Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic
The formation of a blocking anticyclone over the North Atlantic has been examined over its entire life-CyCle using the Zwack-Okossi (Z-O) equation as the diagnostic tool. This blocking anticyclone occurred in late October and early November of 1985. The data used were provided by the NASA Goddard La...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19960038408 2023-05-15T17:31:42+02:00 Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic Smith, Phillip J. Unclassified, Unlimited, Publicly available Mar. 06, 1995 application/pdf http://hdl.handle.net/2060/19960038408 unknown Document ID: 19960038408 Accession ID: 96N30880 http://hdl.handle.net/2060/19960038408 No Copyright CASI Meteorology and Climatology NASA-CR-201430 NAS 1.26:201430 (ISSN 0280-6495) 1995 ftnasantrs 2019-07-21T03:17:49Z The formation of a blocking anticyclone over the North Atlantic has been examined over its entire life-CyCle using the Zwack-Okossi (Z-O) equation as the diagnostic tool. This blocking anticyclone occurred in late October and early November of 1985. The data used were provided by the NASA Goddard Laboratory for Atmospheres on a global 2.O degree latitude by 2.5 degree longitudinal grid. The horizontal distribution of the atmospheric forcing mechanisms that were important to 500 mb block formation, maintenance and decay were examined. A scale-partitioned form of the Z-O equation was then used to examine the relative importance of forcing on the planetary and synoptic scales, and their interactions. As seen in previous studies, the results presented here show that upper tropospheric anticyclonic vorticity advection was the most important contributor to block formation and maintenance. However, adiabatic warming, and vorticity tilting were also important at various times during the block lifetime. In association with precursor surface cyclogenesis, the 300 mb jet streak in the downstream (upstream) from a long-wave trough (ridge) amplified significantly. This strengthening of the jet streak enhanced the anti-cyclonic vorticity advection field that aided the amplification of a 500 mb short-wave ridge. Tile partitioned height tendency results demonstrate that the interactions between the planetary and sn,noptic-scale through vorticity advection was the most important contributor to block formation. Planetary-scale, synoptic-scale. and their interactions contributed weakly to the maintenance of the blocking anticyclone with the advection of synoptic-scale vorticity by the planetary-scale flow playing a more important role. Planetary-scale decay ofthe long-wave ridge contributed to the demise of this blocking event. Other/Unknown Material North Atlantic NASA Technical Reports Server (NTRS) Tilting ENVELOPE(-54.065,-54.065,49.700,49.700) |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
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topic |
Meteorology and Climatology |
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Meteorology and Climatology Smith, Phillip J. Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic |
topic_facet |
Meteorology and Climatology |
description |
The formation of a blocking anticyclone over the North Atlantic has been examined over its entire life-CyCle using the Zwack-Okossi (Z-O) equation as the diagnostic tool. This blocking anticyclone occurred in late October and early November of 1985. The data used were provided by the NASA Goddard Laboratory for Atmospheres on a global 2.O degree latitude by 2.5 degree longitudinal grid. The horizontal distribution of the atmospheric forcing mechanisms that were important to 500 mb block formation, maintenance and decay were examined. A scale-partitioned form of the Z-O equation was then used to examine the relative importance of forcing on the planetary and synoptic scales, and their interactions. As seen in previous studies, the results presented here show that upper tropospheric anticyclonic vorticity advection was the most important contributor to block formation and maintenance. However, adiabatic warming, and vorticity tilting were also important at various times during the block lifetime. In association with precursor surface cyclogenesis, the 300 mb jet streak in the downstream (upstream) from a long-wave trough (ridge) amplified significantly. This strengthening of the jet streak enhanced the anti-cyclonic vorticity advection field that aided the amplification of a 500 mb short-wave ridge. Tile partitioned height tendency results demonstrate that the interactions between the planetary and sn,noptic-scale through vorticity advection was the most important contributor to block formation. Planetary-scale, synoptic-scale. and their interactions contributed weakly to the maintenance of the blocking anticyclone with the advection of synoptic-scale vorticity by the planetary-scale flow playing a more important role. Planetary-scale decay ofthe long-wave ridge contributed to the demise of this blocking event. |
format |
Other/Unknown Material |
author |
Smith, Phillip J. |
author_facet |
Smith, Phillip J. |
author_sort |
Smith, Phillip J. |
title |
Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic |
title_short |
Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic |
title_full |
Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic |
title_fullStr |
Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic |
title_full_unstemmed |
Planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the North Atlantic |
title_sort |
planetary and synoptic-scale interactions during the life cycle of a mid-latitude blocking anticyclone over the north atlantic |
publishDate |
1995 |
url |
http://hdl.handle.net/2060/19960038408 |
op_coverage |
Unclassified, Unlimited, Publicly available |
long_lat |
ENVELOPE(-54.065,-54.065,49.700,49.700) |
geographic |
Tilting |
geographic_facet |
Tilting |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
CASI |
op_relation |
Document ID: 19960038408 Accession ID: 96N30880 http://hdl.handle.net/2060/19960038408 |
op_rights |
No Copyright |
_version_ |
1766129405184180224 |