Arctic warming goes with the floe

4 11 2009

Past Arctic Warming Also Created by Currents

Guest posted by Jeff Id of The Air Vent

Image: Met Office UK

The bear is fine, don't freak out. Image: Met Office UK

I’ve stated here on several occasions that the ‘Recent’ Arctic ice thinning is more likely a current change issue rather than a temperature issue.  Differences in flow change the transfer of vastly more energy than a couple of degrees of air temp, however changing air temperatures are a strong indicator of differences in regional water flow.  This effect is very visible in the arctic ice videos posted here.  Recently Dr. Arnd Bernaerts asked by email that I call attention to  his paper on Arctic Warming for a period we don’t hear about enough.  He has a shorter version link which he also gave here. I really enjoy the historic discussions of climate and the paper is quite readable so I’ve put the whole paper up instead.

——————

The Circumstances of the Arctic Warming in the early 20th Century

Author: Arnd Bernaerts

Dr. Arnd Bernaerts
Hamburg, Germany

Abstract

The Arctic has a crucial role in the world’s climatic system, and global warming may have an amplifying effect. The recently observed thinning of the sea ice has alerted scientists and policy makers alike. That was quite different when a similar warming occurred 90 years ago, which is still regarded as one of the most puzzling climatic event during the last century. That needs not to be, if the situation is being viewed from on oceanic perspective, together with the fact that the winter air temperatures in the higher Northern Hemisphere are greatly influenced by the ocean, particularly in the North Atlantic, which is partly free of sea ice up to the Fram Strait. Here also ends the West Spitsbergen Current, a current which supplies the Arctic Ocean with warm and saline Atlantic water. Already back in 1920s air temperature observation showed a strong warming at Spitsbergen during the winter season. By analyzing the winter temperature profile of five coastal stations it can be demonstrated that the climatic shift at the end of the 1910s had been closest to Spitsbergen, allowing the conclusion that circumstances related to the West Spitsbergen Current have caused the early Arctic warming almost a century ago. Read the rest of this entry »


Comments : 54 Comments »

Categories : Arctic, sea ice

The Top Ten Reasons why I think Catlin Arctic Ice Survey data can’t be trusted

15 10 2009

First, I loathe having to write another story about Pen Hadow and his Catlin Arctic Ice expedition, which I consider the scientific joke of 2009. But these opportunistic explorers are once again getting some press over the “science” data, and of course it is being used to make the usual alarmist pronouncements such as this badly written story in the BBC:

Click for a larger image

Click for a larger image

WUWT followed the entire activist affair disguised as a science expedition from the start. You can see all of the coverage here. It’s not pretty. When I say this expedition was the “scientific joke of 2009″, I mean it.

On to the Top Ten List. Read the rest of this entry »


Comments : 202 Comments »

Categories : Alarmism, Arctic, ridiculae, sea ice

Another possible DMSP/SSMI sea ice sensor failure?

14 10 2009

Readers may recall that I brought an issue with NSIDC’s sea ice data to their attention back in February 09. The official response from Walt Meier then was “its not worth blogging about”. Shortly afterwards that tune changed when it was announced:

NSIDC: satellite sea ice sensor has “catastrophic failure” – data faulty for the last 45 or more days

Not only was the glitch I pointed out part of the sensor failure real, there was also a long term drift in the sensor readings.

Cryosphere Today followed soon afterwards, pulling the plug on their data plot.

This image below is what prompted me to bug NSIDC about the issue, the downspike was highly atypical of the dataset.

http://wattsupwiththat.files.wordpress.com/2009/02/nsidc_extent_timeseries_021509.png?w=519&h=421

The glitch seen above turned out to be a “catastrophic failure” of the SSMI sensor on the Defense Meteorological Program (DMSP) satellite that NSIDC (and many others, including Cryosphere Today) also use. Here’s a look at the problem in more detail that WUWT covered in June.

So today, I was advised in an email that I should have a look at the data from Danish Meteorological Institute (DMI), which also uses DMSP SSMI data to make their web graphic presentation. To quote Yogi Berra, it was “deja vu all over again”. Here’s the DMI image from today: Read the rest of this entry »


Comments : 49 Comments »

Categories : Arctic, sea ice

New paper: Barents Sea Temperature correlated to the AMO as much as 4C – potential for sea ice effect

8 10 2009

A new paper just published in the Geophysical Review Letters finds a significant correlation between the Atlantic Multidecadal Oscillation (AMO) and the water temperature of the Barents Sea.

Barents_sea_map

Barents Sea - click for larger map

This was made possible by a significant network of hydrographical stations in the Barents Sea which resulted in a 230,000 temperature profiles used in this analysis. The hint in the conclusion (which the authors stop short of defining)  is that the pattern of data, seen below, might be linked to the recent pattern of Arctic sea ice melt and some partial recovery seen in the last two years. Their figure 2 below, certainly seems to suggest a strong correlation between water temperature in the Barents Sea and the AMO index.

Monthly temperature (°C) in the Barents Sea for the 100–150 m layer, from 1900 to 2006. Years without all 12 months of data are not plotted. The red line is the Atlantic Multidecadal Oscillation Index.

Monthly temperature (°C) in the Barents Sea for the 100–150 m layer, from 1900 to 2006. Years without all 12 months of data are not plotted. The red line is the Atlantic Multidecadal Oscillation Index.

The paper is:

Levitus, S., G. Matishov, D. Seidov, and I. Smolyar (2009), Barents Sea multidecadal variability, Geophys. Res. Lett., 36, L19604, doi:10.1029/2009GL039847.

We present area-averaged time series of temperature for the 100–150 m depth layer of the Barents Sea from 1900 through 2006. This record is dominated by multidecadal variability on the order of 4C which is correlated with the Atlantic Multidecadal Oscillation Index. Read the rest of this entry »


Comments : 102 Comments »

Categories : Arctic, Science, oceans, sea ice

Operation ice bridge in Antarctica

8 10 2009
While we have no mention in press of the record amounts of ice for the entire Antarctic continent as shown here, scientists are focusing on the one part of the continent that seems to get all the press. No word yet on whether Ted Scambos has a statement prepared already for the press.
From a press release of:

Peering under the ice of a collapsing polar coast

Low-level aerial surveys aim to understand rapid Antarctic melting

IMAGE: The cabin of a DC-8 aircraft has been converted for instruments and engineers.

Click here for more information.

Starting this month, a giant NASA DC-8 aircraft loaded with geophysical instruments and scientists will buzz at low level over the coasts of West Antarctica, where ice sheets are collapsing at a pace far beyond what scientists expected a few years ago. The flights, dubbed Operation Ice Bridge, are an effort by NASA in cooperation with university researchers to image what is happening on, and under, the ice, in order to estimate future sea-level rises that might result.

Since 2003, laser measurements of ice surfaces from NASA’s ICESat satellite have shown that vast ice masses in Greenland and West Antarctica are thinning and flowing quickly seaward. Last month, a report in the journal Nature based on the satellite’s measurements showed that some parts of the Antarctic area to be surveyed have been sinking 9 meters (27) feet a year; in 2002, one great glacial ice shelf jutting from land over the ocean on the Antarctic Peninsula simply disintegrated and floated away within days.

IMAGE: Antarctica’ Larsen Ice Shelf has deteriorated in recent years, and it is one target of the flights.

Click here for more information.

NASA’s satellite reaches the end of its life this year, and another will not go up until 2015; in the interim, Operation Ice Bridge flights will continue and expand upon the satellite mission. In addition to lasers, the plane will carry penetrating radars to measure snow cover and the thickness of ice to bedrock, and a gravity-measuring system run by Columbia University’s Lamont-Doherty Earth Observatory that will, for the first time, plot the geometry and depth of ocean waters under the ice shelves. The gravity study is seen as key because many scientists believe warm ocean currents may be the main force pulling the ice sheets seaward, melting the undersides of ice shelves and thus removing the buttresses that hold back the far greater masses of ice on land.

“What our colleagues see from modeling of these glaciers is that warm ocean water is providing the thermal energy to melt the ice,” said Lamont geophysicist Michael Studinger, a co-leader of the gravity team who will be on some of the flights. “To really understand how the glaciers are going to behave, we need the firsthand measurements of water shape and depth.” Earlier this year, an icebreaker cruise co-led by another Lamont scientist, Stan Jacobs, sent an automated submarine to look under the region’s Pine Island Glacier, which has been moving forward rapidly in recent years. Its bed, where the ice contacts rock, is below sea level, and scientists are concerned about what would happen if a sudden large movement were to introduce seawater underneath. The plane flights, over some six weeks starting Oct. 15, are aimed at providing a wider-scale picture of Pine Island and other targets. Read the rest of this entry »


Comments : 67 Comments »

Categories : Antarctic, sea ice

NSIDC still pushing ice free Arctic summers

6 10 2009

NSIDC seems to be saying: It’s slightly less worse than we thought. For another view, see Dr. Tony Berry’s sea ice analysis on WUWT yesterday.

From a University of Colorado Press Release

Arctic sea ice recovers slightly in 2009, remains on downward trend, says U. of Colorado report

IMAGE: This graphics show multi-year Arctic sea ice changes.

Click here for more information.

Despite a slight recovery in summer Arctic sea ice in 2009 from record-setting low years in 2007 and 2008, the sea ice extent remains significantly below previous years and remains on a trend leading toward ice-free Arctic summers, according to the University of Colorado at Boulder’s National Snow and Ice Data Center.

According to the CU-Boulder center, the 2009 minimum sea ice extent was the third lowest since satellite record-keeping began in 1979. The past five years have seen the five lowest Arctic sea ice extents ever recorded.

“It’s nice to see a little recovery over the past couple of years, but there’s no reason to think that we’re headed back to conditions seen in the 1970s,” said NSIDC Director Mark Serreze, also a professor in CU-Boulder’s geography department. “We still expect to see ice-free summers sometime in the next few decades.”

The average ice extent during September, a standard measurement for climate studies, was 2.07 million square miles (5.36 million square kilometers). This was 409,000 square miles (1.06 million square kilometers) greater than the record low for the month in 2007, and 266,000 square miles (690,000 square kilometers) greater than the second-lowest extent recorded in September 2008. Read the rest of this entry »


Comments : 151 Comments »

Categories : Arctic, sea ice

Interesting analysis of IARC-JAXA Arctic sea ice data

5 10 2009

Analysis of the AMSR-E data on Arctic Ice

Guest post by Dr Tony Berry, 4th October 2009

AMSRE_Sea_Ice_Extent_100509

The latest value : 5,824,688 km2 (October 5, 2009)

The Arctic Ice extent prepared IARC-JAXA demonstrates the cyclical annual trend of freezing and thawing in the Arctic. It is clear that the cycles vary from year to year and it has been suggested that the data supports the hypothesis that AGW is responsible for a long term decline in Arctic ice although recent data has shown a recovery in the Arctic ice extent.

The raw data provide daily IARC-JAXA shows trend nicely but it is difficult to carry out comparative analysis and examine long term trends. Therefore I have calculated average monthly ice extent for each complete month from July 2002 and used this to prepare rolling averages for the data. NOTE: there are gaps in the daily data of up to 11days especially during 2002 to 2004. In these cases the gaps have been filled in using linear interpolation; I do not believe that this has affected the monthly averages in any significant way. The resulting data is as follows:- Read the rest of this entry »


Comments : 57 Comments »

Categories : Arctic, sea ice

2009 Arctic Sea Ice Extent exceeds 2005 for this date

21 09 2009

Those that have been watching the IARC-JAXA Arctic sea ice plot, and noting the slope of gain, rather expected this to happen. Today it did.

Here’s the current IARC-JAXA Sea Ice Extent plot:

JAXA_AMSRE_Sea_Ice_Extent_092009

source:  http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

And here is the plot magnified and annotated to show the crossing: Read the rest of this entry »


Comments : 180 Comments »

Categories : Arctic, sea ice

Antarctica – warming, ice melting – not yet

20 09 2009

I thought it might be time for an update on this.

SMH_antarctica_headline

Earlier this year we had the big news that even though everything else says otherwise, the statistical wizards of Steig et al (with a cameo appearance by stat-stickster Michael Mann) managed to make Antarctica show a warming trend.

At left here’s the headline from the Sydney Morning Herald January 20th 2009, introducing Steig’s results.

Gosh. This new warm picture proves it. Right? Colors don’t lie. They quote Dr. Steig who says:

“The thing you hear all the time is that Antarctica is cooling. But it’s more complex than that,” Professor Steig said. “Antarctica isn’t warming at the same rate everywhere and, while some areas have been cooling for a long time, the evidence shows the continent as a whole is getting warmer.”

Yes it is more complex than that. A part of that complex story is emerging this month. Right about the time when things should start warming up in Antarctica due to their onset of spring, it seems to be stalled according to one scientist on the ground there who writes ICE STORIES: dispatches from polar scientists (emphasis mine):

MCMURDO STATION, ANTARCTICA– Wednesday, September 16, 2009. It has been a slow, and sometimes frustrating, effort to get our first successful science flight of the project, but we did succeed last night. Before discussing that flight I’d like to write about some of the hurdles we have had to overcome to get to this point.

The first obstacle, and the one least in our control, was the weather. The Aerosonde unmanned aerial vehicles (UAVs) have been flown in temperatures as cold as -30 degrees C (-22 deg F), and this was the intended minimum operating temperature for this project.

Prior to coming to Antarctica one of the members of my research group, Shelley Knuth, analyzed 14 years of automatic weather station data from a weather station located at the Pegasus runway that we are using for our UAV flights.

Based on her analysis the temperature at Pegasus is above -30 degrees C for approximately 50% of the time in September, and is below -40 degrees C (which is also -40 degrees F) only 9% of the time in September on average. Of course the weather for any given month rarely follows the average, and this September has been a colder than average September, with most days up until the past few days having temperatures below -30 degrees C at Pegasus, and many days having temperatures below -40 degrees C. This made our attempts to fly the Aerosondes very difficult.

Yes, yes, I know It’s weather, not climate. Hold the caterwauling. But please, also have a look at the NSIDC graph of sea ice for Antarctica. Sea ice forms around the warmer periphery of the continent, not in the cold continental center where Amundsen-Scott base is located. There’s quite the uptick in Antarctic sea ice when the slope should begin heading downward: Read the rest of this entry »


Comments : 121 Comments »

Categories : Alarmism, Antarctic, sea ice, weather

Climate Alarmists rush to judgment on dead walruses, ignore other possibilities

19 09 2009
Click to enlarge

Click to enlarge - Dead walruses litter the beach Thursday, September 17, 2009, on the shore of Icy Cape - Image: Tony Fischbach of the U.S. Geological Survey and distributed via The Associated Press

All over the web today, there’s the theme of: “dead walrus = caused by climate change”. On the Climate Progress blog they have this picture of the dead walruses (seen at left) which have been circulated by the Associated Press. I found the source photo on the Alaskan Daily News (ADN) here.

While uncredited on Climate Progress, the photo appears to have been taken from an airplane or helicopter by Tony Fischbach of the  U.S. Geological Survey and distributed via The Associated Press.

In the ADN news article two things stand out:

1- The USFWS official quoted in the article,  says that he doesn’t know the cause of the deaths:

“It’s just too early to say until we can get someone on the ground,” Woods said.

They report the dead walruses appeared to be mostly new calves or yearlings. However, neither the age of the dead walruses nor the cause of death is known, said Bruce Woods, spokesman for the U.S. Fish and Wildlife Service.

2- The AP reporter, Dan Joling,  gives a platform to somebody who also isn’t on the ground, or even Alaska but works in San Francisco, who assigns climate change as the blame:

Shaye Wolf, spokeswoman for the Center for Biological Diversity, said the walrus deaths were alarming.

“It provides another indicator that climate change is taking a brutal toll on the Arctic,” she said.

This isn’t the first time AP writer Jolin has had a story angle downplayed by Brice Woods. The other poster child for Arctic climate change, the polar bear was part of a 2006 AP story where woods also downplayed the significance.

Before I say anything further, let me point out that I’m no expert on Alaskan wildlife. Read the rest of this entry »


Comments : 134 Comments »

Categories : Alarmism, Arctic, climate_change, media, sea ice

NSIDC still pushing “ice-free Arctic summers”

17 09 2009

This is the press release sent out by NSIDC today (sans image below). Instead of celebrating a two year recovery, they push the “ice free” theme started last year by Marc Serreze. There’s no joy in mudville apparently. My prediction for 2010 is a third year of increase in the September minimum to perhaps 5.7 to 5.9 million square kilometers. Readers should have a look again at how the experts did this year on short term forecasts. – Anthony

NOAA computer model output depicting the trend for the next 30 years

NOAA computer model output depicting the trend for the next 30 years

Image source: NOAA News
Arctic sea ice reaches minimum extent for 2009, third lowest ever recorded

CU-Boulder’s Snow and Ice Data Center analysis shows negative summertime ice trend continues

The Arctic sea ice cover appears to have reached its minimum extent for the year, the third-lowest recorded since satellites began measuring sea ice extent in 1979, according to the University of Colorado at Boulder’s National Snow and Ice Data Center.

While this year’s September minimum extent was greater than each of the past two record-setting and near-record-setting low years, it is still significantly below the long-term average and well outside the range of natural climate variability, said NSIDC Research Scientist Walt Meier. Most scientists believe the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced greenhouse gases being pumped into Earth’s atmosphere. Read the rest of this entry »


Comments : 247 Comments »

Categories : Arctic, sea ice

2nd day – Arctic sea ice is again on the rise

15 09 2009

Yesterday I looked at JAXA data and ventured that:

“Arctic sea ice melt appears to have turned the corner for 2009″

The Sept 15th JAXA Arctic Sea Ice extent graph was published this evening about 8PM PST (and updated overnight which is the image now shown) and shows an increase in sea ice for the second day in a row. It seems clear that Arctic sea ice is now on the rise.

JAXA_seaice_91509-2

click for larger image

The Sept 14th value was: 5,276,563 km2

You can see this minimum and upturn clearly in the zoomed graph below.

Read the rest of this entry »


Comments : 120 Comments »

Categories : Arctic, sea ice

Arctic sea ice melt appears to have turned the corner for 2009

15 09 2009

It appears Arctic sea ice has bottomed out and is now on the growth rebound. The NANSEN Arctic ROOS website shows that in terms of area, sea ice appears to have turned the corner as of Sept 13th data. While that is just one data point, it turned the corner about this time last year, and the year before.

NANSEN Sea Ice Area - click for larger image

NANSEN Sea Ice Area - click for larger image

More data and graphs from NANSEN Arctic ROOS are available here.

Many WUWT readers have been watching JAXA’s sea ice extent graph closely, so have I. Typically JAXA updates the graph twice a day; once around the start of their business day (in Japan), and then a second update that contains the corrected data (after going through processing and QC) a few hours later. Tonight (9/14) about 11:30PM PST JAXA updated their Sept 14th AMSRE data with this new number:

5,269,531 km2

UPDATE: JAXA updated the number again and it now stands at 5,276,563 km2

That is a gain of almost 20,000 26,719 km2 from the Sept 13th value of  5, 249, 844 km2 which may very well turn out to be the minimum extent for 2009.  Here is the Sept 14th chart and the data from JAXA: Read the rest of this entry »


Comments : 159 Comments »

Categories : Arctic, sea ice

Cryosphere Today: Arctic is now ice-free*, Antarctica unaffected

14 09 2009

NSIDC’s Mark Serreze must be thrilled, as he’ll now be able to justify some of his press releases. Gore must be ecstatic that his 2013  “Entire north polar ice cap will be gone in 5 years” prediction has come in way ahead of schedule.

Cryosphere_today_091309

Click for the current Arctic Ice image.

Notice the contrast between Arctic and Antarctic. I can hear the Angelic choruses of “we told you so”  taking flight now. Oh, wait.

Read the rest of this entry »


Comments : 68 Comments »

Categories : Arctic, fun_stuff, sea ice

NASA video tour of the Cryosphere 2009

8 09 2009

WUWT commenter Ray tips us to a new video from NASA “The Tour of the Cryosphere 2009″. With all the interest in sea ice right now, it seems like a good item to review.

LIMA image of Antarctica

The new version of "A Tour of the Cryosphere" features the world’s highest-resolution map of the icy continent, from the NASA-USGS Landsat Image Mosaic of Antarctica (LIMA) project. Credit: NASA/USGS - click for a larger image

I found one thing about it really interesting though, the zoom in of the Larsen B ice shelf saying: “After twelve thousand years, the Larsen B ice shelf collapsed in just five weeks.”. While they didn’t say directly that it was attributable to “global warming”, many others have said so. Watch how that melt pool continues through the animation of sea ice growth as refreeze occurs. That’s a hint. There’s quite a number of volcanic peaks in the area, as listed here. Here’s a ground pix from the scene. and some BAS research that found some unexpected things. More on that another time.

From NASA News

Back in 2002, NASA created a film using satellite data that took viewers on a tour of Earth’s frozen regions. This year, NASA visualizers are taking viewers on a return trip to see how things have changed over the years.

“The Tour of the Cryosphere 2009″ combines satellite imagery and state-of-the-art computer animation software to create a fact-filled and visually stunning tour that shows viewers the icy reaches of Antarctica, the glacier-pocked regions along the Andes Mountains, the winter snows of the American West, the drifting expanse of polar sea ice, and the shrinking Jakobshavn glacier in Greenland. Read the rest of this entry »


Comments : 80 Comments »

Categories : Antarctic, Arctic, media, sea ice, vulcanism

How have the scientists done on Arctic sea ice forecasts this year? – Maybe not so good.

7 09 2009

Steve McIntyre on Climate Audit brings our attention to an interesting sea ice extent forecasting “contest” conducted by the Study of Environmental ARctic CHange (SEARCH). With the end of the Arctic melt season likely just a few days away, it appears that the experts have a lack of forecasting skill for the subject they are experts in.

SEARCH writes:

We received 13 responses for the September Outlook based on July data (Figure 1). Estimates for September sea ice extent are in a narrow range (4.2 to 5.0 million square kilometers), as were the Outlooks based on May and June data. As the submitted uncertainty standard deviations are about 0.4 million square kilometers, most of these Outlook expected value estimates overlap. All sea ice extent estimates for September 2009 are much lower than the past climatological extent of 6.7 million square kilometers.

Here’s the SEARCH graph (Figure1 PDF available here) showing forecasts from several well known Arctic experts and organizations. I’ve added the most recent available data, the September 6th ice extent from IARC-JAXA of 5,345,156 square kilometers in magenta for a current reference.

SEARCH_sea_ice_forecast

While we can’t be certain what nature will reveal as the final number, it is likely that the end number will end up somewhere between 5.1 and 5.25 million square kilometers. What is most interesting is that it appears that all of the Arctic experts overestimated the amount of melt back in August, using July data as a forecast basis. Read the rest of this entry »


Comments : 138 Comments »

Categories : Arctic, sea ice

Sea Ice Open Thread

6 09 2009

It looks like we’ll see the 2009 Arctic sea ice melt season bottom out in a few days and it won’t be a record setter. Even NSIDC admits this. Here is a magnified graph of the IARC-JAXA AMSRE sea ice extent plot that is linked in the sidebar of WUWT.

JAXA_seaice_magnified_090609

Click for the source image

Here is the full sized image: Read the rest of this entry »


Comments : 180 Comments »

Categories : sea ice

DMI arctic temperature data animation doesn’t support claims of recent Arctic warming

4 09 2009

UPDATE: 9/8/09

The University of Colorado made a serious mistake in the press release that I cited. This press release was issued well before the paper was available, and of course the paper itself was not made available to journalists. It was hidden behind the AAS paywall.

I wrote to the press officer at UC on Friday, he responded Saturday night, on a holiday weekend, to his credit, here is my exchange:

Re: question about press release

From: Gifford H. Miller
Sent: Saturday, September 05, 2009 8:02 PM
To: Anthony Watts – mobile
Subject: Re: question about press release
Indeed, this is a typo, Anthony.  Not sure how it escaped my attention.
The sentence should read: “The research team assembled high-resolution records of climate for the past 2,000 years and found that the cooling trend reversed in 20th Century.“
I have passed the correction to our PR folks and it should be fixed soon
Thanks for catching this
Gifford Miller

Hello,

I looked at the Kaufman paper press release on EurekAlert as well as here:http://www.colorado.edu/news/r/bff9b4f453f2f9e1aa1e5d1b699d8525.html

In the second paragraph there is this sentence:“The research team assembled high-resolution records of climate for the past 2,000 years and found that the cooling trend reversed in the mid-1990s.”Is this correct? Is this a typo and instead should it say “mid-1900’s ” ?

Thanks for your consideration. Anthony Watts

UC has updated their press release here on 9/7 and was able to persuade EurekAlert to fix it on their website also.

The last sentence of paragraph 2 now reads:

“The research team assembled high-resolution records of climate for the past 2,000 years and found that the cooling trend reversed in the 20th century.”

It was originally stated as:

The research team assembled high-resolution records of climate for the past 2,000 years and found that the cooling trend reversed in the mid-1990s.

I’ve received some criticism for using the press release and acting on it to look for such a change in the 1990’s per the press release. While that criticism would be valid if the press release and the paper were both made available to me at the same time, the fact is they were not.

This method of pushing a scientific paper via press release, ahead of the paper’s actual journal release, and then hiding it behind a paywall is unprofessional and stinks. If the science organization wants to be seen as credible, then they need to make both the press release AND the paper available to journalists at the same time.

This idiotic “press release but no sci paper” policy needs to be changed. I’ll have more on this soon. As it stands, I’ve going to avoid UC press releases until they change the policy and I encourage others to do the same.

- Anthony

==========================

There’s a lot of buzz about regarding the Kaufman et al paper published today in Science which claims a recent reversal on a long term Arctic cooling trend and “found that the cooling trend reversed in the mid-1990s.” In the NOAA internal newsletter I cited yesterday, NOAA claims that the “According to the most recent Arctic Report Card, the Arctic Ocean continues to warm”. OK fair enough, we’ll have a look.

NOAA based this on Hadley’s CRU dataset, which of course Hadley refuses to show any raw data for or methodology despite repeated FOI requests, making verification impossible. (read more here)

Arctic-wide annual averaged surface air temperature anomalies (60°–90°N)
Figure A1. Arctic-wide annual averaged surface air temperature anomalies (60°–90°N) based on land stations north of 60°N relative to the 1961–90 mean. From the CRUTEM 3v dataset, (available online at www.cru.uea.ac.uk/cru/data/temperature/. Note this curve does not include ship observations.

Note the trend from 1980 to present. Note also that there are few weather stations above 60N and even fewer on the Arctic Ice itself. The data is relatively sparse and interpolation/gridding/averaging is employed to come up with the coverage all the way to 90N. We’ll get back to this.

Let’s first get an understanding of the Kaufman paper. Here’s the abstract. We can’t get a look at the full paper or publish it here yet since it is behind the AAS paywall. If somebody has an external link to it, please advise.

Recent Warming Reverses Long-Term Arctic Cooling

Darrell S. Kaufman,1,* David P. Schneider,2 Nicholas P. McKay,3 Caspar M. Ammann,2 Raymond S. Bradley,4 Keith R. Briffa,5 Gifford H. Miller,6 Bette L. Otto-Bliesner,2 Jonathan T. Overpeck,3 Bo M. Vinther,7 Arctic Lakes 2k Project Members

The temperature history of the first millennium C.E. is sparsely documented, especially in the Arctic. We present a synthesis of decadally resolved proxy temperature records from poleward of 60°N covering the past 2000 years, which indicates that a pervasive cooling in progress 2000 years ago continued through the Middle Ages and into the Little Ice Age. A 2000-year transient climate simulation with the Community Climate System Model shows the same temperature sensitivity to changes in insolation as does our proxy reconstruction, supporting the inference that this long-term trend was caused by the steady orbitally driven reduction in summer insolation. The cooling trend was reversed during the 20th century, with four of the five warmest decades of our 2000-year-long reconstruction occurring between 1950 and 2000.

Here’s the press release from EurekAlert: Read the rest of this entry »


Comments : 127 Comments »

Categories : Arctic, Science, climate_change, sea ice

Arctic temperature headed below freezing

24 08 2009

There’s a couple of indicators that at least for Arctic temperature, the numbers are headed south. First the weather plot from the drifting buoy that is connected with NOAA’s North Pole Cam:
Weather plot

After some very brief excursions above freezing, it is now averaging below freezing. See the raw weather data here. The temperatures from the buoy have been hitting -2°C regularly the past nineteen days.

Another indication is the north pole cam itself.

http://www.arctic.noaa.gov/latest/noaa1.jpg

NOAA's North Pole Cam - click for larger image

Note that there are no melt pools or leads visible. The tilt is a bit puzzling, but as the temperature did get above freezing briefly, it may be a harbinger of things to come from this peer reviewer NASA paper. The buoy has drifted with the sea ice and is now near 84.1N, but started at 89.648N, so presumably, temperatures at the actual North Pole would be colder than what is being measured and seen now.

And finally the third temperature indicator is from the Danish Meteorological Institute. Read the rest of this entry »


Comments : 79 Comments »

Categories : Arctic, sea ice

An update on Jeff Id’s excellent sea ice video

23 08 2009

Arctic Sea Ice Video Update

by Jeff Id

As we approach the Arctic Sea Ice minimum, a lot of eyes are looking and projecting what the minimum will be. In a previous post I calculated the centroid of the sea ice as a method for determining how the weather patterns were affecting the data. About a month ago, it seemed that the weather pattern was going to support a leveling off of the sea ice shrink rate so that’s what I predicted and that’s what happened. The curve cut across the 2008 line and reached over until it touched the 2005 line.

AMSRE_Sea_Ice_Extent[1]
Unfortunately, from this centroid video, it looks like the winds from the Southeast in the image which created the huge reduction in Sea Ice in 2007 appears the have restarted this year. It’s already starting to accelerate the melting which caused this year’s red line to dip below the 2005 green line.

The shift in weather pattern is most visible in the shadows on the ice which are actually clouds blowing through. The shadows indicate the 29GhZ microwave data is sensitive to clouds which is part of the noise in the long term signal.

Below is an updated 2007 – present video. Read the rest of this entry »


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Categories : Arctic, sea ice

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