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Woods Hole Coastal and Marine Science Center

Documentation of the U.S. Geological Survey Oceanographic Time-Series Measurement Database

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Appendix 4. Equatorial Pacific Information Collection (EPIC) keywords commonly used in this database

Coordinate Variables

EPIC number Name Long name Contents (units)
624 time   true Julian Day
625 time2   milliseconds since 0:00 GMT
3 depth   depth (m)
500 lat latitude degrees north
502 lon longitude degrees east
9991 xcoord   Distance from sonar in x-direction (m)
9992 ycoord   Distance from sonar in y-direction (m)
  burst   burst number (counts)
  frequency   frequency (Hz)
  direction   direction (degrees)

Record Variables

EPIC Number Variable name Contents (units)
1 P_1 Pressure (db)
4 P_4 pressure (pa)
4023 P_4023 average burst pressure (mbar)
850 SDP_850 Std. Dev. Pressure (mbar)
20 T_20 temperature (°C)
25 T_25 sea surface temperature (°C)
28 T_28 temperature ITS_1990 Standard (°C)
51 C_51 conductivity (S/m)
40 S_40 salinity (ppt)
41 S_41 practical salinity (unitless)
71 STH_71 sigma-theta (kg/m³)
4211 CTDTMP_4211 temperature (°C)
4218 CTDCON_4218 conductivity (S/m)
4214 CTDSAL_4214 practical salinity (unitless)
5000 flow Average daily river discharge (m³/s)
18 hght_18 sea surface height (m)
1239 hght_std sea surface height standard deviation (m)
310 CD_310 direction to which the current flows (degrees)
300 CS_300 current speed (cm/s)
1205 u_1205 eastward current velocity component (flow to east) (cm/s)
4097 USTD_4097 Std. Dev. of eastward current velocity component (cm/s)
1206 v_1206 northward current velocity component (flow to north) (cm/s)
4098 VSTD_4098 Std. Dev. of northward current velocity component (cm/s)
1204 w_1204 vertical current velocity component (cm/s)
4099 WSTD_4099 Std. Dev. of vertical current velocity component (cm/s)
1211 Tx_1211 transducer temperature (°C)
1201 Werr_1201 error velocity (cm/s)
1202 AGC_1202 average echo intensity (counts)
1203 PGd_1203 percent good pings (counts)
  u_1205min minimum eastward current velocity component (cm/s)
  u_1205max maximum eastward current velocity component (cm/s)
  ResU Mean resolution velocity eastward (cm/s)
  u_dmean Ratio of means for burst after points QA/QC'd
  u_dvar Ratio of variances for burst after points QA/QC'd
  v_1206min minimum northward current velocity component (cm/s)
  v_1206max maximum northward current velocity component (cm/s)
  ResV Mean resolution velocity northward (cm/s)
  v_dmean Ratio of means for burst after points QA/QC'd
  v_dvar Ratio of variances for burst after points QA/QC'd
  w_1204min minimum vertical current velocity component (cm/s)
  w_1204max maximum vertical current velocity component (cm/s)
  ResW Mean resolution velocity vertical (cm/s)
  w_dmean Ratio of means for burst after points QA/QC'd
  w_dvar Ratio of variances for burst after points QA/QC'd
  brange Sensor range to boundary (m)
  vrange Volume range to boundary (m)
1215 Hdg_1215 Median Instrument Heading (degrees)
1216 Ptch_1216 Median Instrument Pitch (degrees)
1217 Roll_1217 Median Instrument Roll (degrees)
1218 HSD_1218 Instrument Heading Std. Dev. (degrees)
1219 PSD_1219 Instrument Pitch Std. Dev. (degrees)
1220 RSD_1220 Instrument Roll Std. Dev. (degrees)
4061 wh_4061 significant wave height (m)
4060 wp_4060 mean wave period (s)
4063 dwp_4063 dominant wave period (s)
4064 mwh_4064 maximum wave height (m)
4062 wd_4062 mean wave direction (degrees true)
4063 wp_peak peak wave period (s)
4062 wvdir peak wave direction (degrees true)
  dspec directional wave energy spectrum (mm²/Hz/degree)
  pspec pressure-derived non-directional wave energy spectrum (mm/Hz1/2)
  sspec surface-derived non-directional wave energy spectrum (mm/Hz1/2)
  vspec velocity-derived non-directional wave energy spectrum (mm/Hz1/2)
  dfreq Frequency band width (Hz)
  spread Wave spreading (degrees)
  badBursts bad ABS bursts
4074 adv_nbad
981 Sed*_981 Sediment concentration (g/l)
56 NEP*_56 Backscatter intensity from a nephylometer
1900 abs_trans*_mean mean ABS transducer amplitude
1901 abs_trans*_mean_sqmean squared ABS transducer amplitude
1902 abs_trans*_std standard deviation ABS transducer amplitude
1903 abs_trans*_std_sq std. dev. squared ABS transducer amplitude
1904 abs_trans*_pctl ABS percentiles
1905 abs_trans*_pctl_sq ABS percentiles squared
  rdistance from ABS sensor head (m)
  pctile percentiles calculated with ABS data
915 BP_915 barometric pressure (mbar)
21 AT_21 air temperature (°C)
922 VIS_922 visibility (miles)
951 DP_951 dew point (°C)
412 WD_412 direction from which the wind blows (degrees true)
402 WG_402 wind gust (m/s)
401 WS_401 wind speed (m/s)
422 WU_422 eastward wind velocity component (cm/s)
423 WV_423 westward wind velocity component (cm/s)
  sonar_image Imagenex Sonar Image
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