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Full-Text Articles in Physical Sciences and Mathematics

Climatology And Change Of Extreme Precipitation Events In Taiwan Based On Weather Types, Yi-Chao Wu, Shih-Yu (Simon) Wang, Yi-Chiang Yu, Chu-Ying Kung, An-Hsiang Wang, Sebastian A. Los, Wan-Ru Huang May 2019

Climatology And Change Of Extreme Precipitation Events In Taiwan Based On Weather Types, Yi-Chao Wu, Shih-Yu (Simon) Wang, Yi-Chiang Yu, Chu-Ying Kung, An-Hsiang Wang, Sebastian A. Los, Wan-Ru Huang

Plants, Soils, and Climate Faculty Publications

Taiwan's most significant natural hazards are caused by hydrological extremes resulting from excessive precipitation. The threat of extreme precipitation is posed by several different types of weather patterns that affect Taiwan. This study examined the bi‐decadal changes in rainfall by defining an extreme precipitation occurrence (EPO) for a range of event durations from 1 to 24 hr. Three major weather types affecting EPO in Taiwan were identified from 1993 to 2015: the front type consisting of either a frontal zone or convective systems developing with an apparent Meiyu cloudband, diurnal rainfall events when no apparent synoptic features are present, and …


Multi-Decadal Drought Cycles In The Great Basin Recorded By The Great Salt Lake: Modulation From A Transition-Phase Teleconnection, Shih-Yu (Simon) Wang, Robert R. Gillies, Thomas Reichler Mar 2012

Multi-Decadal Drought Cycles In The Great Basin Recorded By The Great Salt Lake: Modulation From A Transition-Phase Teleconnection, Shih-Yu (Simon) Wang, Robert R. Gillies, Thomas Reichler

Plants, Soils, and Climate Faculty Publications

This study investigates the meteorological conditions associated with multidecadal drought cycles as revealed by lake level fluctuation of the Great Salt Lake (GSL). The analysis combined instrumental, proxy, and simulation datasets, including the Twentieth Century Reanalysis version 2, the North American Drought Atlas, and a 2000-yr control simulation of the GFDL Coupled Model, version 2.1 (CM2.1). Statistical evidence from the spectral coherence analysis points to a phase shift amounting to 6–9 yr between the wet–dry cycles in the Great Basin and the warmcool phases of the interdecadal Pacific oscillation (IPO). Diagnoses of the sea surface temperature and atmospheric …


Sudden Surface Warming/Drying Events Caused By Typhoon Passages Across Taiwan, T. C. Chen, Shih-Yu (Simon) Wang, M. C. Yen, A. J. Clark, J. D. Tsay Feb 2010

Sudden Surface Warming/Drying Events Caused By Typhoon Passages Across Taiwan, T. C. Chen, Shih-Yu (Simon) Wang, M. C. Yen, A. J. Clark, J. D. Tsay

Plants, Soils, and Climate Faculty Publications

Typhoon passages across Taiwan can generate sudden surface warming in downslope regions. Special characteristics and mechanisms for 54 such warming events that were identified during the 1961–2007 period are examined. Preferred warming regions were identified in northwest Taiwan, where warming is generated by downslope flow from east or northeast winds in westward-moving typhoons, and in southeast Taiwan, where it is generated by downslope flow from west or northwest winds in northwestward-moving typhoons. In addition to the orographic effect, warmings occurred exclusively within nonprecipitation zones of typhoons. Most northwest (southeast) warmings occur during the day (night) with an average lifetime of …


Evaluations Of Nam Forecasts On Midtropospheric Perturbation-Induced Convective Storms Over The U.S. Northern Plains, Shih-Yu (Simon) Wang, T. C. Chen, S. E. Taylor Oct 2009

Evaluations Of Nam Forecasts On Midtropospheric Perturbation-Induced Convective Storms Over The U.S. Northern Plains, Shih-Yu (Simon) Wang, T. C. Chen, S. E. Taylor

Plants, Soils, and Climate Faculty Publications

In the U.S. northern plains, summer progressive convective storms that occur in weakly forced environ- ments are often coupled with short-wave perturbations that are embedded in the midlevel northwesterly flow. These midtropospheric perturbations (MPs) are capable of inducing propagating convection that contributes to a majority of the rainfall over the northern plains during July and August. There is a possibility that the difficulties of numerical weather prediction models in forecasting summer convective rainfall over the northern plains are partly attributed to their deficiency in forecasting MPs. The present study tests this possibility through examining operational forecasts by the North American …


Impact Of The Intraseasonal Variability Of Large-Scale Circulation Over The Western North Pacific On The Characteristics Of Tropical Cyclone Track, T. C. Chen, Shih-Yu (Simon) Wang, M. C. Yen, A. J. Clark Jun 2009

Impact Of The Intraseasonal Variability Of Large-Scale Circulation Over The Western North Pacific On The Characteristics Of Tropical Cyclone Track, T. C. Chen, Shih-Yu (Simon) Wang, M. C. Yen, A. J. Clark

Plants, Soils, and Climate Faculty Publications

The life cycle of the Southeast Asian–western North Pacific monsoon circulation is established by the northward migrations of the monsoon trough and the western Pacific subtropical anticyclone, and is reflected by the intraseasonal variations of mo nsoon westerlies and trad e easterlies in the form of an east–west seesaw oscillation. In this paper, an effort is made to disclose the influence of this monsoon circulation on tropical cyclone tracks during its different ph ases using composite charts of large-scale circulation for certain types of tracks. A majority of straight-moving (recurving) tropical cyclones appear during weak (strong) monsoon west- erlies and …


Summary Of The Noaa/Utah Atmospheric Modification Program: 1990-1996, United States Department Of The Interior, Bureau Of Reclamation Sep 1998

Summary Of The Noaa/Utah Atmospheric Modification Program: 1990-1996, United States Department Of The Interior, Bureau Of Reclamation

Meterology

This final report summarizes physical investigations into the artificial nucleation ("seeding") of winter mountain clouds in central Utah during 1990-96. Program goals were to evaluate the effectiveness of the Utah operational cloud seeding program and to recommend improvements. Field programs employed a wide variety of instrumentation systems. Sophisticated numerical modeling was used in conjunction with the observational programs. Amounts and distributions of SLW (supercooled liquid water) cloud were investigated, as was transport and dispersion of ground-released seeding agents and tracer gases. Several experiments directly monitored ice crystals and snowfall rates resulting from either silver iodide (Agl) or liquid propane seeding. …


Precipitation Gauge Testing On The Wasatch Plateau, Utah, During Early 1993, United States Department Of The Interior, Bureau Of Reclamation Nov 1993

Precipitation Gauge Testing On The Wasatch Plateau, Utah, During Early 1993, United States Department Of The Interior, Bureau Of Reclamation

Meterology

The Bureau of Reclamation performed an independent evaluation of an ETI (Electronic Techniques, Inc.) precipitation gauge at the High Altitude Site on the western slope of the Wasatch Plateau in central Utah. The ETI gauge could provide a desirable alternative to conventional recording gauges in several applications, including evaluation of cloud seeding projects, if it performs as advertised. The testing program was intended to determine its performance in a winter mountain environment. The ETI precipitation gauge proved to be reliable from time of installation in late November 1992 until removal in late March 1993. The only problem found was an …