Quasi-biennial and quasi-triennial oscillations in the growth rates of atmospheric chlorofluorocarbons 11 and 12

The 12-monthly running means of CFC-11 and CFC-12 were examined for 1977-1992. As observed by earlier workers, during 1977-1988, there was a rapid, almost linear increase of these compounds, ~70% in the northern and ~77% in the southern hemisphere. From 1988 up to 1992, growth rates were slower, more so for CFC-11 in the northern hemisphere. Superposed on this pattern were QBO, QTO (Quasi-Biennial and Quasi-Triennial Oscillations). A spectral analysis of the various series indicated the following. The 50 hPa low latitude zonal wind had one prominent QBO peak at 2.58 years and much smaller peaks at 2.00 (QBO) and 5.1 years. The Southern oscillation index represented by (T-D), Tahiti minus Darwin atmospheric pressure, had a prominent peak at 4.1 years and a smaller peak at 2.31 years. CFC-11 had only one significant peak at 3.7 years in the southern hemisphere, roughly similar to the 4.1 year (T-D) peak. CFC-12 had prominent QBO (2.16-2.33 years) in both the hemispheres and a QTO (3.6 years) in the southern hemisphere. For individual locations, CFC-11 showed barely significant QBO in the range (1.95-3.07 years), while CFC 12 showed strong QBO in the range (1.86-2.38 years). The difference in the spectral characteristics of CFC-11 and CFC 12 time series is attributed to differences in their lifetimes (44 and 180 years), source emission rates and transport processes.

Spectral characteristics of the quasi-biennial oscillation of total Ozone

The 12-month running means of the 50 hPa low latitude zonal wind and total ozone values for the latitude zones NP (North Polar), NT (North Temperate), TRO (Tropical), ST (South Temperate), SP (South Polar) were subjected to special analysis, separately over the two successive 18 year intervals, 1958-1975 and 1976-1993. In the interval 1958-1975, the wind had a prominent peak at 2.45 years and two smaller but significant peaks at 1.98 and 3.05 years. For ozone only NP. NT and ST had roughly similar peaks (2.37, 2.41, 2.48 years), while TRO and SP had different peaks (2.27 and 2.12 years). All ozone series had significant peaks at 20-21 months, barely significant in the wind series. Ozone peaks were noticed in the 3-5 years band also. In the interval 1976-1993, the patterns were different. The wind had only one prominent peak at 2.51 years. For ozone, NP, NT, ST had roughly similar peaks (2.41, 2.45, 2.45 years) while TRO. Speed different peaks (2.32 and 2.29 years). All ozone series had significant peaks at 20-22 months and in the 3-5 year band; but these were absent in the wind series. The 3-5 year band probably indicates ENSO effects. A cross-correlation analysis between wind and ozone showed that TRO maxima coincided with westerly wind maxima. while NT, ST and NT, NP were phase shifted by 4 and 6 seasons.

Comparison of quasi-biennial oscillations of stratospheric winds and atmospheric temperatures at different altitudes

During 1959-89, the 12-month running means of 50 hPa zonal winds, the average atmospheric temperatures in the northern and southern hemisphere at four altitude slabs (950 hPa, 850- 300 hPa, 300-100 hPa and 100-50 hPa), Pacific and Atlantic sea surface temperature (SST) and-30hPa temperatures at North Pole and average for (10°-90° N), all showed quasi-biennial oscillations (QBO). However, whereas the wind QBO had an average spacing of 29 months, only temperatures at 300-100 hPa and Atlantic SST had similar average spacing. Other temperatures as also SO index (represented by Tahiti minus Darwin atmospheric pressure) had larger average spacing. Spectral analysis showed that whereas wind QBO had only one prominent peak at T=2.33 years, other parameters had weak QBOs near T=2.5-2.6 years except Pacific SST and 30 hPa North Pole temperature which had small peaks near T=2.3 years. All the temperatures had prominent peaks in the 3-6 year region which matched with similar peaks in the SO index. There is some indication that stratospheric wind QBO had some relation with parameters at all altitudes in tropics and with North Pole, while ENSO had considerable influence at other latitudes/altitudes.

STRUCTURAL AND MORPHOLOGICAL INVESTIGATION OF FUNCTIONALIZED REDUCED GRAPHENE OXIDE-MULTI WALLED CARBON NANOTUBES NANOCOMPOSITE

2D materials like Graphene and its composite has emerged as most valuable and major concern because of their peculiar properties in field of nanotechnology in past few decades. Herein, we report the effective technique for the synthesis of functionalized r-GO/MWCNTs nanocomposite using probe sonication. The synthesized samples were tested via XRD, FESEM, FTIR and Raman Spectroscopy. X-ray diffraction technique was used for the structural analysis of the samples which revealed that most prominent peak was observed around 2θ~26°. Surface morphology of the samples were studied via FESEM, which revealed that r-GO layers were wrapped around the MWCNTs. Raman spectra were recorded for the determination of quality of r-Go and MWCNT via the position and intensity of D and G band. The various functionalities present on the samples were identified via FTIR spectra.

Influence of Incorporated Barium Ion on the Physio-Chemical Properties of Zinc Oxide Nanodisks Synthesized via a Sonochemical Process

Nanostructure materials are of interest in last few decades due to their unique size-dependent physio-chemical properties. In this paper, zinc oxide (ZnO) and barium doped ZnO nanodisks (NDs) were synthesized using sonochemical method and characterized by various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), UV-vis absorption and dielectric measurements. The XRD and FTIR studies confirm the crystalline nature of ZnO NDs, and the average crystallite size was found to be ~25 nm for pure ZnO and ~22 nm for Ba doped ZnO NDs. SEM study confirmed the spherical shaped ZnO NDs with average sizes in the range of 20–30 nm. The maximum absorbance was obtained in the 200–500 nm regions with a prominent peak absorbance were observed by UV-vis spectra. The corresponding band gap for ZnO NDs and Ba doped ZnO NDs were calculated using Tauc’s plot and was found to be 3.12 and 3.04, respectively. The conductivity and dielectric measurements as a function of frequency have been studied.

Siliciclastic provenance of the Cenozoic stratigraphic succession in the southern Gulf of Mexico: Insights from U-Pb detrital zircon geochronology and heavy minerals analysis

ABSTRACT This work presents new geochronological and mineralogical data to investigate the provenance of sediments accumulated in deep-water environments in the southern and southwestern regions of the Gulf of Mexico during the Cenozoic. We integrated U-Pb geochronology with heavy and light minerals data to better understand the provenance of the Paleocene–Miocene strata and the evolution of the sediment source terranes. The analyzed samples came from drill cuttings of sandy levels in five exploration wells offshore in the Gulf of Mexico: Puskon-1, Aktum-1, Kunah-1, Kabilil-1, and Chuktah-201. The material contained abundant barite, a component of the drilling mud. Consequently, a semiquantitative approach to discriminate mineral phases and to quantify concentrations was used. Overall, we recognized 10 zircon populations that range from Proterozoic to Cenozoic ages. Proterozoic ages show a prominent peak at ca. 1.0 Ga and a minor peak at ca. 1.8 Ga. The Neoproterozoic to Cambrian population displays a broad distribution with a peak at ca. 600 Ma. Ordovician–Silurian zircons exhibit minor peaks at ca. 460 and 445 Ma. Devonian and Carboniferous zircons are very scarce in our data set. Permian–Triassic zircons are abundant, and they show a prominent peak at ca. 255 Ma and a minor one at ca. 228 Ma. Jurassic zircons are not common and display several minor peaks at ca. 185, 170, and 155 Ma. The Early Cretaceous population displays a noticeable peak at ca. 120 Ma. Late Cretaceous–Paleocene zircons exhibit several peaks at ca. 92, 82, 72, and 65 Ma. Cenozoic zircons also display several prominent peaks at ca. 40, 35, 25, and 18 Ma. Zircons of Proterozoic to Early Cretaceous ages are interpreted to be derived from the Mesozoic sedimentary cover of basement blocks in southern and eastern Mexico terranes due to their rounded to subrounded morphology. Late Cretaceous and Cenozoic zircons are the most abundant populations in the analyzed samples. These zircon populations exhibit euhedral and subhedral morphology indicating derivation from primary sources in the magmatic arcs. This has important implications in assessing the reservoir quality, since the sediments were directly delivered from the magmatic arc into the deep-water environments. Our results allow us to conclude that the sedimentary provenance of the southwestern and southern strata in the Gulf of Mexico was not associated with Laurentian terranes, as has been proposed for Late Cretaceous–Paleogene strata of northern Mexico and the northern Gulf of Mexico, such as the world-class Wilcox-type hydrocarbon reservoirs. We propose that the provenance of the analyzed strata was related to the tectono-magmatic evolution of the southern Mexico terranes during the Cenozoic; therefore, large NW-SE dispersal systems that eroded Laurentian terranes in the southern United States did not deliver sediments into the southern sectors of the Gulf of Mexico, probably constrained by the Tamaulipas Arch and the Gulf Stream.

Discovery of the Baldy toreva near urban areas along the southern Wasatch Range, Utah

ABSTRACT Structural and geomorphic studies, and lithostratigraphic and biostratigraphic mapping reveal that a giant toreva block (6.125 km3) slid off Mount Timpanogos toward what are now densely populated urban areas along the Wasatch Front of Utah. The block forms a prominent peak known as Big Baldy, which consists of steeply dipping and locally brecciated limestone and quartzarenite over nearly horizontal shale. Preferential erosion of this shale below overlying limestone and quartzarenite cliffs is most likely the cause of this particular landslide and potential future slides along the Wasatch Front. The low-angle contact at the base of the giant toreva block was initially mapped as a thrust, then as a low-angle normal fault. In both cases, these faults were inferred to have large amounts of displacement (900 meters), but no traces of such faults are found in adjacent canyons. The Baldy slide is associated with geomorphologic features, such as faceted spurs, landslide scarps, sackungen, and hummocky terrain. Limestone and quartzarenite beds in the block are back-rotated up to 80° and are locally broken and brecciated. No evidence of hydro-fracturing is found in the breccia or of multiple brecciation episodes, which indicates surficial rather than deep-crustal processes and perhaps a single event of slip. We speculate based on structural reconstructions of the slide block, and interpolation of maximum downcutting rates on nearby streams, that the slide initiated between 700 and 500 ka. Discovery of the Baldy slide attests to the importance of recognizing the influence of surficial processes in mountain front development and demonstrate the ongoing geologic hazard of mass wasting to communities along the seismically active Wasatch Front and similar horst blocks.

FTIR and HPLC-Based Metabolomics of Yacon Leaves Extracts (Smallanthus sonchifolius [Poepp & Endl.] H. Robinson) from Two Locations in Indonesia

Smallanthus sonchifolius [Poepp. & Endl.] H. Robinson (Asteraceae) also known as Yacon or insulin plant, is traditionally used for treating diabetes. Varying geographical origins and postharvest handling, however, seem to affect quantitative and qualitative metabolites in the leaves of Smallanthus sonchifolius [Poepp. & Endl.] H. Robinson (Yacon). The study was conducted to compare and differentiate metabolites profile/fingerprint of Yacon leaves which were grown and obtained from different locations in Pulau Jawa i.e. Lembang (Jawa Barat) and Wonosobo (Jawa Tengah). Three different solvents (95% ethanol, 50% ethanol and water) were used to synthesize Yacon leaves extracts, in order to determine the suitable solvent to produce discernable differentiation through FTIR and HPLC-based metabolomics. Principal Component Analysis (PCA) of FTIR data (4000–400 cm1 wavenumber) indicated that Yacon leaves extracted with ethanol at 95%, had a distinctive FTIR fingerprint profile when compared to others. However, the FTIR-based PCA could not differentiate the extracts based on their geographical origins, although PCA analysis of HPLC-data successfully differentiated the extracts based on their geographical origins. Furthermore, the prominent peak for the leaves extract from Lembang and Wonosobo as regards retention time, was observed at 21.59–25.10 min and 20.69–21.695 min respectively. Notably, R2Y and Q2 value obtained by cross-validation and permutation tests showed all multivariate models were statistically reliable. Overall, there is the need to conduct further research using a more sophisticated tool such as LC-MS, to identify which metabolites represented by the aforementioned FTIR and HPLC data.

Long Period Waves and Oscillations Over Costa Rica, a Tropical Station

Seasonal, annual and interannual variations of Ozone Mixing Ratio (OMR) have been studied for 12 years, from balloonsondes and Ozonesondes that were launched over Costa Rica (10oN, 83.4oW), a tropical station, as part of Southern Hemisphere Additional Ozonesondes (SHADOZ) network. It was found that near tropopause region there exists prominent peak of OMR during July month for most of the years. Lomb-Scargle Periodogram (LSP) analysis has been applied for the years 2005-2017 to identify the wave activities and found that Quasi Biennial Oscillations (QBO) with period of 2-2.5 years and even higher period oscillations of 3-4 years are prominent in middle troposphere and lower stratosphere regions which could cause large annual variabilities of OMR fluctuations. Fluctuations of OMR were subjected to Morlet wavelet transform over a year, 2008, to study seasonal variabilities. The wavelet analysis confirm that Madden Julian Oscillations (MJO) with periods 49-60 days are prominent during summer near tropopuase and in lower stratosphere regions, while lower period equatorial Kelvin waves of 14-20 days periods dominate during winter and spring in troposphere region, which could be responsible for maximum seasonal variability.