http://arxiv.org/abs/2005.14387
Aquatic biospheres reliant on oxygenic photosynthesis are expected to play an important role on Earth-like planets with large-scale oceans insofar as carbon fixation (i.e., biosynthesis of organic compounds) is concerned. We investigate the properties of aquatic biospheres comprising Earth-like biota for habitable rocky planets orbiting Sun-like stars and late-type M-dwarfs such as TRAPPIST-1. In particular, we estimate how these characteristics evolve with the ambient ocean temperature ($T_W$), which is a key environmental variable. We show that many salient properties, such as the depth of the photosynthesis zone and the net primary productivity (i.e., the effective rate of carbon fixation), are sensitive to $T_W$, and eventually decline substantially as the ocean temperature is increased. We conclude by discussing the implications of our analysis for the past and future Earth, and exoplanets orbiting M-dwarfs.
M. Lingam and A. Loeb
Mon, 1 Jun 20
5/50
Comments: 15 pages; 4 figures; 1 table