12-14 September, 2011, Lucknow - Earth Science India

More documents

Recommendations

Info

National Conference on Science of Climate Change and Earth’s Sustainability: Issues and Challenges ‘A Scientist-People Partnership’ 12-14 September, 2011, Lucknow LONG-TERM TREND IN TROPOSPHERIC OZONE AND AEROSOL OVER THE NORTHEASTERN GANGETIC PLAIN, INDIA S.D. Patil, D.M. Lal and S.D. Ghude Indian Institute of Tropical Meteorology, Pune 411008 email: patilsd@tropmet.res.in Using monthly mean Tropospheric Ozone Residual (TOR) and Aerosol Index (AI) datasets from satellite measurements of Total Ozone Mapping Spectrometer (TOMS) during the period 1979-1992, the association between TOR and anthropogenic activity in northeastern part of Indian region (Indo-Gangetic Plain, IGP) has been examined. Increasing trends in tropospheric ozone are observed over most of the regions of India. The regressed TOR pattern during monsoon season shows large trend in TOR over the entire IGP region and is highest, 6 - 7.2%/decade, over the northeastern part of India. The increasing trend in tropospheric ozone over India is quite consistent with the observed trends in coal (9.2%/y) and petroleum (8.3%/y) consumption in India during the study period. Annually, trend of about 0.4 ±0.25 (1σ) % per year has been seen in TOR over then northeastern region of India. Similar trend in AI over this region (1.7 ±1.2 (1σ) % per year) is also detected during the same period. The quality of correlation between TOR and AI suggested that tropospheric ozone appeared to be influenced by the increased anthropogenic activities in this region. CHARACTERIZATION OF IONIC SPECIES IN FINE AND COARSE PARTICLES, IN AN URBAN CITY, DELHI Suresh Tiwari 1 , Khem Singh 2 , Deewan Singh Bisht 1 , Prabhat K. Gupta 2 1 Indian Institute of Tropical Meteorology-Pune, Delhi Branch, New Delhi-110060 2 National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi, 110012 email: smbtiwari@yahoo.co.uk Mass size distribution of PM 10 aerosol was studied for two years during Jan 2006 to Dec 2007 inside the campus of National Physical Laboratory by using 8-stage Andersen Cascade Impactor (ACI) sampler. The mass of fine (PM 2.5 ) and coarse (PM 10- 2.5) particles was integrated from particle mass determined in different stages. Average concentrations of PM 10-25 and PM 2.5 during study period are observed to be 32
National Conference on Science of Climate Change and Earth’s Sustainability: Issues and Challenges ‘A Scientist-People Partnership’ 12-14 September, 2011, Lucknow 170±104µgm -3 and 136±8µgm -3 , respectively which is far in excess of the 60µgm -3 and 40µgm -3 annual averages permitted by the Indian National Ambient Air Quality Standards. Effective Cut Diameter (ECD) for PM 1.0 was also calculated and it was found 77µgm -3 . The percentage contribution of PM10-2.5, PM 2.5, and PM1.0 to PM 10 were about 56%, 44% and 25% respectively. Statistical analyses such as paired sample T - test were performed through SPSS for window software and found that there was no large variation in ECD for PM 2.5 and PM 10-2.5 . Major cations (NH + 4 , Na + , K + , Ca 2+ and Mg 2+ ) and anions (F - , Cl - , SO 2- 4 and NO - 3 ) were analyzed along with pH. The average concentrations of major anions such as SO 2- 4 and NO - 3 were observed to be 12.93±0.98 and 10.33±1.10gm -3 , respectively. Very high concentrations of SO 2- 4 and NO - 3 were found in fine mode aerosols. The major sources of SO 2- 4 are due to thermal power plants which are located in southeast direction and incomplete combustion by vehicle exhaust. A good correlation among secondary species (NH + , NO - 3 and SO 2- 4 ) suggests that, most of NH + 4 is in the atmosphere in the form of ammonium sulphate and ammonium nitrate. During winter, the high concentration of Ca 2+ is observed due to resuspension of road side dust particles and traffic activities. DUST PARTICLE MORPHOLOGY: IMPLICATIONS TO AEROSOL OPTICAL PROPERTIES S.K. Mishra, Sukhvir Singh, T.K. Mandal and B.C. Arya National Physical Laboratory, New Delhi 110012 email: mishrask@mail.nplindia.ernet.in Role of atmospheric aerosols (mineral and carbonaceous) in terms of their radiative effects is still highly uncertain (IPCC, 2007). One of the major sources of this uncertainty is owing to relatively unknown morphology of dust in the atmosphere. Here we present morphological parameters (shape, size, Aspect Ratio (ratio of maximum projection of particle to its width, AR) and Circulatory Parameter (CIR)) of selected ambient particles collected from NPL, New Delhi during pre-monsoon season, 2010. The morphological parameters are determinants of the extent of particle nonsphericity. The Cu-TEM grid and tin sheet were used as collection substrates for atmospheric particles. The morphological studies were carried out using SEM (Scanning Electron Microscope) and HRTEM (High Resolution Transmission Electron Microscope) facilities at NPL. For some of the particles, aggregates of black carbon spherules were found to be adhered on their surfaces. A range of AR was found to be from 1.2 to 2.6 whereas the conventional value of AR of atmospheric particle taken as 1.5 (Okada et al., 2001). The shape distribution has been generated using CIR parameter with limited 33
Page 2 and 3: National Conference on Science of C
Page 45: National Conference on Science of C
Page 97 and 98:
National Conference on Science of C
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149:
Page 152 and 153:
show all

12-14 September, 2011, Lucknow - Earth Science India

Create successful ePaper yourself

Delete template?

Save as template?