共查询到16条相似文献，搜索用时 134 毫秒
1.
Three experiments for the simulation of typhoon Sinlaku (2002) over the western North Pacific are performed in this study by using the Canadian Mesoscale Compressible Community (MC2) atmospheric model. The objective of these simulations is to investigate the air-sea interaction during extreme weather conditions, and to determine the sensitivity of the typhoon evolution to the sea surface temperature (SST)cooling induced by the typhoon. It is shown from the three experiments that the surface heat fluxes have a substantial influence on the slow-moving cyclone over its lifetime. When the SST in the East China coastal ocean becomes 1℃ cooler in the simulation, less latent heat and sensible heat fluxes from the underlying ocean to the cyclone tend to reduce the typhoon intensity. The cyclone is weakened by 7 hPa at the time of its peak intensity. The SST cooling also has impacts on the vertical structure of the typhoon by weakening the warm core and drying the eye wall. With a finer horizontal resolution of (1/6)°×(1/6)°, the model produces higher surface wind, and therefore more surface heat fluxes are emitted from the ocean surface to the cyclone, in the finer-resolution MC2 grid compared with the relatively lower resolution of 0.25°×0.25°MC2 grid. 相似文献
2.
WANG Zi-Qianand DUAN An-Min 《大气和海洋科学快报》2012,(3):170-175
A new mesoscale air-sea coupled model (WRF- OMLM-Noh) was constructed based on the Weather Research and Forecasting (WRF) model and an improved Mellor-Yamada ocean mixed-layer model from Noh and Kim (OMLM-Noh). Through off-line tests and a simulation of a real typhoon, the authors compared the performance of the WRF-OMLM-Noh with another existing ocean mixed-layer coupled model (WRF-OMLM-Pollard). In the off-line tests with Tropical Ocean Global Atmosphere Program’s Coupled Ocean Atmosphere Response Experiment (TOGA-COARE) observational data, the results show that OMLM-Noh is better able to simulate sea surface temperature (SST) variational trends than OMLM -Pollard. Moreover, OMLM-Noh can sufficiently reproduce the diurnal cycle of SST. Regarding the typhoon case study, SST cooling due to wind-driven ocean mixing is underestimated in WRF-OMLM-Pollard, which artificially increases the intensity of the typhoon due to more simulated air-sea heat fluxes. Compared to the WRF- OMLM-Pollard, the performance of WRF-OMLM-Noh is superior in terms of both the spatial distribution and temporal variation of SST and air-sea heat fluxes. 相似文献
3.
While previous studies indicate that typhoons can decrease sea surface temperature(SST) along their tracks, a few studies suggest that the cooling patterns in coastal areas are different from those in the open sea. However, little is known about how the induced cooling coupled with the complex ocean circulation in the coastal areas can affect tropical cyclone track and intensity. The sea surface responses to the land falling process of Typhoon Morakot(2009) are examined observationally and its influences on the activity of the typhoon are numerically simulated with the WRF model. The present study shows that the maximum SST cooling associated with Morakot occurred on the left-hand side of the typhoon track during its landfall. Numerical simulations show that, together with the SST gradients associated with the coastal upwelling and mesoscale oceanic vortices, the resulting SST cooling can cause significant difference in the typhoon track, comparable to the current 24-hour track forecasting error. It is strongly suggested that it is essential to include the non-uniform SST distribution in the coastal areas for further improvement in typhoon track forecast. 相似文献
4.
The Impact of Air-Sea Interactions on Typhoon Structure 总被引：1，自引：1，他引：0
In this work,the results of a coupled experiment and an uncoupled experiment conducted in one of our former works are used to analyze the impact of air-sea interactions on the structure of typhoons.Results reveal that typhoon-induced SST decreases to reduce the latent heat fluxes transporting from the ocean to the atmosphere and cause the flux of sensible heat to transfer downward from the atmosphere to the ocean.Such SST reduction also has remarkable impacts on the typhoon structure by making the typhoon more axisymmetric,especially in the middle and high levels.This study also analyzes the basic characteristics of symmetric typhoon structure. 相似文献
5.
Numerical Simulation of Changes in Tropical Cyclone Intensity Using a Coupled Air-Sea Model 总被引：1，自引：0，他引：1
A coupled air-sea model for tropical cyclones （TCs） is constructed by coupling the Pennsylvania State University/National Center for Atmospheric Research mesoscale model （MM5） with the Princeton Ocean Model.Four numerical simulations of tropical cyclone development have been conducted using different configurations of the coupled model on the f-plane.When coupled processes are excluded,a weak initial vortex spins up into a mature symmetric TC that strongly resembles those observed and simulated in prior research.The coupled model reproduces the reduction in sea temperature induced by the TC reasonably well,as well as changes in the minimum central pressure of the TC that result from negative atmosphere-ocean feedbacks.Asymmetric structures are successfully simulated under conditions of uniform environmental flow.The coupled ocean-atmosphere model is suitable for simulating air-sea interactions under TC conditions.The effects of the ocean on the track of the TC and changes in its intensity under uniform environmental flow are also investigated.TC intensity responds nonlinearly to sea surface temperature （SST）.The TC intensification rate becomes smaller once the SST exceeds a certain threshold.Oceanic stratification also influences TC intensity,with stronger stratification responsible for a larger decrease in intensity.The value of oceanic enthalpy is small when the ocean is weakly stratified and large when the ocean is strongly stratified,demonstrating that the oceanic influence on TC intensity results not only from SST distributions but also from stratification.Air-sea interaction has only a slight influence on TC movement in this model. 相似文献
6.
A 72-h cloud-resolving numerical simulation of Typhoon Hato(2017)is performed by using the Weather Research and Forecasting(WRF)model with the Advanced Research WRF(ARW)core(V3.8.1)on a horizontal resolution of2 km.To enhance the background tropical cyclone structure and intensity,a vortex dynamic initialization scheme with a terrain-filtering algorithm is utilized.The model reproduces reasonably well the track,structure,and intensity change of Typhoon Hato.More specifically,the change trend of simulated maximum wind speed is consistent with that of best-track analysis,and the simulated maximum wind of 49 ms^-1 is close to that(52 ms^-1)of the best-track analysis,indicating that the model has successfully captured the rapid intensification(RI)of Typhoon Hato(2017).Analyses of the model outputs reveal that the total microphysical latent heating of the inner-core region associated with enhanced vertical upward motion reaches its maximum at 9-km height in the upper troposphere during the RI stage.The dominant microphysical processes with positive latent heat contributions(i.e.,heating effect)are water vapor condensation into cloud water(67.6%),depositional growth of ice(12.9%),and generation(nucleation)of ice from vapor(7.9%).Those with negative latent heat contributions(cooling effect)are evaporation of rain(47.6%),melting of snow(27.7%),and melting of graupel(9.8%).Sensitivity experiments further show that the intensification speed and peak intensity of this typhoon are highly correlated to the dominant heating effect.A significant increase in graupel over 5-10-km height and snow at 10-14-km height in the inner-core region of Typhoon Hato corresponds well with its RI stage,and the latent heating from nucleation and depositional growth is crucial to the RI of simulated Hato. 相似文献
7.
Based on MM5,POM,and WW3,a regional atmosphere-ocean-wave coupled system is developed in this work under the environment of Message Passing Interface.The coupled system is applied in a study of two typhoon processes in the South China Sea(SCS).The results show that the coupled model operates steadily and efficiently and exhibits good capability in simulating typhoon processes.It improves the simulation accuracy of the track and intensity of the typhoon.The response of ocean surface to the typhoon is remarkable,especially on the right side of the typhoon track.The sea surface temperature(SST)declines,and the ocean current and wave height are intensified.In the coupling experiment,the decline of SST intensifies and the inertial oscillation amplitude of the ocean current increases when the ocean-wave effect is considered.Therefore,the atmosphere-ocean-wave coupled system can help in the study of air-sea interaction and improve the capability of predicting and preventing weather and oceanic disasters in SCS. 相似文献
8.
The upper-ocean responses to Typhoon Megi(2010)are investigated using data from ARGO floats and the satellite TMI.The experiments are conducted using a three-dimensional Princeton Ocean Model(POM)to assess the storm,which affected the Northwest Pacific Ocean(NWP)and the South China Sea(SCS).Results show that the upwelling and entrainment experiment together account for 93% of the SST anomalies,where typhoon-induced upwelling may cause strong ocean cooling.In addition,the anomalous SST cooling is stronger in the SCS than in the NWP.The most striking feature of the ocean response is the presence of a two-layer inertial wave in the SCS—a feature that is absent in the NWP.The near-inertial oscillations can be generated as typhoon wakes,which have maximum flow velocity in the surface mixed layer and may last for a few days,after the typhoon's passage.Along the typhoon tracks,the horizontal currents in the upper ocean show a series of alternating negative and positive anomalies emanating from the typhoon. 相似文献
9.
Tong ZHU Da-Lin ZHANG 《大气科学进展》2006,23(1):14-22
The effects of storm-induced sea surface temperature （SST） cooling on hurricane intensity are investigated using a 5-day cloud-resolving simulation of Hurricane Bonnie （1998）. Two sensitivity simulations are performed in which the storm-induced cooling is either ignored or shifted close to the modeled storm track. Results show marked sensitivity of the model-simulated storm intensity to the magnitude and relative position with respect to the hurricane track. It is shown that incorporation of the storm-induced cooling, with an average value of 1.3℃, causes a 25-hPa weakening of the hurricane, which is about 20 hPa per 1℃ change in SST. Shifting the SST cooling close to the storm track generates the weakest storm, accounting for about 47% reduction in the storm intensity. It is found that the storm intensity changes are well correlated with the air-sea temperature difference. The results have important implications for the use of coupled hurricane-ocean models for numerical prediction of tropical cyclones. 相似文献
10.
LI Weibiao 《大气科学进展》2004,21(2):269-276
It has long been recognized that the evolution ot marine storms may De strongly alIected Dy the nuxtransfer processes over the ocean. High winds in a storm can generate large amounts of spray, which canmodify the transfer of momentum, heat, and moisture across the air-sea interface. However, the role of seaspray and air-sea processes in western Pacific typhoons has remained elusive. In this study, the impact ofsea spray on air-sea fluxes and the evolution of a typhoon over the western Pacific is investigated using acoupled atmosphere-sea-spray modeling system. Through the case study of the recent Typhoon Fengshenfrom 2002, we found that: (1) Sea spray can cause a significant latent heat flux increase of up to 40% ofthe interfacial fluxes in the typhoon; (2) Taking into account the effects of sea spray, the intensity of themodeled typhoon can be increased by 30% in the 10-m wind speed, which may greatly improve estimatesof storm maximum intensity and, to some extent, improve the simulations of overall storm structure in theatmospheric model; (3) The effects of sea spray are mainly focused over the high wind regions around thestorm center and are mainly felt in the lower part of the troposphere. 相似文献
11.
中尺度海-气耦合模式GRAPES_OMLM对台风珍珠的模拟研究 总被引：1，自引：0，他引：1
利用全球/区域同化与预报系统GRAPES(Global/Regional Assimilation and Prediction System)和改进的Mellor-Yamada型海洋混合层模式OMLM(Ocean Mixed Layer Model),建立了一个新的中尺度海-气耦合模式GRAPES_OMLM,并利用该模式对发生于南海的台风珍珠(0601)进行了模拟研究,检验了GRAPES_OMLM对台风的模拟性能,并分析了局地海-气相互作用对台风的影响。结果表明,GRAPES_OMLM基本能模拟出台风天气过程中的主要物理过程。考虑了海-气相互作用的耦合试验所模拟出的台风强度、近台风中心最大风速以及台风后期移动路径,相对于两组控制试验(单独大气模式)的模拟结果都有较大的改进。而且,采用逐日变化海表温度作为下边界条件的控制试验2的模拟结果相对于SST不变的控制试验1更接近观测。耦合模式GRAPES_OMLM能较好地模拟出台风过境海表温度的变化,台风珍珠在其路径右侧有超过4.0℃的降温。SST的变化和海表风应力的变化呈反相关系,风应力的增大伴随着海洋近表层湍流动能(TKE)的加强,大风动力作用是SST降低的主要原因。SST的降低致使海洋向台风输送的热通量减少,进而削弱了台风的强度并改变台风环流结构,同时通过改变位势涡度趋势的一波结构(WN-1)来影响台风的移动路径。 相似文献
12.
利用一个海气耦合模式对台风Krovanh的模拟 总被引：5，自引：1，他引：4
采用中尺度大气模式MM5和区域海洋模式POM构造了中尺度海气耦合模式, 模拟了Krovanh (0312) 台风过程中台风－海洋相互作用, 分析了台风引起的海面降温影响台风强度的机制和海洋对台风响应的特征。试验结果显示: 考虑台风引起的海面降温使台风强度模拟有了较大改进, 模拟的台风中心气压和近中心最大风速均与实况较符合。POM模拟的海表面温度与TRMM/TMI观测的海表面温度也较为一致, 台风Krovanh在其路径右侧95 km处引起较大的海面降温, 最大降温幅度达5.8℃。与海表面温度降低相对应的是混合层深度的增加, 较大的海面降温对应较大的混合层加深, 表明大风夹卷在海表面温度的降低中起主要作用。分析表明, 台风引起的海面降温降低海洋向大气输送的潜热通量和感热通量, 特别是在台风内核区, 平均总热通量减少了32.1%。热通量的减少使得湿静力能及湿静力能径向梯度减小, 削弱了台风强度。 相似文献
13.
LIU Lei FEI Jianfang LIN Xiaopei SONG Xiangzhou HUANG Xiaogang Cheng Xiaoping 《Acta Meteorologica Sinica》2011,25(5):625-638
The high-resolution Weather Research and Forecasting (WRF) model is coupled to the Princeton Ocean Model (POM) to investigate
the effect of air-sea interaction during Typhoon Kaemi that formed in the Northwest Pacific at 0000 UTC 19 July 2006. The
coupled model can reasonably reproduce the major features of ocean response to the moving tropical cyclone (TC) forcing, including
the deepening of ocean mixed layer (ML), cooling of sea surface temperature (SST), and decaying of typhoon. 相似文献
14.
15.
To quantitatively investigate the dynamic and thermal responses of the South China Sea (SCS) during and subsequent to the passage of a real typhoon, a three-dimensional, regional coupled air–sea model is developed to study the upper ocean response of the SCS to Typhoon Krovanh (2003). Owing to the scarcity of ocean observations, the three-dimensional numerical modeling with high resolution, as a powerful tool, offers a valuable opportunity to investigate how the air–sea process proceeds under such extreme conditions. The amplitude and distribution of the cold path produced by the coupled model compare reasonably well with the TRMM/TMI-derived data. The maximum SST cooling is 5.3 °C, about 80 km to the right of the typhoon track, which is consistent with the well-documented rightward bias in the SST response to typhoons. In correspondence to the SST cooling, the mixed layer depth exhibits an increase; the increases in the mixed layer depth on the right of typhoon track are significantly higher than those on the left, with maxima of 58 m. This correspondence indicates that the SST cooling is caused mainly by entrainment. Under the influence of typhoon, a cyclonic, near-surface current field is generated in the upper ocean layer, which moves with the typhoon. The typhoon-induced horizontal currents in the wake of the storm have strong near-inertial oscillation, which gradually propagates downward. The unique features of the SCS response to Typhoon Krovanh are also discussed, such as Kuroshio intrusion and coastal subsurface jets. 相似文献
16.
《热带气象学报(英文版)》2015,(2)
While previous studies indicate that typhoons can decrease sea surface temperature(SST) along their tracks, a few studies suggest that the cooling patterns in coastal areas are different from those in the open sea. However, little is known about how the induced cooling coupled with the complex ocean circulation in the coastal areas can affect tropical cyclone track and intensity. The sea surface responses to the land falling process of Typhoon Morakot(2009) are examined observationally and its influences on the activity of the typhoon are numerically simulated with the WRF model. The present study shows that the maximum SST cooling associated with Morakot occurred on the left-hand side of the typhoon track during its landfall. Numerical simulations show that, together with the SST gradients associated with the coastal upwelling and mesoscale oceanic vortices, the resulting SST cooling can cause significant difference in the typhoon track, comparable to the current 24-hour track forecasting error. It is strongly suggested that it is essential to include the non-uniform SST distribution in the coastal areas for further improvement in typhoon track forecast. 相似文献