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Post by marchesarosa on Mar 21, 2012 14:43:56 GMT 1
Feynman on pseudo science, into which category much climate science falls.
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Post by StuartG on Mar 21, 2012 20:13:15 GMT 1
MM, Here's something that may interest, from NASA ... helios.gsfc.nasa.gov/qa_sun.html#constantUnder 'SolarConstant' it says "It is 1367 Watts per meter squared" well, OK some say 1366, whatever. Then under "Total Solar Irradiance" it states, "Scientists theorize that as much as 25% of the 20th century anticipated global warming of the Earth may be due to changes in the Sun's energy output. Systematic changes in irradiance as little as 0.25% per century can cause the complete range of climate variations that have occurred in the past, ranging from ice ages to global tropical conditions." To give an idea of this 1/4%, here's 0.34% ~ 1/3% ... ...but of course it would have to drop for a longer period of time for it to change the climate noticeably. As an aside note that the level it drops from is given as 1362-1361.5. nowhere near the mean as given as 1367. Remembering they say about a regular drop of 0.25% [Ice age/tropics], well a 1/4% is around 3.5 Watts/sq m. So, IF that figure of 1367 is about right then 1363.5 is Ice Age and 1370.5 is tropics. Well it's fair to say the relative differences are about correct but the figure is still in the wind [solar!] a bit, here's why ... earthobservatory.nasa.gov/Features/SORCE/sorce_05.php"Uncertainties in Solar Measurements " which basically states that calibration is a problem, that's not meant as a criticism, just a statement of fact. The SORCE satellite is now operational it will, in the future, give a better figure, perhaps. Here's another illustration of a change of TSI ... www.nasa.gov/centers/goddard/images/content/62701main_venus_lg3.jpgand another transit of Venus will happen on 6th June 2012 ... en.wikipedia.org/wiki/Transit_of_Venus,_2012 en.wikipedia.org/wiki/Transit_of_Venuswith Venus it makes 0.001% difference, but the sunspot of Oct 2003 , the one in the box is a similar size to Jupiter [.25%]. Anyway, too much attention to the Sun may blow the CO2 boat out of the water and spoil the Mean Sea Level as well!
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Post by marchesarosa on Mar 22, 2012 11:24:39 GMT 1
Thanks for the details, stu.
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Post by marchesarosa on Apr 2, 2012 14:29:29 GMT 1
Well, whadiyaknow! journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00040.1European hot summers associated with a reduction of cloudinessQiuhong Tang Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China Guoyong Leng Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China, Graduate University of Chinese Academy of Sciences, Beijing, China Pavel Ya. Groisman National Climatic Data Center, Asheville, NC, United States Abstract A pronounced summer warming is observed in Europe since the 1980s that has been accompanied with an increase in the occurrence of heat waves. Water deficit that strongly reduces surface latent cooling is a widely accepted explanation for the causes of hot summers. We show that the variance of European summer temperature is partly explained by changes in summer cloudiness. Using observation-based products of climate variables, satellite-derived cloud cover and radiation products, we show that during the 1984-2007 period Europe has become less cloudy (except of northeastern Europe) and the regions east of Europe have become cloudier in summer daytime. In response, the summer temperatures increased in the areas of total cloud cover decrease, and stalled or declined in the areas of cloud cover increase. Trends in the surface shortwave radiation are generally positive (negative) in the regions with summer warming (cooling or stalled warming), while the signs of trends in top-of-atmosphere (TOA) reflected shortwave radiation are reversed. Our results suggest that total cloud cover is either the important local factor influencing the summer temperature changes in Europe or a major indicator of these changes.
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Post by marchesarosa on Apr 5, 2012 11:26:27 GMT 1
Project EarthshineThe Earth’s climate depends on the net sunlight deposited on the globe, which is critically sensitive to the Earth’s albedo. A global and absolutely calibrated albedo can be determined by measuring the amount of sunlight reflected from the Earth and, in turn, back to the Earth from the dark portion of the face of the Moon (the `earthshine’ or `ashen light’).... In simple terms, the lower the albedo of the Earth, the greater amount of solar radiation it will absorb. The greater the albedo, the more solar radiation is reflected. This of course affects earthly temperatures. The Earthsine project is producing some very interesting results. Notably, that the Earth’s Albedo has risen in the past few years, and by doing reconstructions of the past albedo, it appears that there was a significant reduction in Earth’s albedo leading up to a lull in 1997. 1998 has been touted as one of the warmest years on record, and the time lag may have had to do with the thermal inertia of the oceans. Then the albedo increased, making the earth more reflective. Clouds have the greatest potential for changing albedo on a short time scale.... wattsupwiththat.com/2007/10/17/earths-albedo-tells-a-interesting-story/
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Post by marchesarosa on May 14, 2012 19:07:27 GMT 1
Research Paper “Cleaner Air Brings Better Views, More Sunshine And Warmer Summer Days In The Netherlands” By van Beelen And Van Delden 2012 from Prof Roger Pielke Sr's blog We have been alerted by Jos de Laat to a new article van Beelen, Aldert J. and Aarnout J. van Delden. Institute for Marine and Atmospheric Research Utrecht, Utrecht University, The Netherlands; 2012: Cleaner air brings better views, more sunshine and warmer summer days in the Netherlands. Weather. January 2012. Vol 67 No 1 Excerpts from the paper read [highlight added] Here we analyse the trends in the frequency of days with high visibility at Schiphol (the main airport in the Netherlands, at 52°18!N and 4°46!E) and at De Bilt (the site of the Royal Netherlands Meteorological Institute, the KNMI, at 52°6!N and 5°11!E) (Figure 2). These stations are roughly 45km apart: Schiphol is about 20km, and De Bilt about 60km, from the sea. Reliable measurements of daily maximum visibility at both stations are available since 1955.
Figure 8 demonstrates that the clearing of the atmosphere is occurring in summer only during daytime. Visibility has changed relatively most strongly in the morning. Visibility has hardly changed during the night, probably because of the competing effect of increasing relative humidity (which, again, is much more important at night than during daytime).
All these changes during daytime are leading to an increase in surface solar radiation. This is confirmed by the measurements of global short-wave radiation at De Bilt, which show that this has steadily increased in summer but changed little in winter. It is likely that this effect is responsible for a significant part of the daytime upward temperature trend in summer, which is reflected also in an accelerated increase of the yearly average temperature after 1985. Nevertheless, we should not jump to conclusions too easily. Apparent agreement between trends does not imply causality. Possible causal links can only be identified by a model study in combination with an analysis of observations.The conclusion reads A major clearing of the air has occurred in the Netherlands in the past few decades. These changes are so large that they have become very obvious when looking at the data of individual stations. Strong indications can be found linking human emissions of aerosols to the visibility changes. Coincident with the visibility changes, large trends in cloud cover, sunshine duration and temperature are found, in particular during daytime in summer, showing that these tiny particles might have a significant influence on regional climate.In addition to documenting the benefit of cleaning up regionally emitted particulate and gas emissions, this analysis suggests that a significant fraction of daytime warming that has been attributed to “global warming” may actually be due to the reduction of aerosols overhead.
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Post by marchesarosa on Sept 10, 2012 14:50:55 GMT 1
From the Met Office on 29th August 2012 www.metoffice.gov.uk/news/releases/archive/2012/1981-2010-averagesThe UK was a slightly sunnier place in 1981-2010 compared to 1971-2000, with 18 extra hours of sunshine annually or, looking back to 1961-1990, an extra 35 hours (about a 3% increase on the 1961-1990 period).
the UK annual mean temperature was 0.25 °C higher for the 1981-2010 period compared to 1971-2000, or 0.52 °C if compared to 1961-1990 So how much does UK's increasing insolation over the decades account for its warming? And how much does the global decrease in cloud cover over the decades account for the "global"warming? The Met report above says there has been an increase of 3% in sunshine hours in the UK whereas the data for Heathrow at the top of the thread shows about 15%. Is the Met being economical with the actualité?
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Post by marchesarosa on Sept 16, 2012 11:28:29 GMT 1
Significant decreasing cloud cover during 1954–2005 due to more clear-sky days and less overcast days in China and its relation to aerosolX. Xia LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China Abstract. An updated analysis of cloud cover during 1954–2005 in China was performed using homogeneous cloud cover data from 314 stations. Long-term changes in frequencies of different cloud cover categories and their contributions to long-term changes in cloud cover were assessed.
Furthermore, aerosol effects on cloud cover trends were discussed based on comparison of cloud cover trends in polluted and mildly polluted regions. Frequencies of clear sky (cloud cover <20%) and overcast days (cloud cover >80%) were observed to increase by ~2.2 days and decrease by ~3.3 days per decade, respectively, which accounts for ~80% of cloud cover reduction. Larger decreasing trends in cloud cover due to larger increase in clear sky frequency and larger decreases in overcast frequency were observed at stations with lower aerosol optical depth.
There is no significant difference in trends regarding cloud cover, clear sky frequency, and overcast frequency between mountain and plain stations. These results are inconsistent with our expectation that larger decreasing trends in cloud cover should have been observed in regions with higher aerosol loading where more aerosols could lead to stronger obscuring effect on ground observation of cloud cover and stronger radiative effect as compared with the mildly polluted regions. Aerosol effect on decreasing cloud cover in China appear not to be supported by this analysis and therefore, further study on this issue is required. Full Article (PDF, 2756 KB) Citation: Xia, X.: Significant decreasing cloud cover during 1954–2005 due to more clear-sky days and less overcast days in China and its relation to aerosol, Ann. Geophys., 30, 573-582, doi:10.5194/angeo-30-573-2012, 2012. www.ann-geophys.net/30/573/2012/angeo-30-573-2012.html
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