# # Program information file # PROGRAM_ID 2023B008 PROGRAM_TITLE Evolution of Deep Clouds on Saturn PROGRAM_INV1 Gordon Bjoraker PROGRAM_INV2 Michael H. Wong PROGRAM_INV3 Tilak Hewagama PROGRAM_INV4 Glenn Orton PROGRAM_INV5 Tom Momary PROGRAM_SCICAT major planets / satellites PROGRAM_ABSTRACT_BEG We propose to use iSHELL at 5 microns to study the deep cloud structure and gas composition on Saturn. In addition, we will track the time evolution of a storm that erupted in 2018. This region at 65N was largely cloud-free in 2019. New data will reveal whether or not this region has started to cloud over. We will use a CH3D feature at 4.66 microns and a PH3 absorption line at 5.07 microns to derive the pressure level of the deepest clouds. The broad bandpass and high spectral resolution of iSHELL will be used to develop a cloud model. This, in turn, will be used to derive the abundance of NH3, PH3, and CO on Saturn. PROGRAM_ABSTRACT_END