Open AccessThe Effects of Waves on the Meridional Thermal Structure of Jupiter’s Stratosphere
Author(s) -
Richard Cosentino,
Thomas Greathouse,
A. A. Simon-Miller,
Rohini Giles,
R. Morales-Juberías,
Leigh N. Fletcher,
Glenn S. Orton
Publication year - 2020
Publication title -
the planetary science journal
Language(s) - English
Resource type - Journals
ISSN - 2632-3338
DOI - 10.3847/psj/abbda3
Subject(s) - stratosphere , jupiter (rocket family) , zonal and meridional , equator , atmosphere (unit) , physics , atmospheric sciences , geology , oscillation (cell signaling) , forcing (mathematics) , troposphere , geophysics , astronomy , latitude , spacecraft , meteorology , chemistry , biochemistry
A thermal oscillation in Jupiter’s equatorial stratosphere, thought to have ∼4 Earth year period, was first discovered in 7.8 μ m imaging observations from the 1980s and 1990s. Such imaging observations were sensitive to the 10–20 hPa pressure region in the atmosphere. More recent 7.8 μ m long-slit high-spectroscopic observations from 2012 to 2017 taken using the Texas Echelon cross-dispersed Echelle Spectrograph (TEXES), mounted on the NASA Infrared Telescope Facility (IRTF), have vertically resolved this phenomenon’s structure, and show that it spans a range of pressure from 2 to 20 hPa. The TEXES instrument was mounted on the Gemini North telescope in March 2017, improving the diffraction-limited spatial resolution by a factor of ∼2.5 compared with that offered by the IRTF. This Gemini spatial scale sensitivity study was performed in support of the longer-termed Jupiter monitoring being performed at the IRTF. We find that the spatial resolution afforded by the smaller 3 m IRTF is sufficient to spatially resolve the 3D structure of Jupiter’s equatorial stratospheric oscillation by comparing the thermal retrievals of IRTF and Gemini observations. We then performed numerical simulations in a general circulation model to investigate how the structure of Jupiter’s stratosphere responds to changes in the latitudinal extent of wave forcing in the troposphere. We find our simulations produce a lower limit in meridional wave forcing of ±7° (planetocentric coordinates) centered about the equator. This likely remains constant over time to produce off-equatorial thermal oscillations at ±13°, consistent with observations spanning nearly four decades.