A076-10
Radiative Transfer Modeling of Jovian Hot Spots and NH-3 Plumes with HST and Keck NIRSPEC

Wednesday, 9 December 2020: 16:27
Virtual
Charles Goullaud, University of California Berkeley, Berkeley, CA, United States, Imke De Pater, Univ California Berkeley, Berkeley, CA, United States, Gordon L Bjoraker, NASA, Greenbelt, MD, United States, Michael H. Wong, University of California, Berkeley, CA, United States, Tilak Hewagama, University of Maryland, College Park, MD, United States and Chris Moeckel, Delft University of Technology, Delft, Netherlands
Abstract:
Hot spots are regions of the Jovian atmosphere with thin overlying clouds which appear bright in the thermal infrared and dark at visible wavelengths. Conversely, ammonia (NH-3) plumes are regions with thick overlying clouds which appear dark in the thermal infrared and bright at visible wavelengths. Hot spots create a window into the composition of Jupiter’s deep atmosphere, while the plumes provide an opportunity to study Jupiter’s cloud structure. Hot spots and NH-3 plumes are believed to be regions of atmospheric downwelling and upwelling, respectively. NH-3 serves as a tracer for Jupiter’s atmospheric dynamics, which makes measuring NH-3 abundances in these regions important for constraining dynamical models of the Jovian atmosphere. We present radiative transfer models of Jupiter’s hot spots and NH-3 plumes observed in the North Equatorial Belt using visible (0.3-0.9 um) and thermal infrared (4.5-5.5 um) spectra from the HST WFC3/UVIS and Keck NIRSPEC instruments, respectively. The observations are part of a suite of Juno support observations, which include simultaneous observations with HST, Keck, Gemini, and the VLA. The visible-wavelength observations probe the region from the tropopause at ~0.1 bar down to the uppermost opaque cloud tops, which ranges from ~1-4 bar depending on the cloud opacity. The thermal infrared observations are sensitive to the deep cloud layers and atmospheric composition, ranging from ~2-6 bar depending on the cloud opacity and on the concentration of volatiles, such as NH-3. We use this combined data set to model the structure and composition of the Jovian hot spots and NH-3 plumes from ~0.1-6 bar. Our radiative transfer modeling package, SUNBEAR, takes into account the extent and thickness of tropospheric hazes, location and structure of Jupiter’s clouds, and the abundances of volatile gases. SUNBEAR has previously been used with this dataset to model an outbreak event in the South Equatorial Belt observed in January 2017.
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