Tampilkan postingan dengan label warning. Tampilkan semua postingan
Tampilkan postingan dengan label warning. Tampilkan semua postingan

Rabu, 30 Januari 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
Description:
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. 

Sabtu, 08 September 2012

Update on September Arctic cyclone

By Paul Beckwith, 
edited by Sam Carana


The loss of Arctic sea ice appears to be flattening out at the moment. The above image shows Arctic sea ice extent (total area of at least 15% ice concentration) for the last 7 years, compared to the average 1972-2011, as calculated by the Polar View team at the University of Bremen, Germany.

Paul Beckwith, B.Eng, M.Sc. (Physics),
Ph. D. student (Climatology) and
Part-time Professor, University of Ottawa
 
However, Paul Beckwith warns that Hurricane Leslie looks set to capture Hurricane Michael just off the Canadian maritimes and strongly impact Nova Scotia and Newfoundland (large hurricane), to then continue northward and start to affect Arctic climate by compressing isobars creating large pressure gradients and thus high winds.

Paul points at the image below, from weather.unisys.com/gfsx, showing a 9 day GFSx model for Arctic region.

The model shows that an Arctic cyclone is amplified as a result of Leslie and a strong high pressure ridge is also generated over the Beaufort Sea. As the Arctic cyclone decreases in strength a strong cyclone is generated over Alaska.

“Needless to say this scenario would be very destructive to Arctic sea ice if it plays out,” Paul adds.  “Also, there is no apparent decrease in Arctic sea surface temperatures in projections out to September 12th, and no apparent salinity change. I will be amazed if this melt season does not last until the end of September or even into early October.”




View Paul Beckwith's September 8 presentation by clicking on the following link:
https://docs.google.com/file/d/0ByLujhsHsxP7QndrZjdKX2szTHM/edit


Or, view the presentation in the window below (it may take some time for the file to fully load).