Evaluating the effect of four unknown parameters included in a latitudinal energy balance model on the habitability of exoplanets

Abstract

Among different models for determining the habitable zone (HZ) around a star, a Latitudinal Energy Balance Model (LEBM) is very beneficial due to its parametricity which keeps a good balance between complexity and simulation time. This flexibility makes the LEBM an excellent tool to assess the impact of some key physical parameters on the temperature and the habitability of a planet. Among different physical parameters, some of them, up until now, cannot be determined by any method such as the planet’s spin obliquity, diurnal period, ocean-land ratio, and pressure level. Here we apply this model to study the effect of these unknown parameters on the habitability of three exoplanets located in the inner, outer, and middle of their optimistic HZ. Among the examined parameters, the impact of pressure is more straightforward. It has a nearly direct relation with temperature and also with the habitability in the case of a cold planet. The effect of other parameters is discussed with details. To quantify the impact of all these unknown parameters we utilize a statistical interface which provides us with the conditional probability on habitability status of each planet.

An Energy Balance Model for Rapidly and Synchronously Rotating Terrestrial Planets

“…The discovery of exoplanets has also motivated numerous EBM studies that explore plausible climates of other terrestrial and giant planets to aid in ongoing attempts at identifying habitable planets. This has included investigations of: the extent to which rotation rate (Spiegel et al 2008;Bahraminasr et al 2020), obliquity (Williams & Kasting 1997;Spiegel et al 2009;Armstrong et al 2014;Rose et al 2017;Bahraminasr et al 2020;Palubski et al 2020), eccentricity (Dressing et al 2010;Palubski et al 2020), and Milankovitch cycles (Spiegel et al 2010;Haqq-Misra 2014;Forgan 2016;Deitrick et al 2018aDeitrick et al , 2018bQuarles et al 2022) can affect habitability; the effects of varying surface albedo (Shields et al 2013;Rushby et al 2019;Bahraminasr et al 2020) and surface pressure (Vladilo et al 2013;Bahraminasr et al 2020;Ramirez 2020) on climate; the role of mantle degassing and the carbonate-silicate cycle on climate evolution (Kadoya & Tajika 2014, 2016Menou 2015;Haqq-Misra et al 2016); the climate stability of synchronously rotating planets around low-mass stars (Kite et al 2011;Checlair et al 2017); the possibility of habitable exomoons (Forgan & Yotov 2014;Forgan & Dobos 2016); and plausible climate for planets in binary star systems (Forgan 2014(Forgan , 2016May & Rauscher 2016;Haqq-Misra et al 2019;…”

An Energy Balance Model for Rapidly and Synchronously Rotating Terrestrial Planets

“…The discovery of exoplanets has also motivated numerous EBM studies that explore plausible climates of other terrestrial and giant planets to aid in ongoing attempts at identifying habitable planets. This has included investigations of: the extent to which of rotation rate (Spiegel et al 2008;Bahraminasr et al 2020), obliquity (Williams & Kasting 1997;Spiegel et al 2009;Armstrong et al 2014;Rose et al 2017;Bahraminasr et al 2020;Palubski et al 2020), eccentricity (Dressing et al 2010;Palubski et al 2020), and Milankovitch cycles (Spiegel et al 2010;Haqq-Misra 2014;Forgan 2016;Deitrick et al 2018a,b;Quarles et al 2021) can affect habitability; the effects of varying surface albedo (Shields et al 2013;Rushby et al 2019;Bahraminasr et al 2020) and surface pressure (Vladilo et al 2013;Ramirez 2020;Bahraminasr et al 2020) on climate; the role of mantle degassing and the carbonate-silicate cycle on climate evolution (Kadoya & Tajika 2014;Menou 2015;Kadoya & Tajika 2015;Haqq-Misra et al 2016;Kadoya & Tajika 2016, 2019; the climate stability of synchronously rotating planets around low-mass stars (Kite et al 2011;Checlair et al 2017); the possibility of habitable exomoons (Forgan & Yotov 2014;Forgan & Dobos 2016); and plausible climate for planets in binary star systems (Forgan 2014(Forgan , 2016May & Rauscher 2016;Haqq-Misra et al 2019;Okuya et al 2019;<...>…”