7th Workshop on Forest Fire Management - EARSeL, European ...

Analysis of CO emissions, by forest fires, in the Iberian Peninsula 163
December 2008), N is the total number of data, n is the ordinal of the harmonic
used and F real (n) and F imag (n) are the two coefficients of harmonic
determined through the FFT. Figure 1 shows in grey colour the original data
of the series used; the continuous line superposed represents Inverse FFT.
By means of the FFT, we have also determined the harmonics of the data
series for each year and region. Thus, the curve which establishes the reference
level is determined through the inverse Fourier transform and by
using the group of harmonics that retrieve the general behaviour of data.
Once the adjustment between both curves was carried out, we superimposed
the inverse Fourier transform using further groups of harmonics to
retrieve concrete behaviours. Figure 2 shows all the curves involved in the
process described as well as the temporal situation of the fires. The figure
corresponds to the real case of the region of Castilla y León, year 2005. The
region’s annual curve is labelled as “yearly curve smoothed” and it has been
reproduced through the harmonic groups: [1-3] and [360-364]; the peninsular
synoptic curve of reference was adjusted during the spring season,
and it appears as “adjusted synoptic curve”, eq. (4); finally, the curve that
reproduces the local variations of the CO total column appears as “yearly
curve reproducing data behaviour” and it has been constructed with harmonic
groups [1-25] and [350-364]. The table 1 shows the CO exceeded
percentage, which analytical expression is as following:
References
Deeter, M.N., Emmons,L.K., Francis, G.L., Edwards, D.P., Gille, J.C., Warner,
J.X., Khattatov, B., Ziskin, D., Lamarque, J.-F., Ho, S.-P., Yudin, V.,
Attie, J.-L., Packman, D., Chen, J., Mao, D. and Drummond, J.R., 2003.
Operational Carbon Monoxide Retrieval Algorithm and Selected Results
for the MOPITT Instrument. Journal of Geophysical Research, 108(D14),
4399, doi:10.1029/2002JD003186
Deeter, M.N., 2009. MOPITT (Measurements of Pollution in the Troposphere)
Provisional Version 4 Product User’s Guide. MOPITT Algorithm
Development Team. Atmospheric Chemistry Division. National Center for
Atmospheric Research. Boulder, CO 80307. Last Revised March 31, 2009
Emmons, L.K., Deeter, M.N., Gille, J.C., Edwards, D.P., Attie, J.-L., Warner,
J., et al., 2004. Validation of Measurements of Pollution in the
Troposphere (MOPITT) CO retrievals with aircraft in situ profiles. Journal
of Geophysical Research, 109(D3), D03309.