The global and multi-annual MUSICA IASI {H 2 O, δ D} pair dataset

[摘要] We present a global and multi-annual space-borne dataset of tropospheric { H 2 O , δ D } pairs that is based on radiancemeasurements from the nadir thermal infrared sensor IASI (Infrared Atmospheric Sounding Interferometer) on board the Metop satellites of EUMETSAT(European Organisation for the Exploitation of Meteorological Satellites). This dataset is an a posteriori processed extension of the MUSICA(MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) IASI full product dataset as presented in Schneider et al. ( 2021 b ) . From the independently retrieved H 2 O and δ D proxy states, their a priori settings and constraints,and their error covariances provided by the IASI full product dataset, we generate an optimal estimation product for pairs of H 2 O and δ D . Here, this standard MUSICA method for deriving { H 2 O , δ D } pairs is extended using an a posteriorireduction of the constraints for improving the retrieval sensitivity at dry conditions. By applying this improved water isotopologue post-processing for all cloud-free MUSICA IASI retrievals, this yields a { H 2 O , δ D } pair dataset for the whole period from October 2014 to December 2020 with global coverage twice per day (local morning andevening overpass times). In total, the dataset covers more than 1500 million individually processed observations. The retrievals are most sensitiveto variations in { H 2 O , δ D } pairs within the free troposphere, with up to 30 % of all retrievals containing verticalprofile information in the { H 2 O , δ D } pair product. After applying appropriate quality filters, the largest number ofreliable pair data arises for tropical and subtropical summer regions, but higher latitudes also show a considerable amount of reliabledata. Exemplary time series over the tropical Atlantic and West Africa are chosen to illustrate the potential of the MUSICA IASI { H 2 O , δ D } pair data for atmospheric moisture pathway studies. Furthermore, in order to facilitate the application of this rathercomprehensive MUSICA IASI { H 2 O , δ D } pair dataset (referred to as Level-2), we additionally provide the data in are-gridded and simplified format (Level-3) with focus on the quality-filtered { H 2 O , δ D } pairs in the free troposphere. Atechnical documentation for guiding the use of both datasets is attached as the Supplement. Finally, the Level-2 dataset is referenced with the DOI https://doi.org/10.35097/415 ( Diekmann et al. ,  2021 a ) and the Level-3 dataset with DOI https://doi.org/10.35097/495 ( Diekmann et al. ,  2021 b ) .

[学科分类] 眼科学