T72 Flyby Options

[SFJCody]

Mike Brown posted this on twitter:

looks like my predictions were right!

[remcook]

The zonal atmospheric flow pattern may be different at this time of the equinox. According to Friedson et al http://www.sciencedirect.com/science?_ob=M...=/sdarticle.pdf atmospheric flow rises at low latitudes, flows towards the poles and descends at higher latitudes. Could we be seeing this pattern in the clouds?

Zonal (so, west-east) wind speeds tend to be a lot higher than any vertical motion. But the change in circulation is probably the reason why there are now more clouds at the equator (or clouds at all!).

[remcook]

Mike Brown posted this on twitter:

As far as vague predictions go...
http://www.unmannedspaceflight.com/index.p...amp;#entry89833

[volcanopele]

Mike Brown posted this on twitter:

Umm... yeah.

Let's be honest, we knew from HST that huge equatorial storms form during equinox as far back as well the last equinox in 1995. Not exactly a bold statement to say that weather can change on a seasonal basis...

[remcook]

VP: that's what I thought, but apparently not equatorial
http://www.unmannedspaceflight.com/index.p...st&p=144705

[Littlebit]

This is frustrating: No matter how hard I try to interpret this, I'm certain that I have it wrong:(

In what direction are the dunes running, relative to the cloud? Aren't the ridges running withn ~10 deg as the same direction as the arrow?

[titanicrivers]

Titan with the spectacular T72 S Senkyo cloud were photographed nearly simultaneously through spectral bandpass filter combinations on Sept 27. The CB3 CL1 filter combo provided striking cloud and surface detail at 938 nm http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=228405
whereas photos through the MT3 CL1 filter showed no surface and only a hint of the cloud but emphasized the NS hemispheric asymmetry of the lower stratospheric haze. http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=228415
The stratospheric haze, detached haze layer and dark N polar hood were prominent in the CL1 UV3 image http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=228408
Difference Blending CL1 CB3 and CL1 MT3 filtered images in Photoshop produced some interesting results however! (see below). This blending mode emphasizes color pixel brightness differences between overlaid images producing a darkening of blended pixel areas where the 2 images differ. Adjusting the opacity of the blend to 50% produces interesting effects in the T72 cloud showing preservation of the central portion (yellow arrow) but disappearence of the N>S arms of the cloud (small white arrows, 3rd image in the animation). This attenuation is most prominent at higher latitudes beginning just to the North of the NS hemisphereic asymmetry. Increasing the opacity of the difference blend to 90% reveals much of the cloud (excepting the central portion) as a dark area (last image in the animated sequence below).
The graphic on the right shows the difference blend of a CB3 and UV3 image compared to the CB3 MT3 image at 50% opacity suggesting the entire cloud is well below the level of stratospheric haze level seen through the UV3 filter but only the NS arms of the cloud are below the deeper atmospheric level reached with the MT3 filter.
Making several assumptions, one layman’s interpretation of these observations suggests the ends of the NS arms of the cloud are descending to a lower height in the troposphere as they move to increasing latitudes away from the center of the cloud and are not a uniform flat cloud top. This effect is more pronounced to the North of the zonal hemispheric asymmetry (as suggested in Ugordan's post #13 as well). Perhaps this pattern supports the theoretical pattern of equinox atmospheric flow mentioned in the article of post #17 in this thread.

[machi]

I think that this is largest non-polar cloud photographed by Cassini to date. It's really massive.

[stevesliva]

It's really massive.

That's why they used those badass filter combinations. Oh wait. bandpass

[Paolo]

Let's be honest, we knew from HST that huge equatorial storms form during equinox as far back as well the last equinox in 1995.

There was also this detection of large equatorial storms one year ago: Storms in the tropics of Titan
full PDF here

[titanicrivers]

There was also this detection of large equatorial storms one year ago ...

Yes a remarkable storm! Actually was 2 yrs ago in April 2008. See also http://www.unmannedspaceflight.com/index.php?showtopic=6146.

[titanicrivers]

It would be interesting to see that reprojected to simulate the view from directly above.

Here's a distorted, cartoonish attempt at reprojection of the T72 storm to simulate the view from above. At least it lives up to its nickname of the 'arrow-shaped' storm !

[ngunn]

Thanks for doing that! I never get tired of asking favours here.

[titanicrivers]

T72 storm cloud details using enhancement of the raw images with Photoshop. Originals rotated 205 deg left. The top of cloud appears to have layered structure in (a) CL1 CB3 and a difference blend of that with the CL1 CB1 image shows interesting differences (d) that when magnified (e) look similar to the clusters of cloud tops imaged in 2004 by Cassini (f) see http://ciclops.org/media/sp/2009/5480_12560_0.pdf

While these could be artifacts of processing, clusters of individual storms are predicted in models of Titan methane cloud formations that grow to produce intense precipitation. http://www.nature.com/nature/journal/v442/...ature04933.html

[titanicrivers]

With the stretched T72 storm image map above and VP’s enhanced ISS basemap and SAR swaths one can approximate where the most intense portion of the storm was located and where evidence of localized flooding might be sought. The mid portion of the T50 swath and just south of SENKYO might be good places to revisit to look for changes either with SAR or the WAC or NAC. With Cassini in safe mode and imaging for T73 not likely this may have to wait for some time.