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Post by radiant on Aug 12, 2009 17:18:30 GMT
So if you lower the atmosphere by 200kms then the pressure at mountain height altitudes must change by a measureable amount i am assuming still? Pressure at sea level seems a combination of gravity and diffusion into the thinner atmosphere at higher altitudes so if you decrease the height of maximum diffusion will it not create changes all the way down? The pressure is the weight of the overlying air. Next time you stand on a scale to check your weight, try to bend down in your knees and see how much your weight [your pressure on the scale] changes. Yes but when i am curled up on the scale to check the result i know that the pressure of oxygen at 18000 feet is half that of sea level. Regardless of the constant pressure at sea level if the atmosphere expands it must change the pressure at altitude. Evidently you regard the difference as trivial or irrelevant. I was rather hoping for a paper to show what the results are to demonstrate the exstremely infintesimal influence of the sun upon the atmosphere at relatively low altitudes so that i know while curled up on the scale doing the science others have already proven me wrong. And for the record when i bend down on the scale it appears my weight increases. I think according to Einstein as i get nearer the mass creating the gravitational field or time space distortion that is the expected result also? or maybe the increase was just experimental error?
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Post by lsvalgaard on Aug 12, 2009 18:36:46 GMT
The pressure is the weight of the overlying air. Next time you stand on a scale to check your weight, try to bend down in your knees and see how much your weight [your pressure on the scale] changes. Yes but when i am curled up on the scale to check the result i know that the pressure of oxygen at 18000 feet is half that of sea level. Regardless of the constant pressure at sea level if the atmosphere expands it must change the pressure at altitude. at altitude? I thought you meant at the surface?
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Post by radiant on Aug 12, 2009 18:54:52 GMT
Yes but when i am curled up on the scale to check the result i know that the pressure of oxygen at 18000 feet is half that of sea level. Regardless of the constant pressure at sea level if the atmosphere expands it must change the pressure at altitude. at altitude? I thought you meant at the surface? The point i am getting at is that air flows in such a manner that it tends to travel near the surface of the earth rather than rise over obstacles. However we know that all of the air is not travelling only at the absolute surface Even so effectively air behaves with a mountain like water does with a rock in a shallow stream it will flow around the obstacle if it can rather than travel upwards to go over it. So for example when there is a slight angle to the wind arriving at the coast of new zealand the wind direction at low altitude changes so the air follows the mountain ranges and tends to continue until it gets to the end of those ranges. A forcaster can then say with some certainty that for certain wind angles the local wind direction will be influenced by the ranges rather than the upper air movement If solar minimums reduce the envelope containing the earths atmosphere i was wondering what impact this would have on the habitual air routes around continents and mountain ranges and so forth and particularly the jet streams which are so high normally as to be out of the influence of continental effects because other things being equal the air is now more dense in a smaller space than before and has more inertia at that particular height created by that particular continental barrier or mountain range
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Post by lsvalgaard on Aug 12, 2009 19:32:02 GMT
at altitude? I thought you meant at the surface? The point i am getting at is that air flows in such a manner that it tends to travel near the surface of the earth rather than rise over obstacles. However we know that all of the air is not travelling only at the absolute surface Even so effectively air behaves with a mountain like water does with a rock in a shallow stream it will flow around the obstacle if it can rather than travel upwards to go over it. So for example when there is a slight angle to the wind arriving at the coast of new zealand the wind direction at low altitude changes so the air follows the mountain ranges and tends to continue until it gets to the end of those ranges. A forcaster can then say with some certainty that for certain wind angles the local wind direction will be influenced by the ranges rather than the upper air movement If solar minimums reduce the envelope containing the earths atmosphere i was wondering what impact this would have on the habitual air routes around continents and mountain ranges and so forth and particularly the jet streams which are so high normally as to be out of the influence of continental effects because other things being equal the air is now more dense in a smaller space than before and has more inertia at that particular height created by that particular continental barrier or mountain range The airflow near the surface does not depend in any measurable way on the upper atmosphere that has expanded or shrunk.
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Post by radiant on Aug 13, 2009 7:24:38 GMT
The point i am getting at is that air flows in such a manner that it tends to travel near the surface of the earth rather than rise over obstacles. However we know that all of the air is not travelling only at the absolute surface Even so effectively air behaves with a mountain like water does with a rock in a shallow stream it will flow around the obstacle if it can rather than travel upwards to go over it. So for example when there is a slight angle to the wind arriving at the coast of new zealand the wind direction at low altitude changes so the air follows the mountain ranges and tends to continue until it gets to the end of those ranges. A forcaster can then say with some certainty that for certain wind angles the local wind direction will be influenced by the ranges rather than the upper air movement If solar minimums reduce the envelope containing the earths atmosphere i was wondering what impact this would have on the habitual air routes around continents and mountain ranges and so forth and particularly the jet streams which are so high normally as to be out of the influence of continental effects because other things being equal the air is now more dense in a smaller space than before and has more inertia at that particular height created by that particular continental barrier or mountain range The airflow near the surface does not depend in any measurable way on the upper atmosphere that has expanded or shrunk. I can see that i am resisting, but if 99.99997% of the atmospheres mass is below 100km I suppose you are probably correct. thanks for the feedback
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Post by lsvalgaard on Aug 13, 2009 7:47:19 GMT
The airflow near the surface does not depend in any measurable way on the upper atmosphere that has expanded or shrunk. I can see that i am resisting, but if 99.99997% of the atmospheres mass is below 100km I suppose you are probably correct. thanks for the feedback especially since the shrinking reported was mainly at even higher levels: 300 km and up, so you can add a whole bunch of 9s to the that percentage.
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Post by francisco on Aug 15, 2009 16:42:28 GMT
Dr. Svalgaard, Solar wind speed and temperature are again cyclically declining, as they have in the past, as shown in the link below, but this time around the density is remaining higher, at least for now. In the past, reductions in speed to the the 280 km/s range have usually been accompanied by at least periodic dips in the density to to the 0.1 to1.0/cm3 range, but levels are currently 10 times higher. Does this give any clues to what physical processes are happening? Thanks. www.swpc.noaa.gov/ace/MAG_SWEPAM_24h.html
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Post by lsvalgaard on Aug 15, 2009 17:31:04 GMT
Dr. Svalgaard, Solar wind speed and temperature are again cyclically declining, as they have in the past, as shown in the link below, but this time around the density is remaining higher, at least for now. In the past, reductions in speed to the the 280 km/s range have usually been accompanied by at least periodic dips in the density to to the 0.1 to1.0/cm3 range, but levels are currently 10 times higher. Does this give any clues to what physical processes are happening? The solar wind observed at a given location is divided into 'sectors' of opposite magnetic polarity. These sectors [each lasting about a week] are bounded by a current sheet. In and near the current sheet the solar wind speed is low [300 km/s or lower] and density is high [10 or more] so this is the normal situation. Because the solar wind is very 'gusty' almost any combination of conditions can be observed, so don't attach too much significance to singular occurrences. If you watch the graphs over the next day or so, you'll find that when the speed reaches rock-bottom, the density and the magnetic field will jump up, followed by the speed itself increasing. Then the field and density over the next day will fall back to normal levels, but the speed will stay high for several more days and then decline until the next sector boundary comes along a week or so later, when the whole pattern will repeat. This is all normal, expected, and understood behavior.
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Post by csspider57 on Aug 18, 2009 11:26:10 GMT
Dr. S. I use a yahoo widget and one of the feeds is from CCMC/BATRUS ccmc.gsfc.nasa.gov/cgi-bin/display/RT_t.cgiWell I checked the feed this morning and found what should be the polar coronal fields at the equator. huh So, I went to there web page and found them as they should be. Program glitch? None the less, could you explain how to properly interpret the images?First, image from there web site. Second image a snip of what I found this morning. Wow Attachments:
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Post by lsvalgaard on Aug 18, 2009 13:58:20 GMT
Dr. S. I use a yahoo widget and one of the feeds is from CCMC/BATRUS Well I checked the feed this morning and found what should be the polar coronal fields at the equator. huh So, I went to there web page and found them as they should be. Program glitch? None the less, could you explain how to properly interpret the images?First, image from there web site. Second image a snip of what I found this morning. Wow They calculate the solar wind speed from the photospheric magnetic field. A very high speed [red on the Figures] signifies a coronal hole. The polar fields are difficult to measure and any mall error is magnified greatly. The strange loss of speed near the North pole is likely just some bad field data.
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Post by csspider57 on Aug 18, 2009 23:38:22 GMT
Thank you for the reply Dr. S. The widget feed is still displaying the polar coronal field (winds) at the equator as of 6:11pm cst. I've tried closing and re-opening it. Might have to send them an email. Just re-read "Calibrating the Sunspot Number using the Magnetic Needle," very cool correlations. If this has been known for such a long time, why are you now findiing it so hard for it to be accepted? Thanks for helping me to understand more about the process of reconnection above and below the earth. Based on your last graph in that doc., the last 7 solar cycles remained high over 100 sunspots, 4 of them 150 +, in succession without a substatial cooling period for the heliosphere. So, I disagree with your statement, "We thus see no evidence in the sunspot number of a secular increase in solar activity over the last ~165 years." ;D But nicely done Dr. S. and a significant contribution to the accurracy of the sunspot count over the last 165 years. Now lets correlate this to the galactic level back to the sun.
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Post by brokenheadphonez on Aug 21, 2009 4:35:11 GMT
Hey, Dr. S - how long do you expect the solar windspeed to maintain ~500km/s?
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Post by lsvalgaard on Aug 21, 2009 5:45:59 GMT
Hey, Dr. S - how long do you expect the solar windspeed to maintain ~500km/s? a couple of days
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Post by Bob k6tr on Sept 17, 2009 23:33:56 GMT
Hi Leif
In a similar vein to the questions about the sun's variation in temperature. Is the variation rotational speed tracked ? Both the overall speed and the variation is speed between latitudenal layers ? Have there been any discernable shifts in the last year or so ?
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Post by lsvalgaard on Sept 18, 2009 1:24:44 GMT
Hi Leif In a similar vein to the questions about the sun's variation in temperature. Is the variation rotational speed tracked ? Both the overall speed and the variation is speed between latitudenal layers ? Have there been any discernable shifts in the last year or so ? Yes it is measured too. There are differences between latitudes: a general slow decrease towards to poles and superposed on top of that a variation [the Torsional oscillation - terrible name, but such is it] that varies with the solar cycle: Red is faster, blue is slower. The last couple of years are not on the plot, but they are just 'more of the same'.
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