DOI: 10.6075/j0nk3f7v
title: Scripps Argo trajectory-based velocity product 2001-01 to 2022-12. In Scripps Argo Trajectory-Based Velocity Product

description: This dataset contains absolute velocity estimates from quality controlled Argo trajectory files. Both Scripps trajectory products include trajectories from Core, BGC and Deep Argo floats starting in 2001. Only trajectories with cycles ranging from 5 - 25 days are included in the products. The products include both a transmitted and extrapolated trajectory-based velocity (if available) for each cycle. The extrapolated velocities are only available for floats equipped with the Argos positioning system which have six or more good quality surface fixes. PRODUCTS: There are two product netCDF files within the archive: - Quality controlled Argo trajectory-based velocities within the 800 - 1200 db range - Quality controlled Argo trajectory-based velocities within the 100 - 6200 db range FORMAT: All products are netCDF files and fill value is ‘99999’ for numbers and ‘ ‘ for characters. The products both have the following variables: Locations and times: LATITUDE_ASCENDING_TRANSMITTED – transmitted latitude at surfacing LATITUDE_DESCENDING_TRANSMITTED – transmitted latitude at descending LATITUDE_MIDPOINT_TRANSMITTED - midpoint of the ascending and descending transmitted latitudes LONGITUDE_ASCENDING_TRANSMITTED – transmitted longitude at surfacing LONGITUDE_DESCENDING_TRANSMITTED – transmitted longitude at descending LONGITUDE_MIDPOINT_TRANSMITTED - midpoint of the ascending and descending transmitted longitudes JULD_ASCENDING_TRANSMITTED – transmitted time at surfacing JULD_DESCENDING_TRANSMITTED – transmitted time at descending JULD_MIDPOINT_TRANSMITTED - midpoint of the ascending and descending transmitted times LATITUDE_ASCENDING – if available, extrapolated latitude at surfacing. If not, transmitted latitude at surfacing LATITUDE_DESCENDING – if available, extrapolated latitude at descending. If not, transmitted latitude at descending LATITUDE_MIDPOINT - midpoint of the ascending and descending extrapolated latitudes, if available. If not, the midpoint of the ascending and descending transmitted latitudes LONGITUDE_ASCENDING– if available, extrapolated longitude at surfacing. If not, transmitted longitude at ascending. LONGITUDE_DESCENDING – if available, extrapolated longitude at descending. If not, transmitted longitude at descending LONGITUDE_MIDPOINT - midpoint of the ascending and descending extrapolated longitudes, if available. If not, the midpoint of the ascending and descending transmitted longitudes JULD_ASCENDING – if available, extrapolated time at surfacing. If not, transmitted time at ascending. JULD_DESCENDING – if available, extrapolated time at descending. If not, transmitted time at descending JULD_MIDPOINT - midpoint of the ascending and descending extrapolated times, if available. If not, the midpoint of the ascending and descending transmitted times Velocities: VELOCITY_ZONAL_TRANSMITTED - zonal transmitted velocity VELOCITY_MERIDIONAL_TRANSMITTED - meridional transmitted velocity VELOCITY_ZONAL - if available, extrapolated zonal velocity. If not, transmitted zonal velocity. VELOCITY_MERIDIONAL - if available, extrapolated meridional velocity. If not, transmitted zonal velocity. Speeds: SPEED_TRANSMITTED - speed calculated from the transmitted zonal and meridional velocities SPEED - speed calculated from the zonal and meridional velocities Associated data: DRIFT_PRES = best estimate of drift pressure DRIFT_TEMP = best estimate of drift temperature CYCLE_NUMBER = cycle number of profile used to make subsurface velocity estimates (e.g., '2' means subsurface velocity during cycle 2-3). SURFACE_FIXES - number of surface fixes on descending cycle WMO_NUMBER - WMO number of Argo float POSITIONING_SYSTEM - ‘ARGOS’, ’GPS’, or ’IRIDIUM’. This comes from the ‘POSITIONING_SYSTEM’ variable in the Argo trajectory files. Currently, there are some floats that have ‘IRIDIUM’ in this variable, but it is inaccurate. These floats use ‘GPS’ for their positioning. POSITIONING_SYSTEM_FLAG - 1 means Argos, 2 means GPS or Iridium PLATFORM_TYPE - comes from ‘PLATFORM_TYPE’ variable in Argo files and corresponds to Argo Reference Table 23: PLATFORM_TYPE SENSOR_TYPE_FLAG - 1 means float with CTD only, 2 means oxygen sensor in addition to CTD, 3 means additional BGC sensors, 4 means acoustic sensor or EM sensor, 5 means sea surface temperature MISSION_FLAG - Argo float mission: 1 means core, 2 means bgc, 3 means deep EXTRAP_FLAG - flag to indicate if there is an extrapolated velocity (EXTRAP_FLAG = 1) or just transmitted (EXTRAP_FLAG = 0)