
Ranjeet SokhiUniversity of Hertfordshire | UH · Centre for Climate Change Research (C3R)
Ranjeet Sokhi
BSc, MSc, PhD, PGCE
About
182
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Introduction
Publications
Publications (182)
Shipping is responsible for a range of different pressures affecting air quality, climate, and the marine environment. Most social and economic analyses of shipping have focused on air pollution assessment and how shipping may impact climate change and human health. This risks that policies may be biased towards air pollution and climate change, wh...
Exceedances of critical loads for deposition of sulphur (S) and nitrogen (N) to different ecosystems were estimated using European and North American ensembles of air quality models, under Phase 4 of the Air Quality Model Evaluation International Initiative (AQMEII4), to identify where risk of ecosystem harm is expected to occur based on model depo...
The average global temperature is rising due to anthropogenic emissions. Hence, a systematic approach was used to examine the projected impacts of rising global temperatures on heatwaves in India and provide insights into mitigation and adaptation strategies. With over 24,000 deaths attributed to heatwaves from 1992 to 2015, there is an urgent need...
Exposure to air pollution is a leading public health risk factor in India, especially over densely populated Delhi and the surrounding Indo-Gangetic Plain. During the post-monsoon seasons, the prevailing north-westerly winds are known to influence aerosol pollution events in Delhi by advecting pollutants from agricultural fires as well as from loca...
The sensitivity of air quality model responses to modifications in input data (e.g. emissions, meteorology and boundary conditions) or model configurations is recognized as an important issue for air quality modelling applications in support of air quality plans. In the framework of FAIRMODE (Forum of Air Quality Modelling in Europe, https://fairmo...
The nature and origin of organic aerosol in the atmosphere remain unclear. The gas–particle partitioning of semi-volatile organic compounds (SVOCs) that constitute primary organic aerosols (POAs) and the multigenerational chemical aging of SVOCs are particularly poorly understood. The volatility basis set (VBS) approach, implemented in air quality...
We present a new concept for marine research, applied in the EU-funded project EMERGE, “Evaluation, control and Mitigation of the EnviRonmental impacts of shippinG Emissions” (2020–2024; https://emerge-h2020.eu/). For the first time, both the various marine and atmospheric impacts of the shipping sector have been and will be comprehensively analyze...
The nature and origin of organic aerosol in the atmosphere remain unclear. The gas-particle partitioning of semi-volatile organic compounds (SVOC) that constitute primary organic aerosols (POA) and the multigenerational chemical aging of SVOCs are particularly poorly understood. The volatility basis set (VBS) approach, implemented in air quality mo...
Air pollution is estimated to contribute to approximately 7 million premature deaths, of which around 4.5 million deaths are linked to ambient (outdoor) air pollution (Murray et al. 2020). The deaths attributed to air pollution rank the highest in the Asian Region and thus the implementation of the stricter World Health Organization (WHO) Global Ai...
This review provides a community's perspective on air quality research focusing mainly on developments over the past decade. The article provides perspectives on current and future challenges as well as research needs for selected key topics. While this paper is not an exhaustive review of all research areas in the field of air quality, we have sel...
This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and r...
This review provides a community's perspective on air quality research focussing mainly on developments over the past decade. The article provides perspectives on current and future challenges as well as research needs for selected key topics. While this paper is not an exhaustive review of all research areas in the field of air quality, we have se...
This chapter describes a new World Meteorological Organisation (WMO) approach to the provision of science-based services to assist the planning of safe, healthy, resilient and climate-friendly cities. The approach is outlined in full in the WMO Guidance on Integrated Urban Hydrometeorological, Climate and Environmental Services. Volume I, Concepts...
Surface ozone is a major pollutant threatening public health, agricultural production and natural ecosystems. While measures to improve air quality in megacities such as Delhi are typically aimed at reducing...
Fine particulate matter (PM2.5) and surface ozone (O3) are major air pollutants in megacities such as Delhi, but the design of suitable mitigation strategies is challenging. Some strategies for reducing PM2.5 may have the notable side effect of increasing O3. Here, we demonstrate a numerical framework for investigating the impacts of mitigation str...
A comprehensive modelling approach has been developed to predict population exposure to the ambient air PM2.5 concentrations in different microenvironments in London. The modelling approach integrates air pollution dispersion and exposure assessment, including treatment of the locations and time activity of the population in three microenvironments...
Fine particulate matter (PM2.5) and surface ozone (O3) are major air pollutants in megacities such as Delhi, but the design of suitable mitigation strategies is challenging. Some strategies for reducing PM2.5 may have the notable side-effect of increasing O3. Here, we demonstrate a numerical framework for investigating the impacts of mitigation str...
Introduction:
Previous analysis from the large European multicentre ESCAPE study showed an association of ambient particulate matter <2.5 μm (PM2.5) air pollution exposure at residence with the incidence of gastric cancer. It is unclear which components of PM are most relevant for gastric and also upper aerodigestive tract (UADT) cancer and some o...
Background:
Epidemiological evidence on the association between ambient air pollution and breast cancer risk is inconsistent.
Objective:
We examined the association between long-term exposure to ambient air pollution and incidence of postmenopausal breast cancer in European women.
Methods:
In 15 cohorts from nine European countries, individual...
The impact of air pollution on human health and the associated external costs in Europe and the United States (U.S.) for the year 2010 is modelled by a multi-model ensemble of regional models in the frame of the third phase of the Air Quality Modelling Evaluation International Initiative (AQMEII3). This is the first study known to use a common heal...
Background:
Epidemiological evidence on the association between ambient air pollution and brain tumor risk is sparse and inconsistent.
Methods:
In 12 cohorts from six European countries, individual estimates of annual mean air pollution levels at the baseline residence were estimated by standardized land-use regression models developed within th...
Background:
Tobacco smoke exposure increases the risk of cancer in the liver, but little is known about the possible risk associated with exposure to ambient air pollution.
Objectives:
We evaluated the association between residential exposure to air pollution and primary liver cancer incidence.
Methods:
We obtained data from four cohorts with...
Through the comparison of several regional-scale chemistry transport modeling systems that simulate meteorology and air quality over the European and North American continents, this study aims at (i) apportioning error to the responsible processes using timescale analysis, (ii) helping to detect causes of model error, and (iii) identifying the proc...
Through the comparison of several regional-scale chemistry transport modeling systems that simulate meteorology and air quality over the European and North American continents, this study aims at (i) apportioning error to the responsible processes using timescale analysis, (ii) helping to detect causes of model error, and (iii) identifying the proc...
Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor air pollution at the residence and the incidence of kid...
Simulations from chemical weather models are subject to uncertainties in the
input data (e.g. emission inventory, initial and boundary conditions) as well
as those intrinsic to the model (e.g. physical parameterization, chemical
mechanism). Multi-model ensembles can improve the forecast skill, provided
that certain mathematical conditions are fulfi...
Background
Ambient air pollution contains low concentrations of carcinogens implicated in the etiology of urinary bladder cancer. Little is known about whether exposure to air pollution influences bladder cancer in the general population.
Objective
We aimed to evaluate the association between long-term exposure to ambient air pollution and bladder...
Through the comparison of several regional-scale chemistry transport modelling systems that simulate meteorology and air quality over the European and American continents, this study aims at i) apportioning the error to the responsible processes using time-scale analysis, ii) helping to detect causes of models error, and iii) identifying the proces...
The results of three measurement campaigns are presented in this study. The campaigns have been undertaken at an urban roadside site in London, for more than a year and three months in 2003–2004 and for a year in 2008, and at an urban background site in Birmingham, U.K, for about four months in 2002. The concentrations of PM2.5, PM10, NOx and NO2 w...
Forecasts from chemical weather models are subject to uncertainties in the input data (e.g.
3 emission inventory, initial and boundary conditions) as well as the model itself (e.g. physical
4 parameterization, chemical mechanism). Multi-model ensemble forecasts can improve the
5 forecast skill provided that certain mathematical conditions are fulfi...
Four regional chemistry transport models were applied to
simulate the concentration and composition of particulate matter (PM) in
Europe for 2005 with horizontal resolution ∼ 20 km. The modelled
concentrations were compared with the measurements of PM chemical composition
by the European Monitoring and Evaluation Programme (EMEP) monitoring
network...
Most epidemiological studies have been conducted based on relations between pollution concentrations measured at fixed ambient air quality monitoring sites, or modelled values using land-use regression models, and various health indicators. However, such simplistic modelling ignores several crucial factors, such as, (i) the activity patterns of ind...
We have presented an overview of the modelling of particle number concentrations (PNC’s) in five major European cities, namely Helsinki, Oslo, London, Rotterdam and Athens, in 2008. We have presented emission inventories of particle numbers both on urban and European scales, atmospheric dispersion modelling of PNC’s in the cities and on a European...
Background:
Particulate matter (PM) air pollution is a human lung carcinogen; however, the components responsible have not been identified. We assessed the associations between PM components and lung cancer incidence.
Methods:
We used data from 14 cohort studies in eight European countries. We geocoded baseline addresses and assessed air polluti...
Four regional chemistry transport models were applied to simulate the concentration and composition of particulate matter (PM) in Europe for 2005 with horizontal resolution ~20 km. The modelled concentrations were compared with the measurements of PM chemical composition by the EMEP monitoring network. All models systematically underestimated PM10...
A risk based approach to assessing compliance with EU limit values is described, using the advanced chemical transport model CMAQ to determine the regional component of NO2 and particulate matter under various conditions over the UK. A new air quality data analysis retrieval tool AirDART is used to extract concentrations for selected areas of the c...
An increasing number of epidemiological studies suggest that adverse health effects of air pollution may be related to particulate matter (PM) composition, particularly trace metals. However, we lack comprehensive data on the spatial distribution of these elements. We measured PM2.5 and PM10 in twenty study areas across Europe in three seasonal two...
This paper investigates regional air quality model performance and the regulation of atmospheric emissions. Although evaluation of regional models cannot be reduced to a set of rules, the paper shows ways of developing better understanding of model performance. It draws on studies in recent years by the Environment Agency to quantify the uncertaint...
Abstract The second phase of the Air Quality Model Evaluation International Initiative (AQMEII) brought together sixteen modeling groups from Europe and North America, running eight operational online-coupled air quality models over Europe and North America on common emissions and boundary conditions. With the advent of online-coupled models provid...
Abstract This study reviews the top ranked meteorology and chemistry interactions in online coupled models recommended by an experts' survey conducted in COST Action EuMetChem and examines the sensitivity of those interactions during two pollution episodes: the Russian forest fires 25 Jul–15 Aug 2010 and a Saharan dust transport event from 1 Oct to...
The second phase of the Air Quality Model Evaluation International Initiative (AQMEII) brought together seventeen modeling groups from Europe and North America, running eight operational online-coupled air quality models over Europe and North America using common emissions and boundary conditions. The simulated annual, seasonal, continental and sub...
Abstract Air pollution simulations critically depend on the quality of the underlying meteorology. In phase 2 of the Air Quality Model Evaluation International Initiative (AQMEII-2), thirteen modeling groups from Europe and four groups from North America operating eight different regional coupled chemistry and meteorology models participated in a c...
The Air Quality Model Evaluation International Initiative (AQMEII) has now reached its second phase which is dedicated to the evaluation of online coupled chemistry-meteorology models. Sixteen modelling groups from Europe and five from North America have run regional air quality models to simulate the year 2010 over one European and one North Ameri...
We present an overview of the modelling of particle number concentrations (PNC's) in five major European cities, namely Helsinki, Oslo, London, Rotterdam and Athens, in 2008. Novel emission inventories of particle numbers have been compiled both on urban and European scales. We use atmospheric dispersion modelling for PNC's in the five target citie...
Air quality and heat are strong health drivers, and their accurate assessment and forecast are important in densely populated urban areas. However, the sources and processes leading to high concentrations of main pollutants, such as ozone, nitrogen dioxide, and fine and coarse particulate matter, in complex urban areas are not fully understood, lim...
Studies have shown associations between mortality and long-term exposure to particulate matter air pollution. Few cohort studies have estimated the effects of the elemental composition of particulate matter on mortality.
Our aim was to study the association between natural cause mortality and long-term exposure to elemental components of particulat...
Simple emission scenarios have been implemented in eight United Kingdom air quality models with the aim of assessing how these models compared when addressing whether photochemical ozone formation in southern England was NOx- or VOC-sensitive and whether ozone precursor sources in the UK or in the Rest of Europe (RoE) were the most important during...
Online coupled mesoscale meteorology atmospheric chemistry models have
undergone a rapid evolution in recent years. Although mainly developed by
the air quality modelling community, these models are also of interest for
numerical weather prediction and regional climate modelling as they can
consider not only the effects of meteorology on air qualit...
This paper shows how the advanced chemical transport model CMAQ can be
used to estimate future levels of PM2.5 in the UK, the key
air pollutant in terms of human health effects, but one which is largely
made up from the formation of secondary particulate in the atmosphere.
By adding the primary particulate contribution from typical urban roads
and...
A comparison of the results from two independent CMAQ modelling systems for the same UK 2003 scenario suggests the need for improvement to temporal profiles of the input emissions data used by atmospheric models.
An evaluation has been made of a range of simple and complex atmospheric transport models, applied to estimate sulphur and nitrogen deposition in the UK in order to provide information to policy makers to support decisions on future model use. The models were evaluated by comparison with annually averaged measurements from the national monitoring n...
Over twenty modeling groups are participating in the Air Quality Model Evaluation International Initiative (AQMEII) in which a variety of mesoscale photochemical and aerosol air quality modeling systems are being applied to continental-scale domains in North America and Europe for 2006 full-year simulations for model inter-comparisons and evaluatio...
The CMAQ modeling system has been used to simulate the air quality for North America and Europe for the entire year of 2006 as part of the Air Quality Model Evaluation International Initiative (AQMEII). The operational model performance of tropospheric ozone (O3), fine particulate matter (PM2.5) and total particulate matter (PM10) for the two conti...
This study aims to quantify exhaust/non-exhaust emissions and the uncertainties associated with them by combining innovative motorway tunnel sampling and source apportionment modelling. Analytical techniques ICP-AES and GC–MS were used to identify the metallic and organic composition of PM10, respectively. Good correlation was observed between Fe,...