Table 2 δ13C source signatures calculated with the Keeling plot analysis for each diurnal study.
From: Evaluating methane inventories by isotopic analysis in the London region
Date | δ13C isotopic signature (‰) | Time of samples included in the Keeling Plot | Number of samples included in the Keeling plot analysis |
|---|---|---|---|
9th–10th Jul 2012 | −38.1 ± 4.7 | 2 p.m. (09/07/2012)–9 a.m. (10/07/2012) | 20 |
2nd–3rd Dec 2013 | −38.8 ± 1.7 | 3 p.m. (2/12/2013)–10 a.m. (3/12/2013) | 20 |
10th–11th Dec 2013 | −36.8 ± 2.2 | 3 p.m.–10 p.m. (10/12/2013) | 5 |
−55.2 ± 2.6 | 2 a.m.–11 a.m. (11/12/2013) | 10 | |
20th–21st Jan 2014 | −40.1 ± 1.2 | 2 p.m. (20/01/2014)–7 a.m. (21/01/2014) | 15 |
−50.5 ± 2.6 | 8 a.m.–12 (21/01/2014) | 5 | |
30th–31st Jan 2014 | −35.9 ± 0.5 | 5 p.m.–9 p.m. (30/01/2014) | 6 |
−40.7 ± 0.3 | 11 p.m. (30/01/2014)–8 a.m. (31/01/2014) | 6 | |
−51.1 ± 0.9 | 10 a.m.–12 (21/01/2014) | 3 | |
12th–13th–14th March 2014 | −42.8 ± 1.0 | 2 p.m. (12/03/2014)–12 (13/03/2014) | 9 |
−42.6 ± 0.4 | 2 p.m. (13/03/2014) – 1 p.m. (14/03/2014) | 13 | |
−50.3 ± 0.7 | 11:30 p.m. (12/03/2014) – 2 a.m. (13/03/2014) | 4 | |
−53.6 ± 0.5 | 11:30 p.m. (13/03/2014) – 1 a.m. (14/03/2014) | 3 | |
24th–25th Jul 2014 | −44.2 ± 2.0 | 2 p.m. (24/07/2014) – 8 a.m. (25/07/2014) | 14 |
−50.1 ± 2.0 | 9:30 a.m.–10:30 a.m. (25/07/2014) | 3 | |
7th–8th Aug 2014 | −39.7 ± 1.3 | 1 p.m. – 9 p.m. (07/08/2014) | 9 |
−51.6 ± 2.5 | 5 a.m. – 8 a.m. (08/08/2014) | 4 |
