Journal article
The non‐conservation of potential vorticity by a dynamical core compared with the effects of parametrized physical processes
- Abstract:
- Numerical models of the atmosphere combine a dynamical core, which approximates solutions to the adiabatic, frictionless governing equations for fluid dynamics, with tendencies arising from the parametrization of other physical processes. Since potential vorticity (PV) is conserved following fluid flow in adiabatic, frictionless circumstances, it is possible to isolate the effects of non‐conservative processes by accumulating PV changes in an air‐mass‐relative framework. This ‘PV tracer technique’ is used to accumulate separately the effects on PV of each of the different non‐conservative processes represented in a numerical model of the atmosphere. Dynamical cores are not exactly conservative because they introduce, explicitly or implicitly, some level of dissipation and adjustment of prognostic model variables which acts to modify PV. Here, the PV tracers technique is extended to diagnose the cumulative effect of the non‐conservation of PV by a dynamical core and its characteristics relative to the PV modification by parametrized physical processes. Quantification using the Met Office Unified Model reveals that the magnitude of the non‐conservation of PV by the dynamical core is comparable to those from physical processes. Moreover, the residual of the PV budget, when tracing the effects of the dynamical core and physical processes, is at least an order of magnitude smaller than the PV tracers associated with the most active physical processes. The implication of this work is that the non‐conservation of PV by a dynamical core can be assessed in case‐studies with a full suite of physics parametrizations and directly compared with the PV modification by parametrized physical processes. The non‐conservation of PV by the dynamical core is shown to move the position of the extratropical tropopause while the parametrized physical processes have a lesser effect at the tropopause level.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
Actions
Access Document
- Files:
-
-
(Preview, Version of record, pdf, 1.5MB, Terms of use)
-
- Publisher copy:
- 10.1002/qj.2729
Authors
- Publisher:
- Royal Meteorological Society
- Journal:
- Quarterly Journal of the Royal Meteorological Society More from this journal
- Volume:
- 142
- Issue:
- 696
- Pages:
- 1265-1275
- Publication date:
- 2016-02-05
- Acceptance date:
- 2015-12-16
- DOI:
- EISSN:
-
1477-870X
- ISSN:
-
0035-9009
- Keywords:
- Pubs id:
-
pubs:734264
- UUID:
-
uuid:52c6908f-154c-4eb8-b405-8bc22e5f6951
- Local pid:
-
pubs:734264
- Source identifiers:
-
734264
- Deposit date:
-
2018-03-20
- ARK identifier:
Terms of use
- Copyright holder:
- Saffin et al
- Copyright date:
- 2016
- Notes:
- © 2015 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
If you are the owner of this record, you can report an update to it here: Report update to this record