1. B913

2. B913
Scaled by peak value in Gaussian
Scaled by area under Gaussian 2 1 3 4 5 6 7 8 9

3. 𝑓=𝑎1exp − 𝑥−𝑏 2 2σ𝑦2 8 9 9 6 6 F
Forties 8
Multiple sources? 9
Land. East Knapton?

4. of concentrations above background for 9 plumes identified so far
First-guess
histogram
(not normalized, etc)
of concentrations above background
for 9 plumes identified so far
number
conc / ppb
land points, plume 9
number
conc / ppb

5. Hysplit Back trajectory for peak 6

6. HYSPLIT run with single source at each rig
i.e. 7 runs
Look at T+20H HYSPLIT concentration along

7. B913
Best Hysplit results 21/10-FA (scaled) averaged over Z T+20 d
Obs (baseline removed)
Gaussian fit to obs
𝑓=𝑎0exp − 𝑥−
Hysplit FA-Forties
Gaussian fit to hysplit
conc / ppb
𝑓=𝑎1exp − 𝑥−
longitude

8. Difference between Hysplit and WRF back trajectories…
B913 land plume
HYSPLIT (web) back trajectory
WRF back trajectory
nested, 4km resolution
in inner domain
Difference between Hysplit and WRF back trajectories…

9. B913 land plume

10. Identifying the source
B913 land plume
East Knapton
power station
distance from methane
peak = 3 km
Identifying the source

11. σy = 180 m ±10 m (Matlab) σy = 200 m ±12 m (Stephen) B913 land plume
WRF 10 m wind speed at receptor ~ 5 m / s