A Study To Sereral Climatological Chanctenstic Of Binary Tropical Cyclone Interaction

Binary tropical cyclone interaction is a common phenomenon causing greater forecasting errors. With new data and new criterion, climatological variation characteristics of binary tropical cyclone, such as interannual and seasonal varaiation, original region is helpfol to understand this phenomenon and improve binary tropical cyclone prediction.Most study fousing Pacific Ocean in 20th century and simply combining four parameters, we use the best track data of tropical cyclones (TCs) from Joint Typhoon Warming Center (JTWC) and National Hurricane Center (NOAA-NHC) from 1970-2012, on the basis of generalizing existing Criterion, focusing on the coexist cyclone, which the minimum separation distance is less than 3000 Km, the differences of 6-hr angular change, separation distance change, intensity change between binary tropical cyclones and tropical cyclone pairs is examined. New criterion come forward, which is 1.During the coexist time, the separation distance is less than Rt at one point, at the same time both TCs are on the open ocean; 2. During the coexist time, the separation distance between R1-R2 at least 18 hours, and had attained, at some point, at least one tropical storm status; 3. During the coexist time, the separation distance between R2～R3 at least 48 hours, and had attained, at some point, at least tropical storm status and separation distance less than R’. Then, climatological variation characteristics of binary tropical cyclone, such as interannual and seasonal varaiation, original region are discussed.It is found that, hardly any tropical cylone is single, most of them are multi-TCs, with similar results in different ocean areas and grades. Global storms pairs subject to binary tropical cyclone 13.2 annually over the past 43 years, with a slight growth trends. Northwest Pacific Ocean is the most active region. The number of tropical cyclones in Northeast Pacific Ocean is nearly equal to North Atlantic Ocean, while Northeast Pacific Ocean has much more binary tropical cyclone. The number of tropical cyclones has an obvious yearly variation, and much more tropical cyclone in 1990-1996 than other years. Meanwhile, binary tropical cyclone is proportion to tropical cyclone number on the annual and seasonal scale in global scale, but not in the ocean area.In Northwest Pacific Ocean binary tropical cyclones originate from west of 165°E,4°N-25°N region, mainly from Caroline Islands, central South China Sea, West Philippine Basin, while Northeast Pacific Ocean are concentrated in 105°W～125°W,9°～18° region, with some location generating high frequency binary tropical cyclone. In North Atlantic Ocean, binary tropical cyclones dispersedly originate from 10°N～15°N,10°W～70°W region, deviating from SST warm area. Hardly any binary tropical cylone occurs in South Atlantic Ocean, Centeral Pacific Ocean, North Indian Ocean and Southwest Pacific. In Rose Diagram, binary teopical cyclone most among 330°～360°,0°～+30°,150°～210° and most of them are less than 1600 Km, which means storms pairs subject to binary tropical cyclone closely related to original location.