duration by the record-breaking ice loss this summer. Late-season hurricanes are not unheard of either, but Sandy just happened to come along during this anomalous jet-stream pattern, as well as during an autumn with record-breaking warm sea-surface temperatures off the US east coast. It could very well be that general warming along with high sea-surface temperatures have lengthened the tropical storm season, making it more likely that a Sandy could form, travel so far north, and have an opportunity to interact with a deep jet-stream trough associated with the strong block, which is steering it westward into the mid-Atlantic. While it’s impossible to say how this scenario might have unfolded if sea-ice had been as extensive as it was in the 1980s, the situation at hand is completely consistent with what I’d expect to see happen more often as a result of unabated warming and especially the amplification of that warming in the Arctic.

I haven’t read the entire Noren paper yet, but it does not surprise me that severe flooding in the northeast could be linked with periods of negative AO [Arctic Oscillation]. When the AO is negative, the jet stream tends to be wavier, just like the situation we’re in now, which favors slow-moving weather systems that can cause floods. Losing ice, reducing the poleward temperature gradient, and warming the entire climate system should contribute to increasing the likelihood of condusive to anomalous storms.

The very latest science by Francis, NOAA, and others suggests we may actually be in the midst of a quantum leap or step-function change in extreme weather because of increases in “blocking patterns” and warming-driven Arctic ice loss:

One of the basic predictions of climate science is that extreme weather will make the hydrological cycle more extreme:

1) Here we show that human-induced increases in greenhouse gases have contributed to the observed intensification of heavy precipitation events found over approximately two-thirds of data-covered parts of Northern Hemisphere land areas. These results are based on a comparison of observed and multi-model simulated changes in extreme precipitation over the latter half of the twentieth century analysed with an optimal fingerprinting technique.

Changes in extreme precipitation projected by models, and thus the impacts of future changes in extreme precipitation, may be underestimated because models seem to underestimate the observed increase in heavy precipitation with warming.

2) Occurring during the wettest autumn in England and Wales since records began in 1766 these floods damaged nearly 10,000 properties across that region, disrupted services severely, and caused insured losses estimated at £1.3 billion….

… it is very likely that global anthropogenic greenhouse gas emissions substantially increased the risk of flood occurrence in England and Wales in autumn 2000.

That post ended with its own review of the literature on the connection between global warming and extreme weather. Here are several more recent studies on how warming is already making our weather more extreme:

A new study by a Duke University-led team of climate scientists suggests thatglobal warming is the main cause of a significant intensification in the North Atlantic Subtropical High (NASH) that in recent decades has more than doubled the frequency of abnormally wet or dry summer weather in the southeastern United States….

The models – known as Coupled Model Intercomparison Project Phase 3 (CMIP3) models – predict the NASH will continue to intensify and expand as concentrations of carbon dioxide and other greenhouse gases increase in Earth’s atmosphere in coming decades.”This intensification will further increase the likelihood of extreme summer precipitation variability – periods of drought or deluge – in southeastern states in coming decades,” Li says.

The team calculates that a 1 ºC increase in sea-surface temperatures would result in a 31% increase in the global frequency of category 4 and 5 storms per year: from 13 of those storms to 17. Since 1970, the tropical oceans have warmed on average by around 0.5 ºC. Computer models suggest they may warm by a further 2 ºC by 2100.

  • Nature: Strong Evidence Manmade ‘Unprecedented Heat And Rainfall Extremes Are Here … Causing Intense Human Suffering’
  • Hansen et al: “Extreme Heat Waves … in Texas and Oklahoma in 2011 and Moscow in 2010 Were ‘Caused’ by Global Warming”
  • Study Finds 80% Chance Russia’s 2010 July Heat Record Would Not Have Occurred Without Climate Warming
  • NOAA: Human-Caused Climate Change Already a Major Factor in More Frequent Mediterranean Droughts

    Manmade climate change is one monster we still have some control over. But here’s the final warning. We are already seeing Frankenstorms, and we’ve only warmed about 1.4°F over the past century. We are on track to see more than 5 times that warming this century. The monster storms that would spawn are beyond imagining.

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