Neptune's Stratosphere: The Thermal Structure and Chemical Composition

We request time to make a spatially dependent study of the photochemistry, energetics, and dynamics of Neptune's stratosphere. Using TEXES mounted on Gemini North we plan to map H2 emission across the planet to constrain the spatial variation of stratospheric temperature and infer the stratospheric wind field by application of the thermal wind equation. Mapping the emissions of CH4, C2H2 and C2H6 and using the derived temperatures as a constraint we will measure the abundance of these molecules as a function of latitude. These abundances will be used to constrain the properties of a seasonal radiative climate model for Neptune and as a test of 1- and 2-D seasonal photochemical models. A complete dataset as described will be a valuable asset for comparison to past and future Neptune observations in an attempt to find temporal seasonal changes, to further constrain the cause of the unexpected emission peak at -70 degrees latitude observed in 8.6 and 12.3 micron VISIR VLT and MICHELLE GEMINI images, and in understanding the radiative heat budget in general.