Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters
More realistic simulation of hazards caused by Tropical Cyclones (TCs) requires knowledge of the mechanisms that formulate tropical cyclone. Here, sensitivity of an idealized framework has been tested to investigate role of two external parameters in vertical entropy flux. The first parameter contro...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Iranian Association of Naval Architecture and Marine Engineering
2018-11-01
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| Series: | International Journal of Coastal and Offshore Engineering |
| Subjects: | |
| Online Access: | http://ijcoe.org/article-1-124-en.html |
| _version_ | 1818538384013918208 |
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| author | Nafiseh Pegahfar Maryam Gharaylou |
| author_facet | Nafiseh Pegahfar Maryam Gharaylou |
| author_sort | Nafiseh Pegahfar |
| collection | DOAJ |
| description | More realistic simulation of hazards caused by Tropical Cyclones (TCs) requires knowledge of the mechanisms that formulate tropical cyclone. Here, sensitivity of an idealized framework has been tested to investigate role of two external parameters in vertical entropy flux. The first parameter controls the ratio of width of eyewall and downdraft regions to radius of maximum wind and the second parameter controls radial decay of wind velocity between two regions. This numerical model used conservation principles, assumed axi-symmetry and steadiness to model TC vortex, and let ventilation be occurred via the path-ways of downdrafts outside eyewall and eddy fluxes directly into eyewall. To test this framework, Tropical Cyclone Haiyan (TCH, formed over the Western part of Pacific Ocean on 3 November 2013) has been selected. Two kinds of datasets including Joint Typhoon Warning Centers (JTWC) Best Track data of Japan Meteorology Agency and Global Forecast System Analysis (GFS-ANL) data have been used. The model has been run for 60 different configurations, based on change of the two external parameters and size of two random do-mains. The sensitivity of the modeled convective entropy flux to the applied changes has been examined via two different aspects of investigation. In the first aspect, terms of the reference equation of convective entropy flux have been considered and their responses to the changes have been studies. While in the second aspect, values of the convective entropy flux at TCH peak activity time (PAT), before and after that have been inspected. Results, obtained from the first aspect, obviously indicate that the increase of the first external parameter increases the all terms of the referred equation, while increase of the second external parameter influenced the terms differently. Also enlarging the domains’ size does not impress the results similarly. Outcomes of the second aspect reveal that the implemented changes non-uniformly impact the values of the modeled convective entropy flux in the three considered times. |
| first_indexed | 2024-12-11T21:28:18Z |
| format | Article |
| id | doaj.art-2890b66ae78f48608ee8573eb44529d0 |
| institution | Directory Open Access Journal |
| issn | 2538-2667 2588-3186 |
| language | English |
| last_indexed | 2024-12-11T21:28:18Z |
| publishDate | 2018-11-01 |
| publisher | Iranian Association of Naval Architecture and Marine Engineering |
| record_format | Article |
| series | International Journal of Coastal and Offshore Engineering |
| spelling | doaj.art-2890b66ae78f48608ee8573eb44529d02022-12-22T00:50:14ZengIranian Association of Naval Architecture and Marine EngineeringInternational Journal of Coastal and Offshore Engineering2538-26672588-31862018-11-01234151Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External ParametersNafiseh Pegahfar0Maryam Gharaylou1 Atmospheric Research Center, Iranian National Institute for Ocean-ography and Atmospheric Science Institute of Geophysics, University of Tehran More realistic simulation of hazards caused by Tropical Cyclones (TCs) requires knowledge of the mechanisms that formulate tropical cyclone. Here, sensitivity of an idealized framework has been tested to investigate role of two external parameters in vertical entropy flux. The first parameter controls the ratio of width of eyewall and downdraft regions to radius of maximum wind and the second parameter controls radial decay of wind velocity between two regions. This numerical model used conservation principles, assumed axi-symmetry and steadiness to model TC vortex, and let ventilation be occurred via the path-ways of downdrafts outside eyewall and eddy fluxes directly into eyewall. To test this framework, Tropical Cyclone Haiyan (TCH, formed over the Western part of Pacific Ocean on 3 November 2013) has been selected. Two kinds of datasets including Joint Typhoon Warning Centers (JTWC) Best Track data of Japan Meteorology Agency and Global Forecast System Analysis (GFS-ANL) data have been used. The model has been run for 60 different configurations, based on change of the two external parameters and size of two random do-mains. The sensitivity of the modeled convective entropy flux to the applied changes has been examined via two different aspects of investigation. In the first aspect, terms of the reference equation of convective entropy flux have been considered and their responses to the changes have been studies. While in the second aspect, values of the convective entropy flux at TCH peak activity time (PAT), before and after that have been inspected. Results, obtained from the first aspect, obviously indicate that the increase of the first external parameter increases the all terms of the referred equation, while increase of the second external parameter influenced the terms differently. Also enlarging the domains’ size does not impress the results similarly. Outcomes of the second aspect reveal that the implemented changes non-uniformly impact the values of the modeled convective entropy flux in the three considered times.http://ijcoe.org/article-1-124-en.htmltropical cyclone haiyannumerical modelconvective entropy fluxexternal parameters |
| spellingShingle | Nafiseh Pegahfar Maryam Gharaylou Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters International Journal of Coastal and Offshore Engineering tropical cyclone haiyan numerical model convective entropy flux external parameters |
| title | Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters |
| title_full | Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters |
| title_fullStr | Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters |
| title_full_unstemmed | Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters |
| title_short | Sensitivity of an Axi-Symmetric Tropical Cyclone Model to Two External Parameters |
| title_sort | sensitivity of an axi symmetric tropical cyclone model to two external parameters |
| topic | tropical cyclone haiyan numerical model convective entropy flux external parameters |
| url | http://ijcoe.org/article-1-124-en.html |
| work_keys_str_mv | AT nafisehpegahfar sensitivityofanaxisymmetrictropicalcyclonemodeltotwoexternalparameters AT maryamgharaylou sensitivityofanaxisymmetrictropicalcyclonemodeltotwoexternalparameters |