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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Prescribing Zonally Asymmetric Ozone Climatologies in Climate Models
T2 - Performance Compared to a Chemistry-Climate Model
AU - Rae, Cameron D.
AU - Keeble, James
AU - Hitchcock, Peter
AU - Pyle, John A.
N1 - Publisher Copyright: ©2019. The Authors.
PY - 2019/4/30
Y1 - 2019/4/30
N2 - Three different methods of specifying ozone in an atmosphere-only version of the HadGEM3-A global circulation model are compared to the coupled chemistry configuration of this model. These methods include a specified zonal-mean ozone climatology, a specified 3-D ozone climatology, and a calculated-asymmetry scheme in which a specified zonal-mean ozone field is adapted online to be consistent with dynamically produced zonal asymmetries. These simulations all use identical boundary conditions and, by construction, have the same climatological zonal-mean ozone, that of the coupled chemistry configuration of the model. Prescribing ozone, regardless of scheme, results in a simulation which is 3–4 times faster than the coupled chemistry-climate model (CCM). Prescribing climatological zonal asymmetries leads to a vortex which is the correct intensity but which is systematically displaced over regions with lower prescribed ozone. When zonal asymmetries in ozone are free to evolve interactively with model dynamics, the modeled wintertime stratospheric vortex shape and mean sea level pressure patterns closely resemble that produced by the full CCM in both hemispheres, in terms of statistically significant differences. Further, we separate out the two distinct pathways by which zonal ozone asymmetries influence modeled dynamics. We present this interactive-ozone zonal-asymmetry scheme as an inexpensive tool for accurately modeling the impacts of dynamically consistent ozone fields as seen in a CCM which ultimately influence mean sea level pressure and tropospheric circulation (particularly during wintertime in the Northern Hemisphere, when ozone asymmetries are generally largest), without the computational burden of simulating interactive chemistry.
AB - Three different methods of specifying ozone in an atmosphere-only version of the HadGEM3-A global circulation model are compared to the coupled chemistry configuration of this model. These methods include a specified zonal-mean ozone climatology, a specified 3-D ozone climatology, and a calculated-asymmetry scheme in which a specified zonal-mean ozone field is adapted online to be consistent with dynamically produced zonal asymmetries. These simulations all use identical boundary conditions and, by construction, have the same climatological zonal-mean ozone, that of the coupled chemistry configuration of the model. Prescribing ozone, regardless of scheme, results in a simulation which is 3–4 times faster than the coupled chemistry-climate model (CCM). Prescribing climatological zonal asymmetries leads to a vortex which is the correct intensity but which is systematically displaced over regions with lower prescribed ozone. When zonal asymmetries in ozone are free to evolve interactively with model dynamics, the modeled wintertime stratospheric vortex shape and mean sea level pressure patterns closely resemble that produced by the full CCM in both hemispheres, in terms of statistically significant differences. Further, we separate out the two distinct pathways by which zonal ozone asymmetries influence modeled dynamics. We present this interactive-ozone zonal-asymmetry scheme as an inexpensive tool for accurately modeling the impacts of dynamically consistent ozone fields as seen in a CCM which ultimately influence mean sea level pressure and tropospheric circulation (particularly during wintertime in the Northern Hemisphere, when ozone asymmetries are generally largest), without the computational burden of simulating interactive chemistry.
KW - circulation
KW - feedback
KW - interactive chemistry
KW - ozone
KW - stratosphere-troposphere coupling
KW - zonal asymmetries
U2 - 10.1029/2018MS001478
DO - 10.1029/2018MS001478
M3 - Journal article
AN - SCOPUS:85064488554
VL - 11
SP - 918
EP - 933
JO - Journal of Advances in Modeling Earth Systems
JF - Journal of Advances in Modeling Earth Systems
SN - 1942-2466
IS - 4
ER -