{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/70927"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/70927","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Numerical Simulations of the Rapid Cyclogenesis Over Canada and Evolution of a Cold Front Observed on 25-26 April 1979 (sesame-Ave-Iii)","abstract":"The rapid development of a cyclone over Canada and a cold front over the United States were the major weather systems observed on 25-26 April 1979 during the period of SESAME-AVE (Severe Environment Storm and Mesoscale Experiment-Atmospheric Variability Experiment) III. The objectives of this study are two-fold; one is to investigate the mechanisms of this rapid cyclogenesis, the other is to discuss the synoptic- and meso-scale environment with the cold front. A regional scale prediction model, which is the quasi-Lagrangian nested model developed by Mathur (1983) and modified in this study, was used to achieve these objectives. FGGE (First GARP (Global Atmosphere Research Program) Global Experiment) level IIIb and IIb data were used as input and verification data for numerical simulations, and for a diagnostic study.","abstract_html":"The rapid development of a cyclone over Canada and a cold front over the United States were the major weather systems observed on 25-26 April 1979 during the period of SESAME-AVE (Severe Environment Storm and Mesoscale Experiment-Atmospheric Variability Experiment) III. The objectives of this study are two-fold; one is to investigate the mechanisms of this rapid cyclogenesis, the other is to discuss the synoptic- and meso-scale environment with the cold front. A regional scale prediction model, which is the quasi-Lagrangian nested model developed by Mathur (1983) and modified in this study, was used to achieve these objectives. FGGE (First GARP (Global Atmosphere Research Program) Global Experiment) level IIIb and IIb data were used as input and verification data for numerical simulations, and for a diagnostic study.","abstract_has_math":false,"creators":["Juang, Hann-Ming Henry"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Atmospheric Sciences","degree_department":null,"school":null,"contributors":["Ogura, Yoshimitsu,"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-16T04:22:13Z","date_published":"2014-12-16T04:22:13Z","updated_at":"2026-07-22T22:26:03Z","subjects":["Physics, Atmospheric Science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8908724"],"render_values":[{"text":"(UMI)AAI8908724","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/70927","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Ogura, Yoshimitsu,"]},{"key":"dc:creator","label":"Author","values":["Juang, Hann-Ming Henry"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-16T04:22:13Z","10000-01-01","1988"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Atmospheric Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics, Atmospheric Science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8908724","http://hdl.handle.net/2142/70927"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The rapid development of a cyclone over Canada and a cold front over the United States were the major weather systems observed on 25-26 April 1979 during the period of SESAME-AVE (Severe Environment Storm and Mesoscale Experiment-Atmospheric Variability Experiment) III. The objectives of this study are two-fold; one is to investigate the mechanisms of this rapid cyclogenesis, the other is to discuss the synoptic- and meso-scale environment with the cold front. A regional scale prediction model, which is the quasi-Lagrangian nested model developed by Mathur (1983) and modified in this study, was used to achieve these objectives. FGGE (First GARP (Global Atmosphere Research Program) Global Experiment) level IIIb and IIb data were used as input and verification data for numerical simulations, and for a diagnostic study.","There were two cyclones involved in the event over Canada (designated as cyclones A and B). Cyclone A was given rise as a shallow surface pressure low. As the incipient cyclone A was moving southeastward, a region of high potential vorticity in the upper- and mid-troposphere, representing the tropopause folding, closed in. As a result, horizontal advection of absolute vorticity as well as differential temperature advection increased over the center of cyclone A, making cyclone A more intense and deep in its vertical extent. On the other hand, cyclone B was born shallow and remained shallow until it merged with cyclone A. Before merging, it propagated northeastward within a zone of small Richardson number. Further, relative vorticity associated with it had its maximum at the level just above the planetary boundary layer. It is concluded that cyclone B was intensified by localized baroclinic instability. The evolution of these cyclones were well simulated even with a dry model, suggesting that condensation heating was not crucial for their development. The evolution of environments associated with the cold front was well predicted by the model in comparison with the observations. The moist southerly low-level flow provided moisture convergence ahead of the front, while temperature inversion ahead of the southern portion of the cold front prohibited convection there.","Made available in DSpace on 2014-12-16T04:22:13Z (GMT). No. of bitstreams: 1 8908724.pdf: 10821324 bytes, checksum: fda9039aa8f0fe18fd544e84ee28ea70 (MD5) Previous issue date: 1988","Embargo set by: Seth Robbins for item 71093 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","231 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988."]},{"key":"dc:title","label":"Title","values":["Numerical Simulations of the Rapid Cyclogenesis Over Canada and Evolution of a Cold Front Observed on 25-26 April 1979 (sesame-Ave-Iii)"]}]}],"canonical_facts":{"dc:contributor":["Ogura, Yoshimitsu,"],"dc:creator":["Juang, Hann-Ming Henry"],"dc:date":["2014-12-16T04:22:13Z","10000-01-01","1988"],"dc:description":["The rapid development of a cyclone over Canada and a cold front over the United States were the major weather systems observed on 25-26 April 1979 during the period of SESAME-AVE (Severe Environment Storm and Mesoscale Experiment-Atmospheric Variability Experiment) III. The objectives of this study are two-fold; one is to investigate the mechanisms of this rapid cyclogenesis, the other is to discuss the synoptic- and meso-scale environment with the cold front. A regional scale prediction model, which is the quasi-Lagrangian nested model developed by Mathur (1983) and modified in this study, was used to achieve these objectives. FGGE (First GARP (Global Atmosphere Research Program) Global Experiment) level IIIb and IIb data were used as input and verification data for numerical simulations, and for a diagnostic study.","There were two cyclones involved in the event over Canada (designated as cyclones A and B). Cyclone A was given rise as a shallow surface pressure low. As the incipient cyclone A was moving southeastward, a region of high potential vorticity in the upper- and mid-troposphere, representing the tropopause folding, closed in. As a result, horizontal advection of absolute vorticity as well as differential temperature advection increased over the center of cyclone A, making cyclone A more intense and deep in its vertical extent. On the other hand, cyclone B was born shallow and remained shallow until it merged with cyclone A. Before merging, it propagated northeastward within a zone of small Richardson number. Further, relative vorticity associated with it had its maximum at the level just above the planetary boundary layer. It is concluded that cyclone B was intensified by localized baroclinic instability. The evolution of these cyclones were well simulated even with a dry model, suggesting that condensation heating was not crucial for their development. The evolution of environments associated with the cold front was well predicted by the model in comparison with the observations. The moist southerly low-level flow provided moisture convergence ahead of the front, while temperature inversion ahead of the southern portion of the cold front prohibited convection there.","Made available in DSpace on 2014-12-16T04:22:13Z (GMT). No. of bitstreams: 1 8908724.pdf: 10821324 bytes, checksum: fda9039aa8f0fe18fd544e84ee28ea70 (MD5) Previous issue date: 1988","Embargo set by: Seth Robbins for item 71093 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","231 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988."],"dc:identifier":["(UMI)AAI8908724","http://hdl.handle.net/2142/70927"],"dc:subject":["Physics, Atmospheric Science"],"dc:title":["Numerical Simulations of the Rapid Cyclogenesis Over Canada and Evolution of a Cold Front Observed on 25-26 April 1979 (sesame-Ave-Iii)"],"dc:type":["text"],"thesis:degree_discipline":["Atmospheric Sciences"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:03Z"}