近岸波浪引起的水流及长波研究进展

从现场观测、理论分析和数值计算、试验室研究三个方面回顾了近岸波浪引起水流以及长波的研究进展，并对今后着重研究的几个方向提出看法。     

气压长周期变化的一种模型

从海水的平衡潮理论出发，推导出气压长周期变化的一种模型，在此基础上首次提出了气候潮的概念，并构造出了气候潮的公式，为预报山东的特大型气象灾害找到了一条有用的线索。     

Biometry, Bathymetric Distribution, and Reproductive Cycle of the Holothuroid Holothuria tubulosa (Echinodermata) from Mediterranean Sea grass Beds

Abstract. Holothuria tubulosa individuals were sampled regularly at three different depths (6, 19, and 33m) over a 20-month period in a Posidonia oceanica meadow off Ischia Island (Italy). Biometrical analysis demonstrated that holothuroids have a well-marked size-related distribution according to depth, with the smallest individuals in the shallowest part of the meadow and the large ones in its deepest part. The observed distributions reflect the ability of H. tubulosa to grow more efficiently in areas of low water turbulence where Posidonia shoots are scattered and detrital food is more easily accessible. Recruitment takes place in the shallow meadow, and holothuroids with high reproductive potential only occur in the deep meadow. Small holothuroids (shallow individuals of similar sizes) may be either juveniles or sexually mature individuals; environmental constraints apparently restrict the growth of individuals and their gonads. There is a progressive downward migration of growing individuals when the whole population is considered, although at the level of the individual the migration occurs randomly. Accordingly, the size of a sexually mature individual is more a function of its past history in the meadow than of its real age.     

海洋放线菌对大黄鱼病原弧菌的拮抗作用和抗菌谱

在大黄鱼（Pseudosciaena crocea)病原弧菌的拮抗放线菌筛选和人工诱变基础上，选择出对溶藻弧菌（Vibrio alginolyticus)和副溶血弧菌（V.paradaemolyticus)同时具有较强拮抗作用的4株放线菌，采用琼脂块法测定4株放线菌的抗菌谱，并检测4株放线菌分别在固体和液体培养液中的拮抗作用，结果表明：4株放线菌的抗菌谱均较窄，在固体和液体培养基中对2种病原弧菌都有较强的拮抗作用。     

基于Landsat长时间序列数据估算树高和生物量

以Landsat长时间序列数据为研究对象,旨在以光谱序列信息反演森林参数为视角,应用Landtrendr算法从时间序列数据中提取森林扰动变量,使用随机森林计算方法建立扰动变量、反射率和GLAS激光点森林参数之间的关系模型,获取树高和生物量的空间分布信息。为多源遥感数据反演森林参数提供参考,研究证明基于Landsat长时间序列数据获得的森林扰动变量能够增强反射率和森林参数之间的相关性,可提高预测精度。     

相位平滑伪距GNSS PPP/INS紧耦合算法

针对在导航实践中低成本MEMS使用传统紧耦合方法计算精度受到限制的问题,提出了一种采用载波相位平滑伪距GNSS PPP/INS紧耦合的算法。实验表明,使用相位平滑伪距的GNSS PPP/INS紧耦合方法后低精度的MEMS和GPS组合位置精度为dm级,速度精度为cm/s甚至mm/s,比传统C/A码紧耦合定位精度高,有较好的收敛性;其次当增加相位平滑的历元数后精度也相应提高。当出现GPS信号中断时,该方法能够加速中断以后滤波收敛的速度,将导航精度控制在中高精度惯导作业要求范围内。该方法节约了导航作业的设备成本,具有一定实际意义。     

全球经纬度网格的雷达探测范围真三维建模

针对雷达探测范围会受到复杂地形因素影响,单一地依靠电磁传播模型可视化雷达探测区域很难真实有效地展现电磁覆盖情况的问题,该文提出一种基于GeoSOT-3D空间剖分的雷达探测范围的计算与表达一体化的真三维模型。GeoSOT-3D剖分框架将上至地球50 000km,下至地心的全部地球空间划分成多层次、多尺度空间体元,体元可承载多源异构空间数据。依据GeoSOT-3D的剖分流程,将地形数据、雷达探测空间数据离散化。最后,开发了雷达探测范围可视化验证平台。实验结果表明,该建模方法对复杂的地形适应性强,可视化表现效果真实直观。     

On the Contrasting Decadal Changes of Diurnal Surface Temperature Range between the Tibetan Plateau and Southeastern China during the 1980s–2000s

The diurnal surface temperature range(DTR) has become significantly smaller over the Tibetan Plateau(TP) but larger in southeastern China, despite the daily mean surface temperature having increased steadily in both areas during recent decades.Based on ERA-Interim reanalysis data covering 1979–2012, this study shows that the weakened DTR over TP is caused by stronger warming of daily minimum surface temperature(Tmin) and a weak cooling of the daily maximum surface temperature(Tmax); meanwhile, the enhanced DTR over southeastern China is mainly associated with a relatively stronger/weaker warming of Tmax/Tmin. A further quantitative analysis of DTR changes through a process-based decomposition method—the Coupled Surface–Atmosphere Climate Feedback Response Analysis Method(CFRAM)—indicates that changes in radiative processes are mainly responsible for the decreased DTR over the TP. In particular, the increased low-level cloud cover tends to induce the radiative cooling/warming during daytime/nighttime, and the increased water vapor helps to decrease the DTR through the stronger radiative warming during nighttime than daytime. Contributions from the changes in all radiative processes(over-2?C) are compensated for by those from the stronger decreased surface sensible heat flux during daytime than during nighttime(approximately 2.5?C), but are co-contributed by the changes in atmospheric dynamics(approximately-0.4?C) and the stronger increased latent heat flux during daytime(approximately-0.8?C). In contrast, the increased DTR over southeastern China is mainly contributed by the changes in cloud, water vapor and atmospheric dynamics. The changes in surface heat fluxes have resulted in a decrease in DTR over southeastern China.     

基于低频振荡信号的中国南方冬半年持续性低温指数延伸期预报试验

利用1961-2009年36°N以南、108°E以东中国大陆191个站点逐日最低气温和NCEP/NCAR再分析日平均格点,研究与区域持续性低温事件有关的大气低频振荡信号,寻找可以在一定程度上表征不同类型区域持续性低温事件的指数,并尝试结合DERF2.0系统的预报产品进行持续性低温指数的延伸期预报试验。结果表明:（1）在研究范围内的区域持续性低温事件可以归纳为江北型、江南型和全区域型3类,其中江北型和江南型事件的环流背景差异体现在异常环流中心的纬度位置上,而全区域型事件属于增强型的江北型事件;（2）江北型和江南型区域平均最低气温时间序列的10-30 d低频分量的位相和强度变化与区域持续性低温事件的发生有显著关系,可以作为表征区域持续性低温事件指数和预报量;（3）100°-120°E范围内850 hPa温度场距平的经验正交函数分解前两个主模态具有显著的10-30 d变化周期,并且其空间结构分别与江北型和江南型事件的典型环流特征一致,前两个主模态时间系数能够作为持续性低温指数的预报因子;（4）检验结果表明,DERF2.0系统对上述预报因子有一定的预报能力。在延伸期预报时效内,利用统计学和动力学相结合的方法制作的持续性低温指数的预报效果好于模式直接预报的2 m气温,该预报方法有助于提升区域持续性低温事件的延伸预报能力。      

2016年12月至2017年2月T639、ECMWF及日本模式中期预报性能检验

对2016年12月至2017年2月T639、ECMWF及日本（文中简称JP）数值模式的中期预报产品进行了分析和检验。结果表明：3个模式对亚洲中高纬环流形势的调整和演变均具有较好的预报性能,其中ECMWF模式预报效果最好。3个模式对850 hPa温度的转折性变化趋势均有较好的预报能力,对南方地区温度变化的预报能力优于北方地区;T639模式对北方地区的温度预报存在整体偏低的误差,而JP模式对南方地区的温度预报整体偏高,ECMWF预报综合效果最好。对于2017年2月影响全国的寒潮天气过程中地面冷高压的预报,T639模式对地面冷高压中心强度的预报效果优于ECMWF和JP模式,ECMWF模式对高压中心位置预报较为准确,T639和JP模式对高压中心位置预报均存在明显偏差。