HR: 0830h
AN: A21D-1014    [PDF]
TI: Tropical tropospheric ozone morphology and seasonality seen in satellite, model, and in-situ measurements: No paradox in North Africa
AU: * Newchurch, M
EM: mike@nsstc.uah.edu
AF: University of Alabama in Huntsville, 320 Sparkman Dr., Huntsville, AL 35805 United States
AU: Kim, J H
EM: jaekim@hyowon.pusan.ac.kr
AF: Pusan National University, Kumjungku Jangjundong, Pusan, 609-735 Korea, Republic of
AU: Na, S
EM: sunmi@sabunim.com
AF: Pusan National University, Kumjungku Jangjundong, Pusan, 609-735 Korea, Republic of
AU: Martin, R V
EM: rvmartin@fas.harvard.edu
AF: Dalhousie University, Life Sciences Centre, Halifax, B3H4J1 Canada
AB: An important issue in satellite remote sensing techniques for retrieving tropical tropospheric ozone is to understand the cause of the disparity between ozone derived from satellite residual-based methods and the precursor distributions seen in both the fire-count distribution and the Measurements Of Pollution In The Troposphere (MOPITT) CO distributions in boreal winter and spring. This disparity has sometimes been termed the Northern Atlantic Paradox. We have employed an approach to probe the paradox problem with a new retrieval algorithm, the Scan Angle Method (SAM). This algorithm takes advantage of the difference in the Total Ozone Mapping Spectrometer (TOMS) retrieval information between nadir and high viewing angles. The averaging kernel for this difference exhibits a broad maximum centered at ~5 km in the troposphere and thereby can be used as a surrogate of tropospheric ozone information. We have investigated the seasonality of satellite-derived products of fire counts and MOPITT CO concentration, TOMS Aerosol Index, ozone from GEOS-CHEM model and the Convective Cloud Differential (CCD) method along with the Tropospheric Ozone Index (TOI) from the SAM. In meridional distribution, all products except the CCD clearly reveal the seasonal oscillation between the maximum over northern tropical Africa in boreal winter and over southern tropical Africa in boreal summer. The CCD products always show the ozone maximum over the southern Atlantic off the coast of southwest Africa. Investigation of in-situ measurements from the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) campaign also reveals the ozone maximum in boreal summer and the minimum in boreal winter at three locations over the northern tropics; Abidjan (5,aN, 4,aW), Madras (13,aN, 80,aE), and Bangkok (14,aN, 101,aE). The seasonality of the SAM and the model ozone are in accordance with the MOZAIC measurements, but the CCD ozone is about six months out of phase.
DE: 0315 Biosphere/atmosphere interactions
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting