{"id":944,"date":"2013-12-08T16:30:10","date_gmt":"2013-12-08T14:30:10","guid":{"rendered":"https:\/\/www.planetary-astronomy-and-imaging.com\/?p=944"},"modified":"2013-12-08T17:02:58","modified_gmt":"2013-12-08T15:02:58","slug":"jupiter-barometric-marsh","status":"publish","type":"post","link":"https:\/\/www.planetary-astronomy-and-imaging.com\/en\/jupiter-barometric-marsh\/","title":{"rendered":"Jupiter in a barometric marsh"},"content":{"rendered":"

There is one situation favorable to good seeing that I did not talked about in my article Five good conditions for astronomical seeing<\/a>, because its is rarer and more difficult to identify, the “barometric marsh”. That was the condition for me during the night from 3 to 4 December 2013, when I enjoyed good seeing on Jupiter.<\/strong><\/em><\/p>\n

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The barometric marsh is meteorological situation where the pressure is relatively high, but outside any organized high-pressure : isobars are weakly visible, and winds are low. Here is the GFS map for the 4 December 2013 at midnight, France is between two HP’s:<\/p>\n

\"gfspression4dec2013\"

Ground winds are extremely weak, so is the jet-stream above Nantes (I’m under the little violet patch at the center ;) ):<\/p>\n

\"gfswinds4dec2013\"

There was one drawback unfortunately as transparency was low because of the presence of thin high clouds. This does not deteriorate the seeing but the it does affect contrast a lot for short wavelengths. If IR or color images don’t suffer much, in blue and ultraviolet the diffusion of light was enough to deteriorate noticeably the resolution.<\/p>\n

Click on the images to see them in full resolution.<\/p>\n\n\t\t