The impact of boundary forcing on RegCM4.2 surface energy budget     

Ivan Güttler  Čedo Branković  Lidija Srnec  Mirta Patarčić 《Climatic change》2014,125(1):67-78

The surface energy budget components from two simulations of the regional climate model RegCM4.2 over the European/North African domain during the period 1989–2005 are analysed. The simulations differ in specified boundary forcings which were obtained from ERA-Interim reanalysis and the HadGEM2-ES Earth system model. Surface radiative and turbulent fluxes are compared against ERA-Interim. Errors in surface radiative fluxes are derived with respect to the Global Energy and Water Cycle Experiment/Surface Radiation Budget satellite-based products. In both space and time, we find a high degree of realism in the RegCM surface energy budget components, but some substantial errors and differences between the two simulations are also present. The most prominent error is an overestimation of the net surface shortwave radiation flux of more than 50 W/m² over central and southeastern Europe during summer months. This error strongly correlates with errors in the representation of total cloud cover, and less strongly with errors in surface albedo. During other seasons, the amplitude of the surface energy budget components is more in line with reference datasets. The errors may limit the usefulness of RegCM simulations in applications (e.g. high-quality simulation-driven impact studies). However, by using a simple diagnostic model for error interpretation, we suggest potential sensitivity studies aiming to reduce the underestimation of cloud cover and overestimation of shortwave radiation flux.  相似文献   

Decadal windstorm activity in the North Atlantic-European sector and its relationship to the meridional overturning circulation in an ensemble of simulations with a coupled climate model   总被引：1，自引：1，他引：0  

Katrin M. Nissen  Uwe Ulbrich  Gregor C. Leckebusch  Ivan Kuhnel 《Climate Dynamics》2014,43(5-6):1545-1555

The relationship between decadal variations in the North Atlantic meridional overturning circulation (MOC) and North Atlantic/Western European windstorm activity during the extended winter season is studied. According to an ensemble of three 240-year long simulations performed with the ECHAM5-MPIOM model, periods of high decadal windstorm activity frequently occur in the years following a phase of weak MOC (i.e. when the MOC starts to recover). These periods are characterised by a distinctive pattern in the mixed layer ocean heat content (OHC). A positive anomaly is located in the region 45°N?52°N/35°W?16°W (west of France). Negative anomalies are located to the North and South. The signal can be detected both in the heat content of the oceanic mixed layer and in the sea surface temperatures. Its structure is consistent with anomalously enhanced baroclinic instability in the region with the strong negative OHC gradient (30°W?10°W/45°N?60°N), which eventually produces a higher probability of windstorms.  相似文献   

Dating emplacement and evolution of the orogenic magmatism in the internal Western Alps: 1. The Miagliano Pluton     

Alfons Berger  Tonny B. Thomsen  Maria Ovtcharova  Notburga Kapferer  Ivan Mercolli 《Swiss Journal of Geoscience》2012,105(1):49-65

The Canavese Line in the Western Alps represents the position in the Alpine chain, where alkaline and calc-alkaline magmatism occur in close spatial and temporal association. In addition to available data on the alkaline Valle del Cervo Pluton, we present petrological and geochemical data on the Miagliano tonalite. The latter is of special interest, because it is located in the south-eastern side of the Canavese Line, in contrast to most Periadriatic Plutons. The dioritic to tonalitic rocks of the Miagliano Pluton represent an intermediate stage of a calc-alkaline differentiation, demonstrated by relics of two different pyroxenes as well as the texture of allanite. Hornblende barometry indicates pressures of ~0.46?GPa consistent with the presence of magmatic epidote. Field relationships between the two Plutons, the volcanic and volcaniclastic rocks of the Biella Volcanic Suite and numerous dykes cross-cutting the different units, allow reconstruction of a more refined chronology of the calc-alkaline and alkaline magmatic series. High precision zircon geochronology yields an age of 33.00?±?0.04?Ma for the central tonalitic part of the Miagliano Pluton and 30.39?±?0.50?Ma for the granitic core of the Valle del Cervo Pluton. The difference in age combined with cooling data and intrusion depth indicates dissimilar tectonic transport east and west of the Canavese Line. The earlier emplaced Miagliano Pluton has to be exhumed from an intrusion depth of ~12?C15?km, whereas the neighbouring and younger Valle del Cervo Pluton is exhumed from a depth of 5?C7?km. This tectonic scenario is related to upper crustal rigid block rotation responsible for the burial of the lowermost Rupelian paleosurface of the Sesia?CLanzo Zone. Thus, the new ages constrain the paroxysm of the orogenic magmatism in the internal Western Alps to an extremely short lapse of time in the first half of the Rupelian.  相似文献   

First geophysical and shallow ice core investigation of the Kazbek plateau glacier,Caucasus Mountains     

Stanislav S. Kutuzov  Vladimir N. Mikhalenko  Alexi M. Grachev  Patrick Ginot  Ivan I. Lavrentiev  Anna V. Kozachek  Victoria V. Krupskaya  Alexey A. Ekaykin  Levan G. Tielidze  Pavel A. Toropov 《Environmental Earth Sciences》2016,75(23):1488

First-ever ice core drilling at Mt. Kazbek (Caucasus Mountains) took place in the summer of 2014. A shallow ice core (18 m) was extracted from a plateau at ~4500 m a.s.l. in the vicinity of the Mt. Kazbek summit (5033 m a.s.l.). A detailed radar survey showed that the maximum ice thickness at this location is ~250 m. Borehole temperature of ?7 °C was measured at 10 m depth. The ice core was analyzed for oxygen and deuterium isotopes and dust concentration. From the observed seasonal cycle, it was determined that the ice core covers the time interval of 2009–2014, with a mean annual snow accumulation rate of 1800 mm w. eq. Multiple melt layers have been detected. δ¹⁸O values vary from ?25 to ?5‰. The dust content was determined using a particle sizing and counting analyzer. The dust layers were investigated using scanning electron microscopy and X-ray diffraction analysis. Dust can be separated into two categories by its origin: local and distant. Samples reflecting predominantly local origin consisted mainly of magmatic rocks, while clay minerals were a characteristic of dust carried over large distances, from the deserts of the Middle East and Sahara. The calculated average dust flux over three years at Kazbek was of 1.3 mg/cm² a^?1. Neither δ¹⁸O nor dust records appear to have been affected by summer melting. Overall, the conditions on Kazbek plateau and the available data suggest that the area offers good prospects of future deep drilling in order to obtain a unique environmental record.  相似文献   

Geochemistry of Thermal Waters of Continental Margin of Far East of Russia   总被引：2，自引：0，他引：2  

Ivan V. BRAGIN  Georgy A. CHELNOKOV  Oleg V. CHUDAEV  Natalia A. KHARITONOVA  Sergey V. VYSOTSKIY 《《地质学报》英文版》2016,90(1):276-284

Studied waters belong to warm(T=30-50℃),alkaline(pH=8.9-9.3),low mineralized(TDS235 mg/1)Na-HCO_3 or Na-SO_4-HCO_3 thermal waters with high content of SiO_2(up to 81 mg/l)and F(up to 3.9 mg/1),occur on modern volcano-tectonic rejuvenated areas of Eastern Sikhote-Alin orogenic belt.Low~3He concentration as well as N_2/O_2 and N_2/Ar ratios exclude influence of deep mantle fluid.New rare earth element data constrain our understandmg of water-rock interaction occurring in the water source region.Meteoric origin of waters is proved by stable isotope values varying from-71‰to-136.1‰and from-10.8‰to-18.8‰forδ~2U andδ~(18)O respectively.REE patterns reflect high pH,resultfing from water-rock interaction and oxidative conditions.Calculations of deep aquifer temperature using Na-K and quartz geothermometers show 116.8-131.1°C and 82.2-125.8℃respectively.Presence of deep faults both with abnormal thermal gradient(~45-50 K/km)define unique geochemical shape of thermal waters of Sikhote-Alin,area,where no present volcanic activity is registered.  相似文献   

Lake Shira Level Changes in Late Holocene     

Andrey DARIN  Ivan KALUGIN  Natalya MAKSIMOVA  Tatiana MARKOVICH  Yakov RAKSHUN  Dmitryi SOROKOLETOV  Fedor DARIN  Denis RAGOZIN 《《地质学报》英文版》2014,88(Z1):3-4

正1 Introduction Meromictic Shira Lake is a good represfor detail climate modeling due to its locainformation and annually laminated bottomsediment column of 155 cm in length wahammer corer in the deepest(24 m)central in 2009.2 Sample Preparations and Measuring  相似文献   

A geochemical and stable isotope investigation of groundwater/surface-water interactions in the Velenje Basin,Slovenia     

Tjaša Kanduč  Fausto Grassa  Jennifer McIntosh  Vekoslava Stibilj  Marija Ulrich-Supovec  Ivan Supovec  Sergej Jamnikar 《Hydrogeology Journal》2014,22(4):971-984

The geochemical and isotopic composition of surface waters and groundwater in the Velenje Basin, Slovenia, was investigated seasonally to determine the relationship between major aquifers and surface waters, water–rock reactions, relative ages of groundwater, and biogeochemical processes. Groundwater in the Triassic aquifer is dominated by HCO₃ ^–, Ca²⁺, Mg²⁺ and δ¹³C_DIC indicating degradation of soil organic matter and dissolution of carbonate minerals, similar to surface waters. In addition, groundwater in the Triassic aquifer has δ¹⁸O and δD values that plot near surface waters on the local and global meteoric water lines, and detectable tritium, likely reflecting recent (<50 years) recharge. In contrast, groundwater in the Pliocene aquifers is enriched in Mg²⁺, Na⁺, Ca²⁺, K⁺, and Si, and has high alkalinity and δ¹³C_DIC values, with low SO₄ ^2– and NO₃ ^– concentrations. These waters have likely been influenced by sulfate reduction and microbial methanogenesis associated with coal seams and dissolution of feldspars and Mg-rich clay minerals. Pliocene aquifer waters are also depleted in ¹⁸O and ²H, and have ³H concentrations near the detection limit, suggesting these waters are older, had a different recharge source, and have not mixed extensively with groundwater in the Triassic aquifer.  相似文献   

The 2dF Galaxy Redshift Survey: power-spectrum analysis of the final data set and cosmological implications     

Shaun Cole  Will J. Percival  John A. Peacock  Peder Norberg  Carlton M. Baugh  Carlos S. Frenk  Ivan Baldry  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Matthew Colless  Chris Collins  Warrick Couch  Nicholas J. G. Cross  Gavin Dalton  Vincent R. Eke  Roberto De Propris  Simon P. Driver  George Efstathiou  Richard S. Ellis  Karl Glazebrook  Carole Jackson  Adrian Jenkins  Ofer Lahav  Ian Lewis  Stuart Lumsden  Steve Maddox  Darren Madgwick  Bruce A. Peterson  Will Sutherland  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2005,362(2):505-534

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Paleolithic hunting in a southern Moravian landscape: The case of Milovice IV,Czech Republic     

Ji&#x;í Svoboda  Zbigniew M. Boche&#x;nski  Vra ulíkov  Alena Dohnalov  Srka Hladilov  Martin Hloek  Ivan Hor ek  Martin Ivanov  Miroslav Krlík  Martin Novk  Alexander J.E. Pryor  Sandra Szelov  Rhiannon E. Stevens  Jaros&#x;aw Wilczy&#x;nski  Piotr Wojtal 《Geoarchaeology》2011,26(6):838-866

The Dolní Věstonice–Pavlov–Milovice area (Czech Republic) on the slopes of the Pavlov Hills provides an opportunity for correlating the geomorphology of the Dyje River valley with Gravettian settlement patterns. Although the sites vary in size and complexity, they create a regular chain of strategic locations at elevations between 200 m and 240 m asl. In 2009, a road collapsed into deserted cellars inside the village of Milovice and revealed a complex of archaeological layers deep within loess, at an elevation of only 175 m asl. This paper presents an analysis of this atypical archaeological site location and compares the results with the other sites. We argue that this location allowed direct contact with mammoth herds concentrated on the floodplain, while the aquatic environment offered possibilities for gathering plants and fishing. This site represents a new aspect of organized settlement, hunting strategies, and short‐distance human movements during the Gravettian within this area. © 2011 Wiley Periodicals, Inc.  相似文献   

The Kepler map in the three-body problem     

Ivan I. Shevchenko 《New Astronomy》2011,16(2):94-99

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