Mineralogy and geochemistry of granitoids from Kinnaur region,Himachal Higher Himalaya,India: Implication on the nature of felsic magmatism in the collision tectonics     

Brajesh Singh  Santosh Kumar  Masao Ban  Kazuo Nakashima 《Journal of Earth System Science》2016,125(7):1329-1352

Felsic magmatism in the southern part of Himachal Higher Himalaya is constituted by Neoproterozoic granite gneiss (GGn), Early Palaeozoic granitoids (EPG) and Tertiary tourmaline-bearing leucogranite (TLg). Magnetic susceptibility values (<3 ×10^?3 SI), molar Al₂ O ₃/(CaO + Na₂ O + K ₂O) (≥1.1), mineral assemblage (bt–ms–pl–kf–qtz ± tur ± ap), and the presence of normative corundum relate these granitoids to peraluminous S-type, ilmenite series (reduced type) granites formed in a syncollisional tectonic setting. Plagioclase from GGn (An₁₀–An₃₁) and EPG (An₁₅–An₃₃) represents oligoclase to andesine and TLg (An₂–An₁₅) represents albite to oligoclase, whereas compositional ranges of K-feldspar are more-or-less similar (Or₈₈ to Or₉₅ in GGn, Or₈₆ to Or₉₇ in EPG and Or₈₇ to Or₉₄ in TLg). Biotites in GGn (Mg/Mg + Fe^t= 0.34–0.45), EPG (Mg/Mg + Fe^t= 0.27–0.47), and TLg (Mg/Mg + Fe^t= 0.25–0.30) are ferribiotites enriched in siderophyllite, which stabilised between FMQ and HM buffers and are characterised by dominant 3Fe\(\rightleftharpoons \)2Al, 3Mg\(\rightleftharpoons \)2Al substitutions typical of peraluminous (S-type), reducing felsic melts. Muscovite in GGn (Mg/Mg + Fe^t=0.58–0.66), EPG (Mg/Mg + Fe^t=0.31?0.59), and TLg (Mg/Mg + Fe^t=0.29–0.42) represent celadonite and paragonite solid solutions, and the tourmaline from EPG and TLg belongs to the schorl-elbaite series, which are characteristics of peraluminous, Li-poor, biotite-tourmaline granites. Geochemical features reveal that the GGn and EPG precursor melts were most likely derived from melting of biotite-rich metapelite and metagraywacke sources, whereas TLg melt appears to have formed from biotite-muscovite rich metapelite and metagraywacke sources. Major and trace elements modelling suggest that the GGn, EPG and TLg parental melts have experienced low degrees (～13, ～17 and ～13%, respectively) of kf–pl–bt fractionation, respectively, subsequent to partial melting. The GGn and EPG melts are the results of a pre-Himalayan, syn-collisional Pan-African felsic magmatic event, whereas the TLg is a magmatic product of Himalayan collision tectonics.  相似文献   

Developing synergy regression models with space-borne ALOS PALSAR and Landsat TM sensors for retrieving tropical forest biomass     

Suman Sinha  C Jeganathan  L K Sharma  M S Nathawat  Anup K Das  Shiv Mohan 《Journal of Earth System Science》2016,125(4):725-735

Forest stand biomass serves as an effective indicator for monitoring REDD (reducing emissions from deforestation and forest degradation). Optical remote sensing data have been widely used to derive forest biophysical parameters inspite of their poor sensitivity towards the forest properties. Microwave remote sensing provides a better alternative owing to its inherent ability to penetrate the forest vegetation. This study aims at developing optimal regression models for retrieving forest above-ground bole biomass (AGBB) utilising optical data from Landsat TM and microwave data from L-band of ALOS PALSAR data over Indian subcontinental tropical deciduous mixed forests located in Munger (Bihar, India). Spatial biomass models were developed. The results using Landsat TM showed poor correlation (R² = 0.295 and RMSE = 35 t/ha) when compared to HH polarized L-band SAR (R² = 0.868 and RMSE = 16.06 t/ha). However, the prediction model performed even better when both the optical and SAR were used simultaneously (R² = 0.892 and RMSE = 14.08 t/ha). The addition of TM metrics has positively contributed in improving PALSAR estimates of forest biomass. Hence, the study recommends the combined use of both optical and SAR sensors for better assessment of stand biomass with significant contribution towards operational forestry.  相似文献   

Improving multimodel medium range forecasts over the Greater Horn of Africa using the FSU superensemble     

O. Kipkogei  A. Bhardwaj  V. Kumar  L. A. Ogallo  F. J. Opijah  J. N. Mutemi  T. N. Krishnamurti 《Meteorology and Atmospheric Physics》2016,128(4):441-451

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Prediction of daily modes of South Asian monsoon variability and its association with Indian and Pacific Ocean SST in the NCEP CFS V2     

Namendra Kumar Shahi  Shailendra Rai  D. K. Pandey 《Meteorology and Atmospheric Physics》2016,128(1):131-142

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Investigation of dominant modes of monsoon ISO in the northwest and eastern Himalayan region     

Sandipan Mukherjee  Srabanti Ballav  Sandeep Soni  Kireet Kumar  Utpal Kumar De 《Theoretical and Applied Climatology》2016,125(3-4):489-498

This study investigates the altitudinal variation of dominant modes of summer monsoon intra-seasonal oscillation (ISO) over the Northwest (NWH) and Eastern Himalayan (EH) region using (i) spatially scattered 133 number of station rainfall observations and (ii) latitudinal transect-wise (LT) rainfall variation, obtained from an observed interpolated gridded rainfall data for the period 1995–2004. The altitudinal variation of dominant modes of monsoon ISO were investigated by exploring the strong and weak phases of the principal components of 10–90 days bandpass rainfall data of June to September with respect to location specific station height. Investigation of frequency of days for light and moderate rainfall along with the occurrence of total seasonal rainy days has revealed existence of a rainfall maximum around 2100 m height for the NWH region. Similarly, the total seasonal rainy days of EH region was found to have maxima between 1100 and 1400 m height. Analyses of the spatially scattered station rainfall observation for the NWH region showed that the strong periods of ISO modes exist around 747.9 (±131.7) m and 2227.2 (±100.2) m heights. Over the EH region, the dominant modes of the monsoon ISO were found to be centred around 1200 m. Significant alterations of strong and weak phases of monsoon ISO as a response to altitudinal variation in the mountain surface were observed when latitudinal transect-wise variation of monsoon ISO modes were investigated.  相似文献   

New climatic classification of Nepal     

Ramchandra Karki  Rocky Talchabhadel  Juha Aalto  Saraju Kumar Baidya 《Theoretical and Applied Climatology》2016,125(3-4):799-808

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Characterization and radiative impact of dust aerosols over northwestern part of India: a case study during a severe dust storm     

Atinderpal Singh  Shani Tiwari  Deepti Sharma  Darshan Singh  Suresh Tiwari  Atul Kumar Srivastava  Neeraj Rastogi  A. K. Singh 《Meteorology and Atmospheric Physics》2016,128(6):779-792

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Is the interdecadal variation of the summer rainfall over eastern China associated with SST?   总被引：1，自引：0，他引：1  

Dong Si  Zeng-Zhen Hu  Arun Kumar  Bhaskar Jha  Peitao Peng  Wanqiu Wang  Rongqing Han 《Climate Dynamics》2016,46(1-2):135-146

The present study examined the major features of the interdecadal variation of the summer rainfall over eastern China (IVRC) and the possible association with sea surface temperature (SST). We noted that the first leading mode of IVRC (accounting for nearly half of the total variance and with maximum loading for the summer rainfall anomalies over South China) may be not forced by SST. On the other hand, the second and third leading modes [accounting for 17.1 and 13.6 % of the total variance and mainly associated with the summer rainfall anomalies over the Yangtze River valley (YRV) and North China, respectively] in some extent are forced by SST anomalies. These observational results are confirmed by atmospheric general circulation model (AGCM) simulations forced by observed SST. By eliminating the internal dynamical process driven rainfall though ensemble mean, the simulations further suggest an overall enhancement of the intensity of IVRC in the corresponding ensemble mean, especially in the YRV and North China regions, but not in South China. That implies the different role of SST in driving IVRC over different regions.  相似文献   

Erratum to: Climate change projections over India by a downscaling approach using PRECIS     

Prasanta Kumar Bal  Andimuthu Ramachandran  Kandasamy Palanivelu  Perumal Thirumurugan  Rajadurai Geetha  Balakrishnan Bhaskaran 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(5):519-519

The author “Bhaski Bhaskaran” and his affiliation “Fujitsu Laboratory of Europe, Middlesex, UK” should be replaced by “Balakrishnan Bhaskaran”, “Fujitsu Laboratories of Europe Limited, Hayes Park, Middlesex, UK”, respectively.The corrected name and affiliation are shown in this erratum.  相似文献   

Use of Geospatial Tools to Prioritize Zones of Hydro-Energy Potential in Glaciated Himalayan Terrain     

Lydia Sam  Anshuman Bhardwaj  Vinay S P Sinha  Pawan K Joshi  Rajesh Kumar 《Journal of the Indian Society of Remote Sensing》2016,44(3):409-420

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