Station K: Level-1 subsurface mooring time series in the western tropical Indian Ocean, 2019-2024

The Station K subsurface mooring, located in the western tropical Indian Ocean at 8°S, 61°E in a water depth of 3085 meters, was designed to continuously observe intermediate and deep water properties and operated across three deployment periods from May 2019 to June 2024. Instrumentation was progressively expanded across the deployments to improve vertical coverage. Sampling rates of moored sensors were typically ranging from 1200 to 1800 seconds, while most of instruments in the third deployment (Deployment-03) measured the parameters at 300- or 900-seconds interval to enhance the temporal resolution. Standard quality-assurance (QA) and quality-control (QC) procedures were applied to the original Level-0 dataset (https://doi.org/10.17882/108782), which are global range test, spike test, and gradient (slope) test. Data that failed any of the three tests were flagged, and the majority of these failures originated from the spike test. Across all deployments and sensors, the proportion of missing data or data failing the three QA procedure tests was below 1% (data acquisition rate > 99%) except one sensor at 3030 meters for Deployment-02 and two sensors at 969 meters and 3014 meters for Deployment-03. These QA-ed and QC-ed continuous time series observational data will support a wide range of research and development for various purposes.