《Argo Delayed-Mode Process》.pptVIP

Argo Delayed-Mode Process * Annie Wong University of Washington Data from floats Delayed-mode (DM) data stream Function: Apply accepted DM procedures to float data. Provide statistically justified corrections using accepted methods. Provide feedback to RT system. Users: All needing adjusted data with error estimates. Timeframe: 6-12 months after transmission. Who/Where: Perform by PIs. Real-time (RT) data stream Function: Apply agreed RT QC tests to float data. Assign quality flags. Users: Operational centres, data assimilation, researchers needing timely data. Timeframe: 24-48 hrs after transmission. Who/Where: Perform by National Data Assembly Centres. Argo data quality control elements ? Argo delayed-mode procedures are applied to 3 measurement parameters: PRES, TEMP, PSAL. ? There is currently no recommended qc method for other auxiliary parameters, such as DOXY, that are reported in the Argo netCDF files. Introduction Delayed-mode procedure for PRES 1). Check PRES by visual assessment of ensemble vertical profile plots of TEMP vs PRES and PSAL vs PRES. Assessment aims to identify anomalies that cannot be detected by the real-time qc tests on single profiles. Example 1. Bad pressure sensor calibration coefficient. This will show up as anomalous T-S curve at depth when compared with nearby data. Example 2. Druck pressure sensor problem, which can be identified when profiles become more and more shallow. Pressure measurements are erratic and suspect. 2). Adjust PRES using “SURFACE PRESSURE” if there is evidence that the values reported in “SURFACE PRESSURE” represent pressure sensor drift. Examine time series. Use next cycle “SURFACE PRESSURE” to adjust pressure. Then re-calculate salinity. Delayed-mode procedure for TEMP Check TEMP by visual assessment of ensemble vertical profile plots of TEMP vs PSAL and TEMP vs PRES. Assessment aims to identify anomalies that cannot be detected by the real-time qc tests on single profiles. Example. Salinity “hooks” at b