FIELD EXPERIMENTS AND MODELING AT CDG AIRPORTS
Abstract
Richard Ramaroson1,4, Klaus Schaefer2, Stefan Emeis2, Carsten Jahn2, Gregor Schürmann2, Maria Hoffmann2, Mikhael Zatevakhin3, Alexandre Ignatyev3. 1ONERA, Châtillon, France; 4SEAS, Harvard University, Cambridge, USA; 2FZK, Garmisch, Germany; (3)FSUE SPbAEP, St Petersburg, Russia. 2-month field campaigns have been organized at CDG airports in autumn 2004 and summer 2005. Air quality and ground air traffic emissions have been monitored continuously at terminals and taxi-runways, along with meteorological parameters onboard trucks and with a SODAR. This paper analyses the commercial engine emissions characteristics at airports and their effects on gas pollutants and airborne particles coupled to meteorology. LES model results for PM dispersion coupled to microphysics in the PBL are compared to measurements. Winds and temperature at the surface and their vertical profiles have been stored with turbulence. SODAR observations show the time-development of the mixing layer depth and turbulent mixing in summer up to 800m. Active low level jets and their regional extent have been observed and analyzed. PM number and mass size distribution, morphology and chemical contents are investigated. Formation of new ultra fine volatile (UFV) particles in the ambient plume downstream of running engines is observed. Soot particles are mostly observed at significant level at high power thrusts at take-off (TO) and on touch-down whereas at lower thrusts at taxi and aprons ultra the UFV PM emissions become higher. Ambient airborne PM1/2.5 is closely correlated to air traffic volume and shows a maximum beside runways. PM number distribution at airports is composed mainly by volatile UF PM abundant at apron. Ambient PM mass in autumn is higher than in summer. The expected differences between TO and taxi emissions are confirmed for NO, NO2, speciated VOC and CO. NO/NO2 emissions are larger at runways due to higher power. Reactive VOC and CO are more produced at low powers during idling at apron and taxiing. During engine idle, FTIR measurements lead to higher Emission Index (EI) of CO; EI-NOx are lower compared to ICAO certification data bank. Evidence of VOC role on ozone pollution coupled to NO/NO2 is observed in summer. Ozone maximum during hot spots at airports is lower than at surrounding rural stations due to higher airport NOx. PM and O3 concentration are correlated in summer during hot spots possibly linked to meteorological and chemical processes. At runaways and taxiways, air traffic is the main contributor among all emissions whereas at aprons, other sources are contributing to. A broad range of PM emission levels from commercial a/c and significant effects on airborne PM2.5 mass is observed throughout the airports with a maximum beside runways. A kinetics/dynamical model based on LES turbulence model coupled to microphysics is used to simulate the summertime PM in a convective PBL. Results show that kinetics is affected by inhomogeneous vertical turbulent mixing. Turbulence accelerates the PM coagulation, as shown by observations, and ultra fine PM removal to coarser size. Numerical results for PM at the ground are consistent with measurements showing a significant contribution of air traffic to PM loading at airports.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A51C0122R
- Keywords:
-
- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0478 BIOGEOSCIENCES / Pollution: urban;
- regional and global;
- 3379 ATMOSPHERIC PROCESSES / Turbulence