Seasonal Characteristics of Surface Radiation Fluxes on the East Rongbuk Glacier in the Mt. Everest Region

Ground-based measurements are essential for understanding alpine glacier dynamics, especially in remote regions where in-situ measurements are extremely limited. From 1 May to 22 July 2005 (the spring-summer period), and from 2 October 2007 to 20 January 2008 (the autumn-winter period), surface radiation as well as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt. Qomolangma/Everest at an elevation of 6560 m a.s.l. by using an automatic weather station (AWS). The results show that surface meteorological and radiative characteristics were controlled by two major synoptic circulation regimes: the southwesterly Indian monsoon regime in summer and the westerlies in winter. At the AWS site on the East Rongbuk Glacier, north or northwest winds prevailed with high wind speed (up to 35 m s-1 in January) in winter while south or southeast winds predominated after the onset of the southwesterly Indian monsoon with relatively low wind speed in summer. Intensity of incoming shortwave radiation was extremely high due to the high elevation, multiple reflections between the snow/ice surface and clouds, and the high reflective surrounding surface. These factors also caused the observed 10-min mean solar radiation fluxes around local noon to be frequently higher than the solar constant from May to July 2005. The mean surface albedo ranged from 0.72 during the spring-summer period to 0.69 during the autumn-winter period. The atmospheric incoming longwave radiation was greatly affected by the cloud condition and atmospheric moisture content. The overall impact of clouds on the net all-wave radiation balance was negative in the Mt. Qomolangma region. The daily mean net all-wave radiation was positive during the entire spring-summer period and mostly positive during the autumn-winter period except for a few overcast days. On monthly basis, the net all-wave radiation was always positive.     

Seasonal Characteristics of Surface Radiation Fluxes on the East Rongbuk Glacier in the Mt.Everest Region

Ground-based measurements are essential for understanding alpine glacier dynamics,especially in remote regions where in-situ measurements are extremely limited.Prom 1 May to 22 July 2005(the spring-summer period),and from 2 October 2007 to 20 January 2008(the autumn-winter period),surface radiation as well as meteorological variables were measured over the accumulation zone on the East Rongbuk Glacier of Mt. Qomolangma/Everest at an elevation of 6560 m a.s.l.by using an automatic weather station(AWS).The...     

A 108.83-m ice-core record of atmospheric dust deposition at Mt. Qomolangma (Everest), Central Himalaya

The central Himalaya can be regarded as an ideal site for developing a long-term ice core dust record to reflect the environmental signals from regional to semi-hemispheric scales. Here we present a dust record from segments of a 108.83-m ice core recovered from the East Rongbuk (ER) Glacier (27°59′N, 86°55′E; 6518 m a.s.l.) on the northeast slope of Mt. Qomolangma (Everest) in the central Himalaya, covering the period AD 600-1960. Due to rapidly layer thinning and coarse sampling, we primarily discuss the changes in the dust record since AD 1500 in this paper. Results show a significant positive relationship between the dust concentration and reconstructed air temperatures during this period, suggesting a likely cold-humid and warm-dry climatic pattern in the dust source regions, namely Central Asia. This is associated with the variability in the strength of the westerlies and its corresponding precipitation.     

Meteorological Features at 6523 m of Mt.Qomolangma （Everest） between 1 May and 22 July 2005

Introduction Mt. Qomolangma (Everest) (27°54'N, 86°54'E) (Hereafter Mt. Qomolangma) lies between China and Nepal (Figure 1), and is the highest peak in the world, 8844.43 m asl (As promulgated by News Of-fice of the Chinese State Council in October 2005…     

1982-2009 年珠穆朗玛峰自然保护区植被指数变化

植被指数是指示植被变化的重要指标, 本研究基于1982-2009 年珠穆朗玛峰自然保护区(简称珠峰地区)植被指数(NDVI)时间序列数据、土地覆被和野外调查等数据, 采用时序变化趋势和空间分析法, 对珠穆朗玛峰地区植被的时空变化过程及保护区成效进行了定量分析。研究表明:①珠峰地区NDVI分布的总特征是南部和北部高, 中部低。②1982-2009 年珠峰地区NDVI年际变化趋势和空间异质性十分明显:1982-1997 年, 珠峰地区NDVI总体上呈显著上升趋势, 北部地区增幅较大;1998-2009 年, NDVI总体下降(56.96%的NDVI呈下降趋势), 其中, 珠峰地区中部和北部的NDVI下降最为明显, 而南部核心保护区森林和灌丛的NDVI则呈显著上升趋势, 且变化幅度较大。③长时间序列植被指数变化的过程和空间差异性推断:1998 年以来, 天然林保护等生态工程促使珠峰地区保护效果更加明显。     

中国风水地理哲学基础与人地关系

首先用辩证唯物主义哲学观考察了传统风水地理学,在对中国风水地理哲学批判的基础上,构建了从传统风水地理学走向现代风水地理学的模式图。《周易》中的“天人合一”观之所以奠定了传统风水地理学的哲学基础,它由“天人合一”思想的功能所决定。现代风水地理学实践赋予了“天人合一”新内涵,新“天人合一”的哲学思想对现代风水地理研究有着重要意义,“天人合一”观与“人地关系”密切相关。“人地关系”不仅是现代人文地理学研究的主题与核心,也是风水地理学研究的源头与核心。文章系统梳理了“人地关系”理论模式,为风水地理研究人地关系与实践奠定了坚实的理论基础,并指出,传统风水地理学含有大量迷信色彩和伪科学思想,必须进行哲学科学批判,必须进行革新,引入相关的现代科学理论、方法、技术,从定性研究走向实证研究,从传统风水地理学走向现代风水地理学。     

珠穆朗玛峰北坡绒布冰川表面辐射特征观测研究

在资料比较稀少的偏远山地冰川进行地面综合气象观测对于研究冰川变化极其重要.珠穆朗玛峰(27.98°N,86.92°E,海拔8844.43 m)地区位于青藏高原南部边缘喜马拉雅山脉中段,自然地理条件独特,环境脆弱,是气候变化和环境变迁的敏感区,同时也是现代冰川作用中心.2005年5-7月和2007年10月-2008年1月在珠穆朗玛峰北坡东绒布冰川积累区(28°01'N,86°57'E,海拔6560 m)开展了综合气象观测研究.分析表明,在东绒布冰川积累区春末夏初月平均气温从5月的-11.3℃上升到7月的-3.4℃,秋冬季月平均气温则从10月的-11.3℃下降到次年1月的-19.0℃.秋冬季主要受西风气流影响,盛行西风或西北风,而且风速较大,1月最大风速达到35 m/s;而在印度季风爆发后主要以南风或西南风为主,风速相对较小.由于海拔高、冰雪面与云之间的多重反射以及复杂地形影响导致地面总辐射较大.春末夏初和秋冬季总辐射平均值分别达到635和502 W/m2.尤其造成5-6月正午前后10 min短波辐射平均值发生超太阳常数的现象比较频繁,最长持续时间接近3 h.晴天由于周围地形作用可使地面总辐射增加140-310 W/m2,约占短波辐射的10%-23%.春末夏初和秋冬季平均反射率分别为0.72和0.69.云和空气湿度对大气长波辐射的影响比较显著,导致大气长波辐射同样具有日变化特征.在地表辐射平衡中云对地面净辐射起负效应.除在秋冬季阴天日平均净辐射为负值外,其余时间均为正值,说明净辐射是地表能量的主要来源.     

珠穆朗玛峰地区气象要素特征观测研究

利用中央气象台奥运火炬传递珠峰气象保障队获取的第一手资料,对2007年4月12日-5月8日珠穆朗玛峰(简称珠峰)大本营地面自动站和79次探空实测资料进行分析,揭示了珠峰地区气象要素变化的观测事实。结果表明:受珠峰北坡绒布冰川沉降风影响,珠峰大本营盛行南风;风速和气温日变化呈单峰分布,风速极小值和日最低气温出现在08:00(北京时,下同),而极大值出现在15:00前后;相对湿度峰值出现在07:00和23:00,正午前后相对湿度最小。6200 m高度以下几乎昼夜恒吹下山风,偏南风在22:00至次日00:00最强;7200-9000 m高度风向主要以偏西风为主,风速随高度也明显增加。5200-8000 m各高度上,日最低气温始终出现在08:00,最高气温出现在16:00,8200 m以上气温呈现出多波动起伏。在6700-9700 m高度能维持相对湿度的高值中心,大值区主要位于6500-8800 m高度。高空西风锋区位于12000-15000 m,对流层顶高度大约在18200 m左右。     

珠穆朗玛峰地区的地壳运动,地壳厚度,张性冰川的探讨

珠穆朗玛峰是世界最高峰，基高程一直受到世人关注。同时珠穆朗玛峰及其毗邻地区位于欧亚板块和印度板块边缘的冲撞挤压地带，地壳运动，剧烈，地形。复杂，三十年来我国对珠穆朗玛峰高程及其毗邻地区进行了三次大规模大地测量，现将珠穆朗玛峰高程和该地区的地壳运动研究介绍于后。     

西藏珠穆朗玛峰北坡地区三叠纪磁性地层研究

本文对在西藏南部珠穆朗玛峰北坡土隆地区三叠纪地层剖面中采集的728件古地磁定向标本进行了较详细的研究。样品采集是在实测剖面之后进行的。野外样品采集使用国产GSD-1型手提式轻便取样钻机,钻取的岩心直径为24～25mm,长度一般为30～60mm,用磁罗盘定向器定向取心。采样间距一般控制在0.5～3m。在重要地层界线上、下部位进行加密采样,样品间距为0.1～0.2m。分析结果表明,珠穆朗玛峰北坡地区三叠系岩石的天然剩余磁化强度属中偏弱。样品的天然剩磁强度为1.9×10-2A/m～9.4×10-1A/m,特征剩磁强度为3.9×10-2A/m～5.0×10-1A/m。大多数样品在退磁测试到550～600℃时,样品剩余磁化强度已衰减了90%～100%,表明岩样中的磁性载体基本上为磁铁矿。研究表明,在土隆群中获得了12个正向极性和11个反向极性带,这在中生代早期是一个中等频率的正、反向混合极性巨带,命名为土隆混合极性巨带,与ILLAVARA(依拉瓦拉)混合极性巨带相吻合。曲龙共巴组和德日荣组中仅测出2个小的反向极性带,其余样品均为正向极性,笔者将该地层单元命名为土隆正向极性巨带,与GRAHAM正极性巨带相当。德日荣组上部为反向极性带。据此厘定了该区三叠系下统、中统和上统的界线。珠穆朗玛峰地区三叠纪磁性地层的深入研究,为该区三叠系多重地层划分与对比研究,建立珠穆玛朗玛峰地区三叠系古地磁样品数据库和三叠系磁性地层极性柱,为进一步深入研究冈瓦纳大陆的演化、古特提斯洋的形成、消亡历史和青藏高原隆升机制提供科学依据。