The Experts below are selected from a list of 41112 Experts worldwide ranked by ideXlab platform
Chia Chou - One of the best experts on this subject based on the ideXlab platform.
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Changes in precipitation frequency and intensity in the vicinity of Taiwan: Typhoon versus non-Typhoon events
Environmental Research Letters, 2013Co-Authors: Chia ChouAbstract:The hourly rainfall at 21 ground stations in Taiwan is used to investigate changes in the frequency, intensity, and duration of rainfall, which can be divided into Typhoon and non-Typhoon rainfall, in the period of 1970‐2010. As a whole, the frequency of rainfall shows a decreasing trend for lighter rain and an increasing trend for heavier rain. Also, the Typhoon rainfall shows a significant increase for all intensities, while the non-Typhoon rainfall exhibits a general trend of decreasing, particularly for lighter rain. In rainfall intensity, both Typhoon and non-Typhoon rainfall extremes become more intense, with an increased rate much greater than the Clausius‐Clapeyron thermal scaling. Moreover, rainfall extremes associated with Typhoons have tended to affect Taiwan rainfall for longer in recent decades. The more frequent, intense and long-lasting Typhoon rainfall is mainly induced by the slower translation speed of the Typhoons over the neighborhood of Taiwan, which could be associated with a weakening of steering flow in the western North Pacific and the northern South China Sea.
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the abrupt shift of Typhoon activity in the vicinity of taiwan and its association with western north pacific east asian climate change
Journal of Climate, 2009Co-Authors: Jienyi Tu, Chia ChouAbstract:Bayesian analysis is applied to detect changepoints in the time series of seasonal Typhoon counts in the vicinity of Taiwan. An abrupt shift in the Typhoon count series occurs in 2000. On average, 3.3 Typhoons per year have been noted before 2000 (1970‐99), with the rate increasing to 5.7 Typhoons per year since 2000 (2000‐06). This abrupt change is consistent with a northward shift of the Typhoon track over the western North Pacific‐East Asian region and an increase of Typhoon frequency over the Taiwan‐East China Sea region. The northward shift of the Typhoon track tends to be associated with Typhoon-enhancing environmental conditions over the western North Pacific, namely, the weakening of the western North Pacific subtropical high, the strengthening of the Asian summer monsoon trough, and the enhanced positive vorticity anomalies in the lower troposphere. Based on observational analysis and model simulations, warm sea surface temperature anomalies over the equatorial western and central Pacific appear to be a major factor contributing to a northward-shifted Typhoon track.
Hajime Mase - One of the best experts on this subject based on the ideXlab platform.
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Assessment of uncertainties in projecting future changes to extreme storm surge height depending on future SST and greenhouse gas concentration scenarios
Climatic Change, 2020Co-Authors: Jung-a Yang, Nobuhito Mori, Hajime MaseAbstract:We assess uncertainties in projecting future changes in extreme storm surge height (SSH) based on Typhoon data extracted from ensemble experiment results with four sea surface temperature (SST) conditions and three global warming scenarios using a single atmospheric global climate model. In particular, this study focus on Typhoons passing around the Korean Peninsula (KP) defined as the region of 32 to 40° N and 122 to 132° E. It is predicted the number of the Typhoons affecting the KP will decrease by 4~73% while their strength will increase by 0.8~1.4% under the given future conditions. The locations of genesis and lysis of the Typhoons are expected to be shifted towards the northwest and northeast for all ensemble experiment conditions, respectively. However, the extent of their change varies depending on the future SST and global warming conditions. Storm surge simulations were carried out by using predicted Typhoon data as an external force. It is found that future SST patterns and climate warming scenarios affect future Typhoon characteristics, which influences values of extreme SSH and locations of the vulnerable area to storm surge under the future climate conditions. In particular, the values of extreme SSH and the locations of the vulnerable area to storm surge appear to be strongly influenced by both pathway and frequency of intense Typhoons.
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STOCHASTIC Typhoon MODEL AND ITS APPLICATION TO FUTURE Typhoon PROJECTION
Coastal Engineering Proceedings, 2011Co-Authors: Tomohiro Yasuda, Hajime Mase, Shoji Kunitomi, Nobuhito Mori, Yuta HayashiAbstract:This study presents a stochastic Typhoon model (STM) for estimating the characteristics of Typhoons in the present and future climate conditions. Differences of statistical characteristics between present and future Typhoons were estimated from projections by an Atmospheric General Circulation Model (AGCM) under a climate change scenario and are taken into account in the stochastic modelling of future Typhoons as a climate change signal. From the STM results which utilize the Monte Carlo simulation, it was found that the frequency of Typhoon landfall in Osaka bay area, Japan, will decrease, although the mean value of atmospheric central pressure of Typhoon will not change significantly. The arrival probability of stronger Typhoons will increase in the future climate scenario.
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Projection of future Typhoons landing on Japan based on a stochastic Typhoon model utilizing AGCM projections
Hydrological Research Letters, 2010Co-Authors: Tomohiro Yasuda, Hajime Mase, Nobuhito MoriAbstract:This study presents a stochastic Typhoon model (STM) for estimating the characteristics of Typhoons in the present and future climate conditions. Differences between statistical characteristics of present and future Typhoons were estimated from projections by an Atmospheric General Circulation Model (AGCM) under a climate change scenario and are taken into account in the stochastic modeling of future Typhoons as a climate change signal. From the STM results which utilize the Monte Carlo simulation, it was found that the frequency of Typhoon landfall in Japan, especially in three major bay areas, will decrease and the mean value of Typhoon central atmospheric pressure will not change significantly. An important point is that the arrival probability of stronger Typhoons will increase in the future climate scenario.
Kwang-soon Park - One of the best experts on this subject based on the ideXlab platform.
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The effects of a Typhoon-induced oceanic cold wake on Typhoon intensity and Typhoon-induced ocean waves
Journal of Hydro-environment Research, 2017Co-Authors: Ki-young Heo, Kwang-soon ParkAbstract:Abstract In August 2012, binary Typhoon activity occurred near the Korean Peninsula (KP) involving Typhoons Bolaven (1215) and Tembin (1214). Typhoon Bolaven was recorded as the strongest Typhoon to pass over the Yellow Sea since 2000. Typhoon Tembin remained in the southwestern Sea of Taiwan for nine days before moving toward the KP along the track of Typhoon Bolaven. The purpose of this study is to investigate the effects of the oceanic cold wake of Typhoon Bolaven on the intensity, track, and movement speed of Typhoon Tembin. Moreover, we examine the impacts of surface temperature cooling caused by the passing of a previous Typhoon on the intensity of a later Typhoon and Typhoon-induced waves. We use the Advanced Research version of the Weather Research and Forecasting (WRF-ARW) model at grid spacings of 20 km and 4 km in addition to the open ocean wave prediction model (WAM) and the Wavewatch III model (WW3). A large surface temperature cooling caused by vertical mixing and upwelling induced by the previous Typhoon resulted in a significant decrease in intensity and change in the movement speed of the next Typhoon. These results demonstrate that the intensity of the succeeding KP-landfall Typhoon is highly sensitive to the previous Typhoon’s track and resultant upper-ocean thermal structures.
Robert F. Rogers - One of the best experts on this subject based on the ideXlab platform.
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Typhoon kinematic and thermodynamic boundary layer structure from dropsonde composites
Journal of Geophysical Research: Atmospheres, 2015Co-Authors: Jie Ming, Jun A. Zhang, Robert F. RogersAbstract:The data from 438 Global Positioning System dropsondes in six Typhoons are analyzed to investigate the mean atmospheric boundary layer structure in a composite framework. Following a recent study on boundary layer height in Atlantic hurricanes, we aim to quantify characteristics of boundary layer height scales in Western Pacific Typhoons including the inflow layer depth (hinflow), height of the maximum tangential wind speed (hvtmax), and thermodynamic mixed layer depth. In addition, the kinematic and thermodynamic boundary layer structures are compared between the dropsonde composites using data in Typhoons and hurricanes. Our results show that similar to the hurricane composite, there is a separation between the kinematic and thermodynamic boundary layer heights in Typhoons, with the thermodynamic boundary layer depth being much smaller than hinflow and hvtmax in the Typhoon boundary layer. All three boundary layer height scales tend to decrease toward the storm center. Our results confirm that the conceptual model of Zhang et al. (2011a) for boundary layer height variation is applicable to Typhoon conditions. The kinematic boundary layer structure is generally similar between the Typhoon and hurricane composites, but the Typhoon composite shows a deeper inflow layer outside the eyewall than the hurricane composite. The thermodynamic structure of the Typhoon boundary layer composite is warmer and moister outside the radius of maximum wind speed than the hurricane composite. This difference is attributed to different environmental conditions associated with Typhoons compared to the hurricanes studied here.
Yun Hsiang Cheng - One of the best experts on this subject based on the ideXlab platform.
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Empirical relation between the Typhoon surge deviation and the corresponding Typhoon characteristics: a case study in Taiwan
Journal of Marine Science and Technology, 2006Co-Authors: Chyan-deng Jan, Chih Ming Tseng, Ji Shang Wang, Yun Hsiang ChengAbstract:The relation between Typhoon surges and Typhoon characteristics measured at Kenfang Tidal Station on the northeast coast of Taiwan was studied in this paper. Typhoon characteristics include the Typhoon center atmospheric pressure, the Typhoon near-center wind speed, the Typhoon storm radius, the distance between the Typhoon center and the tidal station, and the Typhoon approach tracks. The results show that the Typhoon surge deviation is strongly dependent on Typhoon characteristics. An empirical Typhoon surge formula is proposed in terms of the Typhoon wind speed, the Typhoon storm radius, and the distance between the Typhoon center and the tidal station. The coefficients in the empirical formula were evaluated, based on the measured Typhoon surge data at Kenfang Tidal Station. The storm surge deviations at Kenfang Station during Typhoons Doug (1994) and Herb (1996) estimated using the proposed empirical formula were compared with the measured data as well as with the results of a numerical study.
