Influences of topographic variations of the offshore fringing reef on the harbor oscillations excited by incident Nwaves with different amplitudes and waveform types are studied for the first time.Both the propagation...Influences of topographic variations of the offshore fringing reef on the harbor oscillations excited by incident Nwaves with different amplitudes and waveform types are studied for the first time.Both the propagation of the Nwaves over the reef and the subsequently-induced harbor oscillations are simulated by a Boussinesq-type numerical model,FUNWAVE-TVD.The present study concentrates on revealing the influences of the plane reef-face slope,the reef-face profile shape and the lagoon width on the maximum runup,the wave energy distribution and the total wave energy within the harbor.It shows that both the wave energy distribution uniformity and the total wave energy gradually increase with decreasing reef-face slope.The profile shape of the reef face suffering leading-elevation Nwaves(LEN waves)has a negligible impact on the wave energy distribution uniformity,while for leading-depression N-waves(LDN waves),the latter gradually decreases with the mean water depth over the reef face.The total wave energy always first increases and then decreases with the mean water depth over the reef face.In general,the total wave energy first sharply decreases and then slightly increases with the lagoon width,regardless of the reef-face width and the incident waveform type.The maximum runup subjected to the LEN waves decreases monotonously with the lagoon width.However,for the LDN waves,its changing trend with the lagoon width relies on the incident wave amplitude.展开更多
汉江流域是中国重要的调水水源区,研究其降水特征对防涝抗旱具有重要意义。基于汉江流域62个国家气象站降水资料及美国国家环境预报中心/国家大气研究中心(National Center for Envi⁃ronmental Prediction/National Center for Atmosphe...汉江流域是中国重要的调水水源区,研究其降水特征对防涝抗旱具有重要意义。基于汉江流域62个国家气象站降水资料及美国国家环境预报中心/国家大气研究中心(National Center for Envi⁃ronmental Prediction/National Center for Atmospheric Research,NCEP/NCAR)再分析资料,通过百分位数、相关分析和T-N波作用通量,探讨了2021年伏秋(8—10月)连汛期间汉江降水的季内差异特征及其与大气环流和海温的关系。结果表明:2021年伏秋期间,汉江上游流域出现破纪录降水,极端性强、总量大。降水在伏夏和秋季两个时段均偏多,但秋季的多雨区位置更偏北。伏夏期间,北大西洋经西伯利亚向东频散的Rossby波使得欧亚上空维持“两槽两脊”,冷空气较强,同时西太平洋副热带高压(简称“副高”)强势西伸,通过西南和偏东两支通道向北输送暖湿水汽;冷暖空气在高空急流南侧对峙并辐合上升,导致降水异常偏多。秋季,北太平洋频散的Rossby波使得欧亚上空维持“两槽一脊”,冷空气较弱;副高断裂导致水汽通道偏南,高空急流北抬使冷暖空气辐合上升位置偏北,造成雨区偏北。2021年汉江流域伏夏降水异常受热带东大西洋海温正异常影响,秋季受赤道中太平洋冷海温影响。展开更多
基金financially supported by the National Key Research and Development Program of China(Grant No.2017YFC1404200)the National Natural Science Foundation of China(Grant Nos.51911530205 and 51809039)+5 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20201455)the Natural Science Foundation of the Jiangsu Higher Education Institutions(Grant No.20KJD170005)the Qing Lan Project of Jiangsu Universitiessupported by UK EPSRC(Grant No.EP/T026782/1)the Royal Academy of Engineering(Grant No.UK-CIAPP/73)the Royal Society(Grant No.IEC\NSFC\181321)。
文摘Influences of topographic variations of the offshore fringing reef on the harbor oscillations excited by incident Nwaves with different amplitudes and waveform types are studied for the first time.Both the propagation of the Nwaves over the reef and the subsequently-induced harbor oscillations are simulated by a Boussinesq-type numerical model,FUNWAVE-TVD.The present study concentrates on revealing the influences of the plane reef-face slope,the reef-face profile shape and the lagoon width on the maximum runup,the wave energy distribution and the total wave energy within the harbor.It shows that both the wave energy distribution uniformity and the total wave energy gradually increase with decreasing reef-face slope.The profile shape of the reef face suffering leading-elevation Nwaves(LEN waves)has a negligible impact on the wave energy distribution uniformity,while for leading-depression N-waves(LDN waves),the latter gradually decreases with the mean water depth over the reef face.The total wave energy always first increases and then decreases with the mean water depth over the reef face.In general,the total wave energy first sharply decreases and then slightly increases with the lagoon width,regardless of the reef-face width and the incident waveform type.The maximum runup subjected to the LEN waves decreases monotonously with the lagoon width.However,for the LDN waves,its changing trend with the lagoon width relies on the incident wave amplitude.
文摘汉江流域是中国重要的调水水源区,研究其降水特征对防涝抗旱具有重要意义。基于汉江流域62个国家气象站降水资料及美国国家环境预报中心/国家大气研究中心(National Center for Envi⁃ronmental Prediction/National Center for Atmospheric Research,NCEP/NCAR)再分析资料,通过百分位数、相关分析和T-N波作用通量,探讨了2021年伏秋(8—10月)连汛期间汉江降水的季内差异特征及其与大气环流和海温的关系。结果表明:2021年伏秋期间,汉江上游流域出现破纪录降水,极端性强、总量大。降水在伏夏和秋季两个时段均偏多,但秋季的多雨区位置更偏北。伏夏期间,北大西洋经西伯利亚向东频散的Rossby波使得欧亚上空维持“两槽两脊”,冷空气较强,同时西太平洋副热带高压(简称“副高”)强势西伸,通过西南和偏东两支通道向北输送暖湿水汽;冷暖空气在高空急流南侧对峙并辐合上升,导致降水异常偏多。秋季,北太平洋频散的Rossby波使得欧亚上空维持“两槽一脊”,冷空气较弱;副高断裂导致水汽通道偏南,高空急流北抬使冷暖空气辐合上升位置偏北,造成雨区偏北。2021年汉江流域伏夏降水异常受热带东大西洋海温正异常影响,秋季受赤道中太平洋冷海温影响。
