Intercomparison of a Dynamic Ocean for Earth-like Aqua-planets

• Main Author: Plane, Fredrik
• Format: Bachelor Thesis
• Language: English
• Published: Uppsala universitet, Institutionen för fysik och astronomi 2022
• Subjects: Astrobiology; Planets; Aqua-planets; Atmosphere and Ocean physics; Exoplanet; Habitability; General Circulation Model; GCM; Climate Modelling; Dynamic Ocean; Astronomy; Astrophysics and Cosmology; Astronomi; astrofysik och kosmologi; Sea ice
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-479952

I present herein an ensemble of ROCKE-3D aqua-planet simulations which I compare with the simulations presented in the work of Yang et al. (2019) and other similar works. The focus was on contrasting differences in the greenhouse effect between the models. In contrast to their work, I examined simulations with a dynamic ocean instead of a slab ocean, as well as the inclusion of dynamic sea ice for 2 out of 4 of them. A subset of the simulations examined prevented the formation of sea ice to make them more comparable to Yang et al. (2019), but they never reached radiative equilibrium and this made it difficult to utilize their results. When contrasting the sea ice simulations of ROCKE-3D with the CAM4_Wolf/ExoCAM simulation of Komacek & Abbot(2019), I found that the inclusion of ocean heat transport through a dynamic ocean increases the ice-free region around the sub-tropics for the rapidly rotating aqua-planet around a G-star, thus, resulting in a lower Bond albedo and more surface warming. Supporting previous intercomparisons (Sergeevet al. 2021), ROCKE-3D produces less low- to midlevel clouds toward the equator/substellar point, compared to other models. Consequently, this leads to less cooling through the shortwave cloud radiative forcing. Lastly, I looked at the specific humidity. ROCKE-3D produced the highest stratospheric water vapor content in the M-star scenario, which suggests that ROCKE-3D is closer to the moist greenhouse limit of Kasting et al. (1993); although, the model is still far off. I detta arbete så presenterar jag vattenplanet simulationer producerade med hjälp av ROCKE-3D, som jag sedan jämför med simulationerna som presenteras i Yang et al. (2019). Fokuset för jämförelsen låg på att jämföra skillnader gällande den producerade växthuseffekten. Alla simulationer utnyttjade ett dynamiskt hav i stället för ett enklare "platt hav", varav 2 utav 4 av dom simulationer som presenteras tillåter havsis att formas. De simulationer som inte tillät is uppnådde aldrig termisk jämvikt vilket gjorde ...