Statistical analysis of the position of the monsoon trough

Using surface charts at 0330GMT, the movement of the monsoon trough during the months June to September 1990 at two fixed longitudes, namely 79°E and 85°E, is studied. The probability distribution of trough position shows that the median, mean and mode occur at progressively more northern latitudes, especially at 85°E, with a pronounced mode that is close to the northern-most limit reached by the trough. A spectral analysis of the fluctuating latitudinal position of the trough is carried out using FFT and the Maximum Entropy Method (MEM). Both methods show significant peaks around 7.5 and 2.6 days, and a less significant one around 40–50 days. The two peaks at the shorter period are more prominent at the eastern longitude. MEM shows an additional peak around 15 days. A study of the weather systems that occurred during the season shows them to have a duration around 3 days and an interval between systems of around 9 days, suggesting a possible correlation with the dominant short periods observed in the spectrum of trough position.     

The Tendencies of the Development of the Mineral-Resources Sector at the Turn of the Century

Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base.     

阿克苏河源流区径流量与降水量丰枯变化和相关性研究

利用新疆塔里木河流域阿克苏河源流区出山口沙里桂兰克和协合拉两水文站1957-2008年近50a的径流和降水数据, 借助Z指数法、参数T检验和非参数检验和小波变换等, 分析了阿克苏河两水文站降水量和径流量的变化趋势, 以及二者多时间尺度相关关系.结果表明:近50a来, 沙里桂兰克、协合拉径流量和降水量均呈增加趋势, 两水文站径流量在1993年发生了显著的增多突变, 其中, 降水量突变点沙里桂兰克在1985年, 协合拉在1986年.沙里桂兰克和协合拉降水量和径流量丰枯指数由突变前的"偏枯"和"正常"等级为主转变为突变后的"正常"和"偏涝"等级占优势.沙里桂兰克和协合拉径流量变化分别存在7a和6a的主周期, 降水量变化分别存在7a和4a的主周期.沙里桂兰克径流量和降水量在整个时间尺度上以正相关为主, 协合拉则以负相关为主, 在大于20a的时间尺度上两水文站径流量和降水量均呈不显著的正相关关系.     

青藏高原边缘积雪辐射特征

利用中国陆地生态系统通量观测研究网络的玛曲站观测的一次降雪过程的资料,对青藏高原东部边缘冬季的降雪、积雪过程的辐射特征进行了分析.研究结果表明;积雪期晴天和降雪过程的向上短波辐射的峰值分别约为降雪前晴天的3和2倍.无积雪晴天地表反射率主要分布在0.175～0.36,新雪地表反射率主要分布在0.8～0.9.大气逆辐射变化较小,降雪过程的最大,积雪时的最小.地表长波辐射则为降雪前最大,降雪时最小.积雪覆盖的晴天比无积雪时的净辐射变化幅度减小,且早上由负转正的时间推迟.     

天山南坡科其喀尔冰川表碛区小气候特征研究

利用天山南坡科其喀尔冰川3号观测站2009年全年的气象观测资料,分析研究了科其喀尔冰川表碛区的小气候特征. 结果表明：总辐射和净辐射夏秋季较高、冬春季较低;反射辐射和地表反照率反之. 与其他地区不同,该区主要受积雪物理性质和下垫面状况的影响,冬春季地表反照率日变化表现为由大到小的变化过程,夏秋季表现为倒U型. 温度年变化表现为夏秋季高、冬春季低,最高月均值出现在8月,为9.4℃,最低月均值出现在1月,为-9.6℃. 受山谷风和冰川风的影响,全年的风向以西北风和西北偏西风为主,风向的日变化以11：00为界发生转向. 受降水和冰川消融等的影响,比湿夏秋季月均值较大,冬春季月均值较小.     

Measurements of the dissipation coefficient at the wavemaker in the process of generation of the resonant standing waves in a tank

The complex dissipation at the wavemaker used for direct excitation of nonlinear standing waves in the vicinity of the cut-off frequency, is measured experimentally. The results indicate that the absolute value of this dissipation coefficient exceeds significantly the estimate based on purely viscous dissipation. This is attributed to the turbulent effects resulting from the vortex shedding at the discontinuities of the wavemaker surface. It is shown that incorporation of this dissipation in the boundary condition at the wavemaker as a nonlinear term in a form generally used to describe dissipation in a turbulent boundary layer, is more appropriate allowing to remove hysteresis in the value of the wavemaker dissipation coefficient. Such hysteresis is observed when a linear dissipation model is applied.     

共和盆地层状地貌系统与青藏高原隆升及黄河发育

利用卫星遥感影像,结合实地调查和测年结果,对共和盆地层状地貌系统进行了解译、分析。研究表明,共和盆地层状地貌系统由山麓剥蚀面、洪积扇面、盆地面以及黄河阶地面构成,其空间结构、物质组成对发生于早更新世早期的青藏运动C幕和中更新世末期的共和运动反映清晰。青藏运动C幕使青藏高原主夷平面在高原差异性隆升中彻底解体,垂直变形量高达1700m。共和运动使黄河在0.11Ma进入共和盆地,其后黄河平均以3.5mm/a的侵蚀速率下切盆地,同时在盆地边部的山前古冲洪积扇以大致相近的速率被抬升,最终导致高差在2000m左右的层状地貌系统的出现。     

A review of the thermal regime of the Eastern Alps with respect to the effects of paleoclimate and exhumation

Transient thermal signals such as Pleistocene surface temperature variations or exhumation of great rock volumes are important for the current thermal regime of the Eastern Alpine crust. In this study transient 1-D forward simulations and an analytical approach were used to estimate the order of magnitude of these effects. A comparison with numerical forward simulations and inverse analyses of steady-state heat conduction yields the following main conclusions with respect to the thermal regime of the Eastern Alps along the TRANSALP profile: (1) The change of surface temperatures in the past affects mainly the uppermost part of the Eastern Alpine crust. It results in a maximum thermal signature of more than − 6 K at a depth of 2 km. The deviations from a steady-state temperature gradient and heat flow in the region of the Tauern Window range from 0.3–4 K km^− 1 and 0–6 mW m^− 2, respectively, with maximum values at the surface. (2) Exhumation of the Eastern Alpine lithosphere may result in a thermal signature of up to 4 K at a depth of 1 km. The thermal signature increases further with depth to a maximum of approximately 80 K at a depth of 50 km. As the temperature gradient of the exhumation signal is almost zero at the base of the crust, Moho heat flow appears to be not critically perturbed. (3) The combined effect of exhumation and changing surface temperatures at the Tauern Window amounts to less than 15% of the steady-state temperatures at a depth of  8 km and to less than 10% at the base of Eastern Alpine root. The corresponding perturbation in heat flow is less than 20% at a depth of 4 km, approaching zero below 40 km.     

积雪对祁连山区黑河上游活动层热状态的影响研究

积雪对多年冻土活动层和近地表的热状态具有重要影响。然而,积雪对祁连山区黑河上游地区多年冻土热状态的影响机制尚不清楚,迫切需要可靠的野外观测数据进行定量研究。基于两个典型野外监测站点2012—2019年观测数据,分析积雪对表面能量平衡、5cm地表热通量及活动层热状态的影响。结果表明:厚度约21cm的积雪在秋冬季对活动层具有保温作用;2013—2018年,俄博岭(EB)和野牛沟(PT1)监测场,活动层厚度分别为61～86cm和159～164cm,平均活动层厚度分别为74.2cm和162.1cm。受积雪影响,相隔两年(2015—2017年)的活动层厚度变化达25cm。定量分析了祁连山积雪对多年冻土热状态的影响,为未来祁连山相关研究提供重要资料。     

Inverse problem for the determination of the bounds on the mantle heat flow

This paper presents a method for determining the nature of the spatial structure of the heat flow anomaly at depth given a few observations of surface heat flow. We use the constraint of the positivity of the heat flow throughout the domain under consideration to arrive at the solution. Both Parker’s ideal body and linear programming approaches have been considered. We find that a few measurements are able to give a reasonable good estimation of the heat flow anomaly at depth. The method has been applied to a real case in the French Massif Central. Results point to the presence of enhanced basal heat flow anomaly.     

Controls of surface erosion on the evolution of the Alps: constraints from the stratigraphies of the adjacent foreland basins

 The combined information about the stratigraphies from the foreland basins surrounding the Swiss Alps, exhumation mechanisms and the structural evolution of the Alpine orogenic wedge allow an evaluation of the controls of erosion rates on large-scale Alpine tectonic evolution. Volumetric data from the Molasse Basin and fining-upward trends in the Gonfolite Lombarda indicate that at ∼20 Ma, average erosion rates in the Alps decreased by >50%. It appears that at that time, erosion rates decreased more rapidly than crustal uplift rates. As a result, surface uplift occurred. Because of surface uplift, the drainage pattern of the Alpine hinterland evolved from an across-strike to the present-day along-strike orientation. Furthermore, the decrease of average erosion rates at ∼20 Ma coincides with initiation of a phase of thrusting in the Jura Mountains and the Southern Alpine nappes at ∼50 km distance from the pre-20-Ma thrust front. Coupled erosion-mechanical models of orogens suggest that although rates of crustal convergence decreased between the Oligocene and the present, the reduction of average erosion rates at ∼20 Ma was high enough to have significantly influenced initiation of the state of growth of the Swiss Alps at that time. Received: 8 June 1998 / Accepted: 30 October 1998     

兴蒙、吉黑地区岩石圈电性结构特征

采用具有国际先进水平的二维连续自动反演技术对收集的MT资料进行了二维反演和综合解释。得到了不同地区MT剖面的二维电性结构断面。通过二维反演断面发现了松辽盆地的东西边界较陡,而南部边界较缓的电性结构;发现在火山地区12～30km深度普遍存在低阻物体,为解释火山地区深部存在岩浆囊提供了依据。另外,于桦南—饶河重新实施的MT剖面,其二维反演断面也较清楚地揭示出:剖面西段为高阻特征且具有稳定的岩石圈厚度(80～90km),该区段对应佳木斯地块;剖面中部具有明显的电性梯度带,该梯度带为确定佳木斯地块的东界位置及其深部结构形态提供了依据;剖面东段则揭示了佳木斯地块以东地区浅部为逆冲推覆体,深部为多个高阻块体与低阻条带相间的电性结构。     

The studies of the sorption properties of soils at the base of the ash storage of the projected power station on Sakhalin Island

The soil sorption properties were determined for the base of ash storage at a proposed power station on Sakhalin Island. The analyses of aqueous extracts of the coal ashes that are intended for use at the station resulted in the identification of potential pollutant elements that might be transferred with the infiltrate of atmospheric precipitation. The composition of the infiltrate-modeling solution was selected based on the data. The sorption capacity of the covering soil by identified pollutants was evaluated at static and dynamic conditions, along with the degree of potential desorption of these pollutants.     

城镇化发展背景下那曲地区气温变化的特征分析

根据西藏那曲气象站（NQ站）1955-2014年和其相邻野外站（BJ 站）2001-2014年的气象观测资料,在那曲县城镇化发展背景下,对比分析了NQ站和BJ站气温变化的差异,从自然要素和人类活动要素两方面探讨了两站气温变化差异的原因。结果表明：近60a NQ站气温呈上升趋势,且2001-2014 年的气温上升率大于1955-2014年和1987-2000年的气温变化趋势;NQ站2001-2014年的平均气温、最高和最低气温的升温率,分别为0.52℃·（10a）^-1,0.60℃·（10a）^-1和0.67℃·（10a）^-1;同时期BJ站的平均气温、最高和最低气温升温率,分别为0.76℃·（10a）^-1、2.72℃·（10a）^-1和0.32℃·（10a）^-1。NQ站和BJ 站的最高气温变化均主要与自然要素有关,NQ站的最高气温与日照（0.67）、降水（-0.62）、水汽压（-0.58）相关系数较高,BJ站的最高气温与日照（0.67）、NDVI（-0.63）、水汽压（-0.57）相关系数较高;NQ站的最低气温与人均GDP（0.53）、GDP（0.50）、总人口（0.47）相关系数较高,说明NQ站的最低气温变化主要是受人类活动因素的影响,人类活动对NQ站最低气温的热岛贡献率为52.2%;BJ站的最低气温与各因素相关系数均较小且接近,是在气候背景下的自然变化。     

祁连山区黑河上游多年冻土分布考察

高山多年冻土的分布及土壤季节冻融过程对地表水文过程、 生态系统、 碳循环及寒区工程建设等都有很大的影响. 黑河上游地处祁连山中东部, 属于高原亚寒带半干旱气候, 研究黑河流域多年冻土分布对于系统理解该区域的生态-水文过程、 气候与环境变化以及水资源评价、 工程建设等非常重要. 2011年6-8月对黑河干流源头西支开展了多年冻土调查, 沿二尕公路(S204)在热水大坂垭口至石棉矿岔口之间区域, 完成测温孔7眼, 并布设测温管进行地温监测. 根据勘察、 钻探及测温资料, 确定了黑河源头地区山地多年冻土下界为海拔3 650~3 700 m之间. 受高度地带性的控制, 随着海拔的降低, 活动层厚度由在海拔4 132 m时的1.6 m增加至在多年冻土下界处的约4.0 m, 多年冻土年平均地温也相应的由-1.7℃增加到0.0℃左右, 而多年冻土厚度由100 m以上减小到多年冻土下界处的0.0 m. 同时, 坡度和坡向、 岩性、 含水(冰)量、 地下水、 河水等局地因素对多年冻土温度和厚度也有重要的作用.     

Estimating the mean temperature and salinity of the Chesapeake Bay mouth

We used an extensive temperature and salinity data set to develop a statistically meaningful way of estimating mean temperature and salinity from discrete measurements in the mouth of Chesapeake Bay. From April 1992 to December 1998, the Center for Coastal Physical Oceanography completed 73 monthly hydrographic sections at high spring tide across the mouth of Chesapeake Bay. Time series of area weighted mean bay mouth temperature (MBMT) and salinity (MBMS) were calculated. We found that at any time the temperature at any location in the section correlated with the MBMT with a r² of 0.95 or better. A similar analysis for salinity showed that the best correlation was about 0.9 with many locations below 0.8. A correlation between MBMT and temperature at a nearby tide station indicated it was possible to estimate MBMT from the temperature at the tide station to ±0.74°C (90% confidence interval). Salinity was not measured at the tide station, but the correlation at a location in the section similar to the tide station indicates that MBMS can be estimated with an error of ±1.5 (90% confidence interval).     

五极纵轴测深法在溶洞探测中的应用

以九江某地下溶洞探测工程为例,介绍了五极纵轴测深法的原理、方法及其应用效果.实地钻孔验证说明,五极纵轴测深法在城市地球物理勘探方面具有独特的优势,在未来的应用中必将有广阔的发展前景.     

A high-resolution speleothem proxy record of the Late Glacial in the European Alps: extending the NALPS19 record until the beginning of the Holocene

Previous research has shown that speleothems from the northern rim of the European Alps captured submillennial-scale climate change during the last glacial period with exceptional sensitivity and resolution, mimicking Greenland ice-core records. Here we extend this so-called NALPS19 record across the Late Glacial using two stalagmites which grew continuously into the Holocene. Both specimens show the same high-amplitude δ¹⁸O signal as Greenland ice cores down to decadal resolution. The start of the warming at the onset of the equivalent of Greenland Interstadial (GI) GI-1e at 14.66 ± 0.18 ka agrees with the North Greenland Ice Core Project (NGRIP) (14.64 ± 0.28 ka) and comprised a temperature rise of about 5–6 °C. The transition from the equivalent of GI-1a into the equivalent of Greenland Stadial (GS) GS-1 (broadly equivalent to the Younger Dryas) commenced at 13.02 ± 0.13 ka which is consistent with NGRIP (12.80 ± 0.26 ka) within errors. The onset of the Holocene started at 11.78 ± 0.14 ka (11.65 ± 0.10 ka at NGRIP) and involved a warming of about 4–5 °C. In contrast to δ¹⁸O, δ¹³C values show no response to (sub)millennial climate shifts due to strong rock-buffering and only record a long-term trend of soil development starting with the rapid warming at 14.7 ka.     

西藏纳木错流域冻土环境初步研究

利用在西藏纳木错流域念青唐古拉山北坡（NQN,海拔5 400 m）和西北保吉乡（BJ,海拔4 730 m）布设的两台带有四层土壤探头自动气象站(AWS)2005—2006年冬季10个月观测数据进行了统计分析。结果表明：观测期间NQN日及月平均气温均低于BJ,但变化幅度均小于BJ,土壤冻结时间比BJ长,两处的气温梯度为0.31℃/100 m。与安多月平均气温比较,推断NQN存在高山多年冻土。NQN大气—土壤及土壤内热传输速度快于BJ;冻结期内土壤中未冻水含量在0～-2.5℃时发生跃变且与土壤温度存在较好的线性关系;相同深度处NQN土未冻水含量较小。土壤温度日变化在0～40 cm深度处较明显,40cm深度以下变化很小,未冻水含量日变化在5 cm深度较明显,20 cm以下变化微弱。利用两观测点冻结深度（Df）与冻结积温（Tg）的良好相关建立模型,NQN为：Df n= 0.0016Tg+ 1.69,R2=0.9958;BJ为：Df b= 0.002 Tg+ 1.13,R2= 0.9424,并由此推断出两观测点最大季节冻结深度分别为1.69 m和1.13 m。     

Soil carbon stock of the Central-East Asia in the climate warming

Water samples from the Wujiang River, a typical karst river system, were analyzed for major ion concentrations and δ^34S values of dissolved sulfate in order to identify the sources of sulfate, quantify the sulfate export flux and understand the role of sulfur cycling in chemical weathering rate of carbonate. Spatial variations in sulfate concentration and sulfur isotopic composition of tributaries over the catchment area are obvious, allowing to decipher S sources between rocks and atmosphere. According to the variations in sulfate concentration and isotopic composition, it is inferred that sulfate ions in the upper-reach river waters may have three sources, rain water, sulfate resultant from oxidation of pyrite in coal, and sulfate from sulfide deposits. In the lower reaches, the S isotopic composition of the samples lies mainly on a mixing trend between evaporite sulfate and rainwater sulfate, the contribution of sulfate from oxidation of pyrite being lesser. A pronounced seasonal variation in both content and isotopic composition of sulfate characterizes the Wujiang River. The average sulfate concentration of the waters is 0.65 mmol/L in winter, 0.17 mmol/L higher than that in summer. River water δ^34S values range from -15.7‰ to 18.9‰ in winter, while the δ^34S values of river waters in summer vary to a lesser extent than in winter, from -11.5‰ to 8.3‰. The δ^34S values of the main stream range from -6.7‰ to -3.9‰ in summer, averaging 3‰ lower than in winter. This indicates that in summer, when the discharge increases, the contribution of a source enriched in light isotopes to the atmosphere or the oxidation of pyrite in coal is more important.