This research evaluates the performance of an eddy-resolving forecast system(LFS)in simulating mesoscale eddies over the South China Sea(SCs)through a comparative analysis with satellite observations and the reanalysi...This research evaluates the performance of an eddy-resolving forecast system(LFS)in simulating mesoscale eddies over the South China Sea(SCs)through a comparative analysis with satellite observations and the reanalysis dataset from the Global Ocean Physics Reanalysis product(CMEMS).The findings indicate that the spatial characteristics of eddy kinetic energy,number,and amplitude of coherent mesoscale eddies simulated by LFS exhibit a reasonable agreement with satellite observations.The reproduced seasonal variations are also comparable to outputs from the CMEMS reanalysis dataset.Nevertheless,certain systematic biases have also been identified.In the SCS,LFS generates approximately 17%fewer eddies than observed.Such biases are also evident in the CMEMS reanalysis dataset.Similar to the statistics shown in the CMEMS reanalysis dataset,both cyclonic and anticyclonic eddies are significantly weaker in LFS compared to the observations.Additionally,the composite three-dimensional structures of mesoscale eddies simulated by LFS exhibit a remarkable similarity to those identified in the CMEMS reanalysis datasets.This work lays the foundation for further studies using LFS to investigate the predictability of mesoscale eddies and enhance the accuracy of simulations.展开更多
Marine forecasting is critical for navigation safety and disaster prevention.However,traditional ocean numerical forecasting models are often limited by substantial errors and inadequate capture of temporal-spatial fe...Marine forecasting is critical for navigation safety and disaster prevention.However,traditional ocean numerical forecasting models are often limited by substantial errors and inadequate capture of temporal-spatial features.To address the limitations,the paper proposes a TimeXer-based numerical forecast correction model optimized by an exogenous-variable attention mechanism.The model treats target forecast values as internal variables,and incorporates historical temporal-spatial data and seven-day numerical forecast results from traditional models as external variables based on the embedding strategy of TimeXer.Using a self-attention structure,the model captures correlations between exogenous variables and target sequences,explores intrinsic multi-dimensional relationships,and subsequently corrects endogenous variables with the mined exogenous features.The model’s performance is evaluated using metrics including MSE(Mean Squared Error),MAE(Mean Absolute Error),RMSE(Root Mean Square Error),MAPE(Mean Absolute Percentage Error),MSPE(Mean Square Percentage Error),and computational time,with TimeXer and PatchTST models serving as benchmarks.Experiment results show that the proposed model achieves lower errors and higher correction accuracy for both one-day and seven-day forecasts.展开更多
在全球气候变化与海平面上升的双重影响下,沿海高潮洪水事件的频次与强度显著增加,已成为制约沿海地区可持续发展的常态化气候风险。传统长期趋势预估与高成本数值模型难以满足日尺度的精细预报需求,促使预报方法不断向概率化、业务化...在全球气候变化与海平面上升的双重影响下,沿海高潮洪水事件的频次与强度显著增加,已成为制约沿海地区可持续发展的常态化气候风险。传统长期趋势预估与高成本数值模型难以满足日尺度的精细预报需求,促使预报方法不断向概率化、业务化方向演进。本文系统综述了沿海高潮洪水概率预报模型的研究进展,重点分析了以美国国家海洋和大气管理局(National Oceanic and Atmospheric Administration,NOAA)研发的概率统计模型为代表的国际前沿技术,进一步对比了国内外在该领域的研究现状与面临的差距和挑战。最后,基于我国沿海环境的复杂性与灾害风险特征,在展望中提出应通过发展数值-统计混合预报系统、构建标准化验证数据集、研发区域适配模型等途径,提升我国沿海高潮洪水预报能力与防灾减灾水平。展开更多
Short-term sea surface temperature(SST)forecasting is an essential operational task around China seas.However,the capability of short-term SST forecast from the dynamical numerical model for China seas has not been fu...Short-term sea surface temperature(SST)forecasting is an essential operational task around China seas.However,the capability of short-term SST forecast from the dynamical numerical model for China seas has not been fully evaluated so far.We assessed the short-term SST forecast skill using a global eddy-resolving ocean forecast system,i.e.,the LICOM Forecast System version 1.0(LFS v1.0)for China seas in 2022 against satellite SST.Results show that LFS v1.0 was able to forecast the short-term SST variation in the study area.The SST with 1-,7-,and 15-d lead time well captured the observed SST with average pattern correlation coefficient(PCC)of 0.94,0.93,and 0.92 throughout 2022,the annual mean bias of the forecasted SST of 0.08,-0.16,and-0.33℃,and the average root mean square error(RMSE)of 0.61,0.72,and 0.90℃,respectively.Geographically,the forecast RMSE with 1-d lead time in China seas increased from south to north,and the values were 0.41℃in South China Sea(SCS)and 1.31℃in the Bohai Sea(BS).In addition,LFS v1.0 showed better forecast SST abilities in the SCS and East China Sea(ECS)than those in the Yellow Sea and BS.In the ECS and SCS,the forecasted SST was less influenced by the ocean bottom topography due to accurately simulated ocean circulations like Kuroshio.The RMSEs of the SST forecasted by LFS v1.0 displayed seasonal variations,smaller in the area from the middle of boreal August to the middle of boreal December,and larger in boreal late spring and early summer.展开更多
Due to complex environmental disturbances,high-precision tidal prediction remains a significant challenge in ocean engineering applications.To address tidal variations characterized by nonlinearity,uncertainty,and tim...Due to complex environmental disturbances,high-precision tidal prediction remains a significant challenge in ocean engineering applications.To address tidal variations characterized by nonlinearity,uncertainty,and time-varying dynamics,a hybrid prediction scheme incorporating adaptive module adjustment(AMA)is proposed.The harmonic analysis method is first applied to model tidal effects induced by the movements of celestial bodies.Subsequently,residual components are decomposed using empirical mode decomposition(EMD),with long short-term memory(LSTM)networks and polynomial fitting(PF)employed to construct the tidal prediction model.The decomposition order for LSTM input time series and the selection of polynomial modules are determined adaptively.Finally,the predictions from harmonic analysis and the ensemble model components are combined to generate the final tidal forecast.Experimental simulations are conducted using observed tidal data from gauges at Canaveral Port and Old Port Tampa.Simulation results demonstrate that the proposed adaptive tidal prediction model outperforms conventional methods in terms of prediction accuracy.展开更多
基金supported by the National Key R&D Program for Developing Basic Sciences [grant number 2022YFC3104805]the National Natural Science Foundation of China [grant numbers 92358302 and 42306219]+1 种基金supported by the Tai Shan Scholar Program [grant number tstp20231237]Laoshan Laboratory project [grant number LSKJ202300301]。
摘要This research evaluates the performance of an eddy-resolving forecast system(LFS)in simulating mesoscale eddies over the South China Sea(SCs)through a comparative analysis with satellite observations and the reanalysis dataset from the Global Ocean Physics Reanalysis product(CMEMS).The findings indicate that the spatial characteristics of eddy kinetic energy,number,and amplitude of coherent mesoscale eddies simulated by LFS exhibit a reasonable agreement with satellite observations.The reproduced seasonal variations are also comparable to outputs from the CMEMS reanalysis dataset.Nevertheless,certain systematic biases have also been identified.In the SCS,LFS generates approximately 17%fewer eddies than observed.Such biases are also evident in the CMEMS reanalysis dataset.Similar to the statistics shown in the CMEMS reanalysis dataset,both cyclonic and anticyclonic eddies are significantly weaker in LFS compared to the observations.Additionally,the composite three-dimensional structures of mesoscale eddies simulated by LFS exhibit a remarkable similarity to those identified in the CMEMS reanalysis datasets.This work lays the foundation for further studies using LFS to investigate the predictability of mesoscale eddies and enhance the accuracy of simulations.
基金supported by the National Key Research and Development Program Project(2023YFC3107804)Planning Fund Project of Humanities and Social Sciences Research of the Ministry of Education(24YJA880097)the Graduate Education Reform Project in North China University of Technology(217051360025XN095-17)。
摘要Marine forecasting is critical for navigation safety and disaster prevention.However,traditional ocean numerical forecasting models are often limited by substantial errors and inadequate capture of temporal-spatial features.To address the limitations,the paper proposes a TimeXer-based numerical forecast correction model optimized by an exogenous-variable attention mechanism.The model treats target forecast values as internal variables,and incorporates historical temporal-spatial data and seven-day numerical forecast results from traditional models as external variables based on the embedding strategy of TimeXer.Using a self-attention structure,the model captures correlations between exogenous variables and target sequences,explores intrinsic multi-dimensional relationships,and subsequently corrects endogenous variables with the mined exogenous features.The model’s performance is evaluated using metrics including MSE(Mean Squared Error),MAE(Mean Absolute Error),RMSE(Root Mean Square Error),MAPE(Mean Absolute Percentage Error),MSPE(Mean Square Percentage Error),and computational time,with TimeXer and PatchTST models serving as benchmarks.Experiment results show that the proposed model achieves lower errors and higher correction accuracy for both one-day and seven-day forecasts.
摘要在全球气候变化与海平面上升的双重影响下,沿海高潮洪水事件的频次与强度显著增加,已成为制约沿海地区可持续发展的常态化气候风险。传统长期趋势预估与高成本数值模型难以满足日尺度的精细预报需求,促使预报方法不断向概率化、业务化方向演进。本文系统综述了沿海高潮洪水概率预报模型的研究进展,重点分析了以美国国家海洋和大气管理局(National Oceanic and Atmospheric Administration,NOAA)研发的概率统计模型为代表的国际前沿技术,进一步对比了国内外在该领域的研究现状与面临的差距和挑战。最后,基于我国沿海环境的复杂性与灾害风险特征,在展望中提出应通过发展数值-统计混合预报系统、构建标准化验证数据集、研发区域适配模型等途径,提升我国沿海高潮洪水预报能力与防灾减灾水平。
基金Supported by the National Key R&D Program of China(No.2022YFC3104802)the National Natural Science Foundations of China(No.92358302)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB0500303).
摘要Short-term sea surface temperature(SST)forecasting is an essential operational task around China seas.However,the capability of short-term SST forecast from the dynamical numerical model for China seas has not been fully evaluated so far.We assessed the short-term SST forecast skill using a global eddy-resolving ocean forecast system,i.e.,the LICOM Forecast System version 1.0(LFS v1.0)for China seas in 2022 against satellite SST.Results show that LFS v1.0 was able to forecast the short-term SST variation in the study area.The SST with 1-,7-,and 15-d lead time well captured the observed SST with average pattern correlation coefficient(PCC)of 0.94,0.93,and 0.92 throughout 2022,the annual mean bias of the forecasted SST of 0.08,-0.16,and-0.33℃,and the average root mean square error(RMSE)of 0.61,0.72,and 0.90℃,respectively.Geographically,the forecast RMSE with 1-d lead time in China seas increased from south to north,and the values were 0.41℃in South China Sea(SCS)and 1.31℃in the Bohai Sea(BS).In addition,LFS v1.0 showed better forecast SST abilities in the SCS and East China Sea(ECS)than those in the Yellow Sea and BS.In the ECS and SCS,the forecasted SST was less influenced by the ocean bottom topography due to accurately simulated ocean circulations like Kuroshio.The RMSEs of the SST forecasted by LFS v1.0 displayed seasonal variations,smaller in the area from the middle of boreal August to the middle of boreal December,and larger in boreal late spring and early summer.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52271361 and 52231014)the Natural Science Foundation of Guangdong Province of China(Grant No.2023A1515010684)the Special Projects of Key Areas for Colleges and Universities of Guangdong Province(Grant No.2021ZDZX1008).
摘要Due to complex environmental disturbances,high-precision tidal prediction remains a significant challenge in ocean engineering applications.To address tidal variations characterized by nonlinearity,uncertainty,and time-varying dynamics,a hybrid prediction scheme incorporating adaptive module adjustment(AMA)is proposed.The harmonic analysis method is first applied to model tidal effects induced by the movements of celestial bodies.Subsequently,residual components are decomposed using empirical mode decomposition(EMD),with long short-term memory(LSTM)networks and polynomial fitting(PF)employed to construct the tidal prediction model.The decomposition order for LSTM input time series and the selection of polynomial modules are determined adaptively.Finally,the predictions from harmonic analysis and the ensemble model components are combined to generate the final tidal forecast.Experimental simulations are conducted using observed tidal data from gauges at Canaveral Port and Old Port Tampa.Simulation results demonstrate that the proposed adaptive tidal prediction model outperforms conventional methods in terms of prediction accuracy.