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Post by magellan on May 29, 2010 14:32:03 GMT
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Post by socold on May 29, 2010 19:58:31 GMT
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Post by jurinko on May 29, 2010 20:42:21 GMT
I thought there is almost no atmosphere on the Moon, so "greenhouse effect" is not possible. Much more interesting is, that Mars thin atmosphere consists of 95% CO2 and its concentration is roughly 15x higher than on Earth. Since there are estimations that CO2 is responsible for 5-30% of the "greenhouse effect" (the rest made up by water vapor), Mars effective "greenhouse" effect is similar to the Earth atmosphere. With one difference: Mars blackbody temperature is 210K, and Mars average temperature is.. 210K. nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html
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Post by touko on Jun 2, 2010 20:45:33 GMT
"The atmosphere of Mars is also predominantly carbon dioxide, but Mars does not have a significant Greenhouse condition because the atmosphere is so thin that it cannot absorb much of the infrared energy which is emitted by the surface. The surface pressure on Mars is about 100 times less than it is on Earth, which is itself about 90 times less than it is on Venus. It is estimated that the Greenhouse effect on Mars warms the atmosphere at the surface by less than 10 degrees Fahrenheit." www-star.stanford.edu/projects/mod-x/id-green.htmlTouko
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Post by julianb on Jun 3, 2010 10:00:51 GMT
Jurinko, I see that Mars average temperature is calculated from one point, the lander, wow, and it agrees exactly with the calculated black body temperature, didn't confuse units there !
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Post by jurinko on Jun 3, 2010 15:03:39 GMT
Mars fact sheet:
Black-body temperature (K) 210.1 Average temperature: ~210 K (-63 C)
"because the atmosphere is so thin that it cannot absorb much of the infrared energy which is emitted by the surface" - theory of greenhouse effect does not count with the bulk atmosphere, just with the "greenhouse" gases. Their effective level in Mars is the same as on Earth.
No nitrogen-oxygen bulk atmosphere - no heat storage, no warmer conditions. CO2 by itself does sh*t.
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Post by touko on Jun 4, 2010 18:13:13 GMT
Well Jurinko, I can't see why you're wasting your time here -- the Nobel prize committee will not be following this board! Or at the very least, send an application for a NASA Mars team job now! Early Mars could have kept warm with a blanket of carbon dioxide that would have absorbed and re-radiated heat lost from the surface. Such a greenhouse effect would have raised the temperature enough for water ice to melt. "But everything points to the fact that Mars lost its atmosphere early on," says Bibring.
After a global survey, Mars Express has found none of the carbonate minerals that would form under a dense carbon-dioxide atmosphere. This makes it unlikely that the planet ever experienced significant greenhouse warming, contrary to some scientists' expectations. "In a sense, we've been barking up the wrong tree for 20 years," says planetary geophysicist Lionel Wilson of the University of Lancaster, UK.www.nature.com/news/2005/050214/full/news050214-15.htmlSo you might want to appreciate: no atmosphere to speak of in Earth terms --> no practical CO2 effects. (Although you might have missed the fact that some sources state -55C as the surface temp.) Touko
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Post by socold on Jun 4, 2010 18:50:09 GMT
I always thought the problem with mars was the extreme swing in it's daily temperature range which makes measurement of an absolute global mean temperature very difficult, especially when the expected greenhouse effect is less than 10 degrees. Im not even sure we can measure Earth's mean absolute surface temperature to within one degree and that's really close and has a fairly tight daily temperature range.
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Post by icefisher on Jun 4, 2010 19:20:35 GMT
Im not even sure we can measure Earth's mean absolute surface temperature to within one degree and that's really close and has a fairly tight daily temperature range. Thats a pretty serious problem when one considers its been only about 1 degree C temperature increase during the industrial revolution. Its that rubber band thing, you try to lay it out and measure it and what you get depends entirely upon how you stretch it out.
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Post by socold on Jun 4, 2010 23:37:43 GMT
Relative temperature change is easier to measure than the absolute temperature
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Post by icefisher on Jun 5, 2010 0:19:17 GMT
Relative temperature change is easier to measure than the absolute temperature It is if you have one thermometer that doesn't move and stays in the same environment. But if any of your stations move, are redesigned, or reequipped you have the same problems as measuring absolute temperatures. So that distinction in this case is purely theoretical and we know how well you deal with that.
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Post by socold on Jun 5, 2010 13:23:36 GMT
satellites and surface stations agree well within 1 degree of relative temperature change over the past 30 years.
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Post by trbixler on Jun 12, 2010 1:49:44 GMT
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Post by touko on Jun 12, 2010 12:18:14 GMT
trbixler, a word in your ear: your Author is a straightforward nutcase. Snippets from his various websites, google for Gary Novak independent scientist
I was thinking about Einstein's equation which says that the energy in matter is equal to its mass time the velocity of light squared. It occurred to me that he would have had something if he hadn't squared the velocity of light, because nothing can move at velocity squared. He would have then been saying that there is enough energy in an atom to accelerate small particles to the speed of light.
(...) I evaluated the applications of energy and found contradictions everywhere due to the error. I eventually developed two mathematical proofs of the error, as shown on my website titled Energy Misdefined in Physics.
(...)
Volts and Watts
With corrected definitions, voltage is a field, not a force. Watts correlate with units of force. Just as a mass must enter a field of gravity to create a force, electrons must enter a field of voltage to create a force. The number of electrons per second times the voltage determines the watts of force, which is the rate of energy addition. Electrons per second would be similar to mass per unit time in a field of gravity, because masses would be transient, and forces would be changing, in a large scale system of gravity.
(...)
In studying the morel mushroom I found unprecedented evolution, as the morel is in the process of evolving from a yeast. This is probably the first time in hundreds of millions of years that a single celled organism evolved into a multi celled organism, and it is occurring now. The recent and rapid evolution shows effects unheard of in biology. University scientists who study the morel are not aware of the morel evolution and they create irrational explanations for their unusual results.
(...)
Several decades ago, I got a masters degree at the University of Arizona researching a yeast which adapted to growth on trees. I then studied for a year on a Ph.D. degree at the University of California at Davis. But mental pain caused by distracting environments drove me out.
[and that 1981 paper remains his sole paper as the pain apparently got the better of him]
Touko
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Post by northsphinx on Jun 12, 2010 12:40:59 GMT
"The atmosphere of Mars is also predominantly carbon dioxide, but Mars does not have a significant Greenhouse condition because the atmosphere is so thin that it cannot absorb much of the infrared energy which is emitted by the surface. That is the Greenhouse effect is depending on the atmosphere thickness, or more precisely the heat capacity of the atmosphere. That make sense. But that also mean variances in earth greenhouse effect is a function of water contents. Water as vapor and clouds. That is the only thing that can alter the atmosphere heat capacity of our earth.
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