Ruizhi Zhan (詹睿知)

Ruizhi Zhan (詹睿知)

she/her

Ph.D Candidate

Researches

My work focuses on the atmospheres on rocky planets (or terrestrial planets), especially the tidally locked ones.

  • Habitable Zone Around "Dead Stars"?
    White dwarfs offer a unique opportunity to search nearby stellar systems for signs of life, but the habitable zone around these stars is still poorly understood. We use the ExoCAM Global Climate Model to investigate the inner edge of the habitable zone (HZ) around white dwarfs. Since white dwarf stars are compact and small, planets orbiting them are assumed tidally locked with ultra short orbital period (2.5hr<P<4days). Our results suggest novel atmospheric dynamics expand the inner edge of the habitable zone around white dwarfs and can be distinguished by JWST via thermal phase curve. Read more on [arxiv]/ [journal].


    Surface temperature and zonal mean zonal wind as a function of rotation period. From left to right: bat rotator (P = 0.5 days; this work), compared to a rapid rotator (P = 2 days), Rhines rotator (P = 10 days), and slow rotator (P = 20 days).



    The Runaway Greenhouse Limit (RGHL) around white dwarfs, and comparison to previous studies.

    Estimated rotation regimes inside the habitable zone of white dwarfs with different stellar temperatures, as a function of relative stellar flux.
  • Atmospheres on Hot Tidally Locked Rocky Planets?
    Hot rocky exoplanets are ideal targets for modern telescopes due to their short orbital periods and significant thermal emissions. The atmospheric dynamics of these planets, however, are still poorly understood. Few model with realistic radiative transfer has been employed for hot (non-habitable) rocky exoplanets, mainly due to the incompatibility of standard GCM radiative transfer codes with currently observed hot exoplanets. Here we developed custom correlated-k coefficients and validate them against line-by-line radiative transfer simulations. We then perform GCM simulations with non-grey radiative transfer, Isca coupled with Socrates, to model the atmospheres on hot rocky planets like TRAPPIST-1b, LHS3844b and 55 Cnc e.


    Last update: August 2024