Abstract
Simulation results are presented from a new general circulation model (GCM) of Titan, the Titan Atmospheric Model (TAM), which couples the Flexible Modeling System (FMS) spectral dynamical core to a suite of external/sub-grid-scale physics. These include a new non-gray radiative transfer module that takes advantage of recent data from Cassini-Huygens, large-scale condensation and quasi-equilibrium moist convection schemes, a surface model with "bucket" hydrology, and boundary layer turbulent diffusion. The model produces a realistic temperature structure from the surface to the lower mesosphere, including a stratopause, as well as satisfactory superrotation. The latter is shown to depend on the dynamical core's ability to build up angular momentum from surface torques. Simulated latitudinal temperature contrasts are adequate, compared to observations, and polar temperature anomalies agree with observations. In the lower atmosphere, the insolation distribution is shown to strongly impact turbulent fluxes, and surface heating is maximum at mid-latitudes. Surface liquids are unstable at mid- and low-latitudes, and quickly migrate poleward. The simulated humidity profile and distribution of surface temperatures, compared to observations, corroborate the prevalence of dry conditions at low latitudes. Polar cloud activity is well represented, though the observed mid-latitude clouds remain somewhat puzzling, and some formation alternatives are suggested.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 516-528 |
| Number of pages | 13 |
| Journal | Icarus |
| Volume | 250 |
| DOIs | |
| State | Published - Apr 1 2015 |
Fingerprint
Keywords
- Atmospheres, dynamics
- Titan, atmosphere
- Titan, clouds
- Titan, hydrology
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
GCM simulations of Titan's middle and lower atmosphere and comparison to observations. / Lora, Juan M.; Lunine, Jonathan I.; Russell, Joellen.
In: Icarus, Vol. 250, 01.04.2015, p. 516-528.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - GCM simulations of Titan's middle and lower atmosphere and comparison to observations
AU - Lora, Juan M.
AU - Lunine, Jonathan I.
AU - Russell, Joellen
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Simulation results are presented from a new general circulation model (GCM) of Titan, the Titan Atmospheric Model (TAM), which couples the Flexible Modeling System (FMS) spectral dynamical core to a suite of external/sub-grid-scale physics. These include a new non-gray radiative transfer module that takes advantage of recent data from Cassini-Huygens, large-scale condensation and quasi-equilibrium moist convection schemes, a surface model with "bucket" hydrology, and boundary layer turbulent diffusion. The model produces a realistic temperature structure from the surface to the lower mesosphere, including a stratopause, as well as satisfactory superrotation. The latter is shown to depend on the dynamical core's ability to build up angular momentum from surface torques. Simulated latitudinal temperature contrasts are adequate, compared to observations, and polar temperature anomalies agree with observations. In the lower atmosphere, the insolation distribution is shown to strongly impact turbulent fluxes, and surface heating is maximum at mid-latitudes. Surface liquids are unstable at mid- and low-latitudes, and quickly migrate poleward. The simulated humidity profile and distribution of surface temperatures, compared to observations, corroborate the prevalence of dry conditions at low latitudes. Polar cloud activity is well represented, though the observed mid-latitude clouds remain somewhat puzzling, and some formation alternatives are suggested.
AB - Simulation results are presented from a new general circulation model (GCM) of Titan, the Titan Atmospheric Model (TAM), which couples the Flexible Modeling System (FMS) spectral dynamical core to a suite of external/sub-grid-scale physics. These include a new non-gray radiative transfer module that takes advantage of recent data from Cassini-Huygens, large-scale condensation and quasi-equilibrium moist convection schemes, a surface model with "bucket" hydrology, and boundary layer turbulent diffusion. The model produces a realistic temperature structure from the surface to the lower mesosphere, including a stratopause, as well as satisfactory superrotation. The latter is shown to depend on the dynamical core's ability to build up angular momentum from surface torques. Simulated latitudinal temperature contrasts are adequate, compared to observations, and polar temperature anomalies agree with observations. In the lower atmosphere, the insolation distribution is shown to strongly impact turbulent fluxes, and surface heating is maximum at mid-latitudes. Surface liquids are unstable at mid- and low-latitudes, and quickly migrate poleward. The simulated humidity profile and distribution of surface temperatures, compared to observations, corroborate the prevalence of dry conditions at low latitudes. Polar cloud activity is well represented, though the observed mid-latitude clouds remain somewhat puzzling, and some formation alternatives are suggested.
KW - Atmospheres, dynamics
KW - Titan, atmosphere
KW - Titan, clouds
KW - Titan, hydrology
UR - http://www.scopus.com/inward/record.url?scp=84921477068&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84921477068&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2014.12.030
DO - 10.1016/j.icarus.2014.12.030
M3 - Article
AN - SCOPUS:84921477068
VL - 250
SP - 516
EP - 528
JO - Icarus
JF - Icarus
SN - 0019-1035
ER -