This document analyzes black carbon data collected in Ireland. It begins by defining black carbon as light-absorbing carbon particles produced by incomplete combustion. It then discusses the challenges of measuring black carbon, noting that measurements can vary significantly depending on the instrument and technique used. The document presents data on black carbon levels in Malin Head, Ireland from an Aethalometer over multiple years. It finds that black carbon levels were below 75 ng/m3 59% of the time in 2002 and 62% of the time in 2003. Levels were also frequently below 50 ng/m3, especially in the month of August.

1. Analysis of Black Carbon Data for Ireland Michael Geever, NUI, Galway

2. What is Black Carbon? Light-absorbing carbonaceous particle produced by incomplete combustion of various fuels Light-absorbing subset of particulate matter Soot Elemental Carbon Refractive Carbon Black Carbon Brown Carbon

3. Measurements Range over orders of magnitude Measurements difficult Few instruments good over whole range – usually tuned to particular range: urban or background Techniques differ – can give different results Calibration difficult Instrument artefacts complicate analysis and comparison Good qualitative measurement

4. Aethalometer – Malin Head

5. Aethalometer

6. Mace Head Malin Head monthly averages

7. YEAR 2002: % BC below 75 ngm-3 for whole year 59%

9. YEAR 2003: % BC below 75 ngm-3 for whole year 62%

11. YEAR 2005 : BLACK CARBON FREQUENCY BELOW 50 NG M-3 Average year: 53% of times BC is below 50ng/m3

12. 2005

13. YEAR 2006 : BLACK CARBON FREQUENCY BELOW 50 NG M-3 During August 85% of the time BC is below 50ng m-3, 50% below 15ng/m3!

14. 2006

15. YEAR 2007 : BLACK CARBON FREQUENCY BELOW 50 NG M-3 (no october for 2007) January really cleaned, again August the cleanest of summer months (75% cleaner than 30ng m-3 for August)

16. 2007

17. Average frequency of occurrence

18. Average Frequency by month