The barotropic interaction in the upper troposphere between the synoptic-scale eddies and the Pacific/North American (PNA) pattern is investigated. The study uses NMC data for the years 1965-89 and examines separately the positive and negative phases of the monthly mean PNA anomalies. Northern Hemisphere maps of the eddy kinetic energy, the barotropic conversion between the eddies and the monthly mean flow and the eddy vorticity forcing are presented for both PNA phases. The eddy vorticity forcing of the PNA anomalies by the eddies is presented in terms of monthly mean geopotential tendencies. / It is found that the geopotential tendencies generated by the synoptic-scale eddies are spatially in phase with the PNA anomalies at the 250 hPa level. The characteristic time scale of the forcing in winter is about 6 to 10 days. The strongest anomaly in the eddy forcing is collocated with the largest amplitude PNA centre over the northern Pacific. / During periods of strong PNA patterns, the synoptic-scale eddy kinetic energy and its transfer into the monthly mean flow is most important in the mean jet exits. The maxima in eddy activity and kinetic energy transfer for the positive PNA phase are situated over the eastern Pacific and are significantly greater than the corresponding maxima for the negative phase, which are located over the central Pacific.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.68192 |
| Date | January 1994 |
| Creators | Klasa, Marc |
| Contributors | Derome, Jacques (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Atmospheric and Oceanic Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001394256, proquestno: AAIMM94450, Theses scanned by UMI/ProQuest. |
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