TAO Sampling

Each instrument samples during a set period of time (the sample period) at an instrument-specific rate (the sample rate). At the end of each sample period, the samples are averaged to produce an observation, which is recorded in memory until the data are transmitted to shore. The sampling scheme for each TAO payload is presented in the tables below.

TAO Recap Sampling

Measurement Sample rate Sample period Sample time Data recorded in memory Transmitted data
Wind direction and speed, air temperature, relative humidity 2 Hz 2 min 2359-0001, 0009-0011,... 10 min 1 sample every 10 minutes
Rain accumulated level 1 Hz 1 min 0000-0001, 0001-0002,... 1 min 10 1-min samples every 10 minutes
Shortwave radiation 1 Hz 2 min 2359-0001, 0001-0003,... 2 min 5 2-min samples every 10 minutes
Longwave radiation 1 Hz 2 min 2359-0001, 0001-0003,... 2 min 5 2-min samples every 10 minutes
Barometric pressure 2 Hz 2 min 2359-0001, 0009-0011,... 10 min 1 sample every 10 minutes
Sea surface temperature and conductivity 1 per 10 min instantaneous 0000, 0010,... 10 min 1 sample every 10 minutes
Subsurface temperature, conductivity, and pressure 1 per 10 min instantaneous 2359, 0009,... 10 min 6 samples per hour
Current velocity 1 Hz 6 min 0054-0100, 0154-0200, … Hourly 1 sample per hour
Current Profiles 1 Hz 6 min 0054-0100, 0154-0200, … Hourly 1 sample per hour

TAO Refresh Sampling

Measurement Sample rate Sample period Sample time Data recorded in memory Transmitted data
Wind direction and speed, air temperature, relative humidity 2-hz 2 min 2359-0001, 0009-0011,... 10 min 6 10-min samples per hour
Rain accumulated level 1-hz 1 min 0000-0001, 0001-0002,... 1 min 60 1-min samples per hour
Shortwave radiation 1-hz 2 min 2359-0001, 0001-0003,... 2 min 30 2-min samples per hour
Longwave radiation 1-hz 2 min 2359-0001, 0001-0003,... 2 min 30 2-min samples per hour
Barometric pressure 2-hz 2 min 2359-0001, 0059-0101,... Hourly 1 sample from top of hour
Sea surface temperature and conductivity 1 per 10 min instantaneous 0000, 0010,... 10 min 6 samples per hour
Subsurface temperature, conductivity, and pressure 1 per 10 min instantaneous 2359, 0009,... 10 min 6 samples per hour
Current velocity 1-hz 2 min 2359-0001, 0019-0021,... "20 min 1 sample from top of hour

NextGeneration ATLAS Sampling

Measurement Sample rate Sample period Sample time Data recorded in memory Transmitted data
Wind velocity components, air temperature, relative humidity 2-hz 2 min 2359-0001, 0009-0011,... 10 min Daily mean and 2-min mean from top of most recent hour
Rain rate [1] 1-hz 1 min 0000-0001, 0001-0002,... 1 min Daily mean, standard deviation, and percent time raining
Shortwave radiation 1-hz 2 min 2359-0001, 0001-0003,... 2 min Daily mean and standard deviation
Longwave radiation (thermopile, case and dome temperatures) 1- hz 2 min 2359-0001, 0001-0003,... 2 min Daily mean
Barometric pressure 2-hz 2 min 2359-0001, 0059-0101,... Hourly Daily mean and most recent 2-min average
Sea surface and subsurface temperature and conductivity [2] 1 per 10 min instantaneous 0000, 0010,... 10 min Daily mean
Current velocity 1-hz 2-3 min 2359-0001, 0019-0021,... 20-min Daily mean

Standard ATLAS Sampling

Measurement Sample rate Sample period Sample time Data recorded in memory Transmitted data
Wind velocity components 2-hz 6 min 2357-0003, 0057-0103,... Hourly Daily mean and most recent 6-min mean
Air temperature, relative humidity, sea surface temperature 1 per 10 min 60 min 0000, 0010,... Hourly (Time stamp at end of average) Daily mean and most recent hourly mean
Subsurface temperature 1 per 10 min 1 day 0000, 0010,... Daily Daily mean

Subsurface ADCP Mooring Sampling

Measurement Sample rate Sample period Sample time Data recorded in memory Transmitted data
Water velocity profile
Narrowband 150kHz ADCP		 0.333 hz 15-min 0000-0015, 0100-0115,... Hourly (Time stamp at beginning of average) None

References

Fofonoff, P., and R. C. Millard Jr.: Algorithms for computation of fundamental properties of seawater, Tech. Pap. Mar. Sci., 44, 53 pp., Unesco, Paris, 1983.

Freitag, H.P., M.J. McPhaden, C.S. Coho, and A.J. Shepherd (1991): Equatorial wind, current and temperature data: 108°W to 140°W; April 1983 to October 1987. NOAA Data Report ERL PMEL-35 (PB92-119817), 116 pp.

Kutsuwada, K. and H. Inaba, (1995): "Long-Range Measurement of Surface Oceanic Current in the Western Equatorial Pacific by Acoustic Doppler Current Profiler", J. of Meteor. Soc. of Japan, 73, No. 1, pp. 1-11, 1995.

Mangum, L.J., H.P. Freitag, and M.J. McPhaden (1995): TOGA TAO array sampling schemes and sensor evaluations. Proceedings, Oceans '94 OSATES, 13-16 September 1994, Parc de Penfeld, Brest, France, II-402-II-406.

Plimpton, P.E., H.P. Freitag, and M.J. McPhaden (2000): Correcting moored ADCP data for fish-bias errors at 0°, 110°W and 0°, 140°W from 1993 to 1995. NOAA Tech. Memo. OAR PMEL-117, 35 pp.

Plimpton, P.E., H.P Freitag, M.J McPhaden, and R.H. Weisberg, (1997): "Using echo intensity to correct moored ADCP data for fish-bias error at 0, 170W", NOAA Technical Memorandum ERL PMEL-111, 17pp.

Serra, Y.L., P.A'Hearn, H.P. Freitag, and M.J. McPhaden, 2001: ATLAS self-siphoning rain gauge error estimates. J. Atmos. Ocean. Tech., 18, 1989-2002.

Weisberg, R.H. and S.P. Hayes (1995): "Upper ocean variability on the equator in the west-central Pacific at 170W", J. Geophys. Res., 100, pp. 20485-20498.