Neptune's Global Deep Haze and its Depleted Methane at high Southern Latitudes

Details Neptune's Global Deep Haze and its Depleted Methane at high Southern Latitudes Neptune's Global Deep Haze and its Depleted Methane at high Southern Latitudes

Oct 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010dps....42.4407k&link_type=abstract

American Astronomical Society, DPS meeting #42, #44.07; Bulletin of the American Astronomical Society, Vol. 42, p.1046

Other

1

Scientific paper

Neptune's HST-STIS image cube of 2003 gives an unprecedented ability to distinguish whether features seen in methane bands are due to haze and clouds or due to changes in the methane mixing ratio.
The global brightness asymmetry observed is caused by a depletion of methane at high southern latitudes by up to a factor of 2.7, while the tropics have a constant methane mixing ratio of 0.04 +/- 0.01 up to the methane condensation layer near 1.8 bars. The depletion indicates that methane-dry air sinking from higher altitudes is enriched in methane more slowly than expected.
The two bands just south of the equator and near -60 degrees latitude have relatively low single scattering albedos, and they have Neptune's thinnest and thickest haze, respectively. The latter one has already displayed an unusual shape in Voyager images of 1989.
All observations are consistent with a uniform haze layer extending two scale heights down from the methane condensation level. The depletion of methane and the deep uniform haze on Neptune are quite similar to results about Uranus (Karkoschka and Tomasko 2009, Icarus 202, 287).
In deep methane bands, short-lived cloud features near the tropopause dominate the view. The methane abundance above these clouds was constant throughout each hemisphere, 0.0026 and 0.0017 km-am in the southern and northern hemisphere, respectively, in perfect agreement with Sromovsky et al. (2001, Icarus 149, 459).
While HST images have shown changes in the distribution of clouds over time, they also indicate remarkable stability of some features. New analysis of Voyager images reveals other subtle features associated with these stable features that may give important insights about interactions between Neptune's interior and its observable atmosphere.
This research was supported by NASA grant NNX08AE74G and by STScI grants HST-GO-09725.01-A and HST-AR-11259.01-A.

Affiliated with

Also associated with

No associations

Rating

Neptune's Global Deep Haze and its Depleted Methane at high Southern Latitudes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Neptune's Global Deep Haze and its Depleted Methane at high Southern Latitudes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Neptune's Global Deep Haze and its Depleted Methane at high Southern Latitudes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1229685