Argo Cycle Timing Variables

Click here for a pdf version of this page. Figure showing float cycle and the cycle timing variables with primary and mandatory ones in red. Floats can profile either on descent or ascent. Most floats profile on ascent. Their path is shown with a solid black line. Some floats profile on descent as shown by the dashed line.

Floats that profile on ascent would have the following primary & mandatory cycle timings:

  • DST, DET, PET, DDET, AST, AET, TST, all surface times and TET
Floats that profile on descent might have the following cycle timings:

  • DST, DDET, DAST, DET, PET, AST, AET, TST, all surface times and TET
NOTE: if a float is programmed to experience a primary cycle timing event, but no timing information is sent back and no estimate is possible, fill value should be inserted in the JULD array with the measurement code corresponding to the primary cycle timing event.

Examples of this include:

  • SOLO and APEX APF8 floats which send back no cycle timing information should have fill value for the primary measurement codes unless an estimated time can be determined
  • Ice detection floats that detect ice at the surface and then do not surface should have fill value for measurement codes 600-704 for the affected cycles.
NOTE: the diagram above shows the chronological order of timing events for an Argos float. Iridium floats have a different chronological order of timing events. In either case, times in the JULD variable should be arranged chronologically.

Argo cycle timing variables
Time Measurement Code (MC) Long name N_CYCLE variable name Description
DST 100 Descent Start Time JULD_DESCENT_START Time when float leaves the surface, beginning descent
FST 150 First Stabilization Time JULD_FIRST_STABILIZATION Time when float first becomes water-neutral
DET 200 Descent End Time JULD_DESCENT_END Time when float first approaches within 3% of the eventual drift pressure. Float may be transitioning from the surface or from a deep profile. This variable is based on pressure only and can be measured or estimated by fall-rate. In the case of a float that overshoots the drift pressure on descent, DET is the time of the overshoot.
PST 250 Park Start Time JULD_PARK_START Time when float transitions to its Park or Drift mission. This variable is based on float logic based on a descent timer (i.e. SOLO), or be based on measurements of pressure (i.e. Provor).
PET 300 Park End Time JULD_PARK_END Time when float exits from its Park or Drift mission. It may next rise to the surface (AST) or sink to profile depth (DDET)
DDET 400 Deep Descent End Time JULD_DEEP_DESCENT_END Time when float first approaches within 3% of the eventual deep drift/profile pressure. This variable is based on pressure only and can be measured or estimated by fall-rate.
DPST 450 Deep Park Start Time JULD_DEEP_PARK_START Time when float transitions to a deep park drift mission. This variable is only defined if the float enters a deep drift phase (i.e. DPST not defined in cases of constant deep pressure due to bottom hits, or buoyancy issues).
DAST 550 Deep Ascent Start Time JULD_DEEP_ASCENT_START Time when float begins its rise to drift pressure. Typical for profile-on-descent floats.
AST 500 Ascent Start Time JULD_ASCENT_START Time when float begins to return to the surface.
AET 600 Ascent End Time JULD_ASCENT_END Time when float reaches the surface.
TST 700 Transmission Start Time JULD_TRANSMISSION_START Time when float begins transmitting.
FMT 702 First Message Time JULD_FIRST_MESSAGE Earliest time of all messages received by telecommunications system.
FLT 703 First Location Time JULD_FIRST_LOCATION Earliest location of all float locations
LLT 703 Last Location Time JULD_LAST_LOCATION Latest location of all float locations.
LMT 704 Last Message Time JULD_LAST_MESSAGE Latest time of all messages received by telecommuncations system.
TET 800 Transmission End Time JULD_TRANSMISSION_END Time when float stops transmitting.