Analytics: Daily, Weekly and Monthly Trends
Background
Air pollution changes over the course of the day (due to behaviour changes and changes in the atmosphere), over the week (as people do different things at the weekend than in the week) and over the year (as the weather changes in each season). These charts and graphs capture some of these changes based on our air pollution monitoring in Trim for two key pollutants - nitrogen dioxide and PM2.5.
Nitrogen dioxide (NO₂)
NO₂ is a pollutant made mostly by cars, vans and other vehicles that burn petrol or diesel. As it's closely linked to vehicle use, it changes a lot over the course of the day based on when people are driving or vehicles are idling. The table and graph below show results at each monitoring site and two reference sites over the full data period.
Daily NO₂ values
| Site | 24hr Mean (μg/m³) | 00:00-06:00 Mean (μg/m³) | 06:00-12:00 Mean (μg/m³) | 12:00-18:00 Mean (μg/m³) | 18:00-24:00 Mean (μg/m³) | Highest Hrly Ave | Highest Hr | Lowest Hrly Ave (μg/m³) | Lowest Hr |
|---|---|---|---|---|---|---|---|---|---|
| Market Street (Zephyr) | 4.31 | 1.58 | 3.45 | 6.61 | 5.6 | 8.68 | 17:00-18:00 | 1.14 | 03:00-04:00 |
| Patrick Street (Zephyr) | 16.99 | 14.74 | 14.31 | 17.56 | 21.34 | 24.17 | 18:00-19:00 | 11.08 | 11:00-12:00 |
| Navan (Reference) | 22.62 | 8.78 | 24.77 | 27.96 | 28.95 | 33.93 | 19:00-20:00 | 6.53 | 03:00-04:00 |
| Kilkenny (Reference) | 4.48 | 3.08 | 5.34 | 3.97 | 5.54 | 7.12 | 09:00-10:00 | 2.49 | 04:00-05:00 |
NO₂ Market Street (Zephyr)
NO₂ Patrick Street (Zephyr)
Fine particles (PM2.5)
PM2.5 is a pollutant related to cars, wood, coal and peat fires, and some kinds of industry. It can change over the course of the day as the atmosphere changes, and can be higher in the winter if people use solid fuels as sources of heat at home.
Daily PM2.5 values
| Site | 24hr Mean (μg/m³) | 00:00-06:00 Mean (μg/m³) | 06:00-12:00 Mean (μg/m³) | 12:00-18:00 Mean (μg/m³) | 18:00-24:00 Mean (μg/m³) | Highest Hrly Ave | Highest Hr | Lowest Hrly Ave (μg/m³) | Lowest Hr |
|---|---|---|---|---|---|---|---|---|---|
| Market Street (Zephyr) | 4.6 | 4.21 | 4.03 | 4.66 | 5.52 | 5.85 | 19:00-20:00 | 3.83 | 06:00-07:00 |
| Patrick Street (Zephyr) | 9.55 | 9.36 | 8.65 | 9.35 | 10.85 | 11.21 | 20:00-21:00 | 8.49 | 10:00-11:00 |
| Market Street (enLink) | 9.42 | 9.34 | 8.6 | 9.2 | 10.56 | 10.8 | 20:00-21:00 | 8.53 | 10:00-11:00 |
| Patrick Street (enLink) | 9.55 | 9.36 | 8.65 | 9.35 | 10.85 | 11.21 | 20:00-21:00 | 8.49 | 10:00-11:00 |
| Navan (Reference) | 7.92 | 7.31 | 6.67 | 7.08 | 10.61 | 11.8 | 21:00-22:00 | 6.15 | 05:00-06:00 |
| Carlow (Reference) | 6.78 | 6.7 | 5.81 | 5.78 | 8.82 | 9.58 | 20:00-21:00 | 5.43 | 13:00-14:00 |
PM2.5 Market Street (enLink)
PM2.5 Market Street (Zephyr)
PM2.5 Patrick Street (enLink)
PM2.5 Patrick Street (Zephyr)
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