Archive

Posts Tagged ‘sea ice’

Indications Of A Changing Arctic (Across The Centuries)

2010/11/09 1 comment

(h/t FM)

Is there anything peculiar happening in the Arctic in our time? Unfortunately, satellite-based sea-ice measurements only start from 1979, i.e. have just barely crossed the magic 30-year line that we’re told separates “weather” from “climate” (in other words, we have just been able to say that, according to mainstream climatology, the ice in 1995 was on the decrease).

A different way to look at the issue is to source information from relatively old books and newspaper articles. And there are good indications that their analysis will show quite large changes in the Arctic sea-ice extension across the centuries.

As it happens, I was sent yesterday the link to a very interesting  1818 compendium edition of mid-1770’s North-Pole-related thoughts and reports by Danies Barrington FRS of “young Mozart” fame: “The Possibility of Approaching the North Pole Asserted“.

Barrington goes at great length both in collecting as much evidence as possible from seamen claiming to have been further North than would have been expected; and in examining such evidence with a healthy dose of skepticism. His conclusions: several ships have been beyond 82N, and many of them have reported clear water to the North (see page 61). And yes, uncertainties were put in plain sight: finding a way to reach Asia without going around the tip of South America was considered very serious business, and even a strong advocate for Polar exploration like Barrington didn’t try to hide what he might have found uncomfortable. A quarter of a millennium later, we can be fairly certain ships at Barrington’s time were regularly reaching 81N.

Fast forward to 1858 and a “letter” on the New York Times by a Col. Peter Force, actually the text of a lecture at the New-York Historical Society on July 1st of that year. Col. Force appears extremely skeptical of any claim about the very existence of a Northwest Passage, going as far as to use that old saying, “if it were there we would have discovered it by now”. And if you look at the details reported, the 82N of 80 years earlier was then almost an unreachable goal, as there is plenty of mentions of sea ice going as low as 69N.

Arctic sea ice was therefore extending much further to the South in 1858 than in 1775. But were the CO2 emissions in 1775 higher than in 1858? I do not think so.

Advertisements

Mystery In The Sea Of Okhotsk

2009/05/04 6 comments
sea of Okhotsk

sea of Okhotsk

Whatever happened in the sea of Okhotsk, the area most conspicuously “free” now from polar ice when compared to 30 years ago?

Of the 400,000-odd sq km missing from the average, 300,000 concern the sea of Okhotsk, and 100,000 the sea of Barents.

In any case, anomalies are overrated as a tool to understand what happens at the Poles. For example the Arctic Basin anomaly is zero, simply because there is only so much ice cover possible for it. If the average is 100%, even the coldest year will never show a positive anomaly…

One For The BBC

2009/03/09 1 comment

Nowhere fast, but sometimes at the BBC they do understand when they get it wrong…

On the Science & Environment home page:

  • Yesterday: Arctic diary – The team has a dramatic night on melting Arctic ice
  • Today: Arctic diary – The team has a dramatic night on shifting Arctic ice

Somebody somewhere somehow must have realized that polynias existed long before anybody thought of anthropogenic global warmng…

Arctic Sea Ice Extent: In October 2008, Fastest Ever Growth

2008/11/05 31 comments

As expected a few days ago: October 2008 has seen the fastest Arctic sea ice extent growth ever recorded. According to the data published by IARC-JAXA, the amount of growth has reached 3,481,575 square kilometers for the month, or 112,319 sq km per day on average.

The previous maximum was October 2007, with 3,330,937 sq km for the month and 107,450 sq km per day on average. Record shrinkage remains July 2007, with 2,913,593 sq km lost and 93,987 sq km per day on average.

Growth should be starting levelling off now. November values could be as high as 2,179,844 sq km (2002) or as low as 964,688 sq km (2006).

UPDATE NOV 6: I should have known it. OF COURSE the above is an indication that Climate Change is upon us. Read this comment by Georg Hoffman at Tamino’s:

So I would make the specific prevision that 1) a seasonal cycle will show up in sea ice data and 2) due to 1) the october/november increase and the may/june decrease of seaice will become bigger and faster. I might check that with CMIP model data but I am pretty sure that this is what the model show

Here’s a link for the “CMIP model“. It never ceases to amaze me how elastic AGW theory truly is.

October 2008 Possibly Set for Record Sea Ice Extent Increase Rate

2008/10/24 8 comments

UPDATE NOV 10: October 2008 did show the fastest ever growth in sea ice extent

What is the reason behind the fact that “[Arctic] sea ice area [is] approaching the edge of normal standard deviation“?

It’s because October 2008 is set to break all records in the daily rate of increase in sea ice extent in the Arctic, that’s why.

Just look at the graph below, extracted from the values available at the IARC-JAXA website.

Daily Change Rate (Sea Ice Extent) (sq km, by month)

Daily Change Rate (Sea Ice Extent) (sq km, by month)

(The Y values are the daily rates of change in sea ice extent in the Arctic, averaged across each month. Note that for October I have only computed and plotted the rates between the 1st and the 23rd day of the month).

Some considerations:

(a) The October 2008 average daily rate so far is the largest overall, both in actual value (around 122,400 sq km of increase per day, previous record 100,500 in 2005) and in absolute terms (the overall minimum is around 94,000 sq km of decrease per day, in July 2007)

(b) If confirmed in a week’s time, the above will become the fifth record set in 2008:

largest January daily increase rate (44,000, previous record 39.800 in 2003)
largest February daily increase rate (27.500, previous record 25,400 in 2005)
largest May daily decrease rate (47,100, previous record 46,000 in 2005)
largest August daily decrease rate (66,800, previous record in 62,600 in 2004)

(c) Compared to 2007, the current year 2008 has so far shown

larger daily rates of increase in January (44,000 vs 35,400), February (27,500 vs 12,100), September (8,800 vs -600) and October (122,400 vs 93,500)
larger daily rates of decrease in April (39,800 vs 27,100), May (47,100 vs 44,200) and August (66,800 vs 55,400)
smaller daily rates of decrease in March (11,900 vs 12,200), June (57,900 vs 63,000) and July (78,800 vs 94,000)

========

Let’s see what happens during the upcoming week.

Past values suggest that the final average daily rate of increase for October may be slightly less than today’s. Still, as the current rate is some 20% larger than the previous record in October 2005, it would surprise nobody if October 2008 will remain the month with the largest value ever recorded by JAXA.

ps Who knows what NASA will have to say?

Something Odd About Regional Arctic Sea Ice

There is something strange about the Arctic sea ice data posted at Cryosphere Today.

If I sum up each individual sea’s contribution (plots at the bottom of this post), the totals do no agree with the overall Northern Hemisphere values.

This is a list of anomaly and absolute values in millions sq km, region by region for Sep 10, 2007; March 01, 2008 and Sep 09, 2008:

(Approximated values obtained with Plot Digitizer. I have asked Chapman for the actual figures…if I get them, I’ll change the post accordingly)

Region,Anomaly Sep 07,Anomaly Mar 08,Anomaly Sep 08,Absolute Sep 07,Absolute Mar 08,Absolute Sep 08,Mean Sep 07,Mean Mar 08,Mean Sep 08
Arctic Basin,-0.97,0.07,-0.75,2.37,4.2,2.59,3.34,4.13,3.34
Hudson Bay,-0.02,-0.05,-0.02,0,1.22,0,0.02,1.27,0.02
St Lawrence,0,0,0,0,0.19,0,0,0.19,0
Baffin/Newfoundland,-0.03,0.16,-0.02,0,1.33,0.01,0.03,1.17,0.03
Greenland,0.06,-0.06,-0.04,0.17,0.52,0.07,0.11,0.58,0.11
Barents,-0.04,-0.24,-0.04,0,0.41,0,0.04,0.65,0.04
Kara,-0.1,0.02,-0.09,0.04,0.86,0.05,0.14,0.84,0.14
Laptev,-0.07,0.02,-0.04,0.1,0.7,0.13,0.17,0.68,0.17
East Siberian,-0.31,0.01,-0.31,0.01,0.9,0.01,0.32,0.89,0.32
Chukchi,-0.08,0.02,-0.08,0,0.59,0,0.08,0.57,0.08
Bering,0,0.16,0,0,0.7,0,0,0.54,0
Okhotsk,0,-0.3,0,0,0.7,0,0,1,0
Beaufort,-0.13,0.02,-0.17,0.04,0.52,0,0.17,0.5,0.17
Canadian Archipelago,-0.13,0,-0.1,0.11,0.6,0.14,0.24,0.6,0.24
Totals,-1.82,-0.17,-1.66,2.84,13.44,3,4.66,13.61,4.66

Northern Hemisphere,-2.05,-0.48,-1.92,2.94,13.85,3.17,4.99,14.33,5.09

difference,-0.23,-0.31,-0.26,0.1,0.41,0.17,0.33,0.72,0.43

(The “Mean” columns reconstruct the 1979-2000 mean by subtracting the anomaly from the absolute measured ice cover)

You can see that my digitization appears to consistently underestimate the anomalies, and overestimate the absolute measured ice cover. The result is that there is for example a huge 720,000sq km difference between the total of all 1979-2000 March means, and the value reported for the Northern Hemisphere on Cryosphere Today.

It would be nice to know if anybody else has attempted this, and/or has the actual values rather than the graphs.

NOTE ADDED 11 SEP: Unfortunately the graphs below do not use the same scale, so visual inspection can be misleading

Kayaking at 83N, in 1895

2008/09/09 1 comment

More evidence that the so-called Polar Defense Project has likely been more a publicity stunt than a serious attempt at showing the retreat of Arctic sea ice: contrarily to Lewis Pugh’s claim of having gone “further north than anyone has ever kayaked before“, reports of people paddling northwards of Pugh’s 2008 maximum (80° 31′ 26″ N, or more likely 80° 14′ 56″ N) can be as old as 1895.

That’s the year when famous Norse explorer Fridtjof Nansen reached Franz Josef Land going south, after going nearer to the North Pole than anyone before, travelling with Hjalmar Johansen:

The two men started out on March 14, 1895 with three sleds, two kayaks and a bunch of dogs. They reached 86° 14´ N one month later and then turned back, expecting to find land at 83°N. No such luck though, and that’s when the kayaks came handy for it took open water crossings until July 24, when they finally found [Franz Josef Land]

There are even reports of Nansen swimming to get his kayak back…and that would be another non-first in Lewis Pugh’s career.

And why no mention of Lonnie Dupre and Eric pulling and paddling “modified canoes” all the way to the North Pole in July 2006?

In truth, there are companies offering regular kayaking trips to the North of Pugh’s 2008 “achievement”: for example TraveLearn’s “Arctic Adventures” where tourists are brought to Phipps Island, 80° 42´ N .

For as little as $4,600, Lewis Pugh can better his “achievement” next year.

%d bloggers like this: