Assessment of emissions from transport sector in Delhi

This study presents emissions of different pollutants from transport sector in Delhi. Results show that emissions of pollutants have increased during 2001-2009 as follows: CO2, 4395-6423; CH4, 1.03-3.32; N2O, 0.04-0.05; CO, 238-329; NOx, 44-64; and NMVOC, 44-60 Gg. However, CO2 emissions per unit of vehicle types for gasoline driven vehicles show a decrease as follows: two wheelers, 2.7; and cars, 4.3%; while in case of diesel driven vehicles, this reduction is 1.6%, indicating impact of better vehicle technologies introduced. However, CO2 emissions from per unit of CNG vehicles have been found to increase by 2.4% during this period due to increased consumption of CNG per unit of CNG vehicles

Four-year assessment of ambient particulate matter and trace gases in the Delhi-NCR region of India

A key challenge in controlling Delhi’s air quality is a lack of clear understanding of the impacts of emissions from the surrounding National Capital Region (NCR). Our objectives are to understand the limitations of publicly available data, its utility to determine pollution sources across Delhi-NCR and establish seasonal profiles of chemically active trace gases. We obtained the spatiotemporal characteristics of daily-averaged particulate matter (PM10 and PM2.5) and trace gases (NOX, O3, SO2, and CO) within a network of 12 air quality monitoring stations located over 2000 km2 across Delhi-NCR from January 2014 to December 2017. The highest concentrations of pollutants, except O3, were found at Anand Vihar compared with lowest at Panchkula. A high homogeneity in PM2.5 was observed among Delhi sites as opposed to a high spatial divergence between Delhi and NCR sites. The bivariate polar plots and k-means clustering showed that PM2.5 and PM10 concentrations are dominated by local sources for all monitoring sites across Delhi-NCR. A consequence of the dominance of local source contributions to measured concentrations, except to one site remote from Delhi, is that it is not possible to evaluate the influence of regional pollution transport upon PM concentrations measured at sites within Delhi and the NCR from concentration measurements alone

Morphology of Atmospheric Particles over Semi-Arid Region (Jaipur, Rajasthan) of India: Implications for Optical Properties

The regional dust morphology and spectral refractive indices (RIs; governed by hematite, Fe2O3 content at short wavelengths) are key elements for ascertaining direct radiative forcing of mineral dust aerosols. To provide morphological features of background mineral dust from a semi-arid zone in the vicinity of the Thar Desert, we carried out an expedition to the Jaipur city during late winter of 2012. Morphological analysis reveals the predominance of "Layered", "Angular" and "Flattened" particles, while the frequency distribution of a total of 235 dust particles shows the aspect ratio, AR and circularity parameter, CIR (measures of particle's non-sphericity) typically similar to 1.4 and similar to 0.8, respectively. Sensitivity analysis at 550 nm wavelength reveals the equivalent sphere model may underestimate Single Scattering Albedo, SSA for the dust with low (similar to 1.1%) hematite by similar to 3.5%. Both underestimation (by similar to 5.6%) and overestimation (up to 9.1%) are probable in case of dust with high hematite content (similar to 5.68%). In addition, the effect of AR on the dust scattering is significant in case of dust with high hematite content. More such regionally representative dust morphological data are required for better estimation of regional radiative forcing of mineral dust aerosols

Spatial variations of intra-city urban heat island in megacity Delhi.

This study examines the variation of intra-city Urban Heat Island (UHI) in megacity Delhi by the mobile transverse measurement technique and spatial maps of UHI along the mobile routes have been generated for the city by using the ordinary kriging interpolation tool of ArcGIS. Meteorological data was collected by mobile surveys under clear sky weather days in monsoon and winter months of 2014 using two HOBO data loggers installed on a vehicle along the routes which covered many parts of Delhi intersecting vertical and horizontal transects capturing different land use patterns of the city. UHI values obtained through interpolation were validated with UHI obtained from temperature measurements at five fixed sites spread over the Delhi region, which were found in good agreement (R-2 = 0.91). The variability existing in the two seasons studied has been shown by low UHI values obtained in the monsoon season and high UHI values in winter season. The diurnal pattern of UHI showed higher UHI during the nighttime period, compared to morning and noon periods. The results show variable UHI in different regions of Delhi covered by mobile routes with high UHI values of >6 degrees C observed during the winter period

Assessment of emissions from transport sector in Delhi

155-160This study presents emissions of different pollutants from transport sector in Delhi. Results show that emissions of pollutants have increased during 2001-2009 as follows: CO2, 4395-6423; CH4, 1.03-3.32; N2O, 0.04-0.05; CO, 238-329; NOx, 44-64; and NMVOC, 44-60 Gg. However, CO2 emissions per unit of vehicle types for gasoline driven vehicles show a decrease as follows: two wheelers, 2.7; and cars, 4.3%; while in case of diesel driven vehicles, this reduction is 1.6%, indicating impact of better vehicle technologies introduced. However, CO2 emissions from per unit of CNG vehicles have been found to increase by 2.4% during this period due to increased consumption of CNG per unit of CNG vehicles

Impacts of future Indian greenhouse gas emission scenarios on projected climate change parameters deduced from MAGICC model

The MAGICC (Model for the Assessment of Greenhouse gas Induced Climate Change) model simulation has been carried out for the 2000-2100 period to investigate the impacts of future Indian greenhouse gas emission scenarios on the atmospheric concentrations of carbon dioxide, methane and nitrous oxide besides other parameters like radiative forcing and temperature. For this purpose, the default global GHG (Greenhouse Gases) inventory was modified by incorporation of Indian GHG emission inventories which have been developed using three different approaches namely (a) Business-As-Usual (BAU) approach, (b) Best Case Scenario (BCS) approach and (c) Economy approach (involving the country's GDP). The model outputs obtained using these modified GHG inventories are compared with various default model scenarios such as A1B, A2, B1, B2 scenarios of AIM (Asia-Pacific Integrated Model) and P50 scenario (median of 35 scenarios given in MAGICC). The differences in the range of output values for the default case scenarios (i.e., using the GHG inventories built into the model) vis-A -vis modified approach which incorporated India-specific emission inventories for AIM and P50 are quite appreciable for most of the modeled parameters. A reduction of 7% and 9% in global carbon dioxide (CO2) emissions has been observed respectively for the years 2050 and 2100. Global methane (CH4) and global nitrous oxide (N2O) emissions indicate a reduction of 13% and 15% respectively for 2100. Correspondingly, global concentrations of CO2, CH4 and N2O are estimated to reduce by about 4%, 4% and 1% respectively. Radiative forcing of CO2, CH4 and N2O indicate reductions of 6%, 14% and 4% respectively for the year 2100. Global annual mean temperature change (incorporating aerosol effects) gets reduced by 4% in 2100. Global annual mean temperature change reduces by 5% in 2100 when aerosol effects have been excluded. In addition to the above, the Indian contributions in global CO2, CH4 and N2O emissions have also been assessed by India Excluded (IE) scenario. Indian contribution in global CO2 emissions was observed in the range of 10%-26%, 6%-36% and 10%-38% respectively for BCS, Economy and BAU approaches, for the years 2020, 2050 and 2100 for P50, A1B-AIM, A2-AIM, B1-AIM & B2-AIM scenarios. CH4 and N2O emissions indicate about 4%-10% and 2%-3% contributions respectively in the global CH4 and N2O emissions for the years 2020, 2050 and 2100. These Indian GHG emissions have significant influence on global GHG concentrations and consequently on climate parameters like RF and a dagger T. The study reflects not only the importance of Indian emissions in the global context but also underlines the need of incorporation of country specific GHG emissions in modeling to reduce uncertainties in simulation of climate change parameters

Emission inventory of trace gases from road transport in India

In India, road transport sector is one of the major anthropogenic contributor of GHGs and other pollutants into the atmosphere which have significant adverse human health effects. National and state level pollutants' emissions from road transport in India have been estimated by using VKT approach for the period of 2001-2013 which includes the values of average vehicle kilometres travelled (VKT) by different vehicle types and emission factors (EF) for different vehicle types. The results revealed a Compound Annual Growth Rate (CAGR) of 8.5%, 8.5%, 8.1%, 8.3%, 8.4%, 8.2% and 9% respectively of carbon dioxide (CO2), methane (CH4), nitrogen oxides (NOx), carbon monoxide (CO), sulphur dioxide (SO2), particulate matters (PM) & hydrocarbon (HC) emissions from vehicles in road transport sector during the periods 2001-2013 due to increase of vehicle population. The study also showed a negative temporal trend in the CO2 emissions per unit of GDP indicating reduced CO2 emission intensities in transport sector. Statewise emission estimates from different vehicle categories confirmed that states like Maharashtra, Gujarat, Tamil Nadu, Kerala, Uttar Pradesh, Rajasthan, Andhra Pradesh, Karnataka and Delhi are responsible for about 68% of total emissions of CO2, CO, CH4, NOx, SO2, HC and PM

Decadal emission estimates of carbon dioxide, sulfur dioxide, and nitric oxide emissions from coal burning in electric power generation plants in India

This study aims to estimate the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) for coal combustion in thermal power plants in India using plant-specific emission factors during the period of 2001/02 to 2009/10. The mass emission factors have been theoretically calculated using the basic principles of combustion under representative prevailing operating conditions in the plants and fuel composition. The results show that from 2001/02 to 2009/10 period, total CO2 emissions have increased from 324 to 499 Mt/year; SO2 emissions have increased from 2,519 to 3,840 kt/year; and NO emissions have increased from 948 to 1,539 kt/year from the Indian coal-fired power plants. National average emissions per unit of electricity from the power plants do not show a noticeable improvement during this period. Emission efficiencies for new plants that use improved technology are found to be better than those of old plants. As per these estimates, the national average of CO2 emissions per unit of electricity varies between 0.91 and 0.95 kg/kWh while SO2 and NO emissions vary in the range of 6.9 to 7.3 and 2.8 to 2.9 g/kWh, respectively. Yamunagar plant in Haryana state showed the highest emission efficiencies with CO2 emissions as 0.58 kg/kWh, SO2 emissions as 3.87 g/kWh, and NO emissions as 1.78 g/kWh, while the Faridabad plant has the lowest emission efficiencies with CO2 emissions as 1.5 kg/kWh, SO2 emissions as 10.56 g/kWh, and NO emissions as 4.85 g/kWh. Emission values at other plants vary between the values of these two plants

Studies on Aerosol Optical Properties at High Altitude Station in Western Himalayas Using Raman Lidar

The aerosol optical properties have been investigated using the Raman lidar system for the month of November 2018 at the western Himalayan station of Palampur. Before deriving the optical properties, the lidar data has been applied with initial pre-processing such as Dead time correction, atmospheric noise correction, temporal and spatial averaging, range correction, gluing etc. The optical properties such as backscatter coefficient, extinction coefficient and linear depolarization ratio have been derived by using the inversion algorithm proposed by Fernald. The results show that the backscatter coefficient was found in the range from 9.00E-9 m−1sr−1 to 4.97E-6 m−1sr−1 and the extinction coefficient was found in the range from 3.16E-7m-1 to 1.74E-4m-1. The Linear depolarization ratio was in the range from 0.0179 to 0.621 with lower values at near heights suggesting the dominance of spherical particles at the lower heights. We have also observed a cloud layer at a height of 9.5 km to 12.1 km with high depolarization ratio during the observation period on 22/11/2018

Study of intra-city urban heat island intensity and its influence on atmospheric chemistry and energy consumption in Delhi

Urban heat island intensity (UHII) has been determined as difference in air temperatures between two locations of Delhi namely Safdarjung (SAFD) and National Physical Laboratory (NPL) regions which represent urban and sub-urban areas respectively. High UHI has been obtained in morning time as compared to day and night times, with the highest magnitude ranging from 2.8 to 3 degrees C in spring (MAM), autumn (SON) and winter (DJF) seasons in morning hours (0700-0900 h). Monsoon season (JJA) shows less UHII values compared to other seasons. Wind speed reduced the UHII. Larger impervious area (i. e. 67.2% in SAFD as compared to 33.4% in NPL), lesser vegetated area (i. e. 32.8% in SAFD as compared to 66.6% in NPL) and low Normalized Difference Vegetation Index (NDVI) value (0.15 in SAFD as compared to 0.24 in NPL) in SAFD area supports the existence of UHI there. Ambient O3 concentrations show maximum values during April and May for both regions and remain insignificantly influenced by UHI. Intra city temperature difference of 0.2-3 degrees C is capable of raising electricity demand by 37.87-1856 GWh over the base electricity requirement of the city with corresponding increase in CO2 emissions by 0.031-1.52 million ton