Essay by Jim Steele, Director emeritus, Sierra Nevada Field Campus, San Francisco State University
The heat wave and near record-breaking temperatures in Death Valley provides a superb teaching moment to show why CO2 has nothing to do with heat waves whether the record is ever broken or not.
- Most heat waves are associated with dry conditions. Water vapor contributes between 80 and 94% of the greenhouse effect. But during a dry heat wave, greenhouse gases are reduced, and that fact should alert people that other more critical factors are governing heat waves. The dryness lowers the soil’s heat capacity and allows temperatures to rise more rapidly. The dryness also creates clear skies that increases incoming solar radiation. The winter drought set the stage for this west coast heat wave as well as Europe 2003 and Russia 2010.
- All heat waves are caused by stationary high pressure systems. Always! High pressure systems are driven dry descending air currents. In addition to the dryness amplification mentioned above, Highs cause two other critical weather events.
2.1 High pressure systems force the jet stream northward and prevent cooling air from moving southward.
2.2 Most importantly descending air currents adiabatically generate a thermal ceiling that prevents rising convection currents from carrying away surface heat. Models have demonstrated that if convection stops the global temperature could rise by 100° F. Adiabatic heating means no heat is added. Temperatures rise because the air is compressed and the constrained molecular motion releases heat. Many cultures in southeast Asia used fire pistons to start fires by simply squeezing air in a tube. When that adiabatically heated air reaches the ground we get foehn storms, when it hovers a few hundred feet above the ground we get heat waves. Air only rises if it is warmer than its surroundings. When rising air reaches a layer of adiabatically heated air the rising convection currents stop and the surface heat is trapped just like the raised windows in your car trap the heat.
Descending air currents of High pressure systems are also the reason we have deserts and why the world’s records for hottest temperatures on each continent are not at the equator but about 32 to 36° North.
The reason for this pattern is the Hadley Cells. At the equator despite the greatest heating by the sun, convection currents carry away the heat. Those rising currents are balanced by descending currents that are most powerfully focused in the regions that hold the world’s records. Those dry descending currents also cause the pattern of the world deserts. Those descending currents also create the quasi permanent high pressure system in the Pacific and the Bermuda High in the Atlantic.
Finally heat waves are caused by stationary blocking highs and all research shows that blocking highs are most common during the cool phase of the Pacific Decadal Oscillation or North Atlantic Oscillation. The PDO cool phase occurred from about 1900 to 1920, again from 1946 to 1976, and we have currently been in the cool phase since about 2003. I bet most heat wave records for the western half of the USA occurred during those time periods. Death Valley’s record was 1913. However nearly every single model driven by CO2 failed to predict the cooling in the eastern Pacific Ocean
The CO2 advocates simply predicted heat waves in the future, but anyone can do that and be right eventually. However, the mechanisms of every heat wave contradict nearly every aspect of the global warming theory. They cannot even argue that it is more likely because its warmer. Death Valleys maximum temperatures have not exceeded the 1930s. These heat waves are good examples of how weather dynamics cause extreme heat independently of the sun or CO2.
This article is adapted from Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism
Is not this apparent from considering deserts and tropical rain forests in the same latitude.
Deserts are arid, dry and hot. The lack of the most dominant green house gas (water vapour) does not result in cooler/less warm temperatures.
tropical rain forests are warm and humid. They are rich in the most dominant green house gas (water vapour) and yet they are not as warm/hot as desets.
This tells you something about the effectiveness of GHGs to raise temperature. This is especially so since outgoing LWIR from the surface is at its peak in equatorial/tropical regions and hence back radiation is also at its peak, yet all that supposedlu enhancing water vapour does not result in extremely hot conditions in tropical rain forests.
[Snip. Russell Seitz is persona non grata here. — mod.]
Copy of an apropos comment from this thread:
http://wattsupwiththat.com/2013/06/30/about-the-record-temperature-in-las-vegas-yesterday-it-wasnt-117f/#more-89013
Ian W says at June 30, 2013 at 11:50 am
“Perhaps someone would check my maths the formula is rather nasty – but I just did a rough comparison –
Florida (Daytona Beach) Temp 25.1C Humidity 83% – Heat Content – 1257.6 Kilojoules/Kilogram
Nevada (Las Vegas) Temp 41.6C Humidity 12% – Heat Content – 307.2 Kilojoules/Kilogram
I was under the impression that green house gases trapped heat – not ‘temperature’. There is more heat on the East coast than there is in Nevada because the enthalpy of the air is higher due to its water vapor content.”
richard verney says:
July 1, 2013 at 6:35 pm
“This tells you something about the effectiveness of GHGs to raise temperature. This is especially so since outgoing LWIR from the surface is at its peak in equatorial/tropical regions and hence back radiation is also at its peak, yet all that supposedlu enhancing water vapour does not result in extremely hot conditions in tropical rain forests.”
Right. Surface moisture is the key. Evaporating water soaks up heat and cools the surface. Then, the low molecular weight of water vapor(18 vs an average weight of dry air of 29) adds buoyancy to the air so that it convects rapidly. Greenhouse effect means little at the surface as you say. Its all about evaporation and moist convection. If you want relief from a heat wave, pray for rain (or head for the beach).
I live on an island in Puget Sound. Humidity is fairly low here in the summer, as is rainfall. Our annual rainfall is about 26″, Much less than Dallas, TX. Proximity to large bodies of water is no guarantee of high humidity.
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I know this isn’t “global”. It’s just my little spot on the globe. I’d mentioned this before for record highs. I copy/pasted the record temps into Excel in 2007 and in 2012. I compared them. I’d put up the changes made in the record highs. I just now got done comparing the record lows. I did not include records “set” after 2007. I guess records are made to be broken … one way or another. (And to be fair I should note that since I first brought this up here awhile ago some of the past records have been changed again. Some now match the 2007 list.)
Anyway, here’s the comparison of record highs and lows for Columbus Ohio. (Highs first, then Lows. 2012 first, then 2007)
All temps Fahrenheit
Newer-April ’12 Older-’07 (did not include ties)
6-Jan 68 1946 Jan-06 69 1946 Same year but “new” record 1*F lower
9-Jan 62 1946 Jan-09 65 1946 Same year but “new” record 3*F lower
31-Jan 66 2002 Jan-31 62 1917 “New” record 4*F higher but not in ’07 list
4-Feb 61 1962 Feb-04 66 1946 “New” tied records 5*F lower
4-Feb 61 1991
23-Mar 81 1907 Mar-23 76 1966 “New” record 5*F higher but not in ’07 list
25-Mar 84 1929 Mar-25 85 1945 “New” record 1*F lower
5-Apr 82 1947 Apr-05 83 1947 “New” tied records 1*F lower
5-Apr 82 1988
6-Apr 83 1929 Apr-06 82 1929 Same year but “new” record 1*F higher
19-Apr 85 1958 Apr-19 86 1941 “New” tied records 1*F lower
19-Apr 85 2002
16-May 91 1900 May-16 96 1900 Same year but “new” record 5*F lower
30-May 93 1953 May-30 95 1915 “New” record 2*F lower
31-Jul 100 1999 Jul-31 96 1954 “New” record 4*F higher but not in ’07 list
11-Aug 96 1926 Aug-11 98 1944 “New” tied records 2*F lower
11-Aug 96 1944
18-Aug 94 1916 Aug-18 96 1940 “New” tied records 2*F lower
18-Aug 94 1922
18-Aug 94 1940
23-Sep 90 1941 Sep-23 91 1945 “New” tied records 1*F lower
23-Sep 90 1945
23-Sep 90 1961
9-Oct 88 1939 Oct-09 89 1939 Same year but “new” record 1*F lower
10-Nov 72 1949 Nov-10 71 1998 “New” record 1*F higher but not in ’07 list
12-Nov 75 1849 Nov-12 74 1879 “New” record 1*F higher but not in ’07 list
12-Dec 65 1949 Dec-12 64 1949 Same year but “new” record 1*F higher
22-Dec 62 1941 Dec-22 63 1941 Same year but “new” record 1*F lower
29-Dec 64 1984 Dec-29 67 1889 “New” record 3*F lower
Now the Lows
Newer-’12 Older-’07 (did not include ties)
7-Jan -5 1884 Jan-07 -6 1942 New record 1 warmer and 58 years earlier
8-Jan -9 1968 Jan-08 -12 1942 New record 3 warmer and 37 years later
3-Mar 1 1980 Mar-03 0 1943 New record 3 warmer and 26 years later
13-Mar 5 1960 Mar-13 7 1896 New record 2 cooler and 64 years later
8-May 31 1954 May-08 29 1947 New record 3 warmer and 26 years later
9-May 30 1983 May-09 28 1947 New tied record 2 warmer same year and 19 and 36 years later
30 1966
30 1947
12-May 35 1976 May-12 34 1941 New record 1 warmer and 45 years later
30-Jun 47 1988 Jun-30 46 1943 New record 1 warmer and 35 years later
12-Jul 51 1973 Jul-12 47 1940 New record 4 warmer and 33 years later
13-Jul 50 1940 Jul-13 44 1940 New record 6 warmer and same year
17-Jul 52 1896 Jul-17 53 1989 New record 1 cooler and 93 years earlier
20-Jul 50 1929 Jul-20 49 1947 New record 1 warmer and 18 years earlier
23-Jul 51 1981 Jul-23 47 1947 New record 4 warmer and 34 years later
24-Jul 53 1985 Jul-24 52 1947 New record 1 warmer and 38 years later
26-Jul 52 1911 Jul-26 50 1946 New record 2 warmer and 35 years later
31-Jul 54 1966 Jul-31 47 1967 New record 7 warmer and 1 years later
19-Aug 49 1977 Aug-19 48 1943 New record 1 warmer and 10, 21 and 34 years later
49 1964
49 1953
21-Aug 44 1950 Aug-21 43 1940 New record 1 warmer and 10 years later
26-Aug 48 1958 Aug-26 47 1945 New record 1 warmer and 13 years later
27-Aug 46 1968 Aug-27 45 1945 New record 1 warmer and 23 years later
12-Sep 44 1985 Sep-12 42 1940 New record 2 warmer and 15, 27 and 45 years later
44 1967
44 1955
26-Sep 35 1950 Sep-26 33 1940 New record 2 warmer and 12 earlier and 10 years later
35 1928
27-Sep 36 1991 Sep-27 32 1947 New record 4 warmer and 44 years later
29-Sep 32 1961 Sep-29 31 1942 New record 1 warmer and 19 years later
2-Oct 32 1974 Oct-02 31 1946 New record 1 warmer and 38 years earlier and 19 years later
32 1908
15-Oct 31 1969 Oct-15 24 1939 New tied record same year but 7 warmer and 22 and 30 years later
31 1961
31 1939
16-Oct 31 1970 Oct-16 30 1944 New record 1 warmer and 26 years later
24-Nov 8 1950 Nov-24 7 1950 New tied record same year but 1 warmer
29-Nov 3 1887 Nov-29 2 1887 New tied record same year but 1 warmer
4-Dec 8 1976 Dec-04 3 1966 New record 5 warmer and 10 years later
21-Dec -10 1989 Dec-21 -11 1942 New tied record same year but 1 warmer and 47 years later
-10 1942
Sorry the copy/paste didn’t work that well.
For anyone trying to follow it, as I see it on my screen, the end of the longer comments I made for “tied lows” jumped down a line the the “new” records appear with the temperature then the year.
@ur momisugly Janice Moore .
Florida (Daytona Beach) Temp 25.1C Humidity 83% – Heat Content – 1257.6 Kilojoules/Kilogram
Nevada (Las Vegas) Temp 41.6C Humidity 12% – Heat Content – 307.2 Kilojoules/Kilogram
Excellent post. Perfect example of what a meaningless statistic the global average temperature is. It is a chimera of vastly different quantitites of heat.
Jimbo says:July 1, 2013 at 4:12 pm
” Can you let me know whether Western Europe and the USA should expect colder or warmer winters as a result of Co2 caused global warming?”
In the long run, warmer. As I said above, we can expect the full range of weather – cold spells, heat waves – little different except for the gradual shift in mean. And there is overlaid spatial variation, sometimes from causes. It seems, for example, that melting ice is doing odd things to Arctic circulation patterns.
Not to Antarctic, though. Where I am, it is supposed to be the depths of winter. Right now, 18.7°C and sunny, and we’ve had a two-week spell of this (not always quite as warm, and some frosty mornings). I saw the first Cootamundra wattle flowering about a week ago, at least two weeks early. There’s just a lot of variability.
Anthony obviously does not know the correct explanation for the GHE.
CO2 cannot ”slow” radiation from the surface because ALL radiation travels at the speed of light. Gas molecules in the way have no effect on the speed. The only process that affects heat loss at night is water vapour latent heat surrender as the atmosphere cools.
Anthony explain why a desert, (very dry) is far hotter than a rainforest at the same latitude. Both will have atmospheric CO2 contents the same and the same insolation. If the GHe were true then deserts would be warmer than rainforests.
Eugene WR Gallun says:
July 1, 2013 at 5:19 pm
Neil Stokes July 1 303pm
The AGW logic is simple. GHG causes global warming. Warm days get warmer. Cold days get warmer. Heat waves get warmer.
If i am not mistaken more record cold days have been recorded in the US in recent years than record hot days — by a large margin. Your logic is simple — simple minded. So can you admit that the logic of AGW is flawed?
Eugene WR Gallun
Actually, in recent years the ratio of record high temperatures to record low temperatures across the US has been 2:1, not the other way around.
https://www2.ucar.edu/atmosnews/news/1036/record-high-temperatures-far-outpace-record-lows-across-us
The contradiction is largely a matter of using homogenized versus non-homogenized data. The adjustments procedure commonly dropped high minimum temperatures by several degrees in the early 20th century making it more difficult to register a new low is homogenized data used.
A recent paper looking at climate variability in the USA (Shen 2011) required using non-homogenized data that was only adjusted for documented changes. They concluded, “The conclusion of the reductions in the temperature variability seems counterintuitive since many reports state that climate has become warmer and more violent particularly with stronger cyclones over the ocean” And they also reported “These observations indicate the existence of more cold extremes in all temperatures, but the occurrence of such cold extreme events is more frequent in the maximum temperatures than in the other two.”
Shen, S., et al., (2011) The twentieth century contiguous US temperature changes indicated by daily data and higher statistical moments. Climatic Change Volume 109, Issue 3-4, pp 287-317.
johnmarshall said at July 2, 2013 at 3:32 am: “Anthony explain why a desert, (very dry) is far hotter than a rainforest at the same latitude. Both will have atmospheric CO2 contents the same and the same insolation. If the GHe were true then deserts would be warmer than rainforests.”
The first and last sentences in that paragraph seem contradictory. Perhaps you meant to say that rain forests would be warmer than deserts?
Furthermore, diurnal temperature swings in arid regions tend to be far greater than they are in humid regions at the same latitude. One contributing factor for why this is so is that water vapor “feedback” is probably strongly negative, rather than positive as the IPCC assumes. Which probably helps explain why none of the IPCC climate model temperature “projections” match observations.
@Jonas But you suggest another effect om population, namely drier surface conditions due to a much more efficient use of water resources? Both in cities, around rivers and streams and also i though farming and irrigation practices!? At least during daytimes.Is that what you suggest?
Any practice that reduces the vegetation cover dries the soil and raises surface tempertures. Changing a forest into grassland or a grassland into barren soils can raise temperatures 10 to 30 degrees. Studies of temperatures in Arizona and Mexico have shown that lost vegetation from severe overgrazing and other careless practices had caused the soil surface to dry. This drying process increased temperatures by as much as 7°F compared to adjacent lands that had not been so mistreated.
Thanks, Jim Steele (at 8:56PM on July1). I’m glad that you also thought that Ian W‘s** post was a good one. And, GOOD WORK, here, responding to the comments. It’s always so much better when an author engages in the discussion instead of just doing a post-and-go.
**(just to clear up any possible confusion among WUWT readers as to who wrote that fine post — AS IF I ever could…)
Feedback effects interesting, too. Here in Southern California we’ve had hot mornings, rising air, condensation into clouds, hence less solar radiation reaching the surface, and afternoons cooler than expected. Local weather reports, though, seldom mention the clouds. Effect on human body dramatically different from sun to shade.
jim Steele says: July 2, 2013 at 8:33 am
“The contradiction is largely a matter of using homogenized versus non-homogenized data.”
Do you know that they use homogenized data for daily records? What homogenized daily data could they use?
A “chinook” is a smaller example of a down-welling dry air mass sliding down the eastern slopes of the Rockies in Alberta after its moisture has snowed out (is it called a chinook on the US side?) that occurs in winter. The temperature can vary from above freezing to well below freezing and I was told by a rancher that you could ride on horseback in and out of the two very contrasting air masses at the boundary between “tongues”.
https://www.google.ca/search?q=chinook+winds&client=firefox-a&hs=GtE&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=S5XTUbn4M4amygGg6YHwDA&ved=0CDYQsAQ&biw=1920&bih=917
@Nick Stokes Do you know that they use homogenized data for daily records? What homogenized daily data could they use?
Your criticism is valid and I do not know. I stand corrected. I made a hasty assumption that all records were similar to USHCN temperatures. Perhaps Anthony or anyone ellse could shed some light on how many records are due to homogenization.
I think there is more valid criticism of those records. They are frequently bandied about as proof of CO2 caused warming. However landscape changes have had an enormous effect, especially on minimum temperatures. Relatively fewer cold record my simply be a reflection of increased urbanization effects.
For example, in 1967 Columbia, Maryland was a newly established, planned community designed to end racial and social segregation. Climate researchers following the city’s development found that over a period of just three years, a heat island of up to 8.1°F appeared as the land filled with 10,000 residents. Although Columbia would be classified as a rural town, that small population raised temperatures five times greater than a century’s worth of global warming.
See Erella, E., and Williamson, T, (2007) Intra-urban differences in canopy layer air temperature at a mid-latitude city. Int. J. Climatol. 27: 1243–1255.
@ur momisugly Gary Pearse is it called a chinook on the US side?
I have heard friends from the Columbia River area in northern Oregon as well as in southern Idaho refer to the Chinnoks, or “snow eaters.” I think it is commonly used. Your story of ranchers riding in and out of those warm winds is something have felt just hiking in the Sierra Nevada. It opens your eyes to local variability. The most amazing foehn wind reports come from Antarctica. Some studies have shown that even during the dark winter, adiabatic heating from a foehn storm can raise local temperatures by 90°F in a matter of hours.
Lynn Clarke yes sorry, rainforests hotter than deserts. Fingers not working with brain.
Lynn Clark. yes diurnal variations in deserts are far greater due to lack of water vapour and its latent heat. But I thought more information might cloud the issue and start the usual misunderstanding about latent heat. Can’t have dissent.
johnmarshall @ur momisugly July 3, 2013 at 3:48 am:
The point I was trying to make about diurnal variations in arid regions being larger than in humid regions is that that fact seems to be a clear indication that water vapor “feedback” is strongly negative rather than positive as the IPCC claims. I don’t know if I made that clear. Hopefully, this comment does that.
Thanks Lynn, I think we were both saying the same in a different way. i have asked the desert/rainforest question of warmists before but never received any meaningful answer.