Other anthropogenic emissions

NO$_{x}$ aircraft emissions from the ANCAT/EC2 data base (kg(NO$_{2}$)/month) are read in from airnox.d. They are pre-processed with program ancat. The ANCAT/EC2 data are described in and included on CDROM with [Gardner, 1998]. This updates an older version of the data set decribed in [Gardner and et al, 1997]. It has been attempted to include in ANCAT/EC2 all civil aircraft flights during July 1991, October 1991, January 1992 and April 1992 into monthly data sets, by making use of Air Traffic Control data and when these were not available of timetable sources. The military data were derived in a bottom-up approach. The inventory for 1991/92 accounts for a total fuel burn of 131.3 Tg/year and NO$_{x}$ emissions of 1.8 Tg/year. THe average emission index is 13.7 g(NO$_{x}$)/kg fuel). It accounts for 79 % of the IEA refined jet fuel total for 1992. It also provides a forecast for 2015 (286.8 Tg fuel/yr and 3.5 Tg NO$_{x}$/yr).
The aircraft emissions are scaled for each year in subroutine sources_sinks

y=year-1900

airnoxfac=-0.735237+0.0656734y-0.00185778y$^{2}$+ 2.09864e-05y$^{3}$-6.69317e-08y$^{4}$

This gives a factor 1 for about 1989.25. The emissions of NOx rise much faster than scenario Fa1 in table 6-2 of the IPCC special report. Where does the scaling come from?

A better solution is linear interpolation linearly between 1992 (2000 for Aero2K) and 2000, 2015, 2050.

Emis(year) = Emis(1992) + (year-1992) (Emis(2000)-Emis(1992)) / 8. for $1992 \leq year \leq 2000$

Emis(year) = Emis(2000) + (year-2000) (Emis(2015)-Emis(2000)) / 15. for $2000 \leq year \leq 2015$

Emis(year) = Emis(2015) + (year-2015) (Emis(2025)-Emis(2015)) / 10. for $2015 \leq year \leq 2050$

Emis(year) = Emis(2025) + (year-2025) (Emis(2050)-Emis(2025)) / 25. for 2025 <= year <= 2050

The IPCC special report Fa1 scenario gives for NOx (in Tg NO2 /yr) 2.8 in 2000, 4.3 in 2015, 5.1 in 2025 and 7.2 in 2050 (Table 6-2). Before multiplying normalize the emission total in the distribution to 1.

At KNMI also other data sets of aircraft emissions are available such as those from NASA and Aero2K. Aero2K is probably the best emission data set.