This week is a week of weird weather. In the USA yesterday, temperatures across the country varied by an apparent 140 degrees Fahrenheit (that's
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| Source: NOAA |
(Much of Oregon and most of California have had the driest year on record.)
In the UK, it's flooding. Waves of up to 10 metres are lashing the coast. According to the BBC these are being caused by " a large, deep depression in the Atlantic which was "whipping waves up" out at sea - and these were coming in as a "large swell".
This video is from a couple of days ago.
While back here in Australia's summer after Australia's hottest year on record, we've had cold nights where I am and lovely weather. But we've been lucky. While we were enjoying mild sunny weather, there was a huge heat wave sweeping over the rest of the continent.
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| Source: BoM |
And then there is the drought - and downpours.
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| Source: BoM |
I figured a dose of real weirdness would help counteract the wacky weirdness I've been reporting from WUWT and Judith Curry. (Not that all the weather is weird.)
"varied by an apparent 140 degrees Fahrenheit (that's 60 degrees Celsius)"
ReplyDeleteIts 77.7C - dont subtract the 32 when its a temperature difference not an absolute temperature.
Thanks - fixed.
DeleteWee bit of science about it on the BBC, via Climate & Geohazards blog:
ReplyDeletehttp://climateandgeohazards.wordpress.com/2014/01/06/why-is-it-so-cold-in-the-united-states-2/
Holland.
ReplyDeleteJust smashed the date record, second for this year already, at +14.5° C old record was +13.1° C in 1999.
Just received the third December in row into the top ten warmest since 1706.
"Just received the third December in row into the top ten warmest since 1706."
DeleteThis makes me wonder what meteorological conditions were like in the North Atlantic in December 1703 the year of The Great Storm of 7 December that year (26 November at that period being under the Julian calendar). I have a copy of Defoe's book.
The preceding 17th Century had been one of exceptional periods of weather with as we are often told frost fairs on the Thames. One such occasion was after 23 December with Winter arriving later than usual and the Thames freezing over. But this was in a year 1684 that also saw the Summer become exceptionally hot and dry.
There were other years in the 17th Century which saw unusual weather with hot and dry Springs and exceptionally wet Summers.
This information is found in a book on English Restoration period warships, in particular the story of the 70 Gun 3rd Rate Lenox of the 1677 Thirty Ship Programme. 'The Restoration Warship', Endsor 2009.
Was the changeable nature of the weather during this century linked to human activities such as intensive deforestation to supply timber for house and shipbuilding, the latter consuming vast quantities of timber as well as production of charcoal for iron founding, which began in earlier centuries? There were some particularly intense sea fights during the 17th Century e.g. The Four Day's Battle of 1666.
Which brings us to the Great Fire of London and the tinder-box dry conditions at that time, following on the population sapping Plague of London.
The work of William Ruddiman on the long history of human modification of the atmosphere leads me to wonder if the chaotic seeming weather of the so called MWP and LIA were linked to changes in the fortunes, and thus activity, of the human population, particularly in the northern hemisphere and Eurasia.
Ship's logs of those centuries of sail may hold much information that would yield valuable information by careful scrutiny. Difficult work though involving aspects of language and nautical dialogue.
LIA.
DeleteModern studies increasingly and convincingy suggest that increased volcanic activity between equator and northerly low latitudes in the 14th to half 19th century have induced the LIA.
Which was mainly or entirely a northern hemisphere phenomenon, and set its minima in different regions in different decades or even centuries.
What is new here is the appearance of lesser influence from sun activity on climate than supposed previously.
Volcanic explosions of sufficient magnitude blast SO2 and fine particles into the stratosphere. This cloud mixes around mainly on the hemisphere of the eruption to finally blanket the sky up to the Arctic.
From shielding sunlight, this has a cooling effect for world average surface temperature esp. of a hemisphere.
From absorbing sunlight, this warms the lower stratosphere.
This warming when happening inside the normally very cold upper core of the circumpolar vortex can weaken the vortex or collapse it. In response circulation patterns exhibit more blockings.
Very cold, frosty weather in Western Europe has to come from the east, continent up to Siberia there, and therefore are always associated with blockings.
So apparently the LIA, with not only its frosty winters but also the heat waves and summer droughts, was mainly a time of important circulation change involving more blocked types and less westerlies.
Interestingly the Arctic sea ice extent showed a few centuries of decline during the LIA, while it slowly grew before that and after that until we began to destroy it:
http://tamino.files.wordpress.com/2011/12/kinnard_2011_sea_ice.jpg?w=500
The great North Sea storm of 8-9 December 1703 had indeed special attention in my old 'Bar en Boos', catalog of 700 winters past, the old ones reconstructed from delving into libraries and log books :)
Human contribution to atmospheric composition in that time measurable in old snow et c, but negligable for climate. Deforestation will have mainly changed some precipitation distributions.
DeleteFolks should be very wary about talking about the Frost Fairs. The flow of the Thames was very different then. The Embankments in London did not exist at the time, so the river was much wider. Also the original London Bridge severely restricted flow in the main part of the river (the force of the flow through the bridge could be lethal if misjudged by the boatmen. These factors meant that the upstream flow was much more sluggish than it is nowadays.
Delete"Folks should be very wary about talking about the Frost Fairs."
DeleteIndeed. However, I was aware of the slow restricted flow factor in the freezing over of the Thames during that period (although granted you were not to know this). However that temperatures were unusually cold is demonstrated by, 'Away from the Thames men and cattle perished, fowl, fish birds and many deer died...The frost penetrated trees so they split as if struck by lightning. The seas became locked up with ice; no vessels could stir.'
Accounts of naval operations in the Western Atlantic and Channel over the period of the turn of the 17th to 18th Centuries are replete with stories of ships surviving atrocious wind and sea conditions with many remarks upon the unusual ferocity of the elements.
So they are. The picture of LIA events surely comes together from all such proxy sources. Of course those 'Frost Fairs' need corroboration from other sources including direct thermo measurements as of beginning 17th century. Seas icing up are obvious markers for extreme winter cold too.
DeleteGales and storms might be somewhat harder to assess and compare to today's. Shipping wasn't too robust those days and there were no meteorologists let alone models.
This present weird weather in the US brings the film The Day After Tomorrow to mind. While it is still ridiculously exaggerated, the underlying causes do seem to be becoming true (thankfully the Gulf stream is still flowing quite nicely otherwise the UK would be even more screwed than it presently is!)
ReplyDeleteI think you were using wind chills, not actual temperatures for your range. The national high was 85 and the national low was -37, a range of only 122 degrees F.
ReplyDeleteYes Scott, NOAA called it "apparent" which I gather is code for "feels like", which I gather is like the "wind chill" effect. Some US weather reports I've come across don't even refer to actual temperature, it's all the "feels like" temperature, which seems odd to those of us who live elsewhere.
DeleteLionel, if you are interested im getting data from ships logs, youwill be interested to know there are several such projects around, including ones that want your help, such as oldweather.org (1 million pages of logs from 300 US ships). There is a similar project for a selection of British ships including Bounty, Discovery and Beagle.
ReplyDeletehttp://news.bbc.co.uk/2/hi/science/nature/8291267.stm
FrankD
Thank you for that Frank, this
DeleteAtmospheric Circulation Reconstructions over the Earth,
appears to be a door into a space of twisty little passages with exits North, East, West, South, Up and Down.