Red Spot: Why no eye?, Why does the Great Red Spot not have an eye like a hurricane? Options

[hendric]

Looking at Ike pounding the Texas coast here, I was thinking...Why do the GRS and lesser storms on Jupiter not have eyes like Hurricane's here on Earth? Does Jupiter's rapid rotation somehow prevent their formation, or does an eye require water vapor?

Hmm...a quick Google search didn't turn up any explanations as to why hurricanes have eyes to begin with, so maybe my question is flawed.

[Juramike]

Here's a link that describes hurricane eye and eyewall formation: http://www.aoml.noaa.gov/hrd/tcfaq/A11.html

It seems the eye is kept open by having centrifugal force throwing stuff outside, and also by having gently descending (and warming) air at the center.

I'm not sure why some Hurricane eyes tend to cloud over from time to time. (And I'm not sure if this is related to eyewall replacement cycles, either.)

I wonder if the difference between hurricanes on Earth and the red spot may have something to due to the relative thickness of the two features. (I'm assuming the Earth's hurricanes are much thinner <15 km).

-Mike

[Juramike]

Ah ha! Found something much more relevant!

http://www.wunderground.com/blog/JeffMaste...p;tstamp=200611

The south polar Saturnicane is probably a better analog to Earth's hurricanes.

Jupiter's Red Spot is not considered hurricane-like since it doesn't posess "an eyewall surrounded by a cloud-free eye".

-Mike

[john_s]

One fundamental difference- the Great Red Spot and similar storms on Jupiter are anticyclonic (high-pressure), not cyclonic (low-pressure) like terrestrial hurricanes. For reasons way beyond my expertise, Jovian anticyclonic storms are well-organized while its cyclonic storms are a jumbled mess.

John.

[Juramike]

Wiki-link here: http://en.wikipedia.org/wiki/Great_Red_Spot#Great_Red_Spot

(The full article describes other atmospheric phenomena of Jupiter)

[Juramike]

One fundamental difference- the Great Red Spot and similar storms on Jupiter are anticyclonic (high-pressure), not cyclonic (low-pressure) like terrestrial hurricanes.

Actually, hendric, I'm really, really glad you asked this question. This is something that's been bothering me for quite a while now, hopefully someone can set me straight.


Most hurricanes have surface lows (inflow), but upper level highs (outflow). The cumulonimbus clouds trace out the inflow and convective bands. The upper atmosphere divergence strengthens the lower level convergence. (All that humid air's gotta go somewhere). I'm not sure, but I think upper level outflow might be observable by examining the fine structure in the water vapor loop imagery over time using a rotating coordinate frame (another project for Spin-O-Vision).

Here's the best site I've found to explain hurricane structure (use the tab in the window to scroll through): http://www.newmediastudio.org/DataDiscover...urr_Struct.html

"Upper level flow and the anticyclonic jet. As air leaving the center of the hurricane reaches an elevation of about 12 km above sea level (200 mb level), it produces high pressure near the tropopause, and divergent flow away from the focus of the hurricane. This upper level outflow circulates in an anticyclonic direction, typically at a radius of 300 km, and is termed the anticyclonic jet. "


What I'm wondering (and honestly don't know), is if the upper level outflow (anti-cyclone) we see from the Great Red Spot is coupled to a lower level low pressure system. Could it be that the Great Red Spot is a super-thick big hurricane, with the cyclonic bands hidden way down deep, but the upper level anticyclonic bulge evidenced by the high dark red cloud layers?

-Mike

[Guest_PhilCo126_*]

Jupiter's Atmospheric Pressure near that latitude?

[hendric]

Thanks everyone, I'll give these links a read!