Superrotation in a Venus general circulation model

Lee, C.; Lewis, S. R. and Read, P. L. (2007). Superrotation in a Venus general circulation model. Journal of Geophysical Research: Planets, 112(E04S11) pp. 1–10.

DOI: https://doi.org/10.1029/2006JE002874

URL: http://www.agu.org/journals/je/je0704/2006JE002874...

Abstract

A superrotating atmosphere with equatorial winds of ~ 35 ms-1 is simulated using a
simplified Venus general circulation model (GCM). The equatorial superrotation in the
model atmosphere is maintained by barotropic instabilities in the midlatitude jets
which transport angular momentum toward the equator. The midlatitude jets are
maintained by the mean meridional circulation, and the momentum transporting waves are
qualitatively similar to observed midlatitude waves; an equatorial Kelvin wave is also
present in the atmosphere. The GCM is forced by linearized cooling and friction
parameterizations, with hyperdiffusion and a polar Fourier filter to maintain numerical
stability. Atmospheric superrotation is a robust feature of the model and is spontaneously
produced without specific tuning. A strong meridional circulation develops in the form
of a single Hadley cell, extending from the equator to the pole in both hemispheres, and
from the surface to 50 km altitude. The zonal jets produced by this circulation reach
45 ms-1 at 60 km, with peak winds of 35 ms-1 at the equator. A warm pole and cold
collar are also found in the GCM, caused by adiabatic warming in the mean
meridional circulation. Wave frequencies and zonal wind speeds are smaller than in
observations by cloud tracking but are consistent with a Doppler shifting by wind speeds
in the generating region of each wave. Magnitudes of polar temperature anomalies are
smaller than the observed features, suggesting dynamical processes alone may not
be sufficient to maintain the large observed temperature contrasts at the
magnitudes and periods found in this GCM.

Viewing alternatives

Download history

Metrics

Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions

Item Actions

Export

About

Recommendations