More on clouds above Meridiani.

[exoscientist]

Posted to sci.astro:From: "Robert Clark" <rgregoryclark@yahoo.com>Newsgroups: sci.astro,alt.sci.planetary,sci.physics,sci.geo.meteorologySubject: Re: Polarized clouds on Mars, further evidence for liquid water in Solis Lacus, Mars?Date: Thu, 13 Jan 2005 15:45:50 -0800Seasonal Trend in Water Vapor Seen from Orbit"The seasonal trend in the amount of water vapor in Mars' atmosphere,as observed by thermal emission spectrometer on NASA's Mars GlobalSurveyor orbiter, varies by latitude. This plot starts near thebeginning of fall in the southern hemisphere for the year before theMars Exploration Rover mission began and ends on August 30, 2004,slightly more than one martian year later. Purple represents no waterwhile red represents about 50 precipitable micrometers, which is about10,000 times less than on Earth. The units of time along the horizontalaxis are given in longitude of the Sun (Ls) as measured in aMars-centered coordinate system, a way to reflect the elliptical natureof Mars' orbit. On this scale, Mars is farthest from the Sun at about74, which also corresponds to late fall in the southern hemisphere."During the period when Mars is farthest from the Sun, the migration ofwater vapor from the northern polar region combines with loweredatmospheric temperatures to produce conditions that allow formation ofclouds such as seen in the image "Clouds over 'Endurance' on Sol 290" .Opportunity is further north than Spirit is, so there is a distinctdifference in the amount of water vapor available to form water-iceclouds over the two sites. To date, Spirit has not seen any discrete,cirrus-like clouds such as Opportunity has photographed. Although watervapor is expected to reach a maximum abundance for the Opportunity andSpirit sites near spring equinox (Ls 180 or about March 2005), theatmospheric temperatures will very likely have warmed sufficiently toprevent formation of the type of clouds that Opportunity has observedrecently. "http <div class="Discussion_UserSignature"> </div>

 

[najab]

A little bit of reformatting, hope I got it right. <img src="/images/icons/smile.gif" /><br /><br />Posted to sci.astro:<br />From: "Robert Clark" <rgregoryclark@yahoo.com /> <br />Newsgroups: sci.astro,alt.sci.planetary,sci.physics,sci.geo.meteorology <br />Subject: Re: Polarized clouds on Mars, further evidence for liquid water in Solis Lacus, Mars? <br />Date: Thu, 13 Jan 2005 15:45:50 -0800 <br /><br />Seasonal Trend in Water Vapor Seen from Orbit<br />"The seasonal trend in the amount of water vapor in Mars' atmosphere, as observed by thermal emission spectrometer on NASA's Mars Global Surveyor orbiter, varies by latitude. This plot starts near the beginning of fall in the southern hemisphere for the year before the Mars Exploration Rover mission began and ends on August 30, 2004, slightly more than one martian year later. Purple represents no water while red represents about 50 precipitable micrometers, which is about 10,000 times less than on Earth. The units of time along the horizontal axis are given in longitude of the Sun (Ls) as measured in a Mars-centered coordinate system, a way to reflect the elliptical nature of Mars' orbit. On this scale, Mars is farthest from the Sun at about 74, which also corresponds to late fall in the southern hemisphere. "During the period when Mars is farthest from the Sun, the migration of water vapor from the northern polar region combines with lowered atmospheric temperatures to produce conditions that allow formation of clouds such as seen in the image "Clouds over 'Endurance' on Sol 290".<br /><br />Opportunity is further north than Spirit is, so there is a distinct difference in the amount of water vapor available to form water-ice clouds over the two sites. To date, Spirit has not seen any discrete, cirrus-like clouds such as Opportunity has photographed. Although water vapor is expected to reach a maximum abundance for the Opportunity and Spirit sites near spring equinox (Ls 180 or about March 2005), the atmospheric temperatur

 

[exoscientist]

Thanks for the reformat Naja.<br />BTW, in the news release it states:<br /><br /> Seasonal Trend in Water Vapor Seen from Orbit <br />"The seasonal trend in the amount of water vapor in Mars' atmosphere, <br />as observed by thermal emission spectrometer on NASA's Mars Global <br />Surveyor orbiter, varies by latitude. This plot starts near the <br />beginning of fall in the southern hemisphere for the year before the <br />Mars Exploration Rover mission began and ends on August 30, 2004"<br /><br /><br /> When Mars reaches perihelion will be in late southern Spring. This will be in July, 2005. It would be expected that the melting of the southern ice cap in late Spring to early Summer and subsequent exposure of water ice would result in a great increase in the amount of water vapor in the atmosphere. However, the data shown in the graph accompanying the news release only goes back to southern Fall, 2003 so they may not be including the high water content in late Spring and early Summer. <br />The Hubble images show the clouds over Meridiani in late southern Spring. This is when I'm suggesting clouds will again appear over Meridiani in 2005, not the March 2005 mentioned in the news release. <br /><br /><br /> Bob Clark <br /> <div class="Discussion_UserSignature"> </div>