Seasonal and inter-annual variability of atmosphere CO<Subscript>2</Subscript> based on NOAA Carbon Tracker analysis and satellite observations

A study on seasonal and inter-annual variability of the atmospheric CO₂ is carried out based on National Oceanic and Atmospheric Administration Carbon Tracker (NOAACT) re-analysis and satellite measurements of mid-troposphere CO₂ by Atmosphere Infrared Sounder on board NASA’s Aqua and lower troposphere CO₂ by Greenhouse-gas Observing Satellite. Seasonal and non-seasonal components of each time series were extracted by means of least square based harmonic analysis procedure. The data of surface CO₂ fluxes used in the NOAACT are also analyzed to examine its relationship with the atmosphere CO₂ variability at different time scales. There exists good consistency between NOAACT analysis and satellite observations in their respective seasonal harmonics and climatology. Surface layer CO₂ exhibits large climatological mean over the regions of major anthropogenic sources together with strong seasonal cycle over the humid and cold climatic terrestrial regions especially over the northern hemisphere. Existence of high coherency with the different components of the surface fluxes shows that surface layer atmosphere CO₂ seasonality is primarily contributed from the terrestrial ecosystem exchanges and secondarily by anthropogenic and oceanic exchanges. The mid-troposphere CO₂ exhibits large values associated with climatology and amplitudes of semi-annual and annual cycles over the northern extra tropics and Polar Regions along with a gradual decreasing trend from northern to southern hemisphere. Inter-annual variability of atmospheric CO₂ in the NOAACT in some extent is consistent with the satellite observations. Large scale circulation patterns, its fluctuations associated with ENSO events and large scale ecosystem disturbances have significant influence on the inter-annual variability.     

Benthic coverage and bottom topography of coral reef environment over Pirotan reef,Gulf of Kachchh region,India

Remote sensing measurements in coral reef environments commonly confront the problem of overlying atmosphere and modification of spectral signal due to water column over the bottom substrates. In order to correct these problems, hyperspectral observations offer an advantage over multispectral observations. Airborne hyperspectral remote sensing data from Airborne Visible Infrared Imaging Spectrometer- Next Generation (AVIRIS-NG) sensor was acquired during low tidal condition on 14 February 2016 at Pirotan reef, Gulf of Kachchh region, India. The objective of this study is to map benthic coverage and bottom topography over Pirotan reef. The methodology involved atmospheric correction, simultaneous retrieval of water parameters, bathymetry, water column correction and mapping. Atmospheric correction was performed by removing path radiance and aerosol contribution and dividing by atmospheric transmittance and incoming solar irradiance to obtain remote sensing reflectance. Model derived error minimization technique was used for simultaneous retrieval of water parameters and bathymetry. Derived water parameters were used to account for water column attenuation and retrieve concomitant true bottom signature.     

Urban land use mapping: A case study of ahmedabad city and its environs

Proper urban planning and effective implementation requires reliable urban land use statistics. In this context, satellite remote sensing data has been studied using both visual and digital techniques. A portable eight-band radiometer has been used to collect spectral signatures of surface features present in Ahmedabad city and its environs. Using these signatures a suitable approach employing visual and digital techniques has been developed for urban land use/sprawl mapping. Urban land-use maps of Ahmedabad city and its environs were prepared on 1:25,000 scale and for Ahmedabad Urban Development Authority Area on 1:50,000 scale using this methodology. It has been found that edge-enhancement techniques are useful to enhance the contrast among different urban land uses. Classification techniques such as MXL and Bayes classifiers are not successful in discriminating urban land uses. Tonal characteristics alongwith other elements of interpretation are required to classify urban land uses such as residential, industrial etc. Spatial distribution of various urban and uses and the space devoted to each urban land use has been brought out.     

Paleoecological significance of the trace fossils of Dhosa Oolite Member (Jumara Formation), Jhura dome,Mainland Kachchh,Western India

Dhosa Oolite Member of the Jumara Formation comprises alternating bands of oolitic limestones and shales, exposed in Jhura dome of Mainland Kachchh, Western India. This sequence is highly bioturbated and exhibits a moderate diversity and behaviourally complex assemblage of ichnospecies. The rhythmically bedded sequence shows three different levels of preservation of traces. Epichnial tiering consists of moderately bioturbated oolitic limestone exhibiting horizontal or low-angle protrusive/retrusive biogenic laminae, commonly dominated by feeding structures like Rhizocorallium jenense, R. irregulare, Zoophycos brianteus and Zoophycos isp. The endichnial structures within the oolitic limestone can be separated into two different preservational trace fossil suites. The endichnial shallow suites consist chiefly of deposit feeders like Chondrites intricatus, C. targionii, Planolites beverleyensis, Taenidium cameronensis, Thalassinoides isp., Z. brianteus, Z. cf circinnatus and Zoophycos isp. and few suspension feeder forms like Palaeophycus tubularis; while endichnial deep suites consist of Chondrites intricatus, Skolithos linearis and Zoophycos isp. Hypichnial structures consists abundant, cylindrical, branched, horizontal, large-sized three dimensional feeding burrows of Thalassinoides isp. and somewhat irregular, obtuse angle ramification burrows of Phycodes isp., which are attached to the lower surface of the casting medium. The trace fossil association indicates Cruziana ichnofacies and abundance of Zoophycus species below the fair weather wave base level is largely a preservational artifact. The preservational processes of the trace fossils indicate soft substrate and diversity and their abundance reflects the other palaeoecological parameters of the open shallow marine environments.     

Basin provenance and post-depositional thermal history along the continental P/T boundary of the Raniganj basin,eastern India: Constraints from apatite fission track dating

Apatite fission-track analysis has been applied to the Raniganj and Panchet formations of Raniganj basin of Gondwana Supergroup to unravel its thermal and provenance history. Apatite fission track age population from both Raniganj and Panchet formations indicate partial annealing and point to a maximum temperature of around ～100-110°C during their post depositional evolution. The sandstone of Raniganj Formation has five peak ages at 26.3, 59.3, 109.7, 173.7 and 299.9 Ma, while Panchet Formation has three peak ages at 25.4, 143.5 and 281.3 Ma. This implies that the provenance of the Raniganj Formation of late Permian and Panchet Formation of early Triassic changed obviously. According to thermotectonic evolution of the Gondwana basin, these apatites with different FT ages possibly represent different source components, although partial annealing had occurred to these apatites. Possibly all the apatites had transported from the Precambrian basement which was undergoing deformation due to Gondwana rifting initiated during Carboniferous period. Due to this, the basement was undergoing inhomogeneous thermal history which became source of sediments for Raniganj basin. Apatite FT ages of both Raniganj and Panchet formations have peak ages between 25 and 60 Ma, which perhaps recorded the cooling/uplift history during Cenozoic Alpine-Himalayan orogeny. Given a palaeo-thermal gradient of 40° C/km, it can be deduced that the Raniganj basin has uplifted about 3km at an average rate of about 0.09mm/a since 25–60 Ma.     

The P3 kimberlite and P4 lamproite,Wajrakarur kimberlite field,India: mineralogy,and major and minor element compositions of olivines as records of their phenocrystic vs xenocrystic origin

Distinctly different groundmass mineralogy characterise the hypabyssal facies, Mesoproterozoic diamondiferous P3 and P4 intrusions from the Wajrakarur Kimberlite Field, southern India. P3 is an archetypal kimberlite with macrocrysts of olivine and phlogopite set in a groundmass dominated by phlogopite and monticellite with subordinate amounts of serpentine, spinel, perovskite, apatite, calcite and rare baddeleyite. P4 contains mega- and macrocrysts of olivine set in a groundmass dominated by clinopyroxene and phlogopite with subordinate amounts of serpentine, spinel, perovskite, apatite, and occasional gittinsite, and is mineralogically interpreted as an olivine lamproite. Three distinct populations of olivine, phlogopite and clinopyroxene are recognized based on their microtextural and compositional characteristics. The first population includes glimmerite and phlogopite–clinopyroxene nodules, and Mg-rich olivine macrocrysts (Fo 90–93) which are interpreted to be derived from disaggregated mantle xenoliths. The second population comprises macrocrysts of phlogopite and Fe-rich olivine (Fo 81–89) from P3, megacrysts and macrocrysts of Fe-rich olivine (Fo 85–87) from P4 and a rare olivine–clinopyroxene nodule from P4 which are suggested to have a genetic link with the precursor melt of the respective intrusions. The third population represents clearly magmatic minerals such as euhedral phenocrysts of Fe-rich olivine (Fo 85–90) crystallised at mantle depths, and olivine overgrowth rims formed contemporaneously with groundmass minerals at crustal levels. Close spatial association and contemporaneous emplacement of P3 kimberlite and P4 lamproite is explained by a unifying petrogenetic model which involves the interaction of a silica-poor carbonatite melt with differently metasomatised wall rocks in the lithospheric mantle. It is proposed that the metasomatised wall rock for lamproite contained abundant MARID-type and phlogopite-rich metasomatic veins, while that for kimberlite was relatively refractory in nature.

     

Contamination of Pond with Fluoride and Heavy Metals in the Central India

The ponds are natural water resources used for drinking, bathing, washing and aqua culture. In this work, the contamination of ponds lied in central India with F^– and heavy metals (As, Sb, Cr, Mn, Fe, Cu, Zn, Cd, Pb, Th and U) is described. The F^– concentration in the pond water and sediment (n = 24) was ranged from 1.6–5.5 mg/L and 210–1430 mg/kg with mean value of 2.3 ± 0.4 mg/L and 599 ± 137 mg/kg, respectively. The concentration variation and sources of the elements in the pond water and sediment are discussed. The health hazards of F^– in the domestic animals are described.     

Biotechnological Advances in Detection of Contaminants from Wastewater

Wastewater from industries causes major environmental pollution problems. The urban development and commercialization in developing countries cause deterioration of surface water resources. Hence, for its improvement, it is essential to develop highly sensitive devices with quick response for monitoring of wastewater contamination. In this respect, biotechnological processes such as biosensors can be promising and a robust option for detection of toxic pollutants. Biosensors can be applied in order to acquire real-time quantitative data. Nowadays, the enzymes or whole cell bio-reporters-based biosensors have promising potential due to the possibility of miniaturization and opportunity for development of in situ biosensors. The growing need of convenient, rapid, and efficient biosensing devices explains the current advancement of biosensors with new transduction materials for multiplexed contaminant detection. Considering the extensive range of sensing strategies including immunochemical-based, enzymatic and nonenzymatic signals, different kinds of biosensors can be classified as electrochemical, optical, thermal, etc. For the past few years, more attention has been paid to nanomaterial-based biosensors which exhibit monitoring on the basis of chemical reactions and biological phenomena. Overall, this review focuses on principle and operation (transduction mechanism) of biosensors based on bio-recognition elements, for the early detection of organic and inorganic contaminants existing in wastewater.     

Development and application of Shannon’s entropy integrated information value model for landslide susceptibility assessment and zonation in Sikkim Himalayas in India

Natural Hazards - The state of Sikkim in India has many steep slopes and has been susceptible to landslides. Since 1968 there have been innumerable losses of lives and properties due to landslides....     

Test Of Turbulence Models For Wind Flow Over Terrain With Separation And Recirculation

Several two-equation turbulence models using isotropic eddy viscosity and wall functions are assessed by solution of the neutral atmospheric boundary layer over a flat surface and wind flow over two- and three-dimensional models and real terrain. Calculations are presented for wind flow over the Sirhowy Valley in Wales, an embankment along the Rhine in Germany and the Askervein Hill in Scotland. Comparisons of predictions with previous work, and laboratory and field data, show that the RNG-based k– model gives the best agreement with respect to the flow profiles and length of the separated flow region. The results of this model are analyzed with a non-linear stress-strain relation to gauge the potential effect of turbulence anisotropy.