17 Using Higher Order Sensitivity Approaches …
101
species; NO X , SO 2 , VOC, and three particle phase species; PEC, POC, and PSO 4
are directly emitted from aircrafts and they all can lead to the formation of PM 2.5 in
the atmosphere. For O 3 formation, we consider NO X and VOC emissions to be the
only precursors.
17.1.2 Airport Selection
Our domain consists of the continental United States (CONUS) with a 148 × 112
grid of 36 km × 36 km resolution. We utilize the FAA’s Aviation Emission Design
Tool (AEDT) [8]; Wilkinson et al. [9] for constructing aircraft flight segments, and
LTO segments are processed into gridded emission rate files using AEDTProc [10].
The five airports in attainment regions were chosen based on having no attainment
status (maintenance, marginal, nonattainment) for O 3 , PM 2.5 , and PM 10 ; had at least
0.05% of annual passenger boardings, designated as being small hubs according to the
FAA’s VALE [11]; and that represented the greatest geographic and climatic diversity
while servicing major metropolitan areas (MSA population >1,000,000 people). We
selected four of the top five airports in total number of enplanements for our group
of airports in nonattainment regions. Simulations are performed for the months of
January and July in 2005 with a 10 day spin up for each month. January and July are
chosen to approximately represent winter and summer characteristics seen during
each half of the year. O 3 sensitivities are considered only for July simulations.
17.2 Results
17.2.1 Sensitivities
We calculated first and second order sensitivities at the location of each airport’s
grid cell within our domain. For brevity we show only the first order sensitivities
of O 3 and PM 2.5 to their respective precursor emissions at each airport’s grid cell.
Figure 17.1 shows first order O 3 sensitivities with respect to aircraft VOC and NO X
emissions for the month of July. O 3 sensitivities are dominated by NO X emissions
in the airport’s grid cell and the net negative sum of both VOC and NO X sensitivities
indicate the titration of O 3 in the airport’s grid cell from NO X emissions.
Figure 17.2 shows both first order PM 2.5 sensitivities to VOC, NO X , SO 2 , PSO 4 ,
PEC, and POC aircraft emissions (bottom row) and the breakdown of these PM 2.5
sensitivities by the constituents that make up the total PM 2.5 . PM 2.5 sensitivities can
vary depending on the airport with the airports located in nonattainment regions
having a much larger impact on the formation of PM 2.5 .
101
species; NO X , SO 2 , VOC, and three particle phase species; PEC, POC, and PSO 4
are directly emitted from aircrafts and they all can lead to the formation of PM 2.5 in
the atmosphere. For O 3 formation, we consider NO X and VOC emissions to be the
only precursors.
17.1.2 Airport Selection
Our domain consists of the continental United States (CONUS) with a 148 × 112
grid of 36 km × 36 km resolution. We utilize the FAA’s Aviation Emission Design
Tool (AEDT) [8]; Wilkinson et al. [9] for constructing aircraft flight segments, and
LTO segments are processed into gridded emission rate files using AEDTProc [10].
The five airports in attainment regions were chosen based on having no attainment
status (maintenance, marginal, nonattainment) for O 3 , PM 2.5 , and PM 10 ; had at least
0.05% of annual passenger boardings, designated as being small hubs according to the
FAA’s VALE [11]; and that represented the greatest geographic and climatic diversity
while servicing major metropolitan areas (MSA population >1,000,000 people). We
selected four of the top five airports in total number of enplanements for our group
of airports in nonattainment regions. Simulations are performed for the months of
January and July in 2005 with a 10 day spin up for each month. January and July are
chosen to approximately represent winter and summer characteristics seen during
each half of the year. O 3 sensitivities are considered only for July simulations.
17.2 Results
17.2.1 Sensitivities
We calculated first and second order sensitivities at the location of each airport’s
grid cell within our domain. For brevity we show only the first order sensitivities
of O 3 and PM 2.5 to their respective precursor emissions at each airport’s grid cell.
Figure 17.1 shows first order O 3 sensitivities with respect to aircraft VOC and NO X
emissions for the month of July. O 3 sensitivities are dominated by NO X emissions
in the airport’s grid cell and the net negative sum of both VOC and NO X sensitivities
indicate the titration of O 3 in the airport’s grid cell from NO X emissions.
Figure 17.2 shows both first order PM 2.5 sensitivities to VOC, NO X , SO 2 , PSO 4 ,
PEC, and POC aircraft emissions (bottom row) and the breakdown of these PM 2.5
sensitivities by the constituents that make up the total PM 2.5 . PM 2.5 sensitivities can
vary depending on the airport with the airports located in nonattainment regions
having a much larger impact on the formation of PM 2.5 .