{"ob_id":24957,"uuid":"f66c26bcf7684ed29d14a88825884a19","title":"BITMAP: Western Disturbance Tracks Algorithm","abstract":"Tracks generated using a bespoke tracking algorithm, identifying and linking upper-tropospheric vortices (described fully in Hunt et al, 2018, QJRMS - see linked documentation to this record), using data derived from ERA-Interim reanalysis data and selected CMIP5 model runs (with some modifications such as the vorticity level used).\r\n\r\nIn essence the algorithm works by:\r\n\r\n1. locating all mid-tropospheric relative vorticity maxima;\r\n\r\n2. group multiple peaks by using a neighbourhood filter, then integrate to find the parent vortex centre;\r\n\r\n3. link potential candidates together across time steps to form tracks using a nearest-neighbour approach incorporating local wind speed;\r\n\r\n4. surviving tracks are filtered by duration (> 2 days) and location (must pass through [20-36.5N, 60-80E]).","keywords":"BITMAP, India, Western disturbances, Vortices","inputDescription":null,"outputDescription":null,"softwareReference":null,"identifier_set":[]}