Atmospheric Measurement Techniques
Atmospheric Measurement Techniques
AMT
Articles | Volume 7, issue 12
Articles | Volume 7, issue 12
https://doi.org/10.5194/amt-7-4223-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/amt-7-4223-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 7, issue 12
Research article
 | 
08 Dec 2014
Research article |  | 08 Dec 2014

Extending the satellite data record of tropospheric ozone profiles from Aura-TES to MetOp-IASI: characterisation of optimal estimation retrievals

H. Oetjen, V. H. Payne, S. S. Kulawik, A. Eldering, J. Worden, D. P. Edwards, G. L. Francis, H. M. Worden, C. Clerbaux, J. Hadji-Lazaro, and D. Hurtmans

Abstract. We apply the Tropospheric Emission Spectrometer (TES) ozone retrieval algorithm to Infrared Atmospheric Sounding Instrument (IASI) radiances and characterise the uncertainties and information content of the retrieved ozone profiles. This study focuses on mid-latitudes for the year 2008. We validate our results by comparing the IASI ozone profiles to ozone sondes. In the sonde comparisons, we find a negative bias (1–10%) in the IASI profiles in the lower to mid-troposphere and a positive bias (up to 14%) in the upper troposphere/lower stratosphere (UTLS) region. For the described cases, the degrees of freedom for signal are on average 3.2, 0.3, 0.8, and 0.9 for the columns 0 km – top of atmosphere, (0–6), (0–11), and (8–16) km, respectively. We find that our biases with respect to sondes and our degrees of freedom for signal for ozone are comparable to previously published results from other IASI ozone algorithms. In addition to evaluating biases, we validate the retrieval errors by comparing predicted errors to the sample covariance matrix of the IASI observations themselves. For the predicted versus empirical error comparison, we find that these errors are consistent and that the measurement noise and the interference of temperature and water vapour on the retrieval together mostly explain the empirically derived random errors. In general, the precision of the IASI ozone profiles is better than 20%.

How to cite. Oetjen, H., Payne, V. H., Kulawik, S. S., Eldering, A., Worden, J., Edwards, D. P., Francis, G. L., Worden, H. M., Clerbaux, C., Hadji-Lazaro, J., and Hurtmans, D.: Extending the satellite data record of tropospheric ozone profiles from Aura-TES to MetOp-IASI: characterisation of optimal estimation retrievals, Atmos. Meas. Tech., 7, 4223–4236, https://doi.org/10.5194/amt-7-4223-2014, 2014.
Received: 04 Jun 2014 – Discussion started: 16 Jul 2014 – Revised: 04 Oct 2014 – Accepted: 05 Nov 2014 – Published: 08 Dec 2014
Download
Short summary
We apply the TES ozone retrieval algorithm to IASI radiances and characterise the uncertainties and information content of the retrieved ozone profiles. We find that our biases with respect to sondes and our degrees of freedom for signal for ozone are comparable to previously published results from other IASI ozone algorithms. We find that predicted and empirical errors are consistent. In general, the precision of the IASI ozone profiles is better than 20%.
Read more