Abstract
AbstractTwo field experiments were carried out to observe the variation in wet deposition of ions caused by orography in a polluted region of the UK. the site chosen was Winter Hill which lies on the edge of the industrialised Mersey valley. Rain and cloud samples were collected daily and chemically analysed. Synoptic and meteorological data were used to classify individual rain events as frontal or convective.For the frontal events the altitude related increase in wet deposition was found to be entirely caused by the seeder‐feeder mechanism (the scavenging of cap cloud by rain from above). the concentration of marine ions in the water scavenged from the cap cloud was found to be between five and six times that in the seeder rain whereas for anthropogenically produced ions it was about twice as great. the efficiency of the seeder‐feeder mechanism is correspondingly affected.Convective events accounted for less than a quarter of the rainfall volume. However, this contained over half of the deposition of marine ions in the valley. Deposition of anthropogenically produced ions in convective events was small probably due to a lack of convection over land. A small decrease in deposition with altitude was observed for these events although this is expected to be a highly local effect.It is concluded that reliable predictions of the wet deposition of non‐marine ions can be made on the basis of the seeder‐feeder effect for northern and western regions of the UK. Elsewhere in the UK and for much of continental Europe wet deposition from convective rain should be taken into account.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Quarterly Journal of the Royal Meteorological Society
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.