EMeRGe - the Effect of Megacities on the transport and transformation of pollutants on the Regional and Global scales

At the industrial revolution (1750-1800), the population of the earth was around 1 Billion and less than 5% of population lived in urban areas. In 1950, when the population reached about 2.9 billion, there were two megacities New York/Newark and Tokyo. In 2020, the earth’s population is around 7.8 Billion, more than 50% live in urban areas and there are now approximately 38 around the world. Since 2007, more than 50% of the population live in urban areas and the earth’s population has now reached 7.8 Billion. Anthropogenic activity to sustain and feed MPC is now one of the most important sources of pollution, modifying atmospheric chemistry, air quality and climate.  To assess the impact of MPC emissions locally and regionally requires knowledge of the transport and transformation of the MPC plumes. The EMeRGe project was proposed to address this need and investigate the transport and transformation of the chemical composition of MPC plumes. Secondary objectives include the improvement of our understanding of the impact of biomass burning, which mixes with the plumes from MPC. EMeRGe selected European and Asian MPC as targets, where the regulations on emissions are significantly different.

EMeRGe assumes that the nature of the local emissions, the meteorology and photochemistry/chemistry determines the transport and transformation of the plumes from MPCs. To test this hypothesis, the following scientific questions are addressed:
a) which transport and dispersion processes dominate the MPC outflows in Europe and Asia during the selected measurement periods;
b) which oxidation or other processes determine the chemical transformation of MPC emissions;
c) what are the regional impacts of the emission by the selected European and Asian MPCs;
d) what is the relevance of emission from European and Asian MPCs for radiative forcing and climate change;
e) do our chemical models adequately simulate of transport and transformation processes of European and Asian MPC outflows.

An integrating focus of EMeRGe were the measurement campaigns exploiting the capabilities of the German HALO research were undertaken during EMeRGe, which investigated the outflow from: i) European MPCs in July 2017; ii) MPCs in East and South East Asia during March and April 2018. In addition to the HALO aircraft measurements, the EMeRGe International scientists contributed studies of the measurement from instrumentation from ground based, airborne and satellite platforms. For example in EMeRGe in Europe the UK NERC FAAM (https://nerc.ukri.org/research/sites/facilities/aircraft/) "ERA - CNR - ISAFOM" (https://www.eufar.net/aircrafts/44) were deployed to make measurements around London and Rome respectively. In EMeRGe in Asia, measurement were made ground based and Lidar measurements were made by EMeRGe partners from Taiwan, Japan, the Philippines, Thailand and China. EMeRGe benefited from the support by iCACGP (international Commission on Atmospheric Chemistry and Global Pollution). This presentation will provide an overview of the objectives, the planning, the measurements and some highlights from the EMeRGe HALO campaigns.