Total column density variations of ozone (O3) in presence of different types of clouds

The zenith sky scattered light spectra were carried out using zenith sky UV-visible spectrometer in clear and cloudy sky conditions during May-November 2000 over the tropical station Pune (18°32N, 73°51E). These scattered spectra are obtained in the spectral range 462-498 nm between 75° and 92° solar zenith angles (SZAs). The slant column densities (SCDs) as well as total column densities (TCDs) of NO2, O3, H2O and O4 are derived with different SZAs in clear and cloudy sky conditions. The large enhancements and reductions in TCDs of the above gases are observed in thick cumulonimbus (Cb) clouds and thin high cirrus (Ci) clouds, respectively, compared to clear sky conditions. The enhancements in TCDs of O3 appear to be due to photon diffusion, multiple Mie-scattering and multiple reflections between layered clouds or isolated patches of optically thick clouds. The reductions in TCDs due to optically thin clouds are noticed during the above period. The variations in TCDs of O3 measured under cloudy sky are discussed with total cloud cover (octas) of different types of clouds such as low clouds (CL), medium clouds (CM) and high clouds (CH) during May-November 2000. The variations in TCDs of O3 measured in cloudy sky conditions are found to be well matched with cloud sensitive parameter colour index (CI) and found to be in good correlation. The TCDcloudy are derived using airmass factors (AMFs) computed without considering cloud cover and CI in radiative transfer (RT) model, whereas TCDmodel are derived using AMFs computed with considering cloud cover, cloud height and CI in RT model. The TCDmodel is the column density of illuminated cloudy effect. A good agreement is observed between TCDmodel, TCDDob and TCDGOME

Air ion variation at Poultry-farm, coastal, mountain, rural and urban sites in India

The air ions are continuously generated and destroyed by various processes in the atmosphere. Near the surface, the nature of ions is very complex and they show large variations in their physical properties. The attachment of small ions to the aerosol particles is depending on the mobility of air ions. High mobility air ions immediately are attached to the aerosol particles and settle down on the surface. In this study we report, about the air ion variation at different sites like Rural, Coastal, Mountain, Poultry farm and urban in the state of Maharashtra in India. The aim of this study is to understand the plausible distribution of air ions both diurnally and at different times in a day for long time (three years) and with various meteorological variables. The preliminary analysis of the data has reveled that negative air ions are observed to have attached to the aerosol particles and large aerosol particles are formed from small aerosol particles. Therefore uni-polarity factor observed to be below unity for coastal, mountain and rural site and about 2.8 at an urban site. However worst case is observed at the Poultry farm, where uni-polarity factor is 6.3, which is very harmful for human health. There is also effect of meteorological parameters on air ion concentration in the atmosphere

Diurnal and seasonal air ion variability at rural station Ramanandnagar (17A°2'N, 74A°E), India

High-energy radiations, such as alpha and beta particles or gamma radiation, ionize air molecules into pairs of positive ions and free electrons. The diurnal and seasonal variations of these air ions were measured for the first time at a rural monitoring station in Ramanandnagar (17°2'N, 74°E), India, and the urban tropical station in Pune (18°31'N, 73°55'E) from June 2007 to May 2008. Air ion concentrations, measured using a Gerdien condenser at Pune station, increased from nighttime and reached maximum in the early morning. Compared to Pune, air ion concentration and positive-to-negative air ion ratios at Ramanandnagar increased from morning and reach maximum in the afternoon (12:00-14:00). Plant transpiration and waves in the flooded Krishna River during July-September 2007 were determined as additional sources of atmospheric ion production at Ramanandnagar. Intensive temperature inversion during winter lead to the accumulation of radon and radioactive aerosols near the Earth's surface, and hence increased the rate of ionization. Annual peaks of positive/negative ion maxima and positive-to-negative small ion ratios were observed in January 2008. It was also observed that as human activities increased, more aerosol particles were introduced into the atmosphere between 12:00-14:00 hours, during which time the average positive-to-negative air ion ratio reached peak values. During summer, radioactive gases moved upward, carrying radon and radioactive aerosols, and thereby reducing ionization. Results show a decrease in average positive and negative small ion maxima from February 2008 to May 2008

Total column density variations of NO2 and O3 by automatic visible spectrometry over Pune, India

A single scattering radiative transfer model has been developed to calculate the air mass factors (AMFs) of NO2 and O3 for scattered light observations. The direct and scattered intensities reaching the ground have been calculated using this model, which are utilized for computation of AMFs of these species. AMFs have been used to derive the total column densities (TCDs) from slant column densities (SCDs). Daily intensity data obtained by spectroscopic observations made at Pune (18°32'N, 73°51'E) during May 2000-May 2001 are used for the computation of SCDs of NO2 and O3 by differential optical absorption spectroscopy (DOAS) technique. NO2, O3, H2O and O4 have characteristic absorption features in the visible range 462-498 nm. These features have been used in the DOAS technique. The percentage differential optical depths (DODs) of NO2, O3, H2O and O4 have been computed. The TCD of O3 has also been derived by other methods. They are in good agreement with Dobson spectrophotometer observations. Here, the daily and seasonal variations in TCDs of NO2 and O3 at Pune for the above period are discussed

Influence of wind speed on surface layer stability and turbulent fluxes over southern Indian peninsula station

Surface to atmosphere exchange has received much attention in numerical weather prediction models. This exchange is defined by turbulent parameters such as frictional velocity, drag coefficient and heat fluxes, which have to be derived experimentally from high-frequency observations. High-frequency measurements of wind speed, air temperature and water vapour mixing ratio (eddy covariance measurements), were made during the Integrated Ground Observation Campaign (IGOC) of Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) at Mahabubnagar, India (16∘44′N, 77∘59′E) in the south-west monsoon season. Using these observations, an attempt was made to investigate the behaviour of the turbulent parameters, mentioned above, with respect to wind speed. We found that the surface layer stability derived from the Monin–Obukhov length scale, is well depicted by the magnitude of wind speed, i.e., the atmospheric boundary layer was under unstable regime for wind speeds >4 m s−1; under stable regime for wind speeds <2 m s−1 and under neutral regime for wind speeds in the range of 2–3 m s−1. All the three stability regimes were mixed for wind speeds 3–4 m s−1. The drag coefficient shows scatter variation with wind speed in stable as well as unstable conditions

ASSESSMENT OF DENTAL FLUOROSIS IN CHILDREN OF JAIPUR DISTRICT, RAJASTHAN, INDIA

Objective: The objective of the present study was carried out to explore the potential association between fluoride concentration in drinking water and severity of dental fluorosis (DF) in the children.Methods: The study of dental fluorosis (DF) in the children (6-14 years old) was conducted in the two blocks (a) Jamwaramgarh block ;Heerawala, Palera ,Nayabas, Saipur and Birasana, (b) Amber block; Jugalpura, Chitanukalan, Sunder ka bas, Peelwa and Sirsali of Jaipur district, Rajasthan, India of the study villages. Total 150, children were surveyed. The role of fluoride (F) levels in drinking water in the etiology of dental fluorosis (DF) and the cases of dental fluorosis (DF) in both dentitions and teeth were also assessed using DEAN'S classification. The fluoride (F) concentration in source of drinking water was estimated by fluoride (F) ion specific electrode (Thermo Scientific Orion Star A329, USA).Results: The F concentration in (Tube well and Hand pump) water ranges from 0.7 to 15.0 parts per million (ppm) in Jamwaramgarh block and 1.40 to 5. 10 parts per million (ppm) in Amber block. Prevalence of dental fluorosis (DF) 27 (36%) in Jamwaramgar block and 26 (34.66%) in Amber block out of 75 children were examined in each block. Significantly increase in levels of F in drinking water is positively correlated with dental fluorosis.Conclusion: This study finding has shown the relation of dental fluorosis (DF) to high fluoride (F) levels in drinking water sources. A higher fluoride (F) levels in source of drinking water is a major risk factor for dental fluorosis. In view of the severity of the problem the intake of calcium rich foods and defluoridation techniques may help reducing risk of dental fluorosis (DF) in the children.Â

Installation of an automatic spectrometer at Mauritius and preliminary results of NO2 over Mauritius

An automatic spectrometer developed at Indian Institute of Tropical Meteorology Pune is installed at the University of Mauritius, Reduit, Mauritius for monitoring total column density of NO2 and O3. The spectrometer is programmed for observations between 80° and 90° solar zenith angles in the spectral region 410-450 nm. The observations collected for few days during September and October 1998 are analysed, and total column densities of NO2 found to be of the order of 4* 1015 molecules per cm2. This preliminary result compares with similar southern latitude stations

<i>Albugo candida</i> race diversity, ploidy and host-associated microbes revealed using DNA sequence capture on diseased plants in the field

• Physiological races of the oomycete Albugo candida are biotrophic pathogens of diverse plant species, primarily the Brassicaceae, and cause infections that suppress host immunity to other pathogens. However, A. candida race diversity and the consequences of host immunosuppression are poorly understood in the field. • We report a method that enables sequencing of DNA of plant pathogens and plant-associated microbes directly from field samples (Pathogen Enrichment Sequencing: PenSeq). We apply this method to explore race diversity in A. candida and to detect A. candida-associated microbes in the field (91 A. candida-infected plants).• We show with unprecedented resolution that each host plant species supports colonization by one of 17 distinct phylogenetic lineages, each with an unique repertoire of effector candidate alleles. These data reveal the crucial role of sexual and asexual reproduction, polyploidy and host domestication in A. candida specialization on distinct plant species. Our bait design also enabled phylogenetic assignment of DNA sequences from bacteria and fungi from plants in the field.• This paper shows that targeted sequencing has a great potential for the study of pathogen populations while they are colonizing their hosts. This method could be applied to other microbes, especially to those that cannot be cultured

A Population-Based Evaluation of a Publicly Funded, School-Based HPV Vaccine Program in British Columbia, Canada: Parental Factors Associated with HPV Vaccine Receipt

Analysis of a telephone survey by Gina Ogilvie and colleagues identifies the parental factors associated with HPV vaccine uptake in a school-based program in Canada