Northern elephant seal temperature cast data collected as part of the Tagging of Pacific Predators (TOPP) program from February 22 2004 to January 25, 2011 (NODC Accession 0077805)

This dataset is a large collection of temperature casts recorded by fast-response archival time-depth recorder tags on northern elephant seals during their natural migrations. Only ascents (upcasts) were retained to ensure a similar format to traditional ship-based casts.

Each file represents data from a single instrument on one adult female elephant seal. Temperature and depth data were obtained from data logging tags manufactured by Wildlife Computers (MK9 or MK10). Temperature and depth values are uncorrected, raw instrument readings.

The position of each cast was estimated using a state-space model smoothing algorithm applied to the ARGOS satellite track of the seal.
Position data were obtained from a combination of GPS loggers and ARGOS PTT transmitters manufactured by Wildlife computers (SPOT4, SPOT5, or MK10) or the Sea Mammal Research Unit (SMRU SRDL)). Position data were irregular in time and contained substantial spatial error. So, we estimated a position for each station by smoothing the data using the CRAWL package in R-Cran and then applied a linear interpolation for each station.