Distribution of tropospheric ozone determined from satellite data

Abstract

An analysis of more than 22,000 ozone profiles from Stratospheric Aerosol and Gas Experiment I (SAGE I) (1979–1981) and SAGE II (1984–1987) between 50°N and 50°S is used in conjunction with 9 years (1979–1987) of daily global depictions of total ozone from the Total Ozone Mapping Spectrometer (TOMS) instrument aboard Nimbus 7 to investigate the spatial distribution and seasonal cycle of the integrated amount of ozone in the troposphere. In the tropics, highest concentrations are found in the eastern Atlantic Ocean downwind (west) of Africa and maximize during the time when biomass burning is most prevalent, between July and October. A different seasonal cycle in the tropics is also observed over Indonesia where a relative maximum is present in the March–April time frame, likewise consistent with when biomass burning is most prevalent. At mid‐latitudes, highest concentrations are found downwind of Asia and maximize in the summer. Relatively higher amounts of tropospheric ozone are similarly observed downwind of North America and Europe. At mid‐latitudes, the ratio between the amount of tropospheric ozone in the northern hemisphere and the amount in the southern hemisphere is 1.4, in good agreement with in situ measurements. A detailed comparison of this satellite technique with available ozonesonde measurements suggests that the accuracy of this method for deriving the climatology of tropospheric ozone is probably better than 10% in the tropics and 15% at mid‐latitudes. We also show that TOMS total ozone measurements in the tropics can often be used independently to provide important qualitative insight into the behavior of tropospheric ozone at these low latitudes.

The distribution of light nonmethane hydrocarbons over the mid-Atlantic: Results of the Polarstern cruise ANT VII/1

“…As a consequence of the photochemical oxidation of these tracers elevated 03 mixing ratios were measured (Smit et al, 1990). These results also agree with the data published by Fishman et al (1990), who reported tropospheric ozone distributions determined from satellite data between 1979 and 1987. For the period September to November, they found an area of significantly elevated 0 3 mixing ratios over the mid-Atlantic between 5°Sand 25 0 S.…”

“…South of the equator, the NMHC patterns changed again and tracers of biomass burning such as acetylene, CO, and ethane increased over a latitude range of about 10°followed by a decrease towards increasing southern latitudes. This region of enhanced long-lived NMHC coincides in season and location with the area of elevated tropospheric ozone observed by Fishman et al (1990). Since the pattern of the NMHC and other trace gases indicate aged biomass burning emissions, this supports the assumption that this area of increased tropospheric ozone is due to biomass burning.…”

Tropical tropospheric ozone columns from nadir retrievals of GOME-1/ERS-2, SCIAMACHY/Envisat, and GOME-2/MetOp-A (1996–2012)

“…The Fortuin and Kelder (1998) climatology is reported in volume mixing ratios (vmr) for specific pressure levels. In order to convert the volume mixing ratios (ppm) at the ith level to Dobson units (DU), the following formula was used, taking into account the ideal gas law and the horizontal surface density (Ziemke et al, 2001): Cor ACCO …”

“…Tropospheric ozone was first retrieved from space with the so-called residual method. The stratospheric ozone column above 100 mbar retrieved from the Stratospheric Aerosol and Gas Experiment II (SAGE II) was subtracted from the total ozone column (TCO) retrieved from the Total Ozone Mapping Spectrometer (TOMS) aboard the Nimbus 7 satellite (Fishman et al, 1990). The following years several other methods have been developed, such as the cloud slicing (CS) technique (Ziemke et al, 2001).…”

Model simulations and aircraft measurements of vertical, seasonal and latitudinal O<sub>3</sub> and CO distributions over Europe

“…Although global observations of tropospheric O 3 , carbon monoxide (CO) and nitrogen dioxide (NO 2 ), the latter being important O 3 precursors, have recently become available from satellite-based observations (Fishman et al, 1990;Borrell et al, 2003;Deeter et al, 2004;Buchwitz et al, 2004), the measurements are generally not vertically resolved and refer to cloud-free conditions only, which limits their representativeness. Additionally, satellite retrievals must be validated against independent remote sensing or in-situ data.…”