Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea
Extended abstract1- Introduction The cloudiness effects on the climate in the southern coasts of Caspian Sea through increasing of humidity, precipitation and cloudiness cooling. Spreading of Caspian Sea in the north of area and Elborze Mountains in the south of area cause suitable conditions to gen...
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University of Isfahan
2012-01-01
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| Series: | جغرافیا و برنامهریزی محیطی |
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| Online Access: | http://uijs.ui.ac.ir/gep/browse.php?a_id=683&sid=1&slc_lang=en |
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| author | H. Nouri H.A. Ghayoor A. Masoudian M. Azadi |
| author_facet | H. Nouri H.A. Ghayoor A. Masoudian M. Azadi |
| author_sort | H. Nouri |
| collection | DOAJ |
| description | Extended abstract1- Introduction The cloudiness effects on the climate in the southern coasts of Caspian Sea through increasing of humidity, precipitation and cloudiness cooling. Spreading of Caspian Sea in the north of area and Elborze Mountains in the south of area cause suitable conditions to generate heavier precipitation in the southern coasts of the Sea when low pressure systems pass from area or high pressure systems are located in around of Caspian Sea. The previous researches showed that convective clouds are the most important cause to generate heavier precipitation but non convective clouds can produce this group of precipitation if they accompany with convective clouds. In this research, kinds of low clouds which produce heavy and super heavy precipitation events were studied. 2- MethodologyPrecipitation events are computed on the basis of daily precipitations (1982 to 2003). Precipitation events were divided into 2 groups heavy and super heavy precipitations after sorting with regard to 25 and 50 percent probability. Then, the classes were grouped into two classes convective and non convective clouds based on clouds synoptic indices. Clouds synoptic indices 2, 3, 8 and 9 show convective clouds as well clouds synoptic indices 4, 5, 6 and 7 show non convective clouds. Convective and non convective clouds which generate heavy and super heavy precipitation events analysis and compare were used METEOSAT 5 images were used to survey and determinate clouds location in different geographic places.3- Discussion Precipitations in the southern coasts of Caspian Sea are different from of the rest of places in Iran both amount and duration. Synoptic and dynamic conditions particularly sea surface temperature over the Sea and cold advection from north to south can be the most important factors to produce the clouds. The previous studies have indicated that the main cause to generate heavier events is convective clouds. The results show that the area is divided into 3 regions on the basis of formation conditions of clouds and its daily and monthly regimes in general. The first region is the west and middle coasts of Caspian Sea. Cumulonimbus clouds (type 3 and then 9) produce heavier precipitation and the frequency of convective clouds in heavy group is less than super heavy group. Frequency maximum is at 03 and 15 o'clock GMT in different months for heavy precipitations group. The second region is the east coasts of Caspian Sea. The convective clouds are the main cause to generate heavier precipitation events and its frequency is more than non convective clouds. The most frequency of convective and non convective clouds is between 03 and 15 o'clock GMT. The third region includes mountainous parts in the middle of area. Cumulonimbus clouds (type 3) which are locally and not spread produce heavier precipitations.4- Conclusion convective precipitations particularly cumulonimbus clouds are the main cause to generate heavy and super heavy precipitation events originally in the southern coasts of Caspian Sea even though non convective have been spread throughout of sky. Non convective clouds have the main role in heavy precipitation than super heavy precipitation. Cloudiness percent and monthly regime aren’t similar in different regions as cloudiness in the west region is more than the east and mountainous places. The frequency maximum is 03 and 12 GMT for convective and non convective clouds respectively. Keywords: convective and nonconvective clouds, heavy and super heavy precipitations, southern coasts of Caspian Sea. ReferencesBoguslavsky, S., Kaminsky, S. and Ivashchenko, I., 1996, The impact of Black Sea on the local thermal and baric processes in the atmosphere, Journal of Physical Oceanography, Vol. 7, No. 5, PP.381-388.Hand, W., Fox, N. and Collier, C., 2004, A study of twentieth-century extreme rainfall events in the United Kingdom with implications for forecasting, Meteorol.Appl, 11, 15-31.Hellstrom, C., 2005, Atmospheric conditions during extreme and non-extreme precipitation events in Sweden, Int. J. Climatol. 25:631-648.Jansa, A., Genoves, A., Picornell, M, Angeles, C., Joan, R. and Carretero, O., 2001, Western Mediterranean cyclones and heavy rain. Part2: Statistical approach, Meteoral. Appl. 8: 43-56.Kato, T. and Aranami, K., 2005, Formation Factors of 2004 Niigata-Fukushima and Fukui heavy rainfalls and problems in the predictions using a Cloud-Resolving Model, SOLA, Vol. 1, 001-004 pp 336-347.Kumar, A., Dudhia, J., Rotunno, R., Niyogi, D. and Mohanty, U., 2008, Analysis of the 26 July 2005 heavy rain event over Mumbai, India using the Weather Research and Forecasting(WRF), Q.J.R. Meteoral. Soc. 134:1897-1910.Kyou, L., Gyun, P. and Wan, K., 2008, Heavy rainfall events lasting 18 days from July 31 to August 17, 1998, over Korea, J. of the Meteorogical Society of Japan, Vol, 86, NO.2, PP.313-333.Lana, A., Campins, J., Genov´es, A. and Jans, A., 2007, Atmospheric patterns for heavy rain events in the Balearic Islands, Advances in Geosciences, 12: 27-32.Lasat, M., Mart, F. and Barrera. A., 2007, From the concept of "Kaltlufttropfen"(cold air pool) to the cut-off low. The case of September 1971 in Spain as example of their role in heavy rainfalls, Meteorol Atmos Phys 96: 43-60. Lenderink, G., van Meijgaard, E., Selten, F., 2009, Intense coastal rainfall in the Netherlands in response to high sea surface temperatures: analysis of the event of August 2006, from the perspective of a changing climate, Clim Dyn, 32:19–33.Mesnard, F., Pujol, O., Sauvageot, H., 2008, Dicrimination between convective and stratiform precipitation in radar-observed rainfield using fuzzy logic, J. Atmospheric science, 28:983-994.Mohapatra, M. and Mohanty, U., 2005, Some characteristics of very heavy rainfall over Orissa during Summer monsoon season, J. Earth Syst.Sci., 114, No. 1, Feburary 2005, PP. 17-36.Persson P., Neiman P., Walter B., Bao J-W., Ralph FM, 2005, Contributions from California coastal-zone surface fluxes to heavy coastal precipitation: a CALJET Case Study during the strong El Nin˜o of 1998. Mon Weather Rev 133:1175–1198Rudari. R., Entekhabi, D. and Roth, G., 2004, Large- scale atmospheric patterns associated with mesoscale features leading to extreme precipitation events in Northwestern Italy, Advances in Water Resources 28: 601-614.Sen Roy, S., 2008, A special analysis of extreme hourly precipitation patterns in India, Int. J. of Climatology, DOI: 10.1002/joc.Lang, S., Zeng, X., Shige, S. And Takayabu, Y., 2009, Relating convective and stratiform rain to latent heating, J. Climate, 24: 7, 1847-1893.Tripoli, G. J., Leung, W.-Y., Mugnai, A., P., Sanò and Smith, E.A., 2008, Impact of above-normal Mediterranean SSTs on heavy rain events, 10th Plinius Conference on Mediterranean Storms, Plinius Conference Abstracts, Vol. 10: 108-123.Ulbrich, C. and Atlas, D., 2002, on the separation of tropical Convective and stratiform rains, J. Appel. Meteor., 41:188-195.Webster, P., Holland, G., Curry J. and Chang H-R., 2005, Changes in tropical cyclone number, duration, and intensity in a warming environment. 309:1844–1846. |
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| last_indexed | 2024-03-12T11:01:05Z |
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| publisher | University of Isfahan |
| record_format | Article |
| series | جغرافیا و برنامهریزی محیطی |
| spelling | doaj.art-f83dfc3e80b54a6aa322245c2306dc2f2023-09-02T05:46:31ZfasUniversity of Isfahanجغرافیا و برنامهریزی محیطی2008-53622252-09102012-01-01233122Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian SeaH. NouriH.A. GhayoorA. MasoudianM. AzadiExtended abstract1- Introduction The cloudiness effects on the climate in the southern coasts of Caspian Sea through increasing of humidity, precipitation and cloudiness cooling. Spreading of Caspian Sea in the north of area and Elborze Mountains in the south of area cause suitable conditions to generate heavier precipitation in the southern coasts of the Sea when low pressure systems pass from area or high pressure systems are located in around of Caspian Sea. The previous researches showed that convective clouds are the most important cause to generate heavier precipitation but non convective clouds can produce this group of precipitation if they accompany with convective clouds. In this research, kinds of low clouds which produce heavy and super heavy precipitation events were studied. 2- MethodologyPrecipitation events are computed on the basis of daily precipitations (1982 to 2003). Precipitation events were divided into 2 groups heavy and super heavy precipitations after sorting with regard to 25 and 50 percent probability. Then, the classes were grouped into two classes convective and non convective clouds based on clouds synoptic indices. Clouds synoptic indices 2, 3, 8 and 9 show convective clouds as well clouds synoptic indices 4, 5, 6 and 7 show non convective clouds. Convective and non convective clouds which generate heavy and super heavy precipitation events analysis and compare were used METEOSAT 5 images were used to survey and determinate clouds location in different geographic places.3- Discussion Precipitations in the southern coasts of Caspian Sea are different from of the rest of places in Iran both amount and duration. Synoptic and dynamic conditions particularly sea surface temperature over the Sea and cold advection from north to south can be the most important factors to produce the clouds. The previous studies have indicated that the main cause to generate heavier events is convective clouds. The results show that the area is divided into 3 regions on the basis of formation conditions of clouds and its daily and monthly regimes in general. The first region is the west and middle coasts of Caspian Sea. Cumulonimbus clouds (type 3 and then 9) produce heavier precipitation and the frequency of convective clouds in heavy group is less than super heavy group. Frequency maximum is at 03 and 15 o'clock GMT in different months for heavy precipitations group. The second region is the east coasts of Caspian Sea. The convective clouds are the main cause to generate heavier precipitation events and its frequency is more than non convective clouds. The most frequency of convective and non convective clouds is between 03 and 15 o'clock GMT. The third region includes mountainous parts in the middle of area. Cumulonimbus clouds (type 3) which are locally and not spread produce heavier precipitations.4- Conclusion convective precipitations particularly cumulonimbus clouds are the main cause to generate heavy and super heavy precipitation events originally in the southern coasts of Caspian Sea even though non convective have been spread throughout of sky. Non convective clouds have the main role in heavy precipitation than super heavy precipitation. Cloudiness percent and monthly regime aren’t similar in different regions as cloudiness in the west region is more than the east and mountainous places. The frequency maximum is 03 and 12 GMT for convective and non convective clouds respectively. Keywords: convective and nonconvective clouds, heavy and super heavy precipitations, southern coasts of Caspian Sea. ReferencesBoguslavsky, S., Kaminsky, S. and Ivashchenko, I., 1996, The impact of Black Sea on the local thermal and baric processes in the atmosphere, Journal of Physical Oceanography, Vol. 7, No. 5, PP.381-388.Hand, W., Fox, N. and Collier, C., 2004, A study of twentieth-century extreme rainfall events in the United Kingdom with implications for forecasting, Meteorol.Appl, 11, 15-31.Hellstrom, C., 2005, Atmospheric conditions during extreme and non-extreme precipitation events in Sweden, Int. J. Climatol. 25:631-648.Jansa, A., Genoves, A., Picornell, M, Angeles, C., Joan, R. and Carretero, O., 2001, Western Mediterranean cyclones and heavy rain. Part2: Statistical approach, Meteoral. Appl. 8: 43-56.Kato, T. and Aranami, K., 2005, Formation Factors of 2004 Niigata-Fukushima and Fukui heavy rainfalls and problems in the predictions using a Cloud-Resolving Model, SOLA, Vol. 1, 001-004 pp 336-347.Kumar, A., Dudhia, J., Rotunno, R., Niyogi, D. and Mohanty, U., 2008, Analysis of the 26 July 2005 heavy rain event over Mumbai, India using the Weather Research and Forecasting(WRF), Q.J.R. Meteoral. Soc. 134:1897-1910.Kyou, L., Gyun, P. and Wan, K., 2008, Heavy rainfall events lasting 18 days from July 31 to August 17, 1998, over Korea, J. of the Meteorogical Society of Japan, Vol, 86, NO.2, PP.313-333.Lana, A., Campins, J., Genov´es, A. and Jans, A., 2007, Atmospheric patterns for heavy rain events in the Balearic Islands, Advances in Geosciences, 12: 27-32.Lasat, M., Mart, F. and Barrera. A., 2007, From the concept of "Kaltlufttropfen"(cold air pool) to the cut-off low. The case of September 1971 in Spain as example of their role in heavy rainfalls, Meteorol Atmos Phys 96: 43-60. Lenderink, G., van Meijgaard, E., Selten, F., 2009, Intense coastal rainfall in the Netherlands in response to high sea surface temperatures: analysis of the event of August 2006, from the perspective of a changing climate, Clim Dyn, 32:19–33.Mesnard, F., Pujol, O., Sauvageot, H., 2008, Dicrimination between convective and stratiform precipitation in radar-observed rainfield using fuzzy logic, J. Atmospheric science, 28:983-994.Mohapatra, M. and Mohanty, U., 2005, Some characteristics of very heavy rainfall over Orissa during Summer monsoon season, J. Earth Syst.Sci., 114, No. 1, Feburary 2005, PP. 17-36.Persson P., Neiman P., Walter B., Bao J-W., Ralph FM, 2005, Contributions from California coastal-zone surface fluxes to heavy coastal precipitation: a CALJET Case Study during the strong El Nin˜o of 1998. Mon Weather Rev 133:1175–1198Rudari. R., Entekhabi, D. and Roth, G., 2004, Large- scale atmospheric patterns associated with mesoscale features leading to extreme precipitation events in Northwestern Italy, Advances in Water Resources 28: 601-614.Sen Roy, S., 2008, A special analysis of extreme hourly precipitation patterns in India, Int. J. of Climatology, DOI: 10.1002/joc.Lang, S., Zeng, X., Shige, S. And Takayabu, Y., 2009, Relating convective and stratiform rain to latent heating, J. Climate, 24: 7, 1847-1893.Tripoli, G. J., Leung, W.-Y., Mugnai, A., P., Sanò and Smith, E.A., 2008, Impact of above-normal Mediterranean SSTs on heavy rain events, 10th Plinius Conference on Mediterranean Storms, Plinius Conference Abstracts, Vol. 10: 108-123.Ulbrich, C. and Atlas, D., 2002, on the separation of tropical Convective and stratiform rains, J. Appel. Meteor., 41:188-195.Webster, P., Holland, G., Curry J. and Chang H-R., 2005, Changes in tropical cyclone number, duration, and intensity in a warming environment. 309:1844–1846.http://uijs.ui.ac.ir/gep/browse.php?a_id=683&sid=1&slc_lang=enconvective and nonconvective cloudsheavy and super heavy precipitationssouthern coasts of Caspian Sea |
| spellingShingle | H. Nouri H.A. Ghayoor A. Masoudian M. Azadi Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea جغرافیا و برنامهریزی محیطی convective and nonconvective clouds heavy and super heavy precipitations southern coasts of Caspian Sea |
| title | Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea |
| title_full | Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea |
| title_fullStr | Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea |
| title_full_unstemmed | Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea |
| title_short | Clouds analysis in heavy and super heavy precipitations in the southern coasts of Caspian Sea |
| title_sort | clouds analysis in heavy and super heavy precipitations in the southern coasts of caspian sea |
| topic | convective and nonconvective clouds heavy and super heavy precipitations southern coasts of Caspian Sea |
| url | http://uijs.ui.ac.ir/gep/browse.php?a_id=683&sid=1&slc_lang=en |
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