Modulation of land-sea thermal contrast on the energy source and sink of tropical cyclone activity and its annual cycle

In general,the tropical cyclone(TC) activity is considered to be influenced by the heat content of underlying ocean,vertical shear of horizontal wind,vorticity in the low troposphere,moisture in the troposphere,and favorable condition for deep convection development.However,these factors by nature merely present the internal factors of either atmosphere or ocean which influence the TC activity.In fact,the energy budget of the Earth system and its variation,modulated by the land-sea thermal contrast,are the intrinsic reasons responsible for the variation of TC activity.Here we investigate the modulation of diabatic heating distribution associated with the land-sea thermal contrast on the distribution of TC activity energy source and sink as well as the seasonality.An accumulated energy increment index(AEI) is defined using the TC best track data,and the energy sources and sinks of TC activity are then diagnosed effectively and practically according to the distribution of AEI.Results show that the thermal contrast of land and ocean is the primary reason for asymmetric distribution of TC activity about the Equator as well as the zonally asymmetric distribution of TC activity.The energy sources of TC activity are dominated by condensation heating of deep convection or double-dominant heating,which includes the condensation heating and cooling of longwave radiation(LO),while the sink areas are dominated by LO.The large scale diabatic heating associated with land-sea thermal contrast results in more favorable conditions for TC activity over the west part of oceans than those over the east parts.Moreover,the intensity of interaction of different diabatic heating over the west and east parts of ocean is also affected by the zonal scale of the oceans,which induces the difference of TC activity over the western North Pacific(WNP) and North Atlantic(ATL).The favorable westerlies and anticyclonic vertical shear associated with the tropical zonally asymmetric diabatic heating also contribute to the most intense TC activity over the WNP.The variation of large scale diabatic heating modulates the annual cycle of TC energy sources and sinks.In particular,the annual cycle over the WNP is the most typical one among the three basins(the WNP,the south Indian Ocean,and western South Pacific) that are characterized by the meridional shift of the energy sources and sinks.However,sources over the eastern North Pacific tend to extend westward and withdraw eastward associated with the variation of LO,while over the ATL,sources always merge from small pieces into a big one as the different diabatic heating over its west and east parts interacts with each other.Over the boreal Indian Ocean,the subcontinental scale land-sea heating contrast modifies the large scale circulation,and consequently contributes to the bimodal annual cycle of TC activity.In summary,TC activities are closely related to the interaction among various components of the climate system more than the atmosphere and ocean.     

三峡井网地下流体动态在水库蓄水前后的变化

在系统分析长江三峡诱发地震地下水动态监测井网2001～2002年8个井台16个测项的地下流体正常动态及其影响因素的基础上，调查研究了井网外围50km范围内两个中等地震震例，对比分析了2003年三峡水库蓄水前后各测项动态的变化。发现水库蓄水对三峡井网地下流体动态的影响是局部的．推测三峡库首区近期诱发中等以上水库地震的可能性不大；同时分析了受水库蓄水影响测项的异常特征及其机理，认为深入研究此类问题对推进地震监测与预报科学的发展有重要意义。     

成都市防震减灾工作中的科普宣传

成都市是四川省省会，是国务院确定的西南地区科技、商贸、金融中心和交通、通信枢纽，也是国务院确定的全国地震重点监视防御区。全市共有19个区（市）县，总面积1．24万km^2，全市户籍人口1044．3万人。成都市地跨龙门山、龙泉山构造带和成都凹陷三个地质构造单元，境内地震活动主要受龙门山、龙泉山、蒲江-新津-成都-德阳、邛崃-大邑-彭州四条断裂带影响。     

2-D crustal Poisson′s ratio from seismic travel time inversion in Changbaishan Tianchi volcanic region

Introduction Forward modeling is commonly used in the interpretation of 2D crustal structure with wide-angle seismic reflection/refraction data. But this method not only has mass work and more subjective effects, but also cannot provide quantitative estimates of model parameter error, resolu-tion, and model uniqueness. It also cannot assure that the data consistency is the minimum of par-ticular range. In order to overcome the defects of forward modeling, Zelt and Smith (1992) have developed…     

数据库技术在测井资料分析中的应用

阐述了在测井资料管理及应用方面使用数据库系统与文件管理系统的对比优势,探讨了测井数据库开发的基本原则,并在此基础上,初步实现测井资料数据库管理系统以及基于数据库底层的测井资料处理软件。基于底层数据库以油田-区块-井-井眼为逻辑结构,所建立的测井资料处理解释系统数据管理功能满足处理的需求,数据库的安全性、共享性、运行效率得到了很好的体现。     

我国西南地区一次暴雨过程特征及成因

利用卫星云图、多普勒天气雷达资料和高空风等各种天气学资料,对2009年6月8—9日广西、贵州、以及和湖南交界地带的一次暴雨过程进行了综合分析。结果表明,暴雨是由中尺度对流复合体东移、β中尺度强对流云团发展、以及二者合并造成的;地面α中尺度低压带配合α中尺度纬向切变线的生成,为中尺度对流复合体（mesoscale convective complex,MCC）的东移发展、β中尺度强对流云团的发展、以及二者的合并创造了有利条件;地面能量比低值舌的活动是MCC和β中尺度强对流云团生成和发展的触发机制之一;在多普勒雷达径向速度图上,MCC的生成和发展,伴随西南低空急流的建立和维持,大范围的逆风区的生成;MCC的消亡,伴随西南低空急流的减弱和消失,对应西北气流建立和东扩。MCC发展期和β中尺度强对流云团发展期、MCC消散期和β中尺度强对流云团消散期的涡度收支以及视热源和视水汽汇有很大的不同。     

一次冰雹云演变过程的卫星遥感监测与分析

针对2003年9月21日的一次区域性冰雹云强对流天气过程,结合天气实况、环流场特征和雷达资料,利用NOAA卫星数据,从天气分析、能量转换以及云在可见光、中红外波段的反射特性,分析了冰雹云的演变及特征。结果表明,伴随着大气能量的转换,当日青海湖以北的对流冷云单体在东移过程中,结合了西南部暖舌带来的暖湿气流,午后受地面增温出现了爆发性发展。(1)17：00云团发展最旺盛,云顶温度最低值达到-44℃,并确定冰雹发生的云顶温度临界值为-39．2℃,云顶亮温为221K;(2)冰雹云温度水平梯度介于20～35℃／50km之间,表现为有雹无灾的冰雹强度特征;(3)卫星数据表明,此时雹云与其它云团不同,具有粒子有效半径较大,气溶胶光学厚度也大的特点。     

内波单独作用形成的深水沉积物波

深水沉积物波是一种海底普遍发育、规模较大的波状沉积体,大多数学者将它们解释为等深流沉积或浊流沉积。本文结合内波理论的研究进展，考虑内波沉积作用的水动力学特征，探讨了深水沉积物波的内波成因机制。得出以下几点认识：①海底流动单独作用无法满足沉积物波形成所需的流动层厚度及流动速度，较难解释沉积物波的迁移方向及规则的内部及外部形态。②内波可以引起海底流动，内波比表面波更容易形成更大规模范围内的沉积床形。③内波可以形成大型沉积物波，用内波可以较合理地解释内波的对称波形单元、非对称波形单元及上攀波形单元的成因。波动面离海底距离较大的行进内波及内驻波可以形成对称波形的沉积物波；波动面离海底距离较近的行进内波及内孤立波可以形成非对称波形的沉积物波；内波引起的海底流动进一步增强时，可形成上攀波形沉积物波。④行进内波可以形成向内波传播相反方向迁移的沉积物波，向海盆内部传播的内波可以形成向上坡方向迁移的沉积物波。