Seasonal and Interannual Variability of Trace Gases in the Tropical and Extra-tropical Boundary Layer

Lead Research Organisation: University of Cambridge
Department Name: Chemistry


Natural and anthropogenic emissions from Southeast Asia and the maritime continent exert an important influence on atmospheric composition, climate and air quality. Changes in climate will most likely lead to changed emissions from the terrestrial and marine biospheres. In addition, emissions of air pollutants from Southeast Asia are driven by strong industrial growth and development, a trend likely to continue into the foreseeable future. Understanding these processes and their impacts is a crucial chemistry/climate question. Our aim is to improve quantitative understanding of the atmospheric impacts, on a range of spatial (from local to global) and temporal (from days to years) scales, of emissions of short-lived halocarbons and hydrocarbons in SE Asia and the maritime continent. We propose to establish a climatology of atmospheric concentrations of natural and anthropogenic halocarbons in the tropical boundary layer at five ground stations in Taiwan, Malaysia, Northern Australia and New Zealand from 2008 to 2011. Shorter-term measurements with a roving instrument will be made during research cruises and at other existing sites used by our colleagues at the University of Malaya. In collaboration with marine biologists we will investigate the factors influencing emissions and concentrations under a range of climate conditions. In a second phase, we will measure a range of hydrocarbons at the tropical sites. These measurements will then be used with numerical models to test and improve modelled emission estimates and to investigate their impact on tropospheric oxidative capacity, air quality and regional and global climate.


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Description The aim of this project was to make measurements of halocarbons and trace gas species which are emitted from the ocean and coastal seas. It was based on a number of strong collaborations in the SE Asian and West Pacific region. Instruments are now operational in Malaysia (4 in total), Australia (1), New Zealand (1) and Taiwan (1). Work in this project has provided new observations of the natural concentrations and variability of these species, as well as valuable constraints on the size of the emissions in the region which we find to be significantly smaller than previously thought. This is important in defining the role of these compounds in the amount of ozone-depleting bromine species in the stratosphere. In addition, we have made measurements of halocarbon concentrations on 4 cruises in the southern oceans from the equator to Antarctica. Most of these were made in conjunction with a suite of other measurements which are being interpreted to reveal information about the sea-air fluxes. The measurements in Borneo have been used to infer CHBr3 emissions in coastal waters and in the open ocean. The measurements in Taiwan are being used to constrain the emissions of C2Cl4 in Taiwan and in NE China, and initial analysis shows that Taiwanese emissions have dropped by a factor of 10 over the past 15 years while Chinese ones are very high. Other analyses are on-going.
Exploitation Route These measurements are valuable for providing baseline information during a period of rapid growth of seaweed production in SE Asia. The collaboration has involved a major Malaysian aquaculture company as well as leading researchers on seaweeds and other macroalgae in Malaysia. The Taiwanese C2Cl4 emission estimates will be vauable for policymakers in assessing the success of existing emission control measures. The main exploitation will be by the publication of papers in peer-reviewed journals.
Sectors Environment

Description The emission estimates of CHBr3, an important natural ozone-depleting substance, constrain its role in the overall bromine budget and are used in the current Scientific Assessment of Ozone Depletion.
First Year Of Impact 2014
Sector Environment
Impact Types Policy & public services

Description International partnership building 
Organisation University of Malaya
Country Malaysia 
Sector Academic/University 
PI Contribution Series of group and individual meetings between PIs and development of a collaborative strategy. Meetings held in Norwich (UEA), Cambridge, Kuala Lumpur, Bachok (Malaysia), and opportunistically in New Zealand and Australia, and involving the majority of PI institutes (UEA), University of Cambridge, University of Malaya (UM), the Commonwealth Scientific and Industrial Research Organisation (CSIRO, Australia), and the National Institute of Water and Atmospheric Research (NIWA, New Zealand), as well as verbal contact with the National Central University of Taiwan. There was also a site visit to the the new research facility at Bachok, and the Malaysian Meteorology Department (MMD) weather station/radiosonde launch facility at Kota Bharu, both central to this project, with staff from UEA, Cambridge, UM and MMD. Graduate students from Malaysia are attending courses run by NCAS on atmospheric science. The collaboration continues since my move to Cranfield and we are involved with UM, UKM and MMD in the NERC Newton Fund project looking at air quality in the greater Klang Valley
Collaborator Contribution The demonstration activity held in Bachok, Malaysia in Jan/Feb 2014 successfully showed that several state-of-the-art instruments could be run in camapign mode in conjunction with the suite of instruments being installed by the University of Malaya for long-term observations.
Impact The campaign took place successfully. A joint science meeting was held in Cambridge, UK in September 2014 and a publication policy was agreed.
Start Year 2008