School of Earth & Environmental Science
Capnerhurst, Jordan N.R., Assessing the Predictions of Biogenic Volatile Organic Compound Emissions from Multiple Chemical Transport Models Within the Greater Metropolitan Region NSW, BEnviSci Hons, School of Earth & Environmental Science, University of Wollongong, 2016.
Within the Greater Metropolitan Region NSW, consideration of the accuracy of predicted biogenic emissions inputted into chemical transport models is important. These biogenic emissions react with anthropogenic compounds producing organic aerosol and ground level ozone, which negatively impact the wider environment. Despite this, there have been few studies in the area regarding these compounds and large uncertainty exists.
To address this issue, the predictions of biogenic emissions from MEGAN and the CSIRO-CTM, within the Greater Metropolitan Region, were assessed using computational and statistical methods. This involved: a model intercomparison between three different model implementations run for February 2011, an assessment of seasonal variability of predicted emissions using a complete 2013 dataset, and a comparison between the outputs of one model using February 2011 and 2013 data.
Predicted emissions from these models revealed that photosynthetically active radiation and temperature explain the majority of the temporal variation in the predicted emissions resulting in a diurnal distribution. However, the majority of spatial variation is explained by leaf area index and broadleaf vegetation cover within each of the models. It was also found that implementations of MEGAN predict higher quantities of emissions than the CSIRO-CTM, and high emissions of isoprene and lower emissions of monoterpenes. Each model also predicts high levels of emissions over national parks. Emissions were found to be seasonally variable with emissions at their highest during summer and lowest during winter. While the spatial distribution remained nearly unchanged throughout the year. The emission predictions for February 2013 were found to be significantly higher than those in February 2011 owing to the increased temperatures predicted for 2013.
This research highlights the importance of using up to date and accurate model inputs and the need for further biogenic flux measurements in the area.