By Steve Goddard
Last month, a number of well known web sites and commenters were getting themselves worked up with comments like “Arctic ice dropping at the fastest rate in history” and “Arctic ice is dropping like a rock.” I advised repeatedly that prior to July, looking at the extent graphs is pointless.
July is here now, and the rate of ice extent decline has dropped dramatically over the last week. To put this in perspective, according to JAXA data, the June 28-July 4 rate is -53361 km²/day. In 2007 during the same period, ice was lost at -123104 km²/day.
In other words, 2007 was losing ice 2.31X faster than 2010.
This can be seen most dramatically in the DMI graph, which measures only higher concentration ice (30%.)
http://ocean.dmi.dk/arctic/icecover.uk.php
Close up image below.
So why the dramatic difference in slope? One reason is that sea ice concentration is at the highest level in the satellite record. Compare below vs. 1980, when ice was considered very “healthy.” Current concentration is considerably higher.
Ice concentration is particularly important this time of year because the sun is relatively high in the sky. When the ice concentration is low, sun shines into the water in “Swiss Cheese” holes around the ice, warms it, and corrodes away the edges of the ice. This year, ice concentration has been close to 100% in most of the Arctic – which means very little sunlight is reaching the water in the Arctic Basin. As a result melt will occur more slowly than during low concentration years.
The videos below represent an exaggerated visualization of the process. The first video shows an idealized view of future Arctic Basin melt during 2010 – i.e. a single large circle of ice surrounded by water.
The next video shows what happens in years when the concentration is lower. The sun is heating the water between circles, and because of the smaller circles a much larger surface area of ice is exposed to warm water. Warmer water and more exposed surface area causes melt to proceed faster.
Conclusion : Cold temperatures, cloudy skies, favorable winds and high concentration ice – all point to continued slow melt over the next few days.
anna v says:
July 6, 2010 at 8:41 pm
Anna v, you through up a ref to http://rankexploits.com/musings/2009/fact-6a-model-simulations-dont-match-average-surface-temperature-of-the-earth/ and I bet you already know a lot more than I could gather in an hour or more, so can I ask if you already know? What going on in this chart?
On that chart I see measured GISSTemp in ~1935 at 14.25 ºC and in 2010 at ~14.6 ºC. That’s just 0.35 ºC in 75 years and is about what I have always though the temperature rise actually was after any UHI influences have been removed. Also mostly matches the ocean rise over the same period. I gather the others are GCM (models) but that GISSTemp is actual data or am I missing something.
Many would be very interested to see this one.
This ought to be posted by Anthony or someone if it’s accurate, or, maybe that is already in progress.
R. Gates says:
July 6, 2010 at 10:31 pm
The plot you show, shows rapid increase after 1950s, and it is the main point of AGW to associate the temperature increases in the late 20th century, not to naturally coming out of the little ice age, but to excess CO2 from fuels.
The gradual rise coming out of the Little Ice Age is due to Henry’s law, that the oceans as they are being heated release CO2, as can be seen in the hundreds of thousands of years record from the ice cores:
http://upload.wikimedia.org/wikipedia/commons/b/b8/Vostok_Petit_data.svg
The cause is the rise in temperature, and the rise in CO2 is the effect. AGWmers do not dispute this response of the oceans to CO2 release.
They overlay the extra CO2 from fuels since the middle of the 20th century, to reverse the argument, and make CO2 the cause and temperature rise the effect. But rapid describes only the last part of the last century.
stevengoddard says:
July 6, 2010 at 7:26 pm
R. Gates
You keep going on and on about 4.5 million. It isn’t going to happen.
He seems to not want to accept data. I am trying to figure out why he is stubborn. Maybe he really is a religious, or environmentalist, or political zealot. Maybe the obvious is what is true. He clearly isn’t just an average, unbiased onlooker. He has too much energy toward one side for that.
~2 months to minimum. 🙂
R. Gates says:
July 6, 2010 at 6:12 pm
The Arctic Dipole anomaly could easily be one such effect that appeared (unpredictably but deterministically) as some threshold was passed with the geologically speaking rapid increase in CO2 that began several hundred years ago.
Only dipole in the Arctic is that one of the Earth’s magnetic pole. Perhaps you would be able to show a CO2 correlation to the recent Arctic temperature which is higher than shown here (R = 0.9434):
http://www.vukcevic.talktalk.net/NFC1.htm
That is a challenge, let’s see ‘colour of your money’.
I presume you may decide to side step this ‘little obstacle’, and go on running down the spiral of ever decreasing circles.
R. Gates said
“July 6, 2010 at 4:32 pm
TonyB,
Thanks for that link and other suggestions. I shall do a bit of studying, and spend some recently acquired gift cards to go shopping on Amazon.”
That link you provided shows exactly what I have been saying. Temperatures have been very gently rising (with advances and set backs) virtually throughout the instrumental record to 1660-long before the advent of man made CO2 in sufficient quantities to cause climate change.
The low point was in 1698. The following thirty year period showed an increase in temperature that is the largest and quickest in the record.
Your link plugs into the rising trend AFTER that date. In my web site I wrote of this here;
“Article: 18th Century Climate variability in Sweden. Author: Tony Brown
This short article was the genesis of my interest in long temperature records and the effects of UHI, through the examination of records from Uppsala, Stockholm and CET. It illustrates that even going back just another thirty years (as is possible with Uppsala) can put subsequent temperature rises into better context.”
http://chiefio.wordpress.com/2009/10/09/how-long-is-a-long-temperature-history/
tonyb
Actually, the more I look at whats happened so far this year and compare it with whats happened in previous years, the more I’m convinced we are heading for a September minimum simlar to 2006 – around 6 million sq km.
If you compare this year with both 2006 and 2007, the patterns of ice loss are much more similar to what happened in 2006.
is the climate of 1700 the sort of world you actually would want to live in?
Wouldn’t it be great if the AGW believers could go and live in a 280 ppm world, and all the skeptics could go and live in a 650-900 ppm world?
stevengoddard says:
July 6, 2010 at 7:26 pm
R. Gates
You keep going on and on about 4.5 million. It isn’t going to happen.
And you keep going on about 5.5 million. Why don’t you wait and see, his estimate is as well founded as yours, in fact based on the ice loss between now and minimum for the recent years he’d appear to have a ~80% of being right, whereas you have a ~20% chance of being right.
Phil,
It will be remarkable if the ice retreats back to 5.5 million this summer. My forecast is almost undoubtedly too low.
Phil. says:
July 7, 2010 at 7:27 am
stevengoddard says:
July 6, 2010 at 7:26 pm
R. Gates
You keep going on and on about 4.5 million. It isn’t going to happen.
And you keep going on about 5.5 million. Why don’t you wait and see, his estimate is as well founded as yours,
R. Gates is based on computer models. Goddard’s is from observational data. To some people models must be equivalent to reality.
Phil. says:
July 7, 2010 at 7:27 am
he’d appear to have a ~80% of being right, whereas you have a ~20% chance of being right.
Arctic ice has been quickly increasing to pre 2007 level. That trend appears to continue. Some must be seeing the opposite. They must have a ‘rotten’ viewpoint.
My favorite phrase of the day…
“Natural climate variation denialist” or could we just say NCVD for short?
So, if you think the AGW hypothesis is likely correct, you are automatically a NCVD? Is that the black-and-white, all-or-nothing world that some skeptics want to paint? A person can’t both believe in long and short term natural variation, as well as AGW?
Also, in regards to the September minimum, look for a return to more rapid melting later in July and into August. The melt will appear to parallel 2006 for a few days here, but then turn down to parallel 2007 well into August. Warm meridonal winds with an intensified DA setting up later in the month…
Amino Acids, if we look at the observational data, it is hard to see that this year will see conditions back to pre-2007. For example, taking the average rates of decline for July and August (based on an average from 1979-2000) and applying those to the sea ice extent observed on July 1, you would get a minimum of 4.8 million sq-km.
Of course there is a lot of variability in rates of decline from year to year. If 2006 rates of decline are used the minimum would be 5.3 million sq-km. If 2007 rates are used, the minimum would be 3.7 million sq-km.
Warm meridonal winds with an intensified DA setting up later in the month…
R. Gates, do you have links for this? What is the DA doing at the moment?
Julienne said:
“If 2006 rates of decline are used the minimum would be 5.3 million sq-km. If 2007 rates are used, the minimum would be 3.7 million sq-km.”
___________
And coincidentally, the average right in the middle of the two is 4.5 million sq. km. Now where have I seen that number before?
Günther Kirschbaum says:
July 7, 2010 at 10:54 am
Warm meridonal winds with an intensified DA setting up later in the month…
R. Gates, do you have links for this? What is the DA doing at the moment?
______________
A forecast for the DA is based partially on running a projection of sea level pressure from the June mean, combined with forecasts for Arctic and sub-arctic SST’s, geo height anomalies, and forecasts for atmospheric tempertures for the period. See:
http://nsidc.org/images/arcticseaicenews/20100706_Figure4.png
http://polar.ncep.noaa.gov/sst/ophi/color_anomaly_NPS_ophi0.png
http://iridl.ldeo.columbia.edu/maproom/.Global/.Forecasts/.Temperature/
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.ao.cdas.gif
http://iridl.ldeo.columbia.edu/maproom/.Global/.Forecasts/.SST/index.html (click the July-Sept 2010 period)
The monthly mean seems more important than checking the daily sea level pressure for the DA.
Thank you for those links, R. Gates. Do you think this is a useful tool for forecasting SLP: http://www.esrl.noaa.gov/psd/forecasts/reforecast/maps.html
How does NSIDC make that nice-looking SLP Composite Mean map? Last week Julienne pointed me to a NOAA/ESRL webpage, but I didn’t know what to do with all those variables.
R. Gates says:
July 7, 2010 at 9:30 am
My favorite phrase of the day…
“Natural climate variation denialist” or could we just say NCVD for short?
……
How about we just say denialist.
Günther Kirschbaum says:
July 7, 2010 at 6:49 am
“Wouldn’t it be great if the AGW believers could go and live in a 280 ppm world, and all the skeptics could go and live in a 650-900 ppm world?”
Yes, I think that would be wonderful! Imagine all the plants growing.
Sahara gone! Great!
Of course, in the “Deniers of Natural Climate Change” World (the CAGW crowd) we would have to deny them the following;
-Cars.
-Coal Power Plants
-Nuclear Power
-Hydro Plants
-Airplaines
-Boats on fossil fuels
-Trailers
-Refrigerators
-TV
-IPhone and IPads, and MAC’s
-Sattelites
-Batteries
-DVD’s
-Tuppeware
-Any food from the green revolutions
-Paseurisation
-Anestethics
And on and on and on……
All results of Capitalism…..