天山东部冰芯pH值和电导率的大气环境空间差异

冰芯电导率是大气环境变化的替代性指标.对我国天山东部三个研究点奎屯哈希勒根48号冰川、乌鲁木齐河源1号冰川以及哈密庙儿沟平顶冰川粒雪芯中pH值和电导率的近期环境记录进行了分析研究.结果显示,三个研究点粒雪芯反映的近期pH值和电导率变化趋势不同:奎屯电导率随冰芯深度增加表现出升高趋势,哈密庙尔沟平顶冰川和乌鲁木齐河源1号冰川随冰芯深度增加表现出一定下降趋势;冰芯电导率平均值在哈密庙儿沟冰川最大,而其他两个点相对较小,这与矿物粉尘浓度和离子浓度的分布一致;雪冰电导率与粉尘及离子相关性分析表明,电导率主要受中亚粉尘活动影响,同时与Ca2+、Mg2+、Na+等相关性很高.通过比较显示,天山东部与我国西部其他研究点以及极地雪冰电导率的差异可以很好地反映大气环境的空间差异.     

沙尘天气过程对沈阳大气冰核浓度与尺度分布的影响

为研究沙尘天气对大气冰核浓度及尺度分布的影响,2010-2012年春季用FA-3型安德森采样器在沈阳地区开展了大气冰核观测,采样后的滤膜在中国气象科学研究院的静力扩散云室中进行统一检测分析。针对2011年5月11-12日一次典型沙尘天气过程,分析了沙尘过程前后大气冰核浓度和尺度分布与变化特征。结果表明：沈阳地区春季大气冰核的本底浓度较高,约为0.8个·L^-1（活化温度为-20℃）;沙尘天气出现时可使大气冰核浓度突增10倍以上。约2/3的大气冰核集中在>4.7μm粒径段;有沙尘影响时,2.11～5.80 μm粒径段的大气冰核浓度增加最明显。大气冰核浓度的粒子尺度谱近似服从幂指数n（D）=A·D^B分布,其中A和B的数值在沙尘日明显大于非沙尘日。根据观测,建议在沈阳乃至中国北方地区春季有沙尘天气影响时应慎重选择人工影响天气作业方案。     

A Light Portable Steam-driven Ice Drill Suitable for Drilling Holes in Ice and Firn

The purpose of this contribution is to explain the characteristics of a newly developed ice drill which is particularly geared to the needs of glaciologists. It is primarily designed for drilling holes for ablation stakes and for measuring water levels or temperatures in firn areas. Its distinguishing features are its light weight, making it easy to carry even over long distances, and the variety of tasks to which it can be adjusted. Furthermore, it is easy to operate even by one person.
Water is heated in a boiler by two gas flames to produce steam, which flows through an insulated hose to a nozzle. When the valve is opened the issuing steam condenses, and the heat released in the process melts the ice. The heater is constructed in such a way that it can easily be adapted to any form of gas supply locally available. It can be used for drilling in ice as well as in firn. The maximum drilling depth is 13 m in ice and 30 m in firn; hole diameters range from 25 to 45 mm. Mean drilling time is 16 min for 6 m, 35 min for 12 m in ice. The total weight is somewhat less than 16 kg, including all parts needed for drilling holes of 10 m in depth as well as the gas supply for one day. In recent years, devices of this type have been used successfully by scientists in various glaciated regions.     

Amery冰架DEM及其海洋冰分布研究

Amery冰架是东南极最大的冰架。利用克里格插值法对Amery冰架地区的ICESat激光高度计数据进行空间插值,建立该地区的DEM。依据流体静力学平衡原理构建Amery冰架的冰厚度图,结合冰雷达测厚数据,获得了海洋冰的空间分布。结果显示Amery冰架下的海洋冰主要位于西北部,体积为2.38×1012m3,约占冰架总体积的5.6%,冰架最大厚度为230 m。     

The Little Ice Age in the Canadian Rockies

This paper reviews the evidence and history of glacier fluctuations during the Little Ice Age (LIA) in the Canadian Rockies. Episodes of synchronous glacier advance occurred in the 12th–13th, early 18th and throughout the 19th centuries. Regional ice cover was probably greatest in the mid-19th century, although in places the early 18th century advance was more extensive. Glaciers have lost over 25% of their area in the 20th century. Selective preservation of the glacier record furnishes an incomplete chronology of events through the 14th–17th centuries. In contrast, varve sequences provide continuous, annually resolved records of sediments for at least the last millennium in some highly glacierized catchments. Such records have been used to infer glacier fluctuations. Evaluation of recent proxy climate reconstructions derived from tree-rings provides independent evidence of climate fluctuations over the last millennium. Most regional glacier advances follow periods of reduced summer temperatures, reconstructed from tree rings particularly ca. 1190–1250, 1280–1340, 1690s and the 1800s. Reconstructed periods of higher precipitation at Banff, Alberta since 1500 are 1515–1550, 1585–1610, 1660–1680 and the 1880s. Glacier advances in the early 1700s, the late 1800s and, in places, the 1950–1970s reflect both increased precipitation and reduced summer temperatures. Negative glacier mass balances from 1976 to 1995 were caused by decreased winter balances. The glacier fluctuation record does not contain a simple climate signal: it is a complex response to several interacting factors that operate at different timescales. Evaluation of climate proxies over the last millennium indicates continuous variability at several superimposed timescales, dominated by decade–century patterns. Only the 19th century shows a long interval of sustained cold summers. This suggests that simplistic concepts of climate over this period should be abandoned and replaced with more realistic records based on continuous proxy data series. The use of the term LIA should be restricted to describing a period of extended glacier cover rather than being used to define a period with specific climate conditions.     

新疆区域大气透明度研究

在分析新疆区域大气透明度过程中,为克服福布斯（FORBERS）效应,即大气质量M对太阳光谱成分变化产生的干扰,将复合透明度系数Pm订正到相对大气质量M=2（H=90°）时所计算出来的积分透明度P2来进行描述。利用乌鲁木齐、喀什40多年长序列太阳辐射资料以及塔克拉玛干沙漠腹地及周边地区相关的辐射和气象资料,分析新疆区域大气透明度的年际、月际和日变化以及影响大气透明度的主要气象因子。结果表明,乌鲁木齐、喀什的大气透明度在40多年中,其年际变化特征主要表现为P2呈逐步下降的趋势,这种下降在20世纪90年代至今的近20 a里有加速的趋势;从季节角度分析,P2的这种逐年代下降的趋势在冬季（1月）和春季（4月）更为显著,而在夏季（7月）和秋季（10月）,这种下降则较为温和,无论乌鲁木齐还是喀什,以十年段平均值的振幅来看,乌鲁木齐P2在1月和4月均在0.2以上,而7月和10月则均在0.2以下,表现的更为明显,喀什亦有类似特征;新疆大气透明度在一年中的变化,以冬季为最佳,秋季次之,春季最差,近年来,乌鲁木齐地区冬季大气透明度急剧下降,其最高值已出现在秋季,喀什也呈现出同样现象,这表明了在城市化情况下,以人类活动影响因素为主所导致的大气污染,使空气的透明状况越来越差;新疆大气透明度的日变化表现为早晚高、中午低的特点,其逐日变化则与天气过程相关联;新疆的下垫面多为沙漠、戈壁,大气中的尘埃含量和水汽压变化是新疆大气透明度的重要影响因子,尘埃含量的变化是塔里木盆地大气透明度变化的最重要影响因子,其与大气透明度的变化呈反相关,而水汽压的变化亦与大气透明度变化呈反相关关系。     

小冰期气候的研究进展

小冰期是近2ka来的一个重要气候事件,又是目前全球变暖的背景事件,已成为古气候和古环境研究的热点。对此,科学工作者已经做了大量的研究。本文广泛综合前人研究的成果,介绍了小冰期的概况,认为1450-1890年是小冰期的时限,在此期间有三次冷期和两次暖期。冷期发生在1450-1510年、1560-1690年和1790-1890年,其中第二次冷期表现最甚;暖期发生在1510-1560年和1690-1790年。太阳活动和火山活动是小冰期气候变化的主要因素。并重点从冰芯、树轮、湖泊沉积、历史文献和沙漠地层等方面综述了近年来国内外对小冰期气候变化的研究现状。     

辽宁中部大气可吸入颗粒物浓度与气象要素的相关性

利用辽宁中部地区2012年6月1日至2013年5月31日观测数据,研究了城市大气可吸入颗粒物质量浓度和气象要素的之间的相关性。结果表明:对辽宁中部地区整体来说,秋、冬季的可吸入颗粒物排放在全年贡献比例较大;对区域各城市来说,沈阳和鞍山的颗粒物污染贡献较大。区域颗粒物浓度在午后达到最低,清晨升至最高,而能见度则在这两个时段分别达到最高和最低。颗粒物浓度与相对湿度的变化趋势基本一致,与能见度、气温和风速的变化趋势相反。颗粒物(尤其是大气细粒子)浓度与能见度的相关关系最为显著,这种相关性在夏、秋、冬季更加明显,而在鞍山、本溪两地尤为突出。     

Spatial Sciences on Ice: 50 years of Australian activities on the Amery Ice Shelf,East Antarctica

The Antarctic climate system involves many complex interactions between the atmosphere, oceans and ice and is sensitive to variations in these components. Ice shelves represent the ice–ocean–atmosphere interface of the Antarctic continent and are therefore very important indicators of climate change in the region. The Amery Ice Shelf is the largest ice shelf in East Antarctica and has been the focus of many scientific research projects over the past 50 years. This paper presents a history of the use of spatial science techniques from basic survey equipment to satellite systems in Australian research projects based on the Amery Ice Shelf (and surrounding glaciers) since 1955. The application of these spatial data to projects based primarily in the fields of geodesy, glaciology, climatology, and oceanography has allowed the measurement and monitoring of the physical, dynamic and environmental characteristics of this large and remote region. This new information provides scientists with a better understanding of the ice shelf/ocean/atmosphere system allowing future monitoring to observe the effects of global climate change.     

Enhanced Destriping of Satellite Data of Ice Surface in Antarctica

This paper briefly reviews the cause of the striping and then develops a tapered (Chebwin & Kaiser) window finite impulse response (FIR) filter and a constrained least squares FIR filter by reason of the striping of ASTER satellite data . Both filters minimize the stripes in the visible data and simultaneously minimize any distortion in the filtered data. Finally, the results obtained by using these new filtering methods are quantitatively compared with those produced by other destriping methods.     

向海湿地沉积芯重金属对流域环境污染示踪

选取霍林河下游向海沼泽湿地为研究对象，采用得力沉积芯采样钻钻孔采样与剖面切割采样相结合的方法，采集了10个沉积柱芯及剖面，以沉积物重金属元素Cu、Zn、Cr、Ni、Co、Pb、Fe、Mn及pH、TOC在剖面中的分布进行高分辨率研究。结晶显示，剖面上部沉积物表层沉积序列内明显富集了Fe、Mn、Zn等重金属，并与TOC含量呈显著相关，与此相反，大多数沉积柱芯下层的重金属含量相对较低。研究表明，高分辨率取样易找出元素间相关性，那些水源来自同一相对稳定外源输入的沉积柱芯中的重金属与TOC表现出更显著的相关性，越靠近河流、淹没频率直蒿，沼泽湿地表层沉积物中重金属元素含量趋向增高。     

中国湖泊柱样沉积物中239+240Pu的来源与分布特征

针对当前中国湖泊柱样沉积物中^239+240Pu的研究现状,对中国湖泊^239+240Pu的来源、^239+240Pu最大蓄积峰的年代以及^239+240Pu在湖泊沉积物中的迁移行为进行了研究总结。结果表明：中国湖泊^239+240Pu的主要来源于全球大气核试验沉降,湖泊沉积柱样中表层沉积物²⁴⁰Pu/²³⁹Pu均值为0.177±0.019;柱样²⁴⁰Pu/²³⁹Pu均值为0.177±0.008;柱样^239+240Pu的沉积通量范围在7.45~240.6 MBq/km²之间,因湖泊所处沉积环境及纬度的差异而变化。湖泊柱样剖面中的^239+240Pu的分布多呈单峰分布,湖泊沉积物中^239+240Pu的最大蓄积峰位置改变可以忽略不计,^239+240Pu最大蓄积峰具有时标价值。     

大气颗粒物遥感研究进展

大气污染已成为全球性的环境污染问题之一,PM2.5和PM10已成为当前大气遥感研究的热点,以京沪穗为代表的特大城市更成为相关研究的重要焦点。通过对国内外相关文献的分析,以广州为例描述了地面站点监测的现状和不足,指出PM2.5遥感的关键问题为区域尺度气溶胶光学厚度垂直订正和区域尺度近地面消光系数湿度效应校正研究;通过空气质量模式系统进行相关研究,是包括PM2.5在内的大气颗粒物遥感的重要途径之一。     

沙漠地区大气扩散参数特征分析

1996年4月和5月我们分别在内蒙古吉兰泰气象站和银川机场气象台用南京大学大气科学系研制的三分量风速仪,观测了各类不同天气条件下沙漠地区三维风速脉动量u、v和w,根据Taylor湍流统计理论及Hay和Pasquill的假设,统计计算了各湍流特征值,计算分析了湍流场中水平风向和垂直风向的大气扩散参数e_y和e_z,并结合美制APS-3310A型激光空气动力学气溶胶粒子谱仪的观测结果,初步分析了沙尘天气条件下扩散参数与近地层沙尘气溶胶粒子数浓度和质量浓度的关系。     

中国热带西部的小冰期

中国热带以约105°E为界分为东部和西部。热带西部主要是滇南地区。按照史书记载的25个冷冬降雪年份,小冰期为1498-1896年,期间有3个寒冷阶段(1498-1550年、1694-1826年、1868-1896年)和2个相对温暖阶段。热带西部的小冰期比东部地区历时短,寒冷阶段滞后,影响范围较小。小冰期时水旱灾害频仍。小冰期的寒冷阶段与太阳黑子活动的平静期有一定的相关性。热带东、西部小冰期的差异,主要是由于东部受东亚季风影响,西部受南亚季风影响。     

Greenland Ice Sheet surface melt: A review

Surface melt has great impacts on the Greenland Ice Sheet （GrlS） mass balance and thereby has become the focus of significant GrlS research in recent years. The production, transport, and release processes of surface meltwater are the keys to understanding the poten- tial impacts of the GrlS surface melt. These hydrological processes can elucidate the following scientific questions： How much melt- water is produced atop the GrlS？ What are the characteristics of the meltwater-formed supraglacial hydrological system？ How does the meltwater influence the GrlS motion？ The GrlS supraglacial hydrology has a number of key roles and yet continues to be poorly understood or documented. This paper summarizes the current understanding of the GrlS surface melt, emphasizing the three essential supraglacial hydrological processes： （1） meltwater production： surface melt modeling is an important approach to acquire surface melt information, and areas, depths, and volumes of supraglacial lakes extracted from remotely sensed imagery can also provide surface melt information; （2） meltwater transport： the spatial distributions of supraglacial lakes, supraglacial sarams, moulins, and crevasses demonstrate the characteristics of the supraglacial hydrological system, revealing the meltwater transport process; and （3） meltwater release： the release of meltwater into the englacial and the subglacial ice sheet has important but undetermined impacts on the GrlS motion. The correlation between surface runoff and the GrlS motion speed is employed to understand these influences.