eddie

The Hadley CET is now 6.5C after yesterday was 8.5C

Well I finally managed to track down the answer to this question: "Absolute estimates of global mean surface temperature are difficult to compile for a number of reasons. Since some regions of the world have few temperature measurement stations (e.g., the Sahara Desert), interpolation must be made over large, data sparse regions. In mountainous areas, most observations come from valleys where the people live so consideration must be given to the effects of elevation on a region's average as well as to other factors that influence surface temperature. Consequently, the estimates below, while considered the best available, are still approximations and reflect the assumptions inherent in interpolation and data processing. Time series of monthly temperature records are more often expressed as departures from a base period (e.g., 1961-1990, 1901-2000) since these records are more easily interpreted and avoid some of the problems associated with estimating absolute surface temperatures over large regions. For a brief discussion of using temperature anomaly time series see the Climate of 1998 series. The global monthly surface temperature averages in the table below can be added to a given month's anomaly (departure from the 1901 to 2000 base period average) to obtain an absolute estimate of surface temperature for that month. (Files of absolute estimates are provided below.) Global Mean Monthly Surface Temperature Estimates for the Base Period 1901 to 2000" From: Link I was suprised how much the temperature does vary: Combined Mean Surface Temp. 1901 to 2000 (°C) Jan 12.0 Feb 12.1 Mar 12.7 Apr 13.7 May 14.8 Jun 15.5 Jul 15.8 Aug 15.6 Sep 15.0 Oct 14.0 Nov 12.9 Dec 12.2 Ann 13.9

I know temperatures do vary as a result of weather on a month to month basis. That much is obvious. Perhaps I should ask a more specific question: If you took the absolute temperature (in Kelvin) of Jan between 1850 and 2006 and did the same for every month of the year and then aranged the averages in order of temperature, warmest first, what would the list look like?

I have been looking at the global temperature records from the Hadley centre and it struck me that I have never seen the monthly global temperature expressed as anything other than an anomaly from some mean. My questions is, on average does the absolute temperature of the earth change as you go through the year? So for example is January warmer than June or is every month in the year the same temperature on average.

Since 1772 there have been 77 Marches that were warmer by this point in the month. The warmest March up to the 7th was 1834 which was 9.7C. The the coldest was 1786 at -1.7C. March 1947 was also -1.7C by the 7th. I just can't imagine seeing numbers like that these days. It almost seems like another country.

The Hadley CET is now 6.0C. Yesterday was 6.4C. Looking at the GFS I can't see the CET deviating much from 6C over the next week.

The Hadley CET is now 5.9C. Yesterday's CET was 3.1C.

GW you do realise if we were still 2m sq km above the current date's average that would mean there would be 100% more sea ice than expected? You really have to look at the ice extent figures as a percentage of what should be there rather than an absolute figure. Looking at the cryosphere today graph. (Some of my number might be slightly out since I am reading them from the graph) In Dec 2007: There was one point where the anomaly was 2msqkm. The total ice area was 8.5msqkm. The expected(mean) ice area for that date was 6.5msqkm. The ice area was 30% above average. Currently: The total ice area is about 2.4msqkm. The expected mean ice area is about 1.8msqkm. The anomaly is about 0.6msqkm. The ice area is 33% above average.

Hadley has updated after a slight glitch yesterday. The CET is now 7.5C. Yesterday was 5.0C and Monday was 9.1C.

The Hadley stats are in for the first day of March giving a well above average start: 8.6C. (Min 6.7C, Max 11.5C)

7.5C for me please.

Looking forward to seeing the results of this. Will be interesting to see what comes out other than the obvious 11 year cycle.

According to wikipedia the Maunder minimum ran from 1645 to 1715. The CET record only starts in 1659 but the average annual CET for the period 1645 to 1715 was 8.8C. The average annual CET for the last 30 years is 9.9C. As you can see from the following graph June, July and August during the Maunder minimum were cooler than modern day summers but the real difference can be seen in the rest of the year. Winters were a lot colder and lasted longer. The average January temperature was 2.7C! Mr Data might have some more information on the synoptic conditions although I'm not sure what records were kept so far back.

From a scientific point of view everyone in both camps should be glad if we are now entering another maunder minimum type period. It will be the perfect opportunity to try and establish more exactly the link between solar variability and climate. Having said that, if the sun does something odd and the earth cools I don't think that will necessarily disprove the link between CO2 and warming any more than a large volcano erupting would. Obviously it would invalidate the current model predictions, as any unexpected climate forcing would, but it doesn't change the fact that if the sun maintained its current levels and CO2 increased we would likely continue to warm. I would conceed that if there is a very strong cooling response that would suggest that more of the warming we have seen during the last 50 years should be attributed to solar variability. However if temperatures only plateau despite a long period of low solar activity then that might sugest that global warming is only postponed. This is all conjecture of course because it isn't certain we are heading for another maunder minimum but the next 10 years are going to be very interesting for sure.

An interesting topic you have brought up here Earthtrasher. I would tend to agree that open water during the permanent darkness of an arctic winter would result in more heat radiated away from the earth into space than an ice covered ocean. I would expect over a whole year though that loss of albedo would mean a net increase of ocean/atmosphere energy content despite loosing more in the winter.

Just had about 10 minutes of heavy snow here but it has stopped now. I'm currently at work which is about 900ft above sea level.

There is virtually no chance that the January CET will be record breaking. The record is 7.5C set back in 1916. Today and the next 4 days would have to average over 12C. The warmest January day in the CET series is 11.6C.

Hadley CET now 6.4C. Yesterday was recorded at 5.5C. 8.4C required for the rest of the month to reach 7C. Looking at the 06z GFS I would rate the chances of that happening as slim to none.

Hadley CET now at 6.2C. Yesterday was a crazy 10.8C which makes it the joint 10th warmest January day in the CET series.

Well it looks like I just avoided having to eat my hat but yesterday was very mild indeed coming in at 9.7C. That puts it in the top 1.5% of January days. Hadley CET on 6C to the 19th so.. 8.5C required for the rest of the month to reach 7C. 7.3C required to reach 6.5C.

Getting to 7C would be extremly remarkable from this point and would take something well outside the bounds of what has happened before. I wouldn't like to say never, expecially looking at the last 18 months, but 7C is a tall order.

Last January the Hadley CET was 8.3C by this point in the month. 2.6C warmer than this year.

Well the 06z GFS is showing much warmer temperatures compared to yesterday's 06z which showed some fairly cold nights extending right down to the bottom of the CET zone. Everything seems to have been shunted north 200 miles. Having said that, it does tend to overcook night time minima under a SW flow in the winter. Look at Saturday 19th for example, where a minima of 10C+ is shown right across the CET zone and a datime CET of well over 11. That would put it in the top 0.2% of January days. I'll eat my virtual hat if that happens.

Although it's starting to look less likely it's still far too early to write off a below average January. Ignoring the models for a moment and looking at past Januarys up to the 10th. The highest temperature we have ever got to from being <=5.5C by the 10th was 6.4C. The lowest temperature we have ever got to from being >=5.5C by the 10th was 2.2C. Last year/highest/lowest: January 2007 was 8.1C by the 10th and finished on 7.0C January 1916 was 8.3C by the 10th and finished on 7.5C January 1795 was -2.8C by the 9th and finished on -3.1C (The next year, 1796, the CET was 7.3C!) Looking at the 06z GFS, the CET is going to fall today and tomorrow (3C) and probably rise again slightly on Sunday (6C). Monday and Tuesday both look like coming in at 7C and the next three days after that around 5C. That would leave us at around 5.3C The rest of Janary would then need to average less than 2.5C for us to come in below average. Very achievable. My gut feeling is that we will finish around 4.5C though.

I am guessing it's more to do with the sample size. 30 years is a small enough data set that one really cold or warm day can affect the average a lot. Over the whole series from 1772 no February days are even in the top 20 coldest.