Summarized and detailed time-stamped temperature data can be compressed and transmitted through the Argos satellite system. These data can be combined with locations from Argos, Fastloc® GPS or light-based geolocation to provide information on the thermal structure of the water masses the animal traveled through.
Temperature is a critical habitat parameter for many marine animals. Most models of our tags incorporate fast-response temperature sensors for more accurate readings. Temperature data when combined with depth can be summarized into behavorial summaries and oceanographic profiles.
Wildlife Computers developed efficient compression algorithms to provide low-frequency reporting of readings from more frequently sampled data stored in the archive. This compression allows messages containing a time series of temperature to be transmitted through the Argos system. This type of message is useful for initial insights to the temperature variation encountered by your study animal.
Time-Series messages can be generated using one of five sample intervals (75, 150, 300, 450, 600 seconds.) The sample interval determines the number of messages generated per day. Faster sampling gives more resolution but will result in more messages generated. Selecting a longer sample interval produces fewer messages but decreases the chance that there will be gaps in the time covered by the Time-Series messages. The number of messages received through the Argos system is governed by animal behavior and battery capacity. You will need to balance your animal’s behavior and your study objectives to determine the sampling interval that provides the best balance between coverage and temporal resolution.
Each Time-Series message provides:
- The time-series data sampled at the specified interval for that message period.
- The minimum and maximum values encountered during the period of time covered by the Time-Series message period as measured at the faster archive sampling rate. This gives you insight to the amount of aliasing that has occurred when generating the Time-Series message.
Time-At-Temp (TAT) histograms report the percentage of a specified time period (histogram summary periods of 1 to 24 hours) spent within a temperature range (bin range.) Both the histogram summary periods and bin ranges are user-definable. Each bin value reflects the percentage of the histogram summary period that the temperature readings were within the bin range.
These profiles summarize depth readings and the associated temperature readings taken over a summary period.
- Profiles of Depth and Temperature (PDT): A temperature profile composed of eight equally spaced depths and corresponding temperatures seen during the summary period.
- Deepest Dive Depth Temperature Profiles: For each histogram summary period the tag will select a single deepest dive and send back paired depth and temperature readings from the ascent.
Mixed-Layer Analysis performs a daily analysis of the surface mixed layer and the time the animal spent in this layer. Characteristics of the mixed layer are also reported. Each Mixed-Layer message contains the following parameters:
- Time in the mixed layer
- Depth of mixed layer
- Temperature of mixed layer
- Temperature of the sea surface
- Overall depth
- Overall temperature