南阳市1960—2013年高温日数变化特征及原因分析

根据国家气象信息中心气象资料室1960—2013年南阳市地面气象月报表的观测资料,采用线性回归、简单相关系数法、M-K突变检验和Morlet小波分析等方法,研究了南阳市高温日数的变化特征,结果表明:1960—2013年南阳市共出现788次高温日;出现高温日数最多的是2013年,为37天;1987年无高温日。南阳市高温日数6月份最多,占高温天气发生总次数的36.7%;9月最少,占总次数的2.2%。从1960—2013年高温日的逐年分布情况可以看出,54 a间高温日数整体呈下降趋势,倾向率为-1.59天/10a。南阳市年高温日数在20世纪70年代的降低是一突变,具体是从1971年开始。由南阳高温日数小波系数实部图可见,高温日数存在多重时间周期尺度上的嵌套复杂结构现象,包含了多个不同尺度的周期变化,南阳年高温日数变化存在3个明显的周期振荡,分别是10~12 a、26~28 a和50~51 a的尺度。从小波方差图中可以看出,12 a、28 a、50 a存在峰值,其中尺度50 a峰值最高,能量最大;其次是尺度12 a的。高温日数较多年比高温日数较少年6—8月500 h Pa平均环流场副高西伸脊点更偏西;高温日数较多年500 h Pa平均环流场更为平直,以纬向环流为主,不利于冷空气南下,因此多晴热天气。高温日数较少年环流场上华北地区波动幅度更大,冷空气和降水天气过程较多。1960—2013年5—9月降水量呈增加趋势,这也相应地减少了高温天气。1960—2013年5—9月南阳市日照时数一直处于下降趋势,日照时数的下降也使高温日数减少。     

The characteristics of the shear-wave attenuation field in the Altai lithosphere and their relationship to seismicity

The short-period S-wave attenuation field has been mapped for the lithosphere of the Altai and adjacent areas in Mongolia and southern Siberia. A total of approximately 500 earthquake seismograms were used. These were recorded at the Makanchi and Ulan-Bator stations at distances of ~300–1900 km. It is shown that the attenuation of shear waves is much stronger in the west of the area of study compared with the east. A V-shaped band of high attenuation in the upper mantle has been identified in the west of the area where the epicenters of the magnitude 6.9 1990 Zaisan and the magnitude 7.3 2003 Chuya earthquakes were situated; a similar band extends northwestward to the west of Lake Ubsu Nur. The attenuation is comparatively low in the rupture zones of large (М ≥ 7.0) pre-1970 earthquakes. It was concluded that fluid-charged zones are formed in the lithosphere prior to large earthquakes in the Altai, as well as in other areas of Central Asia. Following large seismic events, the fluids were rising into the crust from the upper mantle during a few tens of years, thus reducing the attenuation of Sn waves. We have identified zones of high attenuation with no significant earthquakes being recorded there during historical time. It is our opinion that earthquake precursory processes may be occurring in these zones.     

Toxic (mercury,berillium) and biogenic (selenium,fluorine) elements in aquatic ecosystems of Baikal Natural Territory

Up-to-date analytical methods are used to collect data on the concentrations of toxic (mercury, beryllium) and biogenic (selenium, fluorine) elements in various aquatic landscape-geochemical systems of Baikal Natural Territory, including the central, buffer zone, and the zone of atmospheric influence. The concentrations of selenium and fluorine were found to far below (with rare exceptions) their hygienic standards for drinking water. By this characteristic, the Baikal Natural Territory is classified as a deficient biogeochemical province. The low concentrations (up to nanograms) of highly toxic elements—mercury and beryllium—in surface and subsurface waters of aquatic landscapes show that the considered ecological zones are quite favorable for human life. Studying microelements in landscape-geochemical zones opens the way for environmentally safe nature management in the territory and enables one to forecast variations in the quality of water resources under growing anthropogenic load.     

Methane Production in a West Siberian Eutrophic Fen Is Much Higher than Carbon Dioxide Production: Incubation of Peat Samples,Stoichiometry, Stable Isotope Dynamics,Modeling

Water Resources - Homoacetogenic bacteria can play an important role in anaerobic degradation of organic matter in peatlands at low temperatures. However, little is known about the conditions when...     

Sulfide Sulfur in Water Objects with Different Mineralization

Water Resources - Hydrogen sulfide, like other sulfides, is formed in aquatic environments due to sulphate reduction processes and putrefactive decomposition of organic matter of bottom sediments,...     

地下城市综合管廊的抗火构造与消防设计

综合管廊作为现代化城市的基础设施,能够从根本上解决管线埋设或架立引起的挖掘道路、影响交通、破坏景观等问题。提高道路和公用管线的管理水平,有效利用地下空间,提高防灾能力,是现代化都市的必然要求。本文从管廊的构造、抗火设计要求、管线布置、消防系统等方面出发,对地下城市综合管廊的设计提出了一些具体的建议。     

Study of neotectonic activity of morphostructures in the central part of the east european craton by remote sensing methods

The combined approach is used for studying recent tectonic activity in the central part of the East European Craton (EEC).This approach incorporates the methods of automated lineament analysis and satellite geodesy with the conventional geological mapping analysis. The space tectonic map (space image based) is reconstructed, and morphostructures that are active at the recent and present tectonic stage are delineated by processing the Landsat image mosaic. The direction and rate of horizontal displacement of crustal blocks, which is caused by deep geodynamical processes, are determined using the GPS data. The study is preliminary since only few GPS stations within the EEC have sufficiently long time series of observations.     

The ADSS-3 broadband stand-alone digital seismic station

The SSD-3 three-channel seismic recorder and the ADSS-3 three-component broadband standalone digital seismic station based on the SSD-3 together with SM-3E seismic sensors were developed. The main advantage of this equipment in comparison with foreign and domestic analogs is simplicity and convenience while maintaining high technical characteristics. The structure and operation of the seismic sensor and seismic recorder are considered, and their main technical characteristics are given. Laboratory, bench, and comparative tests of the seismic recorder and station demonstrated their working capacity and compliance with the development goal. Based on the test results, the ADSS-3 seismic station was commissioned as a three-component broadband observation point of the Mikhnevo small-aperture seismic array. The data obtained using the ADSS-3 made is possible to study the structure of the crust and upper mantle of this region using the receiver function method.     

Global modelling study (GSM TIP) of the ionospheric effects of excited N2, convection and heat fluxes by comparison with EISCAT and satellite data for 31 July 1990

Near-earth plasma parameters were calculated using a global numerical self-consistent and time-dependent model of the thermosphere, ionosphere and protonosphere (GSM TIP). The model results are compared with experimental data of different origin, mainly EISCAT measurements and simultaneous satellite data (N_e and ion composition). Model runs with varying inputs of auroral FAC distributions, temperature of vibrationally excited nitrogen and photoelectron energy escape fluxes are used to make adjustments to the observations. The satellite data are obtained onboard Active and its subsatellite Magion –2 when they passed nearby the EISCAT station around 0325 and 1540 UT on 31 July 1990 at a height of about 2000 and 2200 km, respectively. A strong geomagnetic disturbance was observed two days before the period under study. Numerical calculations were performed with consideration of vibrationally excited nitrogen molecules for high solar-activity conditions. The results show good agreement between the incoherent-scatter radar measurements (N_e, T_e, T_i) and model calculations, taking into account the excited molecular nitrogen reaction rates. The comparison of model results of the thermospheric neutral wind shows finally a good agreement with the HWM93 empirical wind model.