CO2 monitoring and modelling across Greater London

Lester Kwiatkowski

Site characteristics

Urban roadside Urban background

Rural background

Mean = 279.7µgm-3

Mean = 40.1µgm-3

Mean = 34.2µgm-3

Mean = 425.2ppm

Mean = 419ppm

Mean = 396.2ppm

Explanatory factors

•Diurnal mixing depth cycles

• Anthropogenic emissions

• Heat island effects influencing diurnal mixing depth

• Biogenic signals?

• Any suggestions?

BRUTAL model predictions…

Deciphering wind speed/direction relationships

SP

Street canyon effects

NOx enrichment due to easterly winds carrying an enriched “London signal”

CO2 signals difficult to interpret, higher CO2 for directions with lower average wind speeds but other effects going on (European CO2 signal)

0 50 100 150 200 250 300 350 4000

0.51

1.52

2.53

3.54

4.55

wind direction (degrees)

Win

d Sp

eed

m/s

Modelling approaches

• Road transport CO2 emissions run through BRUTAL can explain much of the difference between NK and MR but fails to account for the difference between SP and NK/MR

• Stratified modeling work in progress… (ApSimon & Oxley)

Thanks