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

Abstract

The Tropospheric Emission Spectrometer (TES) is an infrared instrument that was launched on board NASA's Aura satellite in 2004. TES is the first instrument to provide vertical information on tropospheric ozone while simultaneously measuring CO on a global basis. Before they may be used for scientific study, TES profiles must first be validated to determine if there are any systematic biases present. In this study we present a validation of TES tropospheric ozone using airborne differential absorption lidar (DIAL) profiles obtained during the Intercontinental Chemical Transport Experiment–B (INTEX‐B) campaign, which took place during March–May 2006. During INTEX‐B the NASA DC‐8 aircraft conducted several flights, which allowed the DIAL instrument to obtain ozone profile measurements that were spatially coincident with TES special observations in three different geographical regions. Here we present comparisons of TES and DIAL tropospheric ozone profiles that show that, on average, TES exhibits a small positive bias in the troposphere of 5–15%. We also examine the use of in situ profile observations for the validation of TES tropospheric ozone, and we find these to be of most use in clean regions where the background ozone field is homogeneous.

A Tropospheric Emission Spectrometer HDO/H<sub>2</sub>O retrieval simulator for climate models

“…Variants of the technique have been used in validating TES retrievals against collocated measurements of CO from aircraft , O 3 from aircraft (Richards et al, 2008) and sondes , and H 2 O measurements from sondes . It has also been used for comparisons between TES CO retrievals and those from the Atmospheric Chemistry Experiment (ACE) and Measurements of Pollution in the Troposphere (MOPITT) (Luo et al, 2007b).…”

Satellite observations of Mexico City pollution outflow from the Tropospheric Emissions Spectrometer (TES)

“…By contrast, O 3 and CO averaging kernels away from the Mexico City Basin (w23.3 N, w850 hPa; location ''b'' in Fig. 2) show largest sensitivities to 600-800 hPa, typical for the middle and low troposphere under clear sky (e.g., Jones et al, 2003;Luo et al, 2007a;Richards et al, 2008;Worden et al, 2007;Zhang et al, 2006).…”

“…O 3 and CO were measured by ChemiLuminescence Detector (CLD) and Tunable Diode Laser (TDL), respectively (Avery et al, 2001;Madronich et al, 2004;Sachse et al, 1987) on the both C-130 and DC-8. The precisions of O 3 and CO are 3-7% and 1%, respectively with AE5% accuracy (Richards et al, 2008;Sachse et al, 1987;Singh et al, submitted). We used the 1-minute merged data.…”

“…The lightning NO x emissions are parameterized based on cloud top height and regionally scaled to climatological satellite observations of flash rates (Hudman et al, 2007). We conducted GEOS-Chem simulations for To compare GEOS-Chem results with TES retrievals, model profiles of O 3 and CO are convoluted with TES averaging kernels to account for the different sensitivities and a priori information of TES retrievals to different pressure levels (Jones et al, 2003;Richards et al, 2008). The resulting model profiles can then be directly compared with TES retrievals (Zhang et al, 2006;Jourdain et al, 2007;Worden et al, 2007).…”

“…During MILAGRO/INTEX-B there is only one coincident spiral profiling by the DC-8 for TES validation on March 12th (23 N and 98.5 W, w450 km away from the MCMA). Validation results using the profiles from that spiral have been reported by Richards et al (2008) and Luo et al (2007b) and those were cited in Section 2.2. In general, direct comparisons of absolute mixing ratios between TES and in situ data over the MCMA and its surrounding regions can be challenging primarily because of the scarcity of coincident TES and aircraft profiles.…”