The environmental effects of lockdown
Figure 3. The relationship between daily mean of ozone concentrations and max daily temperatures. Daily maximum temperatures in Bournemouth were obtained from ACCUWEATHER (https://www.accuweather.com/) and O 3 concentrations obtained from DEFRA, from January to July in 2020 and 2019.
The data for 2019 indicates that notable maxima in daily temperatures such as those on 22/04/19 and 30/06/2019 were accompanied by maximum daily mean of ozone concentrations. In addition, there does seem to be some correlation as both temperature and ozone concentration increase as summer approaches. In 2020, the general trend of temperature and ozone concentrations does not appear to be the same; however, similar to 2019, the highest temperature reached on 25/06/20 coincides with the highest recording of ozone concentrations. The scatter graphs with trendlines plotted show some correlation between temperature and O 3 concentrations but not to a very larger extent. In fact, it has been observed that in general the relationship between temperature and ozone is linear, for temperatures below 37 ˚ C. 15 As ozone concentrations have many other influencing factors, both meteorological and chemical, at extreme temperatures these factors holdmore influence. For example, the primary physical removal process of ground level ozone is through dry deposition. 16 This is when gaseous or particulate matter is deposited on surfaces without precipitation 17 and is largely caused by ozone entering plants through their stomata. Deposition rates are also very dependent on meteorological and climate conditions, with temperatures, soil water levels, sunlight and wind speed all affecting the plants stomata. 3. Conclusions In summary, the recent measures taken by the UK government in response to the coronavirus (COVID- 19) pandemic, advising against non-essential journeys, shutting down schools, recommending self- isolation and other measures taken to reduce movement, had a significant impact on NO x emissions in Bournemouth. Measurements of NO x concentration showed much lower levels that than the previous year (2019). However, ground-level ozone concentrations have increased, despite the decrease in NO x emissions. This can be attributed to the complex relationship that ozone and its precursors have with meteorological conditions, as both NO x and VOCs have significant biogenic emitters which can behave differently depending on sunlight, soil moisture, temperature, and wind direction. Moreover, as ozone has a long lifetime in the troposphere it can be transported between regions and its precursors can also travel far distances before they react to form ozone. Therefore, a more widescale look at ozone pollution, NO x and VOC concentrations on the UK, taking into account sunlight, temperature and wind, is needed to be able to come to a clear conclusion on the impacts of the 2020 Coronavirus lockdown.
15 Bloomer, B.J., Stehr, J.W., Piety, C.A., Salaw itch, R.J., Dickerson, R.R. ‘ Observed relationships of ozone air pollution with temperature and emissions’ . (2009, May 5). Geophysical Research Letters, Vol.36. https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009GL037308. 16 See note 8. 17 Se infeld, J.H., Pandis, S.N. ‘Atmospheric Chemistry and Physics: From air pollution to climate change’.(2016). Wiley. https://books.google.co.uk/books?hl=en&lr=&id=n_RmCgAAQBAJ&oi=fnd&pg=PR5&dq=Atmospheri c+Chemistry+and+Physics:+From+Air+Pollution+to+Climate+Change+(Second+ed.)&ots=gROaJOwj9 N&sig=_- aYA-_VvPYV_3iQEa2cPOpvwbE#v=onepage&q&f=false.
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