A case study of orographic cyclogenesis over South America
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| Format: | Artículo científico |
| Language: | en |
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Universidad Nacional Autónoma de México
2004
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| _version_ | 1876462067644366848 |
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| author | B. Miky |
| author_facet | B. Miky |
| contents | A case study of orographic cyclogenesis over South America B. Miky E. Caetano M. A Gan Biología Cyclogenesis lee cyclogenesis This study presents a synoptic and dynamic analysis of a cyclogenesis event that occurred between July 8and 9, 1996, over Uruguay, in the region of maximum frequency of cyclogenesis as detected in previousstudies. The study is based on isobaric and isentropic analysis of meteorological variables, and also, onpotential vorticity perspective. The development of the cyclone occurred as a pre-existent midtroposphericcut-off low, over the Pacific Ocean, which propagated crossing over the Andes at the same time as a strongthermal advection was observed to the west of the mountain ridge. The synoptic analysis of this caserevealed that this event can be classified as a lee cyclogenesis, since the existence of the mountain barrierwas fundamental for the intensification of the surface baroclinicity, which, in turn, led to the formation of theextratropical cyclone. Also, the Andes defined the vertical tilt of the system to the west, favoring the cyclonicvorticity advection at higher levels above the warm thermal advection at low levels, and it defined the finalbaroclinic configuration that fed the system in its greater development stage. By using potential vorticityinversion, it was possible to evaluate quantitatively the relative contributions of upper- and low-level potentialvorticity, as well as bottom temperature anomalies. It was observed that the bottom temperature anomaly wasimportant in the initial development stages, contributing to almost 100% of the total circulation. As thesurface cyclone deepened, the contributions of low- and upper- level anomalies became greater. In the stageof maximum development of the system, a phase-locking at low and upper levels seems to occur, where theupper-level advection of cyclonic vorticity, inducing northeasterly flow at surface, had the greater contribution. 2004 artículo científico 0187-6236 https://www.redalyc.org/articulo.oa?id=56517203 en http://www.redalyc.org/revista.oa?id=565 Atmósfera application/pdf Universidad Nacional Autónoma de México Atmósfera (México) Num.2 Vol.17 |
| format | Artículo científico |
| id | redalyc_56517203 |
| institution | Redalyc |
| language | en |
| publishDate | 2004 |
| publisher | Universidad Nacional Autónoma de México |
| spellingShingle | A case study of orographic cyclogenesis over South America B. Miky Biología Cyclogenesis lee cyclogenesis A case study of orographic cyclogenesis over South America B. Miky E. Caetano M. A Gan Biología Cyclogenesis lee cyclogenesis This study presents a synoptic and dynamic analysis of a cyclogenesis event that occurred between July 8and 9, 1996, over Uruguay, in the region of maximum frequency of cyclogenesis as detected in previousstudies. The study is based on isobaric and isentropic analysis of meteorological variables, and also, onpotential vorticity perspective. The development of the cyclone occurred as a pre-existent midtroposphericcut-off low, over the Pacific Ocean, which propagated crossing over the Andes at the same time as a strongthermal advection was observed to the west of the mountain ridge. The synoptic analysis of this caserevealed that this event can be classified as a lee cyclogenesis, since the existence of the mountain barrierwas fundamental for the intensification of the surface baroclinicity, which, in turn, led to the formation of theextratropical cyclone. Also, the Andes defined the vertical tilt of the system to the west, favoring the cyclonicvorticity advection at higher levels above the warm thermal advection at low levels, and it defined the finalbaroclinic configuration that fed the system in its greater development stage. By using potential vorticityinversion, it was possible to evaluate quantitatively the relative contributions of upper- and low-level potentialvorticity, as well as bottom temperature anomalies. It was observed that the bottom temperature anomaly wasimportant in the initial development stages, contributing to almost 100% of the total circulation. As thesurface cyclone deepened, the contributions of low- and upper- level anomalies became greater. In the stageof maximum development of the system, a phase-locking at low and upper levels seems to occur, where theupper-level advection of cyclonic vorticity, inducing northeasterly flow at surface, had the greater contribution. 2004 artículo científico 0187-6236 https://www.redalyc.org/articulo.oa?id=56517203 en http://www.redalyc.org/revista.oa?id=565 Atmósfera application/pdf Universidad Nacional Autónoma de México Atmósfera (México) Num.2 Vol.17 |
| title | A case study of orographic cyclogenesis over South America |
| topic | Biología Cyclogenesis lee cyclogenesis |
| url | https://www.redalyc.org/articulo.oa?id=56517203 |