Representing surface wind stress response to mesoscale SST perturbations in western coast of South America using Tikhonov regularization method

Journal of Oceanology and Limnology - Interaction between mesoscale perturbations of sea surface temperature (SSTmeso) and wind stress (WSmeso) has great influences on the ocean upwelling system...     

Interdecadal variability of the South China Sea monsoon and its relationship with latent heat flux in the Pacific Ocean

We analyzed interdecadal variability of the South China Sea monsoon and its relationship with latent heat flux in the Pacific Ocean, using NCEP wind field and OAFlux heat flux datasets. Results indicate that South China Sea monsoon intensity had an obvious interdecadal variation with a decreasing trend. Variability of the monsoon was significantly correlated with latent heat flux in the Kuroshio area and tropical Pacific Ocean. Variability of latent heat flux in the Kuroshio area had an interdecadal increasing trend, while that in the tropical Pacific Ocean had an interdecadal decreasing trend. Latent heat flux variability in these two sea areas was used to establish a latent heat flux index, which had positive correlation with variability of the South China Sea monsoon. When the latent heat flux was 18 months ahead of the South China Sea monsoon, the correlation coefficient maximized at 0.58 (N=612), with a 99.9% significance level of 0.15. Thus, it is suggested that latent heat flux variability in the two areas contributes greatly to interdecadal variability of the South China Sea monsoon.     

Impact of the central Pacific zonal wind divergence and convergence on the central Pacific El Nio event

The central Pacific(CP) zonal wind divergence and convergence indices are defined, and the forming mechanism of CP El Nio(La Nia) events is discussed preliminarily. The results show that the divergence and convergence of the zonal wind anomaly(ZWA) are the key process in the forming of CP El Nio(La Nia) events. A correlation analysis between the central Pacific zonal wind divergence and convergence indices and central Pacific El Nio indices indicates that there is a remarkable lag correlation between them. The central Pacific zonal wind divergence and convergence indices can be used to predict the CP events. Based on these results, a linear regression equation is obtained to predict the CP El Nio(La Nia) events 5 months ahead.     

坐标观测值的《误差理论与测量平差基础》教学内容设计

回顾了测绘工程专业核心课程《误差理论与测量平差基础》(简称《经典平差》)教学改革主要成果特点,分析指出了现有教材以高差、边长和角度一维观测值为主要研究对象存在的不足,并在此基础上系统探究了二维和三维坐标观测值的点线面测量平差问题.通过5类二维和5类三维坐标观测值的单元整体教学设计,更新了平差模型教学案例并丰富了平差模型属性数据内涵,从而为解决本课程体系"存量更新、增量补充"提供一定参考.     

Greater effect of canopy conductance in regulating the energy partition above the maize field in arid northwest China

The partition of available energy into evapotranspiration affected by environmental and physiological factors is critical in understanding the water cycle and optimizing the water management in the field. Our study attempted to accurately quantify the environmental and physiological control on variability in evaporative fraction (EF) based on the Penman–Monteith model. The eddy covariance method was used to measure water flux over a canopy and then calculate the EF above a maize field in northwest China in 2007. Results indicate that the EF was lower in other growth stages than in the heading stage, so the EF value in the heading stage was taken as the standard value. The decreases in EF caused by canopy conductance and environmental factors were 0.176 and ?0.026, accounting for 117% and ?17% of the total difference in EF, respectively. Such results were mainly due to the following: (1) the variation of maize canopy conductance was greater than that of the environmental factors, such as air temperature, air humidity, wind speed and radiation; (2) the EF of the maize was more sensitive to variation in canopy conductance than the environmental factor. Our study revealed that crop physiological factor played an important role in determining the energy partition processes and reducing the sensible heat flux in the maize field. Copyright © 2012 John Wiley & Sons, Ltd.     

空中重力测量数据代表地面数据的误差分析

利用严密的向上延拓公式将地面重力数据上延至空中不同高度,而后与相应的地面重力数据比较从而得到不同高度的代表误差。通过两个不同地形区域的实际算例表明,对于地形平坦区域,在1km高度以下,5＇空中重力数据直接代表地面重力数据的误差小于1mGal,在满足测量规范要求下,空中重力数据可以不用向下延拓而直接使用。对于地形复杂区域,当空中测量高度大于1km时,空中重力数据的代表误差大于3.3mGal,因此必须考虑向下延拓的问题。     

Mesoscale SST perturbation-induced impacts on climatological precipitation in the Kuroshio-Oyashio extension region,as revealed by the WRF simulations

Mesoscale coupling between perturbations of mesoscale sea surface temperature(SST) and lowlevel winds has been extensively studied using available high-resolution satellite observations. However, the climatological impacts of mesoscale SST perturbations(SST_(meso)) on the free atmosphere have not been fully understood. In this study, the rectified ef fect of SST_(meso) on local climatological precipitation in the KuroshioOyashio Extension(KOE) region is investigated using the Weather Research and Forecasting(WRF)Model; two runs are performed, one forced by low-resolution SST fields(almost no mesoscale signals) and another by additional high-resolution SST_(meso) fields extracted from satellite observations. Climatological precipitation response to SST_(meso) is characterized mainly by enhanced precipitation on the warmer flank of three oceanic SST fronts in this region. The results show that the positive correlation between the 10-m wind speed perturbations and SST_(meso) is well captured by the WRF model with a reasonable spatial pattern but relatively weak strength. The addition of SST_(meso) improves the climatological precipitation simulated by WRF with a better representation of fine-scale structures compared with satellite observations. A closer examination on the underlying mechanism suggests that while the pressure adjustment mechanism can explain the climatological precipitation enhancement along the fronts and the relatively high contribution of the convective precipitation, other factors such as synoptic events should also be taken into consideration to account for the seasonality of the precipitation response.     

河南入境旅游经济区域差异及极化格局研究

以2000-2007年河南入境旅游人次和旅游外汇收入作为衡量入境旅游经济发展水平的指标,对河南地市间入境旅游经济发展水平的区域差异特征及时序演变态势进行分析,继而采用赫芬达尔指数和绝对集中度指数探讨河南入境旅游经济的区域极化程度及空间指向.研究表明,河南入境旅游虽获得了较快发展,但地市间的绝对差异呈持续增大的态势,而相对差异不断减小;入境旅游向热点旅游地集聚的态势较为显著,郑州、洛阳、焦作等地成为入境旅游经济的增长极.最后,对影响河南入境旅游经济区域差异因素进行探讨并提出实现入境旅游经济整体协调发展的对策和建议.     

基于网络药理学探究大黄煎剂治疗轻微型肝性脑病的作用机制

目的：基于网络药理学方法,预测大黄煎剂治疗轻微型肝性脑病(MHE)的作用靶点和作用机制。方法：使用TCMSP平台采集大黄煎剂的有效成分及作用靶点基因;再从Gene Cards、OMIM数据库搜集MHE的靶点,将二者取交集获得药物-疾病交集靶点;使用Cytoscape 3.7.2 软件,将有效成分、药物-疾病交集靶点导入建立关系网络,并绘制网络图;将药物-疾病交集靶点导入String数据库,构建药物对疾病靶点蛋白相互作用的PPI网络;最后使用R语言程序对药物-疾病交集靶点基因进行GO和KEGG富集分析。结果:大黄煎剂筛选出11种活性成分、116个治疗MHE的潜在靶点;PPI网络结果中,筛选出大黄煎剂调控的核心靶点包括 AKT1、JUN、MAPK1等;GO功能富集得到142个功能条;KEGG通路富集分析得到157条通路。结论：该研究初步预测大黄煎剂可能通过靶向作用关键蛋白和重要通路达到治疗MHE的目的,充分体现了中药多成分、多靶点、多通路的特点,并有望对大黄煎剂治疗MHE提供新的证据和研究思路。