Radiative and turbulent fluxes in the nocturnal boundary layer   总被引：1，自引：0，他引：1  

KYUNG-JA HA  LARRY MAHRT 《地球，A辑:动力气象学与海洋学》2003,55(4):317-327

  相似文献   

藏南邛多江地堑的晚新生代沉积地层及对南北向裂谷形成时代的初步限定   总被引：3，自引：0，他引：3  

哈广浩  吴中海  何林 《地质学报》2018,92(10):2051-2067

邛多江地堑构成了藏南近南北向裂谷带最东侧的错那-沃卡裂谷中段,是由地堑西缘高角度正断层主控的半地堑式断陷盆地。详细的地质、地貌调查表明,该地堑内主要充填有晚新生代以来的多套河湖相、冰碛及冰水沉积地层。河湖相地层底部以黏土和粉砂为主,上部以砾石层为主,向上砾石砾径逐渐变大,顶部为早更新世冲积砾石层;冰碛主要发育于地堑中部山前地带,构成宽缓的冰碛台地或者终碛垄、侧碛堤。地层的测年结果表明,该区主要发育两套晚新生代河湖相地层,早期沉积时代早于5Ma,晚期为晚第四纪;而冰碛及冰水沉积的时代主要为中更新世。综合该区地质地貌、沉积和构造等分析结果表明,早期的河湖相沉积与盆地发生初始裂陷后的主边界正断层发生强烈垂直活动有关,而晚期的河湖相沉积主要形成于盆地后期萎缩过程中,成因可能与中更新世以来的冰川堰塞湖有关。由于邛多江地堑受控于西侧主边界正断层,早期沉积应晚于其初始裂陷时代。因此,进一步综合现有年龄数据资料认为,藏南近南北裂谷的初始裂陷时代应早于5~10Ma,但晚于约15Ma。  相似文献   

浅谈高山地区等高线采集特点与经验     

哈长亮  王睿  梁金  乌云毕力格 《测绘与空间地理信息》2018,(1):220-221,224

高山地区地貌具有多样性,制约着等高线成果的质量。本文介绍了高山地区的等高线采集特点,并结合工作实践,分析等高线采集的常见问题,总结了提升高山地区等高线质量的方法和经验,供读者参考。  相似文献   

冰冻圈旅游经济区发展水平及影响因素分析     

康韵婕  杨建平  哈琳  肖杰 《世界地理研究》2022,31(5):1083-1095

大香格里拉地区是我国典型的冰冻圈旅游区,冰冻圈资源丰富,且旅游开发较好。以大香格里拉地区为例,运用熵值法、综合指数评价模型与地理探测器相结合的分析方法,对2008—2017年大香格里拉旅游经济区的发展水平及主要影响因素进行了分析,并提出相应政策建议。结果表明：（1）2008—2017年发展水平明显提高,但受冰冻圈资源变化影响较大;（2）该地区以中等偏下发展水平为主,各地区发展不平衡,发展水平差异呈现先扩大后缩小的趋势;（3）冰川面积、冰川面积覆盖率、人均全社会消费品零售总额、旅行社数量和城镇化率是影响大香格里拉地区发展水平的关键因子,经济和社会发展水平的迅速提升,在一定程度上抵消了冰冻圈资源萎缩的负面影响。基于此,应严格遵循生态保护红线,从实际出发,支持各地区发挥比较优势,利用当前冰冻圈资源优势,重点培育冰雪旅游产业,以促进大香格里拉地区发展进程。  相似文献   

Preface to the Special Issue: Climate Change and Variability of Tropical Cyclone Activity     

Liguang WU  Bin WANG  Johnny CLCHAN  Kyung-Ja HA  Il-Ju MOON  Jun MATSUMOTO  Zhemin TAN  Ke FAN 《大气科学进展》2022,39(2):203-204

Tropical cyclones(TCs) are one of the most destructive natural phenomena on Earth in terms of human-life and economic losses. It is currently a matter of prodigious public and scientific interest how TC activity has changed and will change in a warming climate. This special issue focuses on a challenging subject raised in the Intergovernmental Panel on Climate Change(IPCC) report and numerous research papers.  相似文献   

Two Types of Diurnal Variations in Heavy Rainfall during July over Korea※     

Chang-Kyun PARK  Minhee CHANG  Chang-Hoi HO  Kyung-Ja HA  Jinwon KIM  Byung-Ju SOHN 《大气科学进展》2021,38(12):2201-2211

This study examined the characteristics of the diurnal variations of heavy rainfall (≥110 mm in 12 hours) in Korea and the related atmospheric circulation for July from 1980?2020. During the analysis period, two dominant pattens of diurnal variation of the heavy rainfall emerged: all-day heavy rainfall (AD) and morning only heavy rainfall (MO) types. For the AD-type, the heavy rainfall is caused by abundant moisture content in conjunction with active convection in the morning (0000?1200, LST; LST = UTC + 9) and the afternoon hours (1200?2400 LST). These systems are related to the enhanced moisture inflow and upward motion induced by the strengthening of the western North Pacific subtropical high and upper-tropospheric jet. For the MO-type, heavy rainfall occurs mostly in the morning hours; the associated atmospheric patterns are similar to the climatology. We find that the atmospheric pattern related to severe heavy rainfalls in 2020 corresponds to a typical AD-type and resembles the 1991 heavy-rainfall system in its overall synoptic/mesoscale circulations. The present results imply that extremely heavy rainfall episodes in Korea during the 2020 summer may occur again in the future associated with the recurring atmospheric phenomenon related to the heavy rainfall.  相似文献   

论农村社区在地震保安方面职能的发挥     

徐传捷  哈辉  纪淑果  陈有顺  胡爱真  赵国伟 《高原地震》2013,(4):59-65,58

目前,农村民居的科学抗震设防日益受到社会各界的广泛关注。农村社区作为农村社会的组成部分,其在地震保安方面职能的发挥有着不可替代的地位,充分发挥农村社区的防震减灾功能对提高农村民居的抗震设防水平,最大限度地减轻地震灾害有着深远意义。通过对农村社区特征和功能以及在地震保安方面作用发挥的阐述,针对现今存在的主要制约因素,提出政策建议,供参考。  相似文献   

视觉基本矩阵与摄影测量中相对方位元素的关系推导     

山海涛  郝向阳  哈长亮  陈杰 《海洋测绘》2012,(1):11-13

数字摄影测量与计算机视觉（特别是计算机立体视觉）的研究内容十分相近。基本矩阵是计算机视觉领域里的一个重要概念,其求解的稳健性和精度将直接影响到三维重构的效果和意义。从两者研究的对象出发,找出了两者之间的内在联系,也即视觉基本矩阵F与相对方位元素求解公式之间的表达关系,这将对今后数字摄影测量和计算机视觉两门学科的交叉发展有重要意义。  相似文献   

What drives the global summer monsoon over the past millennium?     

Jian Liu  Bin Wang  So-Young Yim  June-Yi Lee  Jong-Ghap Jhun  Kyung-Ja Ha 《Climate Dynamics》2012,39(5):1063-1072

The global summer monsoon precipitation (GSMP) provides a fundamental measure for changes in the annual cycle of the climate system and hydroclimate. We investigate mechanisms governing decadal-centennial variations of the GSMP over the past millennium with a coupled climate model’s (ECHO-G) simulation forced by solar-volcanic (SV) radiative forcing and greenhouse gases (GHG) forcing. We show that the leading mode of GSMP is a forced response to external forcing on centennial time scale with a globally uniform change of precipitation across all monsoon regions, whereas the second mode represents internal variability on multi-decadal time scale with regional characteristics. The total amount of GSMP varies in phase with the global mean temperature, indicating that global warming is accompanied by amplification of the annual cycle of the climate system. The northern hemisphere summer monsoon precipitation (NHSMP) responds to GHG forcing more sensitively, while the southern hemisphere summer monsoon precipitation (SHSMP) responds to the SV radiative forcing more sensitively. The NHSMP is enhanced by increased NH land–ocean thermal contrast and NH-minus-SH thermal contrast. On the other hand, the SHSMP is strengthened by enhanced SH subtropical highs and the east–west mass contrast between Southeast Pacific and tropical Indian Ocean. The strength of the GSMP is determined by the factors controlling both the NHSMP and SHSMP. Intensification of GSMP is associated with (a) increased global land–ocean thermal contrast, (b) reinforced east–west mass contrast between Southeast Pacific and tropical Indian Ocean, and (c) enhanced circumglobal SH subtropical highs. The physical mechanisms revealed here will add understanding of future change of the global monsoon.  相似文献   

河套平原中东部地下水的环境同位素特征分析          下载免费PDF全文

高晶  郝爱兵  魏亚杰  张顺宝 《水文地质工程地质》2009,36(3):55-58

河套平原由大厚度第四系冲湖积地层组成,地下水水平径流滞缓,以垂向水交替为主。地下水D1、8O3、H同位素特征的分析表明,地下水开发利用和引黄河水灌溉对河套平原中东部地下水循环交替的影响主要是:在没有开采井的地域,灌溉水入渗补给对地下水的影响范围和深度十分有限;在开采井周围,灌溉入渗补给的影响深度、范围和强度明显增加,影响深度取决于主要开采层位,影响范围和强度取决于开采规模。  相似文献