“The MUSICA MetOp/IASI H2O and δD products: characterisation and long-term comparison to NDACC/FTIR data”, paper published in AMTD

Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) ground- and space-based remote sensing as well as in-situ datasets of tropospheric water vapour isotopologues are provided. The space-based remote-sensing dataset is produced from spectra measured by the IASI (Infrared Atmospheric Sounding Interferometer) sensor and is potentially available on a global scale.

Here, we present the MUSICA IASI data for three different geophysical locations (subtropics, mid-latitudes, and arctic) and we provide a comprehensive characterisation of the complex nature of such space-based isotopologue remote sensing products. The quality assessment study is complemented by a comparison to MUSICA’s ground-based FTIR (Fourier-Transform InfraRed) remote sensing data retrieved from the spectra recorded at three different locations within the framework of NDACC (Network for the Detection of Atmospheric Composition Change) (Figure 1).

We confirm that IASI is able to measure tropospheric H2O profiles with a vertical resolution of about 4 km and a random error of about 10%. In addition IASI can observe middle tropospheric δD that adds complementary value to IASI’s middle tropospheric H2O observations. Our study is both, a theoretical and an empirical proof that IASI has the capability for a global observation of middle tropospheric water vapour isotopologues on a daily timescale and at a quality that is sufficiently high for water cycle research purposes.

Figure 1. Correlation between the FTIR and IASI H2O profile data for three different altitudes and three locations. The apriori mixing ratios are denoted by red stars and the 1-to-1 diagonal is indicated as black line.

For more details about this work please refer to: Wiegele, A., Schneider, M., Hase, F., Barthlott, S., García, O. E., Sepúlveda, E., González, Y., Blumenstock, T., Raffalski, U., Gisi, M., and Kohlhepp, R.: The MUSICA MetOp/IASI H2O and δD products: characterisation and long-term comparison to NDACC/FTIR data, Atmos. Meas. Tech. Discuss., 7, 3915-3952, doi:10.5194/amtd-7-3915-2014, 2014. http://www.atmos-meas-tech-discuss.net/7/3915/2014/amtd-7-3915-2014.html