Characterization and source identification of PM and its chemical and carbonaceous constituents during Winter Fog Experiment 2015-16 at Indira Gandhi International Airport, Delhi.

Data on mass concentration of PM and its carbonaceous and water soluble inorganic chemical ions were compiled through sampling of PM at Indira Gandhi International Airport, Delhi during Dec. 16, 2015-Feb. 15, 2016 under Winter Fog Experiment (WIFEX) program of the Ministry of Earth Sciences (MoES) and analysing the samples.

Global and regional trends of atmospheric sulfur.

The profound changes in global SO emissions over the last decades have affected atmospheric composition on a regional and global scale with large impact on air quality, atmospheric deposition and the radiative forcing of sulfate aerosols. Reproduction of historical atmospheric pollution levels based on global aerosol models and emission changes is crucial to prove that such models are able to predict future scenarios. Here, we analyze consistency of trends in observations of sulfur components in air and precipitation from major regional networks and estimates from six different global aerosol models from 1990 until 2015.

Black carbon: source apportionment and its implications on CCN activity over a rural region in Western Ghats, India.

This study presents the characteristics of black carbon aerosol (BC) over a high-altitude site, Mahabaleshwar during the monsoon season. The mass concentration of BC exhibits a morning peak and a daytime build-up with a mean mass concentration of 303 ± 142 ng m. The simultaneous measurements of aerosol particle number concentration (PNC), cloud condensation nuclei concentration (CCN), and non-refractory particulate matter less than 1 μm size (NR-PM) were also made by using a Wide-Range Aerosol Spectrometer (WRAS), CCN counter and Aerosol Chemical Speciation Monitor (ACSM) respectively.

Impact of a Narrow Coastal Bay of Bengal Sea Surface Temperature Front on an Indian Summer Monsoon Simulation.

A dry bias in climatological Central Indian rainfall plagues Indian summer monsoon (ISM) simulations in multiple generations of climate models. Here, using observations and regional climate modeling, we focus on a warm coastal Bay of Bengal sea surface temperature (SST) front and its impact on Central Indian rainfall. The SST front, featuring sharp gradients as large as 0.

Aerosol and pollutant characteristics in Delhi during a winter research campaign.

Urban areas in developing countries are major sources of carbonaceous aerosols and air pollutants, pointing out the need for a detailed assessment of their levels and origin close to the source. A multi-instrument research campaign was performed in Delhi during December 2015-February 2016 aimed at exploring the pollution levels and the contribution of various sources to particulate matter (PM) concentrations, black carbon (BC) aerosols, and trace gases. The weak winds (< 5-6 m s) along with the shallow boundary layer favoured the formation of thick and persistent fog conditions, which along with the high BC (24.

Household solid fuel burning emission characterization and activity levels in India.

Emission factors (EFs) of PM carbon fractions, major ionic (K, Ca, NH, SO, NO and Cl) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g·kg) were: 34.

Elevated Black Carbon Concentrations and Atmospheric Pollution around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground and Satellite Data.

The tropospheric NO₂ concentration from OMI AURA always shows high concentrations of NO₂ at a few locations in India, one of the high concentrations of NO₂ hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health.

The impact of power generation emissions on ambient PM pollution and human health in China and India.

Emissions from power plants in China and India contain a myriad of fine particulate matter (PM, PM ≤ 2.5 μm in diameter) precursors, posing significant health risks among large, densely settled populations. Studies isolating the contributions of various source classes and geographic regions are limited in China and India, but such information could be helpful for policy makers attempting to identify efficient mitigation strategies.

Statistical Evidence for the Role of Southwestern Indian Ocean Heat Content in the Indian Summer Monsoon Rainfall.

This study examines the benefit of using Ocean Mean Temperature (OMT) to aid in the prediction of the sign of Indian Summer Monsoon Rainfall (ISMR) anomalies. This is a statistical examination, rather than a process study. The thermal energy needed for maintaining and intensifying hurricanes and monsoons comes from the upper ocean, not just from the thin layer represented by sea surface temperature (SST) alone.

Development of Ahmedabad's Air Information and Response (AIR) Plan to Protect Public Health.

Indian cities struggle with some of the highest ambient air pollution levels in the world. While national efforts are building momentum towards concerted action to reduce air pollution, individual cities are taking action on this challenge to protect communities from the many health problems caused by this harmful environmental exposure. In 2017, the city of Ahmedabad launched a regional air pollution monitoring and risk communication project, the Air Information and Response (AIR) Plan.

Isotopic study of intraseasonal variations of plant transpiration: an alternative means to characterise the dry phases of monsoon.

The isotopic characteristics of plant transpired water are strongly controlled by soil evaporation process, primarily by relative humidity. The monsoon system is characterised by large variability of several atmospheric parameters; the primary one being the rainfall, which in turn, modulates the relative humidity. Due to the strong dependency of transpiration on relative humidity, it is expected that this process would vary in accordance with the active and break periods of the monsoon season, which are known to produce cycles of humid and relatively dry phases during a monsoon season.

Tropospheric ozone enhancement during post-harvest crop-residue fires at two downwind sites of the Indo-Gangetic Plain.

In the present study, surface ozone (O), nitrogen oxides (NO), and carbon monoxide (CO) levels were measured at two sites downwind of fire active region in the Indo-Gangetic Plain (IGP): Agra (27.16° N, 78.08° E) and Delhi (28.

The local and global climate forcings induced inhomogeneity of Indian rainfall.

India is home for more than a billion people and its economy is largely based on agrarian society. Therefore, rainfall received not only decides its livelihood, but also influences its water security and economy. This situation warrants continuous surveillance and analysis of Indian rainfall.

Temporal and spatial variations of PM organic and elemental carbon in Central India.

This study describes spatiotemporal patterns from October 2015 to September 2016 for PM mass and carbon measurements in rural (Kosmarra), urban (Raipur), and industrial (Bhilai) environments, in Chhattisgarh, Central India. Twenty-four-hour samples were acquired once every other week at the rural and industrial sites. Twelve-hour daytime and nighttime samples were acquired either a once a week or once every other week at the urban site.

Decline and poleward shift in Indian summer monsoon synoptic activity in a warming climate.

Cyclonic atmospheric vortices of varying intensity, collectively known as low-pressure systems (LPS), travel northwest across central India and produce more than half of the precipitation received by that fertile region and its ∼600 million inhabitants. Yet, future changes in LPS activity are poorly understood, due in part to inadequate representation of these storms in current climate models. Using a high-resolution atmospheric general circulation model that realistically simulates the genesis distribution of LPS, here we show that Indian monsoon LPS activity declines about 45% by the late 21st century in simulations of a business-as-usual emission scenario.

Winter Burst of Pristine Kashmir Valley Air.

The Kashmir Valley in India is one of the world's major tourist attractions and perceived as a pristine environment. Long term monitoring of fine particulate matter, PM (particles having aerodynamic diameter of 2.5 μm or less), responsible for deteriorating human health, has been done for the period 2013-14.

Assessment of Unusual Gigantic Jets observed during the Monsoon season: First observations from Indian Subcontinent.

Gigantic Jets are electric discharges from thunderstorm cloud tops to the bottom of ionosphere at ~90 km altitude and electrically connect the troposphere and lower ionosphere. Since their first report in 2002, sporadic observations have been reported from ground and space based observations. Here we report first observations of Gigantic Jets in Indian subcontinent over the Indo-Gangetic plains during the monsoon season.

Prediction of Indian Summer-Monsoon Onset Variability: A Season in Advance.

Monsoon onset is an inherent transient phenomenon of Indian Summer Monsoon and it was never envisaged that this transience can be predicted at long lead times. Though onset is precipitous, its variability exhibits strong teleconnections with large scale forcing such as ENSO and IOD and hence may be predictable. Despite of the tremendous skill achieved by the state-of-the-art models in predicting such large scale processes, the prediction of monsoon onset variability by the models is still limited to just 2-3 weeks in advance.

Response of heterogeneous vegetation to aerosol radiative forcing over a northeast Indian station.

Importance of atmospheric aerosols through direct and indirect effects on hydrological cycle is highlighted through multiple studies. This study tries to find how much the aerosols can affect evapo-transpiration (ET), a key component of the hydrological cycle over high NDVI (normalized difference vegetation index)/dense canopy, over Dibrugarh, known for vast tea plantation. The radiative effects of aerosols are calculated using satellite (Terra-MODIS) and reanalysis data on daily and monthly scales.

Ambient black carbon particulate matter in the coal region of Dhanbad, India.

Light-absorbing, atmospheric particles have gained greater attention in recent years because of their direct and indirect impacts on regional and global climate. Atmospheric black carbon (BC) aerosol is a leading climate warming agent, yet uncertainties in the global direct aerosol radiative forcing remain large. Based on a year of aerosol absorption measurements at seven wavelengths, BC concentrations were investigated in Dhanbad, the coal capital of India.

Atmospheric observations show accurate reporting and little growth in India's methane emissions.

Changes in tropical wetland, ruminant or rice emissions are thought to have played a role in recent variations in atmospheric methane (CH) concentrations. India has the world's largest ruminant population and produces ~ 20% of the world's rice. Therefore, changes in these sources could have significant implications for global warming.

Temporal variability in aerosol characteristics and its radiative properties over Patiala, northwestern part of India: Impact of agricultural biomass burning emissions.

A comprehensive measurements of aerosol optical depth (AOD), particulate matter (PM) and black carbon (BC) mass concentrations have been carried out over Patiala, a semi-urban site in northwest India during October 2008 to September 2010. The measured aerosol data was incorporated in an aerosol optical model to estimate various aerosol optical parameters, which were subsequently used for radiative forcing estimation. The measured AOD at 500 nm (AOD) shows a significant seasonal variability, with maximum value of 0.

Latitudinal variation in summer monsoon rainfall over Western Ghat of India and its association with global sea surface temperatures.

The Western Ghats (WG) of India are basically north-south oriented mountains having narrow zonal width with a steep rising western face. The summer monsoon winds during June to September passing over the Arabian Sea are obstructed by the WG and thus orographically uplift to produce moderate-to-heavy precipitation over the region. However, it is seen that characteristic features of rainfall distribution during the season vary from north to south.