Structure of precipitating systems over Taiwan’s complex terrain during Typhoon Morakot (2009) as revealed by weather radar and rain gauge observations

摘要: Summary This study documents from an observational perspective the structure of precipitation systems over complex topography Taiwan as Typhoon Morakot (2009) impinged on island 8 August 2009. An advanced multiple-Doppler radar synthesis technique particularly designed for dealing with non-flat surfaces is applied to analyze three-dimensional wind fields ocean and terrain. In northern southern portion analysis domain where mountain slope relatively gentle steep, respectively, reflectivity measurements indicate that exhibit very distinct features, namely, horizontal translation in north abrupt intensification south. While still far mountainous region, a north–south oscillation east–west-oriented band strong (>40 dBZ) span 20 km observed. Along slopes, has much wider extent. Both rain gauge observations show major primarily confined windward side mountains. saturated Brunt–Vaisala frequency reveals upstream atmosphere statically unstable, which implies lifting incoming convective cells by will easily trigger precipitation. Thus, most moisture be consumed before air reaches leeward The long duration wide range heavy regions resulted record-breaking average (over gauges) rainfall amount 2000 mm 4 days. prevailing winds approaching mountains are west. cross-barrier speed maximum (∼40 m s −1 ) above crest can reasonably explained simplified shallow water model. capability applying weather provide reliable quantitative estimate large area high temporal spatial resolution demonstrated using dual-polarimetric data. potential applications knowledge characteristics hydrology other addressed this manuscript.