Capturing time and vertical variability of tropospheric ozone: A study using TES nadir retrievals

Abstract

[1] In this paper, the vertical resolution for Tropospheric Emission Spectrometer (TES) nadir ozone retrievals is established and is used to assess the ability of TES to capture time variations of ozone in the troposphere. This characterization is based on retrievals of ozone using simulated radiances generated from ozonesonde profiles taken over Bermuda from 14 April to 25 May 1993. To that end, a two-step retrieval strategy that includes an initial estimate of the ''shape'' of the ozone followed by a finer-resolution estimate was developed to provide rapid and robust convergence against large deviations of ozone profiles in the troposphere and lower stratosphere relative to a climatology. An error analysis is derived that accurately accounts for representation errors of the profile, choices of regularization, and the dependence of the retrieval error on both the statistics of the profile and spectral measurement noise, as well as the sensitivity of these retrievals to errors in temperature. This analysis shows that TES should be able to retrieve ozone in the nadir with an approximately 6 km resolution in the troposphere. The root-mean square errors in estimates of the upper and lower tropospheric columns are about 1.35 Dobson units (DU) each. With this vertical resolution, TES would have the sensitivity to detect both the enhanced and reduced tropospheric ozone present in the Bermuda data set. Coupled with a 2-day near-repeat orbit and global coverage, TES retrievals of ozone could provide invaluable information to distinguish between anthropogenic and meteorological sources for the time variability of ozone in the troposphere.

Aerosol and ozone changes as forcing for climate evolution between 1850 and 2100

“…66 levels). The retrievals and error estimation, already described by Worden et al (2004), Bowman et al (2002Bowman et al ( , 2006 and Kulawik et al (2006) are based on the optimal estimation approach (Rodgers et al 2000). TES ozone has been evaluated on a regular basis since the start of the mission in 2004, and compared against ozone-sonde measurements.…”

Validation of Tropospheric Emission Spectrometer ozone profiles with aircraft observations during the Intercontinental Chemical Transport Experiment–B

“…TES retrievals utilize an optimal estimation scheme [Rodgers, 2000]. An overview of the TES retrieval algorithm and error estimation are discussed by Bowman et al [2002] and Worden et al [2004], and the characterization of errors and vertical information for individual TES profiles are discussed by Kulawik et al [2006]. TES ozone retrievals use a priori information from a climatology developed using the MOZART model [Brasseur et al, 1998;Park et al, 2004].…”

“…TES ozone retrievals use a priori information from a climatology developed using the MOZART model [Brasseur et al, 1998;Park et al, 2004]. The vertical resolution of TES nadir ozone profiles is about 6 km in cloud-free conditions [Bowman et al, 2002;Worden et al, 2004]. Figure 1 shows an example of a TES tropospheric ozone profile and the corresponding averaging kernels obtained over the Pacific in April 2006.…”

Retrieval of tropospheric ozone: The synergistic use of thermal infrared emission and ultraviolet reflectivity measurements from space

“…At present, TIR measurements from space contain the most vertical information on tropospheric ozone. However, these measurements have their limitations when retrieving ozone in the lower troposphere, where the temperature contrast of the atmosphere with respect to the surface is low [Bowman et al, 2002].…”