In this paper, some data analyses and theoretical discussion show that there are frequentactivities of stronger aerotroughs (cold surges) in East Asia during the wintertime priorto the occurrence of El Nino, and the d...In this paper, some data analyses and theoretical discussion show that there are frequentactivities of stronger aerotroughs (cold surges) in East Asia during the wintertime priorto the occurrence of El Nino, and the disturbance energies acompanied with the stronger coldsurges in East Asia are frequently dispersed southeastward from Siberia to the central westernPacific. The trade winds will be weakened and the convections will be enhanced over theequatorial central western Pacific by the strong cold surges. Then the El Nino event willoccur. A possible important process or mechanism to cause the El Nino event is suggested.展开更多
This report briefly summarizes recent progress in storm surge forecasts, one of topics discussed during the fourth International Workshop on Tropical Cyclone Landfall Process(IWTCLP 4) held during 5-8 December, 2017. ...This report briefly summarizes recent progress in storm surge forecasts, one of topics discussed during the fourth International Workshop on Tropical Cyclone Landfall Process(IWTCLP 4) held during 5-8 December, 2017. In the workshop, improvement of storm surge forecasting system was mainly discussed with relevance to the problem of estimating the impacts of tropical cyclone landfall.To deal with storm surges, accurate TC condition(predictions and forecasts) as input, reasonable storm surge predictions(with forecasting systems), and effective advisories/warnings(i.e. useful information products) are necessary. Therefore, we need to improve storm surge related matters systematically: input, prediction system, and ef fective information.This report tries to highlight recent progress in the field of storm surges in relation to three key points: improvement in storm surge forecasting models/system, TC conditions as input for storm surge predictions, and informative products for end users.展开更多
A storm surge is an abnormal sharp rise or fall in the seawater level produced by the strong wind and low pressure field of an approaching storm system.A storm tide is a water level rise or fall caused by the combined...A storm surge is an abnormal sharp rise or fall in the seawater level produced by the strong wind and low pressure field of an approaching storm system.A storm tide is a water level rise or fall caused by the combined effect of the storm surge and an astronomical tide.The storm surge depends on many factors,such as the tracks of typhoon movement,the intensity of typhoon,the topography of sea area,the amplitude of tidal wave,the period during which the storm surge couples with the tidal wave.When coupling with different parts of a tidal wave,the storm surges caused by a typhoon vary widely.The variation of the storm surges is studied.An once-in-a-century storm surge was caused by Typhoon 7203 at Huludao Port in the north of the Liaodong Bay from July 26th to 27th,1972.The maximum storm surge is about 1.90 m.The wind field and pressure field used in numerical simulations in the research were derived from the historical data of the Typhoon 7203 from July 23rd to 28th,1972.DHI Mike21 is used as the software tools.The whole Bohai Sea is defined as the computational domain.The numerical simulation models are forced with sea levels at water boundaries,that is the tide along the Bohai Straits from July 18th to 29th（2012）.The tide wave and the storm tides caused by the wind field and pressure field mentioned above are calculated in the numerical simulations.The coupling processes of storm surges and tidal waves are simulated in the following way.The first simulation start date and time are 00：00 July 18th,2012; the second simulation start date and time are 03：00 July 18th,2012.There is a three-hour lag between the start date and time of the simulation and that of the former one,the last simulation start date and time are 00：00 July 25th,2012.All the simulations have a same duration of 5 days,which is same as the time length of typhoon data.With the first day and the second day simulation output,which is affected by the initial field,being ignored,only the 3rd to 5th day simulation results are used to study the r展开更多
Abnormal glacier movement is likely to result in canyon-type hazards chain,such as the barrier lake of Yarlung Zangbo Grand Canyon formed by glacier debris flow in October 2018 in China.Glacier hazard usually evolves ...Abnormal glacier movement is likely to result in canyon-type hazards chain,such as the barrier lake of Yarlung Zangbo Grand Canyon formed by glacier debris flow in October 2018 in China.Glacier hazard usually evolves from the glacier surge and may occur in a regular cycle.Understanding the characteristics and process of glacier surge is important for early hazard recognition and hazard assessment.Based on field investigations,remote sensing interpretations and SAR offset-tracking surveys,this study confirms a typical glacier surge in the northeast Pamir,and presents its characteristics and processes."Black ice"mixed moraines choking uplift and overflowing lateral marine are the most important scenic characteristics,which were formed under the conditions of stagnant glacier downstream and abundant super-glacial moraine.Glacier movement event can be divided into a five-period cycle including quiescent,inoculation,initiation,fracture and decline.This surge event lasted for about 300 days,initiated in February 2015 developed extensive fracturing zone in spring and early summer at maximum velocity of 10±0.95 m/day,declined after August 2015 and recovered to quiescent status in October 2015 for the next inoculation.The average height of glacier"receiving"area increased by 20-40 m with 2.7-3.6×10^8 m^3 ice transferred from glacier"reservoir",and this volume accumulation again require 50-100 years for glacier mass balance which gives approximately 100 years frequency of the glacier surge.Nevertheless,long-period increase of precipitation and temperature were favorable for the occurrence,hydrological instability is the direct triggering mechanism,and while the Glacier Lake Outburst Flood(GLOF)hazards are unlikely to occur with this surge.展开更多
Lithological, petrographic, and morphoscopic studies were conducted on cuttings and cores from three boreholes drilled in the Loemé salt, Kanga site, Republic of the Congo, to determine 1) the preferential condit...Lithological, petrographic, and morphoscopic studies were conducted on cuttings and cores from three boreholes drilled in the Loemé salt, Kanga site, Republic of the Congo, to determine 1) the preferential conditions for crystallization of carnallite and associated salts and 2) to reconstruct paleoenvironmental and paleoclimatic conditions at the time of sedimentation. Sequential analysis of logs, sedimentary structures, carnallitite facies and associated salts concluded to the existence of a potassic carnallitite lagoon basin with low water cover, on a very wide and extensive plateau, affected by coastal waves and swells resulting from successive collapses. This basin evolved in two phases: confined and then open. The regular stratifications of halite, the rhythmicity of the halite-carnallitite elementary sequences are characteristic of salts that precipitated in relatively stable brines. These salts are therefore tectonosedimentary. The brecciated facies of the carnallitites sometimes associated with tachyhydrite result from the evolution of these deposits into salt crusts reworked by the surges into subaquatic allochemical gravelly cords under water. These crusts mark stages of partial and complete drying of the basin in a very hot and arid climate. Prolonged exposure of halite brines as well as their homogenization by surges accelerated evaporation and their abrupt evolution into carnallite brines obstructing the fossilization of sylvite. The precipitation of tachyhydrite marks the final stage of the successive complete drying of the basin.展开更多
The purpose of this paper is to explore how a tropical cyclone forms from a pre-existing large-scale depression which has been observed and associated with cross-equatorial surges in the western North Pacific. Tropica...The purpose of this paper is to explore how a tropical cyclone forms from a pre-existing large-scale depression which has been observed and associated with cross-equatorial surges in the western North Pacific. Tropical cyclone Bilis(2000) was selected as the case to study.The research data used are from the results of the non-hydrostatic mesoscale model(MM5),which has successfully simulated the transformation of a pre-existing weak large-scale tropical depression into a strong tropical storm.The scale separation technique is used to separate the synoptic-scale and sub-synoptic-scale fields from the model output fields. The scale-separated fields show that the pre-existing synoptic-scale tropical depression and the subsynoptic scale tropical cyclone formed later were different scale systems from beginning to end.It is also shown that the pre-existing synoptic-scale tropical depression did not contract to become the tropical cyclone. A series of weak,sub-synoptic-scale low and high pressure systems appeared and disappeared in the synopticscale depression,with one of the low systems near the center of the synoptic-scale depression having deepened to become the tropical cyclone. The roles of the synoptic-scale flow and the sub-synoptic scale disturbances in the formation of the tropical cyclone are investigated by diagnoses of the scale-separated vertical vorticity equation.The results show that the early development of the sub-synoptic scale vortex was fundamentally dependent on the strengthening synoptic-scale environmental depression.The depression was strengthened by cross-equatorial surges,which increased the convergence of the synoptic-scale depression at low levels and triggered the formation of the tropical cyclone.展开更多
The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide sur...The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.展开更多
Storm surges are one of the most dangerous natural phenomena for the estuary of the Amur River. The generation of surges in this area was investigated by means of a two-dimensional numerical model. The accuracy of the...Storm surges are one of the most dangerous natural phenomena for the estuary of the Amur River. The generation of surges in this area was investigated by means of a two-dimensional numerical model. The accuracy of the numerical calculation was verified by comparison of computed and observed sea levels. A series of numerical experiments was executed to estimate the influence of hypothetical anthropogenic processes on the variation of maximum storm surge heights.展开更多
Rockfalls in reservoirs are prone to induce surges, posing a severe threat to passing vessels and facilities. A scheme combined Single-phase freesurface method(SPF), momentum exchange method(MEM), and Lattice Boltzman...Rockfalls in reservoirs are prone to induce surges, posing a severe threat to passing vessels and facilities. A scheme combined Single-phase freesurface method(SPF), momentum exchange method(MEM), and Lattice Boltzmann method(LBM) is proposed to predict the impact of rockfall-induced surges. First, the LBM-SPF model is used to simulate the motion of the free surface, and the MEM model is used to calculate the hydrodynamic force acting on rock mass. To address the incompatibility issue arising from the coupling of LBM-SPF model and MEM model, a correction scheme inside the solid is induced. The simulation results of the single particle and double particle sedimentation in cavity show the feasibility and accuracy of the method designed in this paper. Moreover, the validation experiments of Scott Russel’s wave generator show that the proposed scheme can simulate wave profile stably. The simulation results emphasize that the waves induced by rockfalls have a significant impact on the safe operation of the Laxiwa dam and the passing vessels in the reservoir.展开更多
A two-dimensional coupled tide-surge model was used to investigate the effects of tide-surge interactions on storm surges along the coast of the Bohai Sea, Yellow Sea, and East China Sea. In order to estimate the impa...A two-dimensional coupled tide-surge model was used to investigate the effects of tide-surge interactions on storm surges along the coast of the Bohai Sea, Yellow Sea, and East China Sea. In order to estimate the impacts of tide-surge interactions on storm surge elevations, Typhoon 7203 was assumed to arrive at 12 different times, with all other conditions remaining constant. This allowed simulation of tide and total water levels for 12 separate cases. Numerical simulation results for Yingkou, Huludao, Shijiusuo, and Lianyungang tidal stations were analyzed. Model results showed wide variations in storm surge elevations across the 12 cases. The largest difference between 12 extreme storm surge elevation values was of up to 58 cm and occurred at Yingkou tidal station. The results indicate that the effects of tide-surge interactions on storm surge elevations are very significant. It is therefore essential that these are taken into account when predicting storm surge elevations.展开更多
The 2014–2016 El Ni?o events consist of a stalled El Ni?o event in the winter of 2014/2015 and a following extreme El Ni?o event in the end of 2015.Neither event was successfully predicted in operational prediction m...The 2014–2016 El Ni?o events consist of a stalled El Ni?o event in the winter of 2014/2015 and a following extreme El Ni?o event in the end of 2015.Neither event was successfully predicted in operational prediction models.Because of the unusual evolutions of these events that rarely happened in the historical observations,few experience was ready for understanding and predicting the two El Ni?o events when they occurred.Also due to their specialties,considerable attention were attracted with aims to reveal the hidden mechanisms.This article reviews the recent progresses and knowledge that were obtained in these studies.Emerging from these studies,it was argued that the key factor that was responsible for the stalled El Ni?o in 2014 was the unexpected summertime Easterly Wind Surges(EWSs)or the lack of summertime Westerly Wind Bursts(WWBs).Most operational prediction models failed to reproduce such stochastic winds and thus made unrealistic forecasts.The two El Ni?o events awakened the research community again to incorporate the state-of-the-art climate models to simulate the stochastic winds and investigate their roles in the development of El Nino.展开更多
To reduce typhoon-caused damages, numerical and empirical methods are often used to forecast typhoon storm surge. However, typhoon surge is a complex nonlinear process that is difficult to forecast accurately. We appl...To reduce typhoon-caused damages, numerical and empirical methods are often used to forecast typhoon storm surge. However, typhoon surge is a complex nonlinear process that is difficult to forecast accurately. We applied a principal component back-propagation neural network (PCBPNN) to predict the deviation in typhoon storm surge, in which data of the typhoon, upstream flood, and historical case studies were involved. With principal component analysis, 15 input factors were reduced to five principal components, and the application of the model was improved. Observation data from Huangpu Park in Shanghai, China were used to test the feasibility of the model. The results indicate that the model is capable of predicting a 12-hour warning before a typhoon surge.展开更多
Marine dynamic disasters,including storm surges,huge waves,and sea ice,are the most harmful natural disasters aff ecting coastal countries in the world.Under the infl uence of global climate change,the mechanisms,freq...Marine dynamic disasters,including storm surges,huge waves,and sea ice,are the most harmful natural disasters aff ecting coastal countries in the world.Under the infl uence of global climate change,the mechanisms,frequencies,and damage severity of marine dynamic disasters are exhibiting new characteristics.The enormity,unpredictability,and chain eff ects of these disasters have become increasingly prominent,and the losses endured by coastal countries around the world have been increasing year by year.Therefore,the prediction of,risk assessment for,and emergency response to marine dynamic disasters are important issues for disaster prevention and mitigation worldwide.展开更多
A combined numerical model of wind, wave, tide, and storm surges was built on the basis of the “wind field model in limited sea surface areas”. When used to forecast the sea surface wind, wave height and water level...A combined numerical model of wind, wave, tide, and storm surges was built on the basis of the “wind field model in limited sea surface areas”. When used to forecast the sea surface wind, wave height and water level, it can describe them very well.展开更多
文摘In this paper, some data analyses and theoretical discussion show that there are frequentactivities of stronger aerotroughs (cold surges) in East Asia during the wintertime priorto the occurrence of El Nino, and the disturbance energies acompanied with the stronger coldsurges in East Asia are frequently dispersed southeastward from Siberia to the central westernPacific. The trade winds will be weakened and the convections will be enhanced over theequatorial central western Pacific by the strong cold surges. Then the El Nino event willoccur. A possible important process or mechanism to cause the El Nino event is suggested.
基金a part of the fund of the project "Study the mechanism of the after-runner storm surge in the north coast of Vietnam by a coupled numerical model and propose the improvement technology of forecasting storm surge under the climate change"Vietnam National Foundation for Science and Technology Development (NAFOSTED)
文摘This report briefly summarizes recent progress in storm surge forecasts, one of topics discussed during the fourth International Workshop on Tropical Cyclone Landfall Process(IWTCLP 4) held during 5-8 December, 2017. In the workshop, improvement of storm surge forecasting system was mainly discussed with relevance to the problem of estimating the impacts of tropical cyclone landfall.To deal with storm surges, accurate TC condition(predictions and forecasts) as input, reasonable storm surge predictions(with forecasting systems), and effective advisories/warnings(i.e. useful information products) are necessary. Therefore, we need to improve storm surge related matters systematically: input, prediction system, and ef fective information.This report tries to highlight recent progress in the field of storm surges in relation to three key points: improvement in storm surge forecasting models/system, TC conditions as input for storm surge predictions, and informative products for end users.
文摘A storm surge is an abnormal sharp rise or fall in the seawater level produced by the strong wind and low pressure field of an approaching storm system.A storm tide is a water level rise or fall caused by the combined effect of the storm surge and an astronomical tide.The storm surge depends on many factors,such as the tracks of typhoon movement,the intensity of typhoon,the topography of sea area,the amplitude of tidal wave,the period during which the storm surge couples with the tidal wave.When coupling with different parts of a tidal wave,the storm surges caused by a typhoon vary widely.The variation of the storm surges is studied.An once-in-a-century storm surge was caused by Typhoon 7203 at Huludao Port in the north of the Liaodong Bay from July 26th to 27th,1972.The maximum storm surge is about 1.90 m.The wind field and pressure field used in numerical simulations in the research were derived from the historical data of the Typhoon 7203 from July 23rd to 28th,1972.DHI Mike21 is used as the software tools.The whole Bohai Sea is defined as the computational domain.The numerical simulation models are forced with sea levels at water boundaries,that is the tide along the Bohai Straits from July 18th to 29th（2012）.The tide wave and the storm tides caused by the wind field and pressure field mentioned above are calculated in the numerical simulations.The coupling processes of storm surges and tidal waves are simulated in the following way.The first simulation start date and time are 00：00 July 18th,2012; the second simulation start date and time are 03：00 July 18th,2012.There is a three-hour lag between the start date and time of the simulation and that of the former one,the last simulation start date and time are 00：00 July 25th,2012.All the simulations have a same duration of 5 days,which is same as the time length of typhoon data.With the first day and the second day simulation output,which is affected by the initial field,being ignored,only the 3rd to 5th day simulation results are used to study the r
基金supported by the National Key R&D Program of China (2018YFC1505002)CGS Research Fund (JYYWF20181501)+1 种基金National Natural Science Foundation of China (41672359)Chinese Academy of Sciences President’s International Fellowship Initiative (grant No. 2018PC0009)
文摘Abnormal glacier movement is likely to result in canyon-type hazards chain,such as the barrier lake of Yarlung Zangbo Grand Canyon formed by glacier debris flow in October 2018 in China.Glacier hazard usually evolves from the glacier surge and may occur in a regular cycle.Understanding the characteristics and process of glacier surge is important for early hazard recognition and hazard assessment.Based on field investigations,remote sensing interpretations and SAR offset-tracking surveys,this study confirms a typical glacier surge in the northeast Pamir,and presents its characteristics and processes."Black ice"mixed moraines choking uplift and overflowing lateral marine are the most important scenic characteristics,which were formed under the conditions of stagnant glacier downstream and abundant super-glacial moraine.Glacier movement event can be divided into a five-period cycle including quiescent,inoculation,initiation,fracture and decline.This surge event lasted for about 300 days,initiated in February 2015 developed extensive fracturing zone in spring and early summer at maximum velocity of 10±0.95 m/day,declined after August 2015 and recovered to quiescent status in October 2015 for the next inoculation.The average height of glacier"receiving"area increased by 20-40 m with 2.7-3.6×10^8 m^3 ice transferred from glacier"reservoir",and this volume accumulation again require 50-100 years for glacier mass balance which gives approximately 100 years frequency of the glacier surge.Nevertheless,long-period increase of precipitation and temperature were favorable for the occurrence,hydrological instability is the direct triggering mechanism,and while the Glacier Lake Outburst Flood(GLOF)hazards are unlikely to occur with this surge.
文摘Lithological, petrographic, and morphoscopic studies were conducted on cuttings and cores from three boreholes drilled in the Loemé salt, Kanga site, Republic of the Congo, to determine 1) the preferential conditions for crystallization of carnallite and associated salts and 2) to reconstruct paleoenvironmental and paleoclimatic conditions at the time of sedimentation. Sequential analysis of logs, sedimentary structures, carnallitite facies and associated salts concluded to the existence of a potassic carnallitite lagoon basin with low water cover, on a very wide and extensive plateau, affected by coastal waves and swells resulting from successive collapses. This basin evolved in two phases: confined and then open. The regular stratifications of halite, the rhythmicity of the halite-carnallitite elementary sequences are characteristic of salts that precipitated in relatively stable brines. These salts are therefore tectonosedimentary. The brecciated facies of the carnallitites sometimes associated with tachyhydrite result from the evolution of these deposits into salt crusts reworked by the surges into subaquatic allochemical gravelly cords under water. These crusts mark stages of partial and complete drying of the basin in a very hot and arid climate. Prolonged exposure of halite brines as well as their homogenization by surges accelerated evaporation and their abrupt evolution into carnallite brines obstructing the fossilization of sylvite. The precipitation of tachyhydrite marks the final stage of the successive complete drying of the basin.
基金sponsored by the National Program on Key Basic Research Project(973 Program) under Grant No.2009CB421500the National Natural Science Foundation of China under Grant No.40675026.
文摘The purpose of this paper is to explore how a tropical cyclone forms from a pre-existing large-scale depression which has been observed and associated with cross-equatorial surges in the western North Pacific. Tropical cyclone Bilis(2000) was selected as the case to study.The research data used are from the results of the non-hydrostatic mesoscale model(MM5),which has successfully simulated the transformation of a pre-existing weak large-scale tropical depression into a strong tropical storm.The scale separation technique is used to separate the synoptic-scale and sub-synoptic-scale fields from the model output fields. The scale-separated fields show that the pre-existing synoptic-scale tropical depression and the subsynoptic scale tropical cyclone formed later were different scale systems from beginning to end.It is also shown that the pre-existing synoptic-scale tropical depression did not contract to become the tropical cyclone. A series of weak,sub-synoptic-scale low and high pressure systems appeared and disappeared in the synopticscale depression,with one of the low systems near the center of the synoptic-scale depression having deepened to become the tropical cyclone. The roles of the synoptic-scale flow and the sub-synoptic scale disturbances in the formation of the tropical cyclone are investigated by diagnoses of the scale-separated vertical vorticity equation.The results show that the early development of the sub-synoptic scale vortex was fundamentally dependent on the strengthening synoptic-scale environmental depression.The depression was strengthened by cross-equatorial surges,which increased the convergence of the synoptic-scale depression at low levels and triggered the formation of the tropical cyclone.
文摘The author’s combined numerical model consisting of a third generation shallow water wave model and a 3 D tide surge model with wave dependent surface wind stress were used to study the influence of waves on tide surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.
文摘Storm surges are one of the most dangerous natural phenomena for the estuary of the Amur River. The generation of surges in this area was investigated by means of a two-dimensional numerical model. The accuracy of the numerical calculation was verified by comparison of computed and observed sea levels. A series of numerical experiments was executed to estimate the influence of hypothetical anthropogenic processes on the variation of maximum storm surge heights.
基金supported by the National Natural Science Foundation of China (Nos.41902290,42007276,41972297)Program of Hundred Promising Innovative Talents in Hebei provincial education office (No.SLRC2019027)Natural Science Foundation of Hebei Province (Nos.D2020202002,D2021202001)。
文摘Rockfalls in reservoirs are prone to induce surges, posing a severe threat to passing vessels and facilities. A scheme combined Single-phase freesurface method(SPF), momentum exchange method(MEM), and Lattice Boltzmann method(LBM) is proposed to predict the impact of rockfall-induced surges. First, the LBM-SPF model is used to simulate the motion of the free surface, and the MEM model is used to calculate the hydrodynamic force acting on rock mass. To address the incompatibility issue arising from the coupling of LBM-SPF model and MEM model, a correction scheme inside the solid is induced. The simulation results of the single particle and double particle sedimentation in cavity show the feasibility and accuracy of the method designed in this paper. Moreover, the validation experiments of Scott Russel’s wave generator show that the proposed scheme can simulate wave profile stably. The simulation results emphasize that the waves induced by rockfalls have a significant impact on the safe operation of the Laxiwa dam and the passing vessels in the reservoir.
基金provided by the National Natural Science Foundation of China(Grant No.41371496)the National Science and Technology Support Program(Grant No.2013BAK05B04)+2 种基金the Natural Science Foundation of Shandong Province of China(Grant No.ZR2014DM017)the Opening Fund of Shandong Provincial Key Laboratory of Marine Ecology and Environment&Disaster Prevention and Mitigation(Grant No.201411)the Applied Research Fund for Postdoctoral Researchers of Qingdao(Grant No.82214263)
文摘A two-dimensional coupled tide-surge model was used to investigate the effects of tide-surge interactions on storm surges along the coast of the Bohai Sea, Yellow Sea, and East China Sea. In order to estimate the impacts of tide-surge interactions on storm surge elevations, Typhoon 7203 was assumed to arrive at 12 different times, with all other conditions remaining constant. This allowed simulation of tide and total water levels for 12 separate cases. Numerical simulation results for Yingkou, Huludao, Shijiusuo, and Lianyungang tidal stations were analyzed. Model results showed wide variations in storm surge elevations across the 12 cases. The largest difference between 12 extreme storm surge elevation values was of up to 58 cm and occurred at Yingkou tidal station. The results indicate that the effects of tide-surge interactions on storm surge elevations are very significant. It is therefore essential that these are taken into account when predicting storm surge elevations.
基金supported by the National Program on Global Change and Air-sea Interaction(Grant No.GASI-IPOVAI-06)the National Natural Science Foundation of China(Grant Nos.41976015&41805045).
文摘The 2014–2016 El Ni?o events consist of a stalled El Ni?o event in the winter of 2014/2015 and a following extreme El Ni?o event in the end of 2015.Neither event was successfully predicted in operational prediction models.Because of the unusual evolutions of these events that rarely happened in the historical observations,few experience was ready for understanding and predicting the two El Ni?o events when they occurred.Also due to their specialties,considerable attention were attracted with aims to reveal the hidden mechanisms.This article reviews the recent progresses and knowledge that were obtained in these studies.Emerging from these studies,it was argued that the key factor that was responsible for the stalled El Ni?o in 2014 was the unexpected summertime Easterly Wind Surges(EWSs)or the lack of summertime Westerly Wind Bursts(WWBs).Most operational prediction models failed to reproduce such stochastic winds and thus made unrealistic forecasts.The two El Ni?o events awakened the research community again to incorporate the state-of-the-art climate models to simulate the stochastic winds and investigate their roles in the development of El Nino.
基金Supported by National Marine Public Scientific Research Fund of China(No. 200905010)the Talent Training Fund Project for Basic Sciences of the National Natural Science Foundation of China (No. J0730534)+2 种基金the Fundamental Research Funds for the Central Universitiesthe Open Research Funding Program of KLGIS (No. KLGIS2011A12)the Open Fund from Key Laboratory of Marine Management Technique of State Oceanic Administration (No. 201112)
文摘To reduce typhoon-caused damages, numerical and empirical methods are often used to forecast typhoon storm surge. However, typhoon surge is a complex nonlinear process that is difficult to forecast accurately. We applied a principal component back-propagation neural network (PCBPNN) to predict the deviation in typhoon storm surge, in which data of the typhoon, upstream flood, and historical case studies were involved. With principal component analysis, 15 input factors were reduced to five principal components, and the application of the model was improved. Observation data from Huangpu Park in Shanghai, China were used to test the feasibility of the model. The results indicate that the model is capable of predicting a 12-hour warning before a typhoon surge.
基金the National Key Research and Development Program of China’s “Severe marine dynamic disasters: causing mechanism, risk assessment, response technology, and demonstration application” project (No. 2016YFC1402000) for financial support
文摘Marine dynamic disasters,including storm surges,huge waves,and sea ice,are the most harmful natural disasters aff ecting coastal countries in the world.Under the infl uence of global climate change,the mechanisms,frequencies,and damage severity of marine dynamic disasters are exhibiting new characteristics.The enormity,unpredictability,and chain eff ects of these disasters have become increasingly prominent,and the losses endured by coastal countries around the world have been increasing year by year.Therefore,the prediction of,risk assessment for,and emergency response to marine dynamic disasters are important issues for disaster prevention and mitigation worldwide.
基金This work supported by Stress Project(KZ952-S1-420)Chinese Academy of Sciences+1 种基金863 Project(863-818-06-05)(863-818-Q-07).
文摘A combined numerical model of wind, wave, tide, and storm surges was built on the basis of the “wind field model in limited sea surface areas”. When used to forecast the sea surface wind, wave height and water level, it can describe them very well.
