Dust Optical Corrections

Role on od550lt1aer

od550lt1aer represents the aerosol optical depth for sizes smaller than 1 mu m. The procedure used here to calibrate the dust contribution to od550lt1aer relies on an experimental definition of the distribution of sizes of the optical depth of dust \(\tau_{dust}(D)dD\) of Jasper F. Kok et al 2017 (Nature Geosciences).

The supplementary figure S1 can be decomposed as a table:

Dmin Dmax \(\Delta D\) \(\tau\) \(\Delta D*\tau\)
0.2 0.5 0.3 4.2e-4 0.000126
0.5 1 0.5 4.0e-3 0.002000
1 2 1 9.0e-3 0.009000
2 5 3 1.1e-2 0.033000
5 10 5 3.8e-3 0.019000
10 20 10 5.7e-4 0.0057

The sum of \(\sum_{i}\Delta D_{i} \cdot \Delta \tau_{i} = 0.068826\) which is our normalization factor

The contribution of dust optical depth of particles between 0.2 and 1 mu m is:

\((0.000126+0.002000)/0.068826 = 0.0309\)

so the fraction of particles with sizes between 0.2 and 1 contribute with the 0.0309% to the total optical dust depth, and the biggest contribution is between 2 and 5 with a factor close to 50%.

Ascertain the dust optical depth distribution