排序方式： 共有11条查询结果，搜索用时 15 毫秒
1.
M N PATIL T DHARMARAJ R T WAGHMARE T V PRABHA J R KULKARNI 《Journal of Earth System Science》2014,123(1):177-185
An increase in carbon dioxide (CO2) concentrations in the atmosphere due to anthropogenic activities is responsible for global warming and hence in recent years, CO2 measurement network has expanded globally. In the monsoon season (July–September) of year 2011, we carried out measurements of CO2 and water vapour (H2O) concentrations along with wind and air temperature over a tropical site in south-east India having rural topography. To collect these observations, the instrumentations used were the sonic anemometer for wind and temperature, and the open path H2O/CO2 infrared gas analyzer for CO2 and H2O concentrations. Using these observations, we explored the diurnal variability of CO2 flux along with sensible and latent heat. The CO2 flux was positive during night-time and negative during daytime and in phase with convective instability. The CO2 flux relationships with the meteorological parameters such as wind speed, temperature and heat fluxes have been analysed. The seasonal (monsoon) half hour mean of CO2 flux which was ?3.55 μmol m???2 s???1 indicated the experimental site as a CO2 sink region (net seasonal uptake). An increase in CO2 concentrations during weekends was not observed due to unavailability of heavy vehicular traffic. 相似文献
2.
3.
S P ANAND Vinit C ERRAM J D PATIL N J PAWAR GAUTAM GUPTA R A SURYAVANSHI 《Journal of Earth System Science》2016,125(2):301-310
Ground magnetic data collected over Chikotra River in the peripheral region of Deccan Volcanic Province (DVP) of Maharashtra located in Kolhapur district was analysed to throw light on the structural pattern and distribution of magnetic sources within the basin. In order to isolate the magnetic anomalies showing varying trend and amplitude, several transformation operations including wavelength filtering, and upward continuation has been carried out on the reduced to pole anomaly map. Qualitative interpretation of these products help identify the distribution of magnetic sources, viz., the Deccan basalts, dolerite intrusives and older greenstone and schist belts in the subsurface. Present study suggests that the Chikotra basin is composed of three structural units; a NE–SW unit superposed on deeper NW–SE unit with randomly distributed trap flows on the surface. One of the major outcome of the present study is the delineation of almost 900-m thick Proterozoic Kaladgi sediments below the Deccan trap flows. The NE–SW magnetic sources may probably represent intrusives into the Kaladgi sediments, while the deeper NW–SE trends are interpreted as the northward extension of the Dharwars, underneath the Deccan lava flows, that forms the basement for the deposition of Kaladgi sediments. 相似文献
4.
5.
6.
AMBALIKA NIYOGI JAYANTA K PATI SURESH C PATEL DIPAK PANDA SHIV K PATIL 《Journal of Earth System Science》2011,120(6):1043-1054
This paper provides first report of silica-rich anthropogenic spherules of varying colour, shape, size, surface texture and
chemical composition found in road-deposited sediments (RDS) of Allahabad city, Uttar Pradesh, India. Morphological details
and lithophile elemental composition of the silica-rich spherules are compared to microtektites and impact spherules from
India to demonstrate their striking morphological similarities and chemical variability. This study suggests the need to use
spherule data carefully while assigning an impact origin to spherule-finds or spherule-bearing lithological horizons. 相似文献
7.
FRANK OLDFIELD QINGZHEN HAO JAN BLOEMENDAL ZOË GIBBS‐EGGAR SHIVA PATIL ZHENGTANG GUO 《Sedimentology》2009,56(7):2091-2106
Using a combination of particle size analysis, magnetic measurements, scanning electron microscopy and transmission electron microscopy imaging, this study shows that in a wide range of depositional environments, there is a strong link between particle size classes and magnetic response, especially below the upper limit of stable single domain magnetic behaviour. Ferrimagnetic grain assemblages dominated by stable single domain magnetosomes regularly have peak susceptibility and remanence values in coarser grades than do those containing finer‐grained, viscous and superparamagnetic secondary magnetic minerals formed during pedogenesis. This effect is despite the fact that there is a one to two orders of magnitude size difference between the particle size boundaries (at 1 or 2 μm) and key domain state transitions (mostly below 0·05 μm). The implications of these results are explored using samples spanning 22 Myr of loess accumulation on the Chinese Loess Plateau. The results from the loess sections, complemented by data from low‐temperature magnetic experiments, show that there are subtle distinctions in mean ferrimagnetic grain‐size between the Pleistocene and Miocene parts of the record, thus allowing more refined rock magnetic interpretations of the fine‐grained ferrimagnetic mineral assemblages arising from the effects of weathering, pedogenesis and possibly diagenesis in the sections studied. 相似文献
8.
9.
Assessing a local ensemble Kalman filter: perfect model experiments with the National Centers for Environmental Prediction global model 总被引：1，自引：0，他引：1
10.
Four-dimensional ensemble Kalman filtering 总被引：3，自引：0，他引：3