Snow distribution from SSM/I and its relationships to the hydroclimatology of the Mackenzie River Basin,Canada     

Jinjun Tong  Stephen J. Déry  Peter L. Jackson  Chris Derksen 《Advances in water resources》2010

The spatial and temporal distribution of snow cover extent (SCE) and snow water equivalent (SWE) play vital roles in the hydrology of northern watersheds. We apply remotely sensed Special Sensor Microwave Imager (SSM/I) data from 1988 to 2007 to explore the relationships between snow distribution and the hydroclimatology of the Mackenzie River Basin (MRB) of Canada and its major sub-basins. The Environment Canada (EC) algorithm is adopted to retrieve the SWE from SSM/I data. Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day maximum snow cover extent products (MOD10A2) are used to estimate the different thresholds of retrieved SWE from SSM/I to classify the land cover as snow or no snow for various sub-basins in the MRB. The sub-basins have varying topography and hence different thresholds that range from 10 mm to 30 mm SWE. The accuracy of snow cover mapping based on the combination of several thresholds for the different sub-basins reaches ≈ 90%. The northern basins are found to have stronger linear relationships between the date on which snow cover fraction (SCF) reaches 50% or when SWE reaches 50% and mean air temperatures, than the southern basins. Correlation coefficients between SCF, SWE, and hydroclimatological variables show the new SCF products from SSM/I perform better than SWE from SSM/I to analyze the relationships with the regional hydroclimatology. Statistical models relating SCF and SWE to runoff indicate that the SCF and SWE from EC algorithms are able to predict the discharge in the early snow ablation seasons in northern watersheds.  相似文献   

Migration and Diversity in Asian Contexts edited by  Lai Ah Eng , Francis Leo Collins and Brenda Yeoh Saw Ai (eds). Institute of Southeast Asian Studies,Singapore, 2012, pp. xii + 293 (ISBN 978‐981‐4380‐47‐8) (pbk).     

Lucy Jackson 《Singapore journal of tropical geography》2013,34(2):280-282

  相似文献   

The interrill erosion for a sandy loam soil   总被引：1，自引：0，他引：1  

Gabriella BALACCO 《国际泥沙研究》2013,28(3):329-337

This paper resumes a laboratory experience on a slope adjustable plot with the aim of examining the role of rainfall intensity and slope gradient for a sandy loam soil, typical of Southern Italy, with particular initial moisture content. The results of the simulations performed show that a rainfall reduction causes a corresponding percentage reduction of sediment output. A similar behaviour can be attributed to slope gradient, while runoff moderately increases with rainfall intensity but it is not sensitive to slope gradient. Data also highlight that the degree of saturation can affect runoff and soil loss values.  相似文献   

An Overview of Thunderstorm-Related Research on the Atmospheric Electric Field, Schumann Resonances, Sprites, and the Ionosphere at Sopron, Hungary     

Gabriella Sátori  Michael Rycroft  Pál Bencze  Ferenc Märcz  József Bór  Veronika Barta  Tamás Nagy  Károly Kovács 《Surveys in Geophysics》2013,34(3):255-292

This paper gives a resume of the papers written in English which (a) describe some of the recording instruments in use at the Nagycenk Observatory (NCK) since the International Geophysical Year (IGY 1957–1958) and up to the present time, (b) summarise the most important and different types of observations associated with thunderstorms which have been made there, and (c) discuss their various geophysical interpretations. The paper describes the main results which have been obtained in four areas of thunderstorm associated atmospheric and geospace science within the context of Earth system science. These relate to the following parameters of atmospheric electricity: the vertical electric potential gradient just above the Earth’s surface and the air–Earth current as well as the point discharge current, Schumann resonance (SR) signals of the Earth-ionosphere cavity at 8, 14 and 20 Hz, transient luminous events (TLEs), and some aspects of the behaviour of the ionosphere. Deductions from these data sets are concerned with the global lightning activity and the conductivity of the air, with diurnal, seasonal, annual and long-term variations of the SR amplitudes and resonant frequencies in terms of migrating thunderstorm centres, with transient SR excitations and with sprites and other TLEs, and with ionospheric disturbances. The paper closes with some thoughts on future research directions based on the observations at NCK and Sopron and the results achieved since the IGY.  相似文献   

PM10 Source Apportionment in Ahvaz,Iran, Using Positive Matrix Factorization     

Mohammad Hossein Sowlat  Kazem Naddafi  Masud Yunesian  Peter L. Jackson  Saeedeh Lotfi  Abbas Shahsavani 《洁净——土壤、空气、水》2013,41(12):1143-1151

Source apportionment of particulate matter <10 µm in diameter (PM₁₀), having considerable impacts on human health and the environment, is of high priority in air quality management. The present study, therefore, aimed at identifying the potential sources of PM₁₀ in an arid area of Ahvaz located in southwest of Iran. For this purpose, we collected 24‐h PM₁₀ samples by a high volume air sampler. The samples were then analyzed for their elemental (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Se, Si, Sn, Sr, Li, Ti, V, Zn, Mo, and Sb) and ionic (NH, Cl^?, NO, and SO) components using inductively coupled plasma optical emission spectrometry and ion chromatography instruments, respectively. Eight factors were identified by positive matrix factorization: crustal dust (41.5%), road dust (5.5%), motor vehicles (11.5%), marine aerosol (8.0%), secondary aerosol (9.5%), metallurgical plants (6.0%), petrochemical industries and fossil fuel combustion (13.0%), and vegetative burning (5.0%). Result of this study suggested that the natural sources contribute most to PM₁₀ particles in the area, followed closely by the anthropogenic sources.  相似文献   

A response from Elsevier     

Patrick S. Jackson 《Geoforum》2012,43(4):659-661

  相似文献   

Fluid inclusion studies in datolite of low grade metamorphic origin from a Jurassic pillow basalt series in northeastern Hungary     

Gabriella Kiss  Ferenc Molnár  Federica Zaccarini 《Central European Journal of Geosciences》2012,4(2):261-274

The Jurassic pillow basalt blocks in the Szarvask? Unit in the SW-Bükk Mountains are incorporated into an accretionary mélange of Cretaceous age which had been displaced from the Dinarides to NE-Hungary during the Alpine-Carpathian collision. The pillow basalt series is a part of an incomplete remnant of an ophiolite-like sequence from which ultramafic units and sheeted dikes are almost completely absent. At the studied Egerbakta quarry, closely packed pillow, pillow fragmented hyaloclastite breccia and peperitic facies of submarine basaltic volcanism were recognized. Peperitic facies was formed by local admixture of unconsolidated siliciclastic sediment into the basaltic lava. Basaltic pillows contains short and thin prehnite-chlorite-carbonate-quartz veins formed during the interaction of seawater with the cooling lava, as well as cross-cutting datolite-prehnite-quartzchlorite-albite bearing veins. Calcite in the short cooling cracks crystallised from upheated seawater at around 160°C temperature and 0.5?C0.6 kbar pressure (water depth of about 5?C6 km). Datolite precipitations in veins can be classified into at least three different textural-morphological types but all of them contain methane bearing primary fluid inclusion assemblages, with variable methane/water ratios, suggesting an inhomogeneous entrapment from a heterogeneous aqueous-carbonic fluid. End member primary fluid inclusions contain aqueous liquid with methane rich vapour phase and apparently methane only inclusions characterized by liquid phase on room temperature. A combination of results from fluid inclusion microthermometry, Raman spectroscopy (used not only for phase identification but also for determination of salinities) and temperatures calculated from chlorite compositions, show that the precipitation of datolite had taken place from low salinity (0.2?C2 NaCl equiv. mass%) aqueous-methane fluids under increasing temperature and pressure (from 160 to 210°C, and from 0.6 to 1.1 kbar) conditions. The elevated pressures and temperatures in comparison to the submarine hydrothermal processes suggest that the datolite bearing mineral parageneses had been formed during the progression of Alpine very low grade metamorphic processes.  相似文献   

著名科学家莱昂·诺波夫(Leon Knopoff)逝世     

David D.Jackson  Paul M. Davis  毛桐恩 《世界地震译丛》2011,(2)

莱昂·诺波夫(1925~2011),是一位对物理学、地震学和音乐领域做出贡献的国际著名科学家,于2011年1月20日在妻子和3个孩子的陪伴下于家中辞世。莱昂·诺波夫1949年在加州理工学院获得物理学和数学博士学位,翌年开始在洛杉矶加州大学任教。1960年洛杉矶加州  相似文献   

Secondary carbonates in loess-paleosoil sequences: a general review     

Gabriella Barta 《Central European Journal of Geosciences》2011,3(2):129-146

The literature dealing with secondary carbonates in loess-paleosoil sequences is in many cases ambiguous, which means that different concepts are used for the same features, whereas certain concepts referring to different types are used as collective nouns. The aim of this study is to give a review on this nomenclature and to draw comparision between the various types and concepts. As a main guiding principle the article of Becze-Deák et al. (1997) is used, because it has formulated a proposition of a nomenclature which would be worthwhile to adopt. The terms and concepts introduced by their work are exact, referring to certain separated secondary carbonates and are of decisive importance with a view to paleoenvironmental reconstruction. The research of secondary carbonates in loess-paleosoil sequences is of great importance, through providing detailed information on the paleoenvironment, especially on the former moisture conditions (including leaching processes). Secondary carbonates originate from the vertical, horizontal or in situ resettlement of carbonates during pedogenesis in the soil-sedimentary environment. Among others, calcified root cells, hypocoatings and needle-fiber calcite are classified into the microscale category, while concretions (e.g. loess dolls) belong to the macroscale types.  相似文献   

Erratum to: Central European Journal of Geosciences, volume 3, number 2     

János Kovács  Szabolcs Á. Fábián  Gábor Varga  Karoly Németh  Corina Risso  Francisco Nullo  Gabor Kereszturi  Titusz Bugya  Szabolcs Á. Fábián  Noémi L. Görcs  István P. Kovács  Bertalan Radvánszky  Gabriella Barta  Rudolf Musil  Alice Ghiselli  Marzio Merazzi  Andrea Strini  Roberto Margutti  Michele Mercuriali  Rauf Gardashov  Daria Gushchina  Boris Dewitte  Martin Michálek  Marián Putiš  Christoph A. Hauzenberger  Jindřich Šancer  Martin Štrejbar  Aneta Maleňáková  George Migiros  George D. Bathrellos  Hariklia D. Skilodimou  Theodoros Karamousalis 《Central European Journal of Geosciences》2011,3(2):229-229

  相似文献