Research Projects

Thermochemistry and Microwave Remote Sensing of Jupiter’s Deep Atmosphere

Protostar

The Juno Microwave Radiometer has allowed observation of Jupiter’s atmosphere down to previously inaccessible depths, although the complexity of the atmospheric dynamics has complicated analysis. The longest-wavelength channel (600 MHz) is sensitive to pressure levels of hundreds of bars, and has observed opacity sources other than the known gaseous and cloud components, likely caused by thermally ionized free electrons from alkali metal vapor. We extend previous analysis of limb darkening at these wavelengths, using radiative transfer and thermal equilibrium modeling, by considering the effect of anions in the deep Jovian atmosphere, which act as a sink for free electrons and will thus decrease opacity for a given alkali metal abundance. We show that MWR observations are consistent with a sodium and potassium abundance on the order of 0.1× solar around the 1-kilobar level, higher than previously estimated but still substantially depleted compared to other heavy elements, a value that would be within the range of observed alkali metal abundances on giant exoplanets; alternatively, MWR observations may be consistent with 3× solar sodium abundance, but only if potassium is even more strongly depleted. Such depletion may be the result of either chemical processes yet deeper in the atmosphere, such as in the silicate clouds, or of a long-lived stable layer shallower than the alkali salt clouds.

Astrophysical Journal Letters paper

Icarus paper

Sensing the Martian Atmosphere

Occultation

Airborne dust plays an active role in determining the thermal structure and chemical composition of the present-day atmosphere of Mars and possibly the planet’s climate evolution over time through radiative–convective and cloud microphysics processes. Thus, accurate measurements of the distribution and variability of dust are required. Observations from the Mars Global Surveyor/Thermal Emission Spectrometer Mars Mars Reconnaissance Orbiter/Mars Climate Sounder and Mars Express/Fourier Transform Spectrometer and the Curiosity Rover have limited capability to measure dust. We show that spacecraft occultation of the Martian atmosphere at far-infrared frequencies between 1 and 10 THz can provide the needed global and temporal data on atmospheric dust by providing co-located measurements of temperature and dust opacity from the top of the atmosphere all the way down to the surface. In addition, spacecraft occultation by a small-satellite constellation could provide global measurements of the development of dust storms.

AIAA SciTech conference

Remote Sensing paper

Earth System Modeling: Investigating Lake Atmosphere Coupling for NOAA UFS

The Great Lakes region have some of the largest freshwater bodies on planet Earth. Interaction of these lakes with the atmosphere influences the regional weather and climate, driving extreme winter storms and precipitation. Accurate forecasting of these lake effect phenomenon is crucial to the livelihood and economic activities in the region. An operational short and medium term weather forecast system is coupled to a lake dynamics model. An accurate representation of lake surface temperature, and ice will help in improvement of prediction systems.

Particle Precipitation and Giant Planet Aurora

Jupiter’s auroral ionosphere is characterized by high electron density due to energetic particle precipitation near the polar regions resulting in a plasma environment that exhibits reflection and absorption at microwave frequencies. Juno Microwave Radiometer (MWR) observations have detected cold brightness temperatures over the auroral oval in Jupiter’s northern hemisphere. These features are found to be prominent at 600 MHz to 5 GHz frequency channels, showing a temporal variation in brightness temperature over a time span less than a minute encompassing length scale of MWR polar footprint e.g. 0.1 RJ. We analyze Juno MWR observations of the northern aurora, and simulate the electron densities corresponding up to 10 MeV energetic particle precipitation events inferred from the JEDI and UVS instruments. The plasma environment of Jupiter’s northern aurora is investigated using microwave opacity models to characterize the nature of reflection and absorption required to explain the MWR observations. Sinclair et al., (2025) analyzed the IRTF-TEXES and SOFIA-EXES observations to understand elevation of methane homopause at Jupiter’s auroral region. Energy deposition due to auroral electron precipitation may heat up the atmosphere at pressure levels close to 0.1 to 1 mbar.

JGR: Space Physics paper

Planetary Science Journal paper

TREX: Temporarily-Captured Orbiter Rendezvous Explorer

IAA Planetary Defense Conference

A mission concept focused on rendezvous and remote sensing of Temporarily Captured Object (TCO) in Earth’s orbit. Stepping into the shoes of Project Scientist, and Instrument Lead, I worked with an interdisciplinary team as a part of Cornell SmallSat Mission Design School. Watch this space for more updates. We are presenting our work at IAA Planetary Defense Conference (PDC) 2025.