This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the pred...This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the prediction of the movement track and intensity of Typhoon Kompasu in 2021 is examined.Additionally,the possible reasons for their effects on tropical cyclone(TC)intensity prediction are analyzed.Statistical results show that both parameterization schemes improve the predictions of Typhoon Kompasu’s track and intensity.The influence on track prediction becomes evident after 60 h of model integration,while the significant positive impact on intensity prediction is observed after 66 h.Further analysis reveals that these two schemes affect the timing and magnitude of extreme TC intensity values by influencing the evolution of the TC’s warm-core structure.展开更多
This study investigates the width of the secondary eyewall(SE)immediately following its formation in tropical cyclones with surface environmental winds aligned and counter-aligned with environmental vertical wind shea...This study investigates the width of the secondary eyewall(SE)immediately following its formation in tropical cyclones with surface environmental winds aligned and counter-aligned with environmental vertical wind shear(VWS),using idealized numerical experiments.Results reveal that the SE develops greater radial extent when surface winds align with VWS compared to counter-aligned conditions.In alignment configurations,shear-enhanced surface winds on the right flank amplify surface enthalpy fluxes,thereby elevating boundary-layer entropy within the downshear outer-core region.Subsequently,more vigorous outer rainbands develop,inducing marked acceleration of tangential winds in the outer core preceding SE formation.The resultant radial expansion of supergradient winds near the boundary-layer top triggers widespread convective activity immediately beyond the inner core.Progressive axisymmetrization of this convective forcing ultimately generates an expansive SE structure.展开更多
利用台风资料、海南灾情资料、再分析资料和多种统计分析方法,确定1967—2015年影响海南岛的15个强台风事件并探析海南岛强台风事件(Hainan violent typhoon event,HNVTE)的影响因子。结果表明,HNVTE发生的气候背景信息表现为多时间尺...利用台风资料、海南灾情资料、再分析资料和多种统计分析方法,确定1967—2015年影响海南岛的15个强台风事件并探析海南岛强台风事件(Hainan violent typhoon event,HNVTE)的影响因子。结果表明,HNVTE发生的气候背景信息表现为多时间尺度因子的协同作用:1980年代后期西北太平洋副热带高压(以下简称“西北太平洋副高”)突变式变强可能为HNVTE的减少提供了年代际尺度背景,厄尔尼诺-南方涛动(El Ni o-Southern Oscillation,ENSO)和平流层准两年振荡(quasi-biennial oscillation,QBO)的共同作用提供了HNVTE变化的年际异常背景。西北太平洋副高突变前出现中等强度的La Ni a状态和突变后出现中等强度的El Ni o状态均有利于HNVTE发生,而平流层西风位相下低层强西风切变则会抑制这两种状态下的HNVTE活动。根据西北太平洋海面温度的年代际位相、ENSO循环位相及强度和QBO位相及强度构建的BEST-QBO协同作用指数能很好地识别HNVTE的发生,可为HNVTE的气候预测提供有用的信号。展开更多
利用欧洲中期天气预报中心提供的全球大气再分析资料、美国国家海洋和大气管理局提供的高分辨率海表温度逐日数据集和最佳路径数据集(the international best track archive for climate stewardship,IBTrACS)等资料,采用WRF(weather re...利用欧洲中期天气预报中心提供的全球大气再分析资料、美国国家海洋和大气管理局提供的高分辨率海表温度逐日数据集和最佳路径数据集(the international best track archive for climate stewardship,IBTrACS)等资料,采用WRF(weather research and forecasting)模式,对2022年第11号台风“轩岚诺”在东海黑潮快速增强的原因进行了诊断分析和数值模拟研究。结果表明,台风快速增强期间其中心处于东海黑潮主轴上,此时台风中心远离高空槽和高空急流,环境风垂直切变在增强时段维持在较高水平,超过8 m·s^(-1),均不利于台风增强,而东海黑潮区海表温度异常达到1~3℃,为台风发展提供大量热通量,同时26℃等温线深度达85~110 m,0~250 m深度范围内海水温度异常在台风快速增强前达2.5℃左右,表明上层海洋热含量丰富,有助于抑制台风经过引起的冷却作用。因此,东海黑潮区显著的海表温度暖异常和海洋上层热含量正异常对台风的快速增强起了关键作用。展开更多
基金supported by the National Key R&D Program of China[grant number 2023YFC3008004]。
文摘This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the prediction of the movement track and intensity of Typhoon Kompasu in 2021 is examined.Additionally,the possible reasons for their effects on tropical cyclone(TC)intensity prediction are analyzed.Statistical results show that both parameterization schemes improve the predictions of Typhoon Kompasu’s track and intensity.The influence on track prediction becomes evident after 60 h of model integration,while the significant positive impact on intensity prediction is observed after 66 h.Further analysis reveals that these two schemes affect the timing and magnitude of extreme TC intensity values by influencing the evolution of the TC’s warm-core structure.
基金jointly supported by the National Natural Science Foundation of China[grant numbers U2342202,42175005,and 42175016]the Qing Lan Project[grant number R2023Q06]。
文摘This study investigates the width of the secondary eyewall(SE)immediately following its formation in tropical cyclones with surface environmental winds aligned and counter-aligned with environmental vertical wind shear(VWS),using idealized numerical experiments.Results reveal that the SE develops greater radial extent when surface winds align with VWS compared to counter-aligned conditions.In alignment configurations,shear-enhanced surface winds on the right flank amplify surface enthalpy fluxes,thereby elevating boundary-layer entropy within the downshear outer-core region.Subsequently,more vigorous outer rainbands develop,inducing marked acceleration of tangential winds in the outer core preceding SE formation.The resultant radial expansion of supergradient winds near the boundary-layer top triggers widespread convective activity immediately beyond the inner core.Progressive axisymmetrization of this convective forcing ultimately generates an expansive SE structure.
文摘利用台风资料、海南灾情资料、再分析资料和多种统计分析方法,确定1967—2015年影响海南岛的15个强台风事件并探析海南岛强台风事件(Hainan violent typhoon event,HNVTE)的影响因子。结果表明,HNVTE发生的气候背景信息表现为多时间尺度因子的协同作用:1980年代后期西北太平洋副热带高压(以下简称“西北太平洋副高”)突变式变强可能为HNVTE的减少提供了年代际尺度背景,厄尔尼诺-南方涛动(El Ni o-Southern Oscillation,ENSO)和平流层准两年振荡(quasi-biennial oscillation,QBO)的共同作用提供了HNVTE变化的年际异常背景。西北太平洋副高突变前出现中等强度的La Ni a状态和突变后出现中等强度的El Ni o状态均有利于HNVTE发生,而平流层西风位相下低层强西风切变则会抑制这两种状态下的HNVTE活动。根据西北太平洋海面温度的年代际位相、ENSO循环位相及强度和QBO位相及强度构建的BEST-QBO协同作用指数能很好地识别HNVTE的发生,可为HNVTE的气候预测提供有用的信号。
文摘利用欧洲中期天气预报中心提供的全球大气再分析资料、美国国家海洋和大气管理局提供的高分辨率海表温度逐日数据集和最佳路径数据集(the international best track archive for climate stewardship,IBTrACS)等资料,采用WRF(weather research and forecasting)模式,对2022年第11号台风“轩岚诺”在东海黑潮快速增强的原因进行了诊断分析和数值模拟研究。结果表明,台风快速增强期间其中心处于东海黑潮主轴上,此时台风中心远离高空槽和高空急流,环境风垂直切变在增强时段维持在较高水平,超过8 m·s^(-1),均不利于台风增强,而东海黑潮区海表温度异常达到1~3℃,为台风发展提供大量热通量,同时26℃等温线深度达85~110 m,0~250 m深度范围内海水温度异常在台风快速增强前达2.5℃左右,表明上层海洋热含量丰富,有助于抑制台风经过引起的冷却作用。因此,东海黑潮区显著的海表温度暖异常和海洋上层热含量正异常对台风的快速增强起了关键作用。
