A5071448630- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Climate variability and models
- Precipitation Measurement and Analysis
- Ocean Waves and Remote Sensing
- Soil Moisture and Remote Sensing
- Coastal and Marine Dynamics
- Geophysics and Gravity Measurements
- Flood Risk Assessment and Management
- Wind and Air Flow Studies
- Atmospheric aerosols and clouds
- Landslides and related hazards
- Plant Water Relations and Carbon Dynamics
- Oceanographic and Atmospheric Processes
- GNSS positioning and interference
- Radio Wave Propagation Studies
- Earthquake and Tsunami Effects
- Fire effects on ecosystems
- Atmospheric and Environmental Gas Dynamics
- Statistical and numerical algorithms
- Geological and Geophysical Studies
- Climate Change, Adaptation, Migration
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Infrastructure Resilience and Vulnerability Analysis
- Solar and Space Plasma Dynamics
National Taiwan University
2013-2024
National Taipei University
2021
City University of Hong Kong
2019
NSF National Center for Atmospheric Research
2019
National Science and Technology Council
2012
National Central University
2006
Abstract During the presummer rainy season (April–June), southern China often experiences frequent occurrences of extreme rainfall, leading to severe flooding and inundations. To expedite efforts in improving quantitative precipitation forecast (QPF) Meteorological Administration (CMA) initiated a nationally coordinated research project, namely, Southern Monsoon Rainfall Experiment (SCMREX) that was endorsed by World Organization (WMO) as development project (RDP) Weather Research Programme...
Abstract A long‐lived mesoscale convective system (MCS) with extreme rainfall over the western coastal region of Guangdong on 10 May 2013 during Southern China Monsoon Rainfall Experiment (SCMREX) is studied. The environmental conditions are characterized by little inhibition, low‐lifting condensation level, moderate available potential energy and precipitable water, lack low‐level jets from tropical ocean. Repeated back building subsequent northeastward “echo training” cells found MCS's...
Abstract This study investigates a long-duration mesoscale system with extremely heavy rainfall over southwest Taiwan during the Terrain-influenced Monsoon Rainfall Experiment (TiMREX). convective develops offshore and stays quasi-stationary upstream ocean coast of Taiwan. New convection keeps developing but decays or dies after moving into island, dropping heaviest rain coastal regions. Warm, moist, unstable conditions low-level jet (LLJ) are found only ocean, while island is under control...
Deducing the three-dimensional primary circulation of landfalling tropical cyclones (TCs) from single ground-based Doppler radar data remains a difficult task. The evolution and structure TCs their interactions with terrain are left uncharted due to lack dual-Doppler observations. Existing single-Doppler TC algorithms provide only qualitative information on axisymmetric center location intensity. In order improve understanding wind structures using widely available WSR-88D along U.S. coastal...
Abstract The spatial and temporal characteristics distributions of thunderstorms in Taiwan during the warm season (May–October) from 2005 to 2008 under weak synoptic-scale forcing are documented using radar reflectivity, lightning, radiosonde, surface data. Average hourly rainfall amounts peaked midafternoon (1500–1600 local solar time, LST). maximum frequency rain was located a narrow strip, parallel orientation mountains, along lower slopes mountains. Significant diurnal variations were...
Typhoon Morakot hit Taiwan the night of 7 August 2009 as a Category 1 storm and caused up to 3000 mm rain, leading worst flooding there in 50 years well devastating mudslides.The Weather Research Forecasting model (WRF) is used at high resolution simulate this extreme weather event.The results indicate that WRF able capture amount location observed surface rainfall typhoon-induced circulation, orographic lifting moisture-abundant southwest flow are main mechanisms together produced...
Radial velocity (Vr) and reflectivity (Z) data from eight coastal operational radars of mainland China Taiwan are assimilated for the first time using ARPS 3DVAR cloud analysis package Pacific Typhoon Meranti 2010. It is shown that vortex‐scale circulations can be adequately established after only 2 hourly assimilation cycles while additional provide more details subvortex‐scale structures. Subsequent 12 h forecasts typhoon structure, intensity, track, precipitation greatly improved over one...
Four types (2D-video disdrometer: 2DVD; precipitation occurrence sensor system: POSS; micro-rain radar: MRR; and Joss–Waldvogel JWD) of sixteen instruments were collocated within a square area 400 m2 from 16 April to 8 May 2008 for intercomparison drop size distribution (DSD) rain. This unique dataset was used study the inherent measurement uncertainty due diversity measuring principles sampling sizes four instruments. The DSD shows generally good agreement among them, except that POSS MRR...
Abstract Three years’ worth of radar reflectivity data from four radars in an area complex terrain (Taiwan) 2005 to 2007 were analyzed and a climatology was developed. The applied the construction new hybrid scans minimize impacts ground clutter beam blockages. showed significant seasonal variations captured distributions ground/sea clutters, blockages, anomalous propagations addition precipitation systems domains. By comparing with gauge observations, it found that 15 (20) dBZ good...
Severe convective storms frequently occur in Taiwan, bringing heavy rainfall, strong winds, and lightning. These events significantly disrupt critical infrastructure, including railways, by causing operational delays damage to facilities. The proximity of the railway network high-frequency thunderstorm zones highlights need for tailored meteorological applications mitigate these risks. Heavy rainfall wind gust are key characteristics severe storms. Analysis a event Taipei Basin...
This paper is the third of a series that focuses on applications ground-based velocity track display (GBVTD) technique and GBVTD-simplex center finding algorithm developed in previous two papers to real tropical cyclone (TC). The evolution structure Typhoon Alex (1987), including full tangential winds, mean radial one component flow, their derived axisymmetric angular momentum perturbation pressure fields are reconstructed from 16 volume scans (6.5 h data with 2-h gap) Civil Aeronautic...
Abstract During the Terrain-Influenced Monsoon Rainfall Experiment (TiMREX), which coincided with Taiwan’s Southwesterly Experiment—2008 (SoWMEX-08), upper-air sounding network over Taiwan region was enhanced by increasing radiosonde (“sonde”) frequency at its operational sites and adding several additional (three that were land based two ship based) aircraft dropsondes. special observing period of TiMREX (from 15 May to 25 June 2008), 2330 observations successfully taken from network. Part...
Abstract Extreme weather events, such as typhoons, have occurred more frequently in the last few decades Philippines. The heavy precipitation caused by typhoons is difficult to measure with traditional instruments, rain gauges and ground‐based radar because these instruments an uneven distribution remote areas. Satellite data sets (SPDs) provide integrated spatial coverage of rainfall measurements, even for However, speed direction wind has interaction terrain, which leads uncertainty SPDs....
Abstract This study documents offshore convective lines along the southeastern coast of Taiwan, a frequent but poorly understood mesoscale phenomenon that influences coastal weather during Taiwan mei-yu season. Doppler radar and surface observations were gathered from specially chosen period (11–15 May 1998) when active off Taiwan. These used to show basic character, structure, possible formative processes lines. The synoptic environment accompanying these events was found be relatively...
Landfalling Typhoon Saomai (2006) was observed by the CINRAD WSR‐98D radar on southeast coast of China. This study documents formation and evolution a concentric eyewall episode using axisymmetric circulation derived from ground‐based velocity track display technique. Saomai's outer formed after reaching its peak intensity, ∼5 hours before landfall. Updraft, tangential wind maximum shallow low‐level inflow coincided with high reflectivity voriticity ring in both inner eyewalls, surrounding...
The physical characteristics of rain are reflected by the shape raindrop size distribution (RDSD). Specifically, RDSD is result different precipitation formation processes. We measured at surface in heavy rainfall during SoWMEX/TiMREX (2008) Taiwan. was characterized a squall line accompanied trailing stratiform precipitation, and it partitioned into three regions based on radar reflectivity patterns: convective line, stratiform, trough. further center, leading edge, edge using threshold...
Abstract In this study, a fuzzy logic algorithm is developed to provide objective guidance for the prediction of afternoon thunderstorms in northern Taiwan using preconvective predictors during warm season (May–October) from 2005 2008. The are derived surface stations and sounding measurements. study limited 277 days when synoptic forcing was weak thermal instability produced by solar heating primarily responsible thunderstorm initiation. contains 29 associated weights. weights based on...
In this study, the 2.5 km Cloud-Resolving Storm Simulator was applied to forecast rainfall by three landfalling typhoons in Philippines at high resolution: Mangkhut (2018), Koppu (2015), and Melor using a time-lagged strategy for ensemble. The penetrated northern Luzon, central middle of Philippine Archipelago, respectively, present study verified track quantitative precipitation forecasts (QPFs) categorical statistics against observations 56 rain-gauge sites seven thresholds up 500 mm....
Abstract A tropical cyclone (TC) eye tracking (TCET) algorithm is presented in this study to objectively identify and track the center of a using radar reflectivity data. Twelve typhoon cases were studied for evaluating TCET algorithm. Results show that can TC centers several hours. The longest time about 35 h. Eye locations estimated from different radars showed consistency with mean distance bias 3.5 km standard deviation 1.5 km. analysis shows decreasing radius as TCs approach land,...
Abstract The primary circulation of atmospheric vortices, such as tropical cyclones and tornadoes, can be estimated from single-Doppler radar observations using the ground-based velocity track display (GBVTD) algorithm. GBVTD algorithm has limitations in following four areas: 1) distortion retrieved asymmetric wind fields, 2) a limited analysis domain, 3) inability to resolve cross-beam component mean wind, 4) separate tangential radial winds. This paper presents generalized (GVTD)...
Abstract This study examines a subtropical oceanic mesoscale convective vortex (MCV) that occurred from 1800 UTC 4 June to 1200 6 2008 during intensive observing period (IOP) of the Southwest Monsoon Experiment (SoWMEX) and Terrain-influenced Rainfall (TiMREX). A dissipating system reorganized within nearly barotropic vorticity strip, which formed as southwesterly low-level jet developed south subsiding easterly flow over southern Taiwan Strait. cyclonic circulation was revealed on northern...