Articles | Volume 11, issue 21
Atmos. Chem. Phys., 11, 11207–11220, 2011
https://doi.org/10.5194/acp-11-11207-2011
Atmos. Chem. Phys., 11, 11207–11220, 2011
https://doi.org/10.5194/acp-11-11207-2011

Research article 10 Nov 2011

Research article | 10 Nov 2011

Optimal estimation of tropospheric H2O and δD with IASI/METOP

M. Schneider1,2 and F. Hase1 M. Schneider and F. Hase
  • 1Karlsruhe Institute of Technology (KIT), IMK-ASF, Karlsruhe, Germany
  • 2Agencia Estatal de Meteorología (AEMET), CIAI, Santa Cruz de Tenerife, Spain

Abstract. We present optimal estimates of tropospheric H2O and δD derived from radiances measured by the instrument IASI (Infrared Atmospheric Sounding Interferometer) flown on EUMETSAT's polar orbiter METOP. We document that the IASI spectra allow for retrieving H2O profiles between the surface and the upper troposphere as well as middle tropospheric δD values. A theoretical error estimation suggests a precision for H2O of better than 35% in the lower troposphere and of better than 15% in the middle and upper troposphere, respectively, whereby surface emissivity and atmospheric temperature uncertainties are the leading error sources. For the middle tropospheric δD values we estimate a precision of 15–20‰ with the measurement noise being the dominating error source. The accuracy of the IASI products is estimated to about 20–10% and 10‰ for lower to upper tropospheric H2O and middle tropospheric δD, respectively. It is limited by systematic uncertainties in the applied spectroscopic parameters and the a priori atmospheric temperature profiles. We compare our IASI products to a large number of near coincident radiosonde in-situ and ground-based FTS (Fourier Transform Spectrometer) remote sensing measurements. The bias and the scatter between the different H2O and δD data sets are consistent with the combined theoretical uncertainties of the involved measurement techniques.

Download
Altmetrics
Final-revised paper
Preprint