photo: iStockphoto/PuiYuen Ng

Megacities and the coastal zone: air-sea interactions

As the world’s population and urbanisation increase simultaneously, so does the number of cities with over 10 million inhabitants – megacities. Many megacities, such as Mumbai and Los Angeles, are located in coastal regions. This juxtaposition leads to particular environmental consequences that have a direct impact on the health and prosperity of people living in and around such cities.

The environmental and ecological effects of the alteration of coastlines and input of sewage from cities have received much attention over the years. But the effect of urban atmospheric emissions on the adjacent coastal waters and that of emissions from coastal waters on urban air quality have received lesser attention.

This fast-track initiative, jointly funded by IGBP and SCOR (Scientific Committee on Oceanic Research)*, seeks to investigate how large-scale urban emissions adjacent to coastal areas lead to specific, complex and interlinked environmental problems. Understanding the interaction between megacities and the coastal regions that they fringe should help devise mitigation strategies for air and water pollution.  

Megacities proposalWord (word, 165 kB)

Roland von Glasow (University of East Anglia),
Tim Jickells (University of East Anglia) and
Sarah Doherty (NOAA), Tong Zhu (Peking University, China), Ramesh Ramachandran (Institute for Ocean Management, India) and Josef Pacyna (Norwegian Institute for Air Research, Norway).
Specific goals
1. To understand how air-sea interactions (such as trace-gas emissions and aerosol formation) within the coastal zone affect air quality within and around megacities
2. To explain how urban and oceanic emissions interact to affect atmospheric chemistry in the marine boundary layer
3. To determine how the interactions of large urban emissions and the marine boundary layer affect local climate
4. To explore how the atmospheric deposition of both contaminants and nutrients from megacities affect the productivity of adjacent coastal waters
5. Related to all of the above, to understand feedback mechanisms between highly integrated, multidisciplinary questions in order to identify major societal issues and key research needed for environmental management.

First workshop: 13-15 April 2010, Norwich
* SCOR approved US$75,00 for the travel of developing country/Russian/Eastern European scientists to participate in this fast-track initiative.

von Glasow R et al. (2012) Megacities and Large Urban Agglomerations in the Coastal Zone: Interactions Between Atmosphere, Land, and Marine Ecosystems. AMBIO, doi: 10.1007/s13280-012-0343-9.