Connection between the Silk Road Pattern in July and the following January temperature over East Asia

This study investigates a cross-seasonal influence of the Silk Road Pattern (SRP) in July and discusses the related mechanism. Both the reanalysis and observational datasets indicate that the July SRP is closely related to the following January temperature over East Asia during 1958/59–2001/02. Linear regression results reveal that, following a higher-than-normal SRP index in July, the Siberian high, Aleutian low, Urals high, East Asian trough, and meridional shear of the East Asian jet intensify significantly in January. Such atmospheric circulation anomalies are favorable for northerly wind anomalies over East Asia, leading to more southward advection of cold air and causing a decrease in temperature. Further analysis indicates that the North Pacific sea surface temperature anomalies (SSTAs) might play a critical role in storing the anomalous signal of the July SRP. The significant SSTAs related to the July SRP weaken in October and November, re-emerge in December, and strengthen in the following January. Such an SSTA pattern in January can induce a surface anomalous cyclone over North Pacific and lead to dominant convergence anomalies over northwestern Pacific. Correspondingly, significant divergence anomalies appear, collocated in the upper-level troposphere in situ. Due to the advection of vorticity by divergent wind, which can be regarded as a wave source, a stationary Rossby wave originates from North Pacific and propagates eastward to East Asia, leading to temperature anomalies through its influence on the large-scale atmospheric circulation.     

北京地区玉米风灾损失定量评估模型研究

风灾是北京地区玉米减产的一个重要因素,是影响玉米产量最常见的一种气象灾害,严重的风灾可造成玉米绝收。为实现对玉米风灾造成损失的定量评估,利用收集到的历史上出现的玉米风灾及产量损失数据,结合自动气象站观测资料,分析了风灾发生过程中对玉米产量损失影响显著的气象因子,最终确定选取玉米受灾过程中的最大风速的最大值、持续时间内的最大风速的平均值、最大风速持续时间和过程降水量4个气象因子,并考虑到玉米不同生育期抗风能力的不同,增加了玉米生育期影响因子,利用这5个要素,运用统计学方法建立了北京地区玉米风灾损失定量评估统计模型。通过对样本数据的拟合及剩余样本的检验,建立的定量损失评估模型具有一定的准确性和实用性,可为政策性农业保险的定损,以及生产部门确定风灾损失及保险公司理赔提供科学依据。     

Somali Jet Changes under the Global Warming

Somali Jet changes will influence the variability of Asian monsoon and climate. How would Somali Jet changes respond to the global warming in the future climate？ To address this question, we first evaluate the ability of IPCC-AR4 climate models and perform the 20th century climate in coupled models （20C3M） experiments to reproduce the observational features of the low level Somali Jet in JJA （June-July-August） for the period 1976 1999. Then, we project and discuss the changes of Somali Jet under the climate change of Scenario A2 （SRESA2） for the period 2005 2099. The results show that 18 IPCC-AR4 models have performed better in describing the climatological features of Somali Jet in the present climate simulations. Analysis of Somali Jet intensity changes from the multi-model ensemble results for the period 2005-2099 shows a weakened Somali Jet in the early 21st century （2010-2040）, the strongest Somali Jet in the middle 21st century （2050 2060）, as well as the weakest Somali Jet at the end of the 21st century （2070-2090）. Compared with the period 1976-1999, the intensity of Somali Jet is weakening in general, and it becomes the weakest at the end of the 21st century. The results also suggest that the relationship between the intensity of Somali Jet in JJA and the increment of global mean surface air temperature is nonlinear, which is reflected differently among the models, suggesting the uncertainty of the IPCC-AR4 models. Considering the important role of Somali Jet in the Indian monsoon and East Asian monsoon and climate of China, the variability of Somali Jet and its evolvement under the present climate or future climate changes need to be further clarified.     

用增强显示云图确定热带气旋强度的方法

文章介绍了用增强显示红外云图确定热带气旋强度的方法。利用1983—1988年GMS增强显示云图资料，对中央气象台使用的《用地球同步气象卫星红外云图估计热带气旋强度》的方法中的云特征指数进行了修改与调整，增加了眼区的温度、中心强对流云区和螺旋云带的云顶温度等新的云特征因子。经统计、拟合，得到云特征指数与热带气旋中心附近最大风速、最低海平面气压的对应关系，给出了计算热带气旋强度的人-机交互方法流程，此方法对各种强度的热带气旋都能客观地计算其强度，使用简便，且精度满足业务应用要求。     

A sensitivity study of IAP AGCM to radiation changes: Climate simulation of 125kyr and 115kyr before present

The IAP AGCM was used to simulate the climate of 12Skyr and 115kyr before present. We analysed the results and then studied the sensitivity of the model to the changes of radiation distribution induced by orbital parameter changes. The reasonability of the results was also discussed.     

甲基异丁基酮负载泡塑富集—原子吸收测定岩矿中痕量金银铊镉

研究了多种负载泡塑对Au、Ag、Ti、Cd的富集行为。提出了在HCI-KI-抗坏血酸介质中用甲基异丁基酮(MIBK)负载泡塑同时萃取,然后用2％硫脲-1％HCl解脱的富集方法,并采用火焰原子吸收连续测定地质样品中痕量Au、Ag、Tl和Cd,方法的测定下限(μg/g)分别为:0.2g、0.05、0.20和0.04。     

用数字云图确定热带气旋强度的原理和方法

本文采用数字云图资料，分析热带气旋强度与热带气旋中云系结构的关系，提出了云系结构紧密度因子的概念并用云带旋转的圈数表示热带气旋强度的方法。本文对原有关于热带气旋中云系结构的某些因子的取值作了适当调整， 改进了用增强红外云图确定热带气旋强度的方法。 经过对2446组样本的拟合，热带气旋强度最大风速估计值的平均绝对误差为2.48 m/s。本方法可以实现人机交互，能更客观地作出定量估计。对1993年12个热带气旋检验，最大风速平均绝对误差为2.31 m/s。     

The East Asian Monsoon Simulation with IAP AGCMs-A Composite Study

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