獐子岛养殖区夏季底层水温快速变化的机理分析     

南学良  魏皓  凡仁福  杨伟 《海洋学报(英文版)》2020,42(5):46-54

Rapid changes in the near-bottom water temperature are important environmental factors that can significantly affect the growth and development of species in the bottom culture. The object of this research is to investigate the mechanism causing these rapid changes within a bottom culture area near the Zhangzi Island. The hydrographic transects observations in the North Yellow Sea(NYS) suggest that our mooring station is very close to the tidal mixing front. The horizontal advection of the tidal front has induced the observed tidal change of bottom temperature at the mooring station. Analysis of the mooring near-bottom temperature and current measurements show that the angle between the tidal current horizontal advection and the swing of the tidal front is crucial in determining the variation trend of temperature. When the angle equals 90°, the horizontal tidal current advects along the isotherms so the temperature remains the same. When the angle is between 0° and 90°, the seawater moves from deep water to the warmer coastal zone and the temperature decreases. In contrast, the horizontal tidal advection moves the coastal warm water to the mooring station and the water temperature increases when the angle is between 90° and 180°. The amplitude of the temperature change is proportional to the magnitude of the horizontal temperature gradient and the tidal excursion in the direction of the temperature gradient. This study may facilitate the choice of culture area in order to have a good aquaculture production.  相似文献   

The impact of northern Indian Ocean rivers on the Bay of Bengal using NEMO global ocean model     

Srivastava Atul  Gera Anith  Momin Imran M.  Mitra Ashis Kumar  Gupta Ankur 《海洋学报(英文版)》2020,39(3):45-55

The effect of river runoff over the northern Indian Ocean(NIO) especially over the Bay of Bengal(Bo B) has been studied using global Nucleus for European Modelling of the Ocean(NEMO). Two sensitivity experiments, with and without river runoff are conducted and the influence of river runoff on the Indian Ocean hydrography,stratification and circulation features are studied. It is found that due to river runoff surface salinity over the northern Bo B decreases by more than 5 and the East India Coastal Current strengthens by 2 cm/s during post monsoon season. The fresh river water reaches up to 15°N in the Bo B and is the main cause for low salinity there.Sea surface temperature in the northwestern Bo B increases by more than 0.2℃ due to the river runoff in summer monsoon while surface cooling upto 0.2℃ is seen in north-west part of Bo B in winter season. The seasonal mixed layer depth in the region is found to be dependent on river runoff. The effect of vertical shear and Brunt Vaisala frequency on stratification is also examined. The ocean water becomes highly stratified up to 3 035 m due to the river runoff. It is found that the energy required for mixing is high in the northern and coastal Bo B.  相似文献   

致密砂岩层内强钙质胶结物成因机制及其意义——以鄂尔多斯盆地三叠系延长组长7油层组为例     

崔景伟  朱如凯 《吉林大学学报(地球科学版)》2020,50(4):957-967

通过岩心和薄片观察，利用荧光显微镜、阴极发光显微镜、同位素质谱仪、冷热台等设备，对鄂尔多斯盆地长7油层组强钙质胶结砂岩及其附近含油砂岩开展研究。结果表明：钙质胶结是致密砂岩储层含油非均质性的主要因素，胶结期次主要为一期；簇同位素揭示该期钙质胶结物的形成温度为18~42℃，对应地质时代为中晚三叠世—中侏罗世，为早成岩期产物，推测与盆地早期小规模构造运动相关；相邻的含油砂岩中油气包裹体伴生的同期盐水包裹体的均一化温度为90~120℃，结合盆地模拟揭示油气主要为一期充注，充注期为100~130 Ma，处于早白垩世；长7油层组不含油致密砂岩内钙质胶结物形成时间早于含油砂岩内石油的充注时间。  相似文献   

山西芦芽山地区树木年轮记录的1676 AD以来5～7月温度变化   总被引：7，自引：1，他引：6  

易亮  刘禹  宋惠明  李强  蔡秋芳  杨银科  孙军艳 《冰川冻土》2006,28(3):330-336

在山西芦芽山地区采取了符合国际树轮库要求的油松样本,通过交叉定年和应用区域生长模型,建立长度为328 a的标准宽度年表.根据RCS序列所揭示的气候低频变化特征,确定1676 AD以来夏季温度可划分为两个时段:1676—1865 AD和1866—2003 AD.在1676—1865 AD时期,夏季温度变化主要表现为“冷强暖弱”,其中1710—1720s为最冷时段.1866—2003 AD时期,夏季温度呈现出“总体持续变暖,冷暖交替频繁”的变化特征.  相似文献   

不同天气现象下毕节高温特征及预报回归检验分析          下载免费PDF全文

吴姗  姚浪  刘健平  帅龙  聂祥 《中低纬山地气象》2022,46(1):68-72

利用毕节2010-2019年观测资料,分析不同天气现象下日最高气温特征,建立高温模型,并对近5 a 24 h高温进行检验,得出如下结论:(1)毕节高温日变化在夏季最稳定,春季波动最大。气温日较差晴天最大,阴天最小,多云时略大于阴间多云。(2)毕节8~10成云出现频率高达65.7%,夏季晴天频率波动大,春、夏季多云频率较高,且按天气现象分类统计月平均高温时,其峰值均出现在7月。(3) 24 h高温预报准确率月、季变化特征明显,夏季准确率最高,较最低的冬季高出21.4%,在区别天气现象的情况下,阴雨天时预报准确率最高,多云时最低,其中12月多云时最低为25%。(4)回归模型分析发现不同季节同种天气现象24 h高温预报影响因子权重差异明显,日照时数和平均本站气压对模型影响程度较高。不同季节晴天影响因子差异最大,拟合效果最好时段在夏季,平均估计误差为1.2℃,估计误差最大在冬季,平均估计误差为1.7℃。  相似文献   

Contributions of Fuqing ZHANG to Predictability,Data Assimilation,and Dynamics of High Impact Weather: A Tribute     

Zhiyong MENG  Eugene E.CLOTHIAUX 《大气科学进展》2022,39(5):676-683

This article reviews Fuqing ZHANG’s contributions to mesoscale atmospheric science,from research to mentoring to academic service,over his 20-year career.His fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are highlighted.His extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are summarized.Special appreciation is given to his tremendous contributions to the development of mesoscale meteorology in China and the education of Chinese graduate students and young scientists.  相似文献   

影响华南汛期持续性强降水年际变化的大气环流和海温异常          下载免费PDF全文

林爱兰  谷德军  李春晖  郑彬  彭冬冬 《热带气象学报》2022,38(1):1-10

利用1961—2017年中国地面观测站日降水资料、全球大气多要素和海表温度月资料,分析华南区域持续性强降水过程的气候特征,诊断并比较与华南前汛期、后汛期区域持续性强降水年际变化相关的大气环流和海表温度异常特征。结果表明,3—12月华南都可能出现持续性强降水过程,其中汛期4—9月的占了94.4%。伴随着区域持续性强降水的年际变化,华南本地垂直上升运动显著异常是前汛期和后汛期的共同点,但前汛期、后汛期在华南及周边环流异常、水汽输送来源以及海温异常分布等方面都存在一定差异。在前汛期华南区域持续性强降水偏重年,赤道西太平洋区域海温偏低,由于大气罗斯贝波响应使西太平洋副热带高压偏强,热带西太平洋向华南区域水汽输送加强,从而有利于区域持续性强降水偏重。后汛期华南区域持续性强降水偏重年的海温异常分布是赤道中东太平洋区域正异常、东印度洋至西太平洋暖池区负异常,海温异常通过西北太平洋副热带高压、南海热带季风强度、水汽输送和垂直环流等多方面,导致后汛期区域持续性强降水偏重。   相似文献   

红鳍东方鲀(Takifugu rubripes)耐低温性状和生长性状遗传参数评估     

赵海池  刘志峰  王新安  包玉龙  刘圣聪  杨明超  闫鹏飞  马爱军 《海洋与湖沼》2024,55(2):517-525

采用人工控温的方式, 对构建的31个F₁红鳍东方鲀(Takifugu rubripes)全同胞家系开展低温胁迫实验, 获得耐低温性状低温累计存活时间(CDH), 基于混合线性模型分别开展耐低温性状和生长性状遗传参数评估,对每一性状是否需要考虑共同环境效应所构建的两种模型进行似然比检验。结果显示, 经似然比检验, 最终选用模型A和模型BF进行耐低温和生长性状遗传评估; 耐低温性状CDH遗传力为(0.27±0.08),属于中等遗传力; 体重BW遗传力为(0.36±0.13), 属于中等遗传力, 体长BL遗传力为(0.14±0.06), 属于低等遗传力, 经检验, 遗传力估计值均达到极显著水平(P<0.01)。CDH和体重、体长的遗传相关分别为(-0.40±0.22)和(-0.44±0.24), 表型相关分别为(-0.09±0.06)和(-0.16± 0.05), 均为负相关; 体重和体长之间的遗传相关为(0.92±0.05), 表型相关为(0.80±0.02), 呈正相关且结果极显著(P<0.01)。研究结果表明, 红鳍东方鲀的耐低温性状和生长性状都具有较好的改良潜力, 考虑到两性状间存在负遗传相关, 在开展耐低温选育时, 对首先不同性状进行品系选育, 然后利用品系间杂交培育出耐高温、生长快的新品种。该项研究首次完成了红鳍东方鲀耐低温性状的遗传参数评估, 为制订红鳍东方鲀耐低温选育育种规划提供了理论依据。  相似文献   

Extensive Cold-Precipitation-Freezing Events in Southern China and Their Circulation Characteristics   总被引：2，自引：0，他引：2  

Jing-Bei PENG  Cholaw BUEH  Zuo-Wei XIE 《大气科学进展》2021,38(1):81-97

Concurrence of low temperature,precipitation and freezing weather in an extensive area would cause devastating impacts on local economy and society.We call such a combination of concurrent disastrous weather“extensive coldprecipitation-freezing”events(ECPFEs).In this study,the ECPFEs in southern China(15°?35°N,102°?123°E)are objectively defined by using daily surface observational data for the period 1951?2013.An ECPFE in southern China is defined if the low temperature area,precipitation area and freezing area concurrently exceed their respective thresholds for at least three consecutive days.The identified ECPFEs are shown to be reasonable and reliable,compared with those in previous studies.The circulation anomalies in ECPFEs are characterized by a large-scale tilted ridge and trough pairing over mid-and high-latitude Eurasia,and the intensified subtropical westerlies along the southern foot of the Tibetan Plateau and the anomalous anticyclonic circulation over the subtropical western Pacific.Comparative analysis reveals that the stable cold air from the north and the warm and moist air from the south converge,facilitating a favorable environment for the concurrence of extensive low-temperature,precipitation and freezing weather.  相似文献   

Future Changes in Extreme High Temperature over China at 1.5℃-5℃ Global Warming Based on CMIP6 Simulations   总被引：1，自引：0，他引：1  

Guwei ZHANG  Gang ZENG  Xiaoye YANG  Zhihong JIANG 《大气科学进展》2021,38(2):253-267

Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China.  相似文献