Mid-Term Report Summary 2 - MUSICA (Multi-platform remote sensing of isotopologues for investigating the cycle of atmospheric water)
The cycle of water in the troposphere, the bottom layer of the Earth’s atmosphere, determines the weather and plays a central role in climate change. Evaporation and condensation processes as well as the strong greenhouse effect of water vapour and clouds decisively influence the energy balance of the atmosphere and the entire planet. For a reliable climate prediction an understanding of the complex water cycle is essential.
The isotope composition of water vapour, i.e. the ratio of light and heavy water molecules, provides insight into water cycle processes. However, so far research in this field has been limited by the lack of high quality and global datasets. Providing such data and thereby investigating the water cycle processes is the objective of the MUSICA project. MUSICA stands for “MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water”.
Global data can only be achieved by remote sensing observations, ideally performed from space. Within MUSICA we retrieve water vapour isotopologue data from ground-based infrared spectra measured by high resolution FTIR (Fourier Transform Infrared) spectrometers within the global network NDACC (Network for the Detection of Atmospheric Composition Change) and from the spectra measured by the sensor IASI (Infrared Atmospheric Sounding Interferometer) aboard EUMETSAT’s operational weather satellite METOP. NDACC-FTIR instruments have been in operation since the beginning of the 1990’s and METOP’s operation is guaranteed between 2006 and 2020. Such high quality long-term observations are very interesting for climate studies.
Due to an agreement with different institutions from several countries the project MUSICA performs centralized and consistent NDACC retrievals for ten globally distributed sites. The ground-based remote sensing water isotopologue data are complemented by consistent space-based data from IASI: the IASI retrieval algorithm has been developed in consistency to the NDACC-FTIR retrieval algorithm.
Remote sensing of tropospheric water vapour isotopologues is rather difficult and an extensive quality analysis of the data is indispensable. Therefore, the MUSICA project combines ground- and space-based remote sensing techniques with in-situ measurement methods performed from the surface and from aircraft. By this strategy it is possible to document the accuracy and precision of the remote sensing products. Please note that carefully performed in-situ measurements are well accurate since their measurement principle includes continuous calibrations with respect to well-known isotopologue ratio standards. The in-situ measurements are also very helpful for investigating small scale processes or particular atmospheric situations.
After the first 30 month of the project MUSICA ground- and space-based water isotopologue data are produced and their quality has been theoretically well described. Preliminary results of the comparison to the surface- and aircraft-based in-situ measurements show for the first time that both the worldwide measurement network NDACC with its ground stations and modern weather satellites (IASI/METOP) provide reliable global data for the isotope composition of tropospheric water vapour.
The isotope composition of water vapour, i.e. the ratio of light and heavy water molecules, provides insight into water cycle processes. However, so far research in this field has been limited by the lack of high quality and global datasets. Providing such data and thereby investigating the water cycle processes is the objective of the MUSICA project. MUSICA stands for “MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water”.
Global data can only be achieved by remote sensing observations, ideally performed from space. Within MUSICA we retrieve water vapour isotopologue data from ground-based infrared spectra measured by high resolution FTIR (Fourier Transform Infrared) spectrometers within the global network NDACC (Network for the Detection of Atmospheric Composition Change) and from the spectra measured by the sensor IASI (Infrared Atmospheric Sounding Interferometer) aboard EUMETSAT’s operational weather satellite METOP. NDACC-FTIR instruments have been in operation since the beginning of the 1990’s and METOP’s operation is guaranteed between 2006 and 2020. Such high quality long-term observations are very interesting for climate studies.
Due to an agreement with different institutions from several countries the project MUSICA performs centralized and consistent NDACC retrievals for ten globally distributed sites. The ground-based remote sensing water isotopologue data are complemented by consistent space-based data from IASI: the IASI retrieval algorithm has been developed in consistency to the NDACC-FTIR retrieval algorithm.
Remote sensing of tropospheric water vapour isotopologues is rather difficult and an extensive quality analysis of the data is indispensable. Therefore, the MUSICA project combines ground- and space-based remote sensing techniques with in-situ measurement methods performed from the surface and from aircraft. By this strategy it is possible to document the accuracy and precision of the remote sensing products. Please note that carefully performed in-situ measurements are well accurate since their measurement principle includes continuous calibrations with respect to well-known isotopologue ratio standards. The in-situ measurements are also very helpful for investigating small scale processes or particular atmospheric situations.
After the first 30 month of the project MUSICA ground- and space-based water isotopologue data are produced and their quality has been theoretically well described. Preliminary results of the comparison to the surface- and aircraft-based in-situ measurements show for the first time that both the worldwide measurement network NDACC with its ground stations and modern weather satellites (IASI/METOP) provide reliable global data for the isotope composition of tropospheric water vapour.