title: A drifter for measuring water turbidity in rivers and coastal oceans.
abstract: A disposable instrument for measuring water turbidity in rivers and coastal oceans is described. It transmits turbidity measurements and position data via a satellite uplink to a processing server. The primary purpose of the instrument is to help document changes in sediment runoff from river catchments in North Queensland, Australia. The 'river drifter' is released into a flooded river and drifts downstream to the ocean, measuring turbidity at regular intervals. Deployment in the Herbert River showed a downstream increase in turbidity, and thus suspended sediment concentration, while for the Johnstone River there was a rapid reduction in turbidity where the river entered the sea. Potential stranding along river banks is a limitation of the instrument. However, it has proved possible for drifters to routinely collect data along 80 km of the Herbert River. One drifter deployed in the Fly River, Papua New Guinea, travelled almost 200 km before stranding.
authors.affiliation: Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4812, Australia.
authors.forename: Ross
authors.initials: R
authors.lastname: Marchant
authors.affiliation: Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4812, Australia.
authors.forename: Dean
authors.initials: D
authors.lastname: Reading
authors.affiliation: Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4812, Australia; PortMap Remote Ocean Sensing Pty Ltd., P.O. Box 806, Aitkenvale, Queensland 4814, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Ridd
authors.affiliation: Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4812, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Campbell
authors.affiliation: Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4812, Australia. Electronic address: peter.ridd@jcu.edu.au.
authors.forename: Peter
authors.initials: P
authors.lastname: Ridd
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D019015:Geologic Sediments / Q000032:analysis; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation* / Q000379:methods; D009791:Oceanography / Q000295:instrumentation* / Q000379:methods; D009792:Oceans and Seas; D010219:Papua New Guinea; D011793:Queensland; D045483:Rivers; D017215:Satellite Communications / Q000295:instrumentation*; D014872:Water Movements
keywords: Drifter; River plumes; Satellite tracking; Turbidity