Year: 2013
Type: article
Abstract: Recent studies have shown that baroclinic vortex amplification is strongly dependent on certain factors, namely, the global entropy gradient, the efficiency of thermal diffusion and/or relaxation as well as numerical resolution. We conduct a comprehensive study of a broad range and combination of various entropy gradients, thermal diffusion and thermal relaxation timescales via local shearing sheet simulations covering the parameter space relevant for protoplanetary disks. We measure the Reynolds stresses as a function of our control parameters and see that there is angular momentum transport even for entropy gradients as low as β = − d ln s / d ln r = 1/2. Values we expect in protoplanetary disks are between β = 0.5–2.0 The amplification-rate of the perturbations, Γ, appears to be proportional to β 2 and thus proportional to the square of the Brunt-Väisälä frequency (Γ∝β 2 ∝ N 2 ). The saturation level of Reynolds stresses, on the other hand, seems to be proportional to β 1/2 . This highlights the importance of baroclinic effects even for the low entropy gradients expected in protoplanetary disks.
Source: The Astrophysical Journal
Authors: Natalie Raettig, Wladimir Lyra, Hubert Klahr
Language: Spanish
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2047163933