[ Objective] The research aimed to analyze formation reason of a gale induced by Bohai Sea cyclone. [ Method] Yantai buoy station and Jimu Island automatic station were selected as reference of the actual situation. G...[ Objective] The research aimed to analyze formation reason of a gale induced by Bohai Sea cyclone. [ Method] Yantai buoy station and Jimu Island automatic station were selected as reference of the actual situation. Gale weather process which occurred in Yantai during 26 -27 April, 2010 was analyzed. [ Result] This gale weather was caused by Bohai Sea cyclone. Upper strong cold air invaded, which promoted ground low pressure quickly developing and deepening into Bohai Sea cyclone. Momentum download effect of the upper wind made ground wind speed in- crease. In forecast process of the gale, weather online and Yantai Grapes model both had basic accurate forecasts to magnitude, direction and influ- ence system of the gale, especially to the wind field at 10 m. [Conclusion] This research provided reference basis for forecast of such gale in future.展开更多
The study examined extreme wind characteristics of the coastal communities in Bayelsa State, Nigeria for possible community planning and development. To achieve this aim, data on wind speed were sourced from the Niger...The study examined extreme wind characteristics of the coastal communities in Bayelsa State, Nigeria for possible community planning and development. To achieve this aim, data on wind speed were sourced from the Nigerian Meteorological Agency (NIMET). Personal interview and focused group discussions were done with the aid of well structured questionnaire in the various coastal communities sampled to identify impact and coping strategies from extreme winds. The Beaufort Winds Scale and regression analysis were the statistical tools used for the analysis of the data in order to achieve the objectives of the study. The results indicate that, the return period to obtain maximum 1-year wind speed value of 29.3 m/s (violent storm), 27.8 m/s (storm), 24.3 m/s (strong Gale) and 20.6 m/s (fresh Gale) will be 17 years, 5.7 years, 2.8 years and 1.4 years respectively. Fresh Gale characterized the extreme wind events in the area. Result further showed that out of 19 occurrences of wind events, 11 were extreme cases, while 2 occurred as violent storm of 29.3 m/s. Findings also showed that extreme winds occurred more (8 cases) during the early part (March-April) of the raining season when the area is under the influence of maritime moisture laden air mass than the dry season which is dried and dusty. Using a combination of return period of the magnitude of extreme wind and the log of wind speed for the 16 years a model predicting the incidence of extreme wind was done. Awareness on the dangers of wind hazard increases while early warning systems are advocated to mitigate the associated dangers with extreme wind events in the study area.展开更多
文摘[ Objective] The research aimed to analyze formation reason of a gale induced by Bohai Sea cyclone. [ Method] Yantai buoy station and Jimu Island automatic station were selected as reference of the actual situation. Gale weather process which occurred in Yantai during 26 -27 April, 2010 was analyzed. [ Result] This gale weather was caused by Bohai Sea cyclone. Upper strong cold air invaded, which promoted ground low pressure quickly developing and deepening into Bohai Sea cyclone. Momentum download effect of the upper wind made ground wind speed in- crease. In forecast process of the gale, weather online and Yantai Grapes model both had basic accurate forecasts to magnitude, direction and influ- ence system of the gale, especially to the wind field at 10 m. [Conclusion] This research provided reference basis for forecast of such gale in future.
文摘The study examined extreme wind characteristics of the coastal communities in Bayelsa State, Nigeria for possible community planning and development. To achieve this aim, data on wind speed were sourced from the Nigerian Meteorological Agency (NIMET). Personal interview and focused group discussions were done with the aid of well structured questionnaire in the various coastal communities sampled to identify impact and coping strategies from extreme winds. The Beaufort Winds Scale and regression analysis were the statistical tools used for the analysis of the data in order to achieve the objectives of the study. The results indicate that, the return period to obtain maximum 1-year wind speed value of 29.3 m/s (violent storm), 27.8 m/s (storm), 24.3 m/s (strong Gale) and 20.6 m/s (fresh Gale) will be 17 years, 5.7 years, 2.8 years and 1.4 years respectively. Fresh Gale characterized the extreme wind events in the area. Result further showed that out of 19 occurrences of wind events, 11 were extreme cases, while 2 occurred as violent storm of 29.3 m/s. Findings also showed that extreme winds occurred more (8 cases) during the early part (March-April) of the raining season when the area is under the influence of maritime moisture laden air mass than the dry season which is dried and dusty. Using a combination of return period of the magnitude of extreme wind and the log of wind speed for the 16 years a model predicting the incidence of extreme wind was done. Awareness on the dangers of wind hazard increases while early warning systems are advocated to mitigate the associated dangers with extreme wind events in the study area.
