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Post by vukcevic on Apr 2, 2009 20:39:39 GMT
I just put following post on WUWT:
SC18, second strongest cycle of the 20th centaury was 1945-1955, and yet global temperature recorded largest fall over period of just few years, SC19 from 1955 to 1965 was strongest solar cycle ever recorded, and yet global temperature recorded only small rise, to be reversed as soon as cycle was over. Now, if global temperature is affected by solar activity, then period from 1945 to 1965 should have recorded steepest temperature rise of the 20th centaury. It was precisely reverse, drop 1945-1955 was comparable to that one achieved during early 1900s when solar activity fell. Why this would be? Upper atmosphere was loaded with radioactivity as result of the atmospheric nuclear tests, producing effect similar to that of cosmic rays (only recently explained by Svensmark). Atmospheric tests were banned in 1963. We heard lot about ‘nuclear winter’, but no significant research was done at the time, possibly not politically suitable subject, in either of the two nuclear blocs. We cannot have it both ways, if low solar activity causes global temperature to fall, we should know why global temperature was falling during most intense solar activity ever recorded. Any climatologists on the blog?
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Post by tilmari on Apr 2, 2009 21:43:01 GMT
I have many times thought that the nuclear tests would be a good explanation for the cooling just when the Sun was at its greatest maximum. US began in 1945, Soviet Union 1949, soon with hydrogen bombs. The greatest blast ever was detonated by Soviet Union in 1960 in Novaja Zemlja (50 Megatons!). The agreement to stop the nuclear tests in atmosphere were really agreed in 1963. I have nowhere seen any study of the huge nuclear blankett containing much dust and other particles over Earth that must have existed. It could have acted as a cooling blankett many times the greatest volcano explosions.
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Post by vukcevic on Apr 2, 2009 21:53:58 GMT
I have many times thought that the nuclear tests would be a good explanation for the cooling just when the Sun was at its greatest maximum. US began in 1945, Soviet Union 1949, soon with hydrogen bombs. The greatest blast ever was detonated by Soviet Union in 1960 in Novaja Zemlja (50 Megatons!). The agreement to stop the nuclear tests in atmosphere were really agreed in 1963. I have nowhere seen any study of the huge nuclear blankett containing much dust and other particles over Earth that must have existed. It could have acted as a cooling blankett many times the greatest volcano explosions. Thanks Timo I entirely agree.
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Post by twawki on Apr 2, 2009 21:55:21 GMT
Also there is stored heat and radiant heat. The radiant heat of the sun has a direct impact but the stored heat of the oceans or lack thereof has a lag effect. The interplay of these as well as other factors probably equate to what we get.
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Post by poitsplace on Apr 3, 2009 2:05:17 GMT
Well for starters the temperature more closely matches the DURATION of the solar cycle, not the sunspot counts. The overall sunspot AREA may have increased in spite of lower sunspot counts.
Of course, solar forcing probably isn't the only game in town. Even though the patterns of nature GENERALLY synchronize somewhat with each other, they're not in 100% agreement. The PDO and other subsystems in Earth's climate are still doing their own thing to their own rhythm. Perhaps the PDO was just in a minor cycle while the sun was in a major cycle in the 40's but a major one in the 80's and 90's (see: 1998 El Nino)
The bottom line is this...the same thing we use to criticize global climate models makes it difficult to make any prediction at all. We're not really very sure how all the pieces come together or even if we have all the pieces. All we can tell is that it's probably time for it to get colder for a while. The solar activity is down and the ocean currents have kicked into cold mode. Another question is how close we are to the next ice age...although THANKFULLY it appears that the big temperature drop will take thousands of years.
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Post by icefisher on Apr 3, 2009 4:57:41 GMT
A better question might be why wasn't 1940 to 1970 cooler than it was.
Bottom line is the 1940-70 negative PDO resulted in less temperature drop than seen previously.
1878-1910 was minus .63, 1910 to 1944 was plus .73. 1944-56 was minus .47 and 1956 to 1998 was plus .89 for a net plus .52
Those are peak to peak but somewhere around 1956 something happened to shorten that pdo negative cycle. It could have been a burst of solar activity. Some are suggesting it might take a year or two for the effects to be felt, something about filling the heliosphere.
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Post by cyberzombie on Apr 3, 2009 14:33:07 GMT
Are both the PDO and AMO negative?
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Post by socold on Apr 3, 2009 20:11:49 GMT
Are both the PDO and AMO negative? yep
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Post by cyberzombie on Apr 3, 2009 21:28:01 GMT
Are both the PDO and AMO negative? yep I should have checked before asking - lazy! A better question might be why wasn't 1940 to 1970 cooler than it was. Bottom line is the 1940-70 negative PDO resulted in less temperature drop than seen previously. 1878-1910 was minus .63, 1910 to 1944 was plus .73. 1944-56 was minus .47 and 1956 to 1998 was plus .89 for a net plus .52 Those are peak to peak but somewhere around 1956 something happened to shorten that pdo negative cycle. It could have been a burst of solar activity. Some are suggesting it might take a year or two for the effects to be felt, something about filling the heliosphere. From icecap.us/index.php/go/new-and-cool/pdo_and_amo_as_the_real_pacemakers_for_climate_cycles/Not sure I agree with their statements about "so called rapid global warming period of 1976-2007"...
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Post by icefisher on Apr 3, 2009 23:33:50 GMT
Also there is stored heat and radiant heat. The radiant heat of the sun has a direct impact but the stored heat of the oceans or lack thereof has a lag effect. The interplay of these as well as other factors probably equate to what we get. I agree. In fact the one single remarkable feature in the temperature record (besides the corrolation of the 30 year PDO phase changes) is an interruption of the cold PDO influence after 1956 after only being in place for a bit over a decade. That anomaly alone (being 2 out of 4 cycles that dominate the grand maximum) accounts for about half the warming we have seen.
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Post by jimg on Apr 4, 2009 6:15:17 GMT
Regarding solar, it is far more likely that the climatological effects are due to the integral of the activity, not a corresponding rise and fall due to the number of sunspots at any point in time.
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Post by poitsplace on Apr 4, 2009 18:01:20 GMT
Also there is stored heat and radiant heat. The radiant heat of the sun has a direct impact but the stored heat of the oceans or lack thereof has a lag effect. The interplay of these as well as other factors probably equate to what we get. I agree. In fact the one single remarkable feature in the temperature record (besides the corrolation of the 30 year PDO phase changes) is an interruption of the cold PDO influence after 1956 after only being in place for a bit over a decade. That anomaly alone (being 2 out of 4 cycles that dominate the grand maximum) accounts for about half the warming we have seen. Well it might have just been fluke weather during that cooling period further skewed an already existing warming trend. Of course, we have no reason to believe the rate will increase, only reason to believe it will decrease (other than from models which are totally unproven). This minimum is likely to last at least two (long) cycles...this will likely counteract the normal warming trend no matter what that warming trend's source might be. We're probably going to feel every last bit of a normal cooling cycle (.4C smoothed or there abouts). If we only return to NORMAL volcanic activity over this period, something that should generally be expected, the anomaly will probably be pushing close to...zero. Then again, if David Archibald is right, we'll be freezing our posteriors off as the anomaly drops into negative numbers (I doubt that).
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Post by kiwistonewall on Apr 6, 2009 4:41:20 GMT
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Post by glc on Apr 6, 2009 8:56:47 GMT
One factor that drove the temperature down from the 1940's was sulphur aerosols. There has been a major drive to reduce sulphur aerosols, and total sulphur emissions have leveled off from about 1975. (When "global warming" started to occur) I don't believe sulphate aerosols were responsible for the mid-20th century cooling. Reasons: 1. Aerosols are short-lived in the atmosphere. it would have taken a sudden, massive and sustained increase in aerosols to not only reverse the 1910-1940 warming but to also induce a decade-long cooling trend. There is no evidencde for this. Signiificant increases in industrial production didn't happen until the 1950s. 2. The effect of aerosols is regionally specific, i.e. most aerosols are "rained" out (or simply fall out) of the atmosphere within a few days - or weeks at the most. There is some dispersal but it's very weak. UK studies in the 1960s and 1970s showed that in indiustrial towns, Mondays and Tuesdays were often the sunniest days of the week because the "aerosol effect" had been fallen following the week-end break. 3. Bearing in mind the regional effect, it's clear that if the post-1940 cooling were due to aerosols, the cooling would be most noticeable in the industrialised regions of the world, i.e. the mid latitude regions of the NH. However it was the Arctic which cooled most. Between 1940-1970, the Arctic cooled just under 1 degree C while the regions between 24N-64N only cooled ~0.2 deg C. Arctic cooling was 4 times the rate of the industrial regions. All of which becomes more interesting when we look at the warming periods. Because again it's the Arctic which sees the most change. Between 1910-1940, the Arctic warmed by almost 2 deg C. A 2 deg C warming was also observed between 1975 and 2005. Now before anyone accuses me of being a warmer for disagreeing with kiwi, I'd just like to point out that the above observations suggest cyclical processes are at work which have very little to do with to do CO2 and which have most impact in Arctic regions. All above temperature data is taken from GISS, by the way.
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Post by kiwistonewall on Apr 6, 2009 9:24:49 GMT
glc, you are entitled to your opinion, but those links point to clear negative forcings. In addition, some climate scientists are of the opinion that sulphate aerosols could be used to reverse "global warming" I appreciate that any science contrary to the current paradigms does get little attention. The recent cooling decades and following cooling is entirely consistent with the rise then leveling off & falling of human sulphate aerosol emissions. For the inquiring scientist, it is an area that needs examining. I have no opinion, belief or an "feelings" toward sulphate emissions. I'm just pointing out that others have noted the correlation, and, given the current sate of ignorance on all things climate, we should keep every possible cause in mind. It is a possible explanation.
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