# vocabulary

Label: relative_humidity
UnitOfMeasure: precent
Abbreviation: rel_humid
Definition:
Amount of moisture in the air as vapor relative to how much it can possibly hold at the same temperature.


Label: wind_gust
UnitOfMeasure: m s-1
Abbreviation: wgust
Definition:
Maximum instantaneous wind speed (usually no more than but not limited to 10 seconds) within a sample averaging interval.


Label: salinity
UnitOfMeasure: PSS or PSU or PPT
Abbreviation: salinity
Definition:
Measure of salt content of a seawater sample follows UNESCO standards; approximately parts per thousand.


Label: swell_height
UnitOfMeasure: meter
Abbreviation: swell_ht
Definition:
Average height of the highest one-third of the swells, if a separation between swell and wind-wave energy peak exists.


Label: wind_wave_height
UnitOfMeasure: meter
Abbreviation: wind_wv_ht
Definition:
Average height of the highest one-third of the wind-waves, if a separation between swell and wind-wave energy peak exists.


Label: light_attenuation_coefficient
UnitOfMeasure: m-1
Abbreviation: attenuate
Definition:
Measure of combined effects on light caused by absorption and scattering over a defined distance for a specific wavelength of light.


Label: spectral_radiance
UnitOfMeasure: W m-2 m-1 sr-1
Abbreviation: L
Definition:
Light energy of specific wavelength from a set of directions (solid angle) at a point and time in space.


Label: visibility
UnitOfMeasure: m
Abbreviation: visibility
Definition:
Greatest distance an object can be seen and identified. Usually refering to visibility in air but could be other medium.


Label: latitude
UnitOfMeasure: degrees_north
Abbreviation: lat
Definition:
Y-coordinate of dependent observation in geographic coordinate. North is positive.  Alternate definition: The angular distance north and south of the equator, with the equator being 0° and the poles 90°.


Label: longitude
UnitOfMeasure: degrees_east
Abbreviation: lon
Definition:
X-coordinate of dependent observation in geographic coordinate. East is positive. Alternate definition: The angular distance east and west of the prime meridian (0° lon.),  that runs through Greenwich, England.


Label: date_time_string
UnitOfMeasure: string YYYY MM DD hh mm ss
Abbreviation: date_time_string
Definition:
Date and time character string of observation that includes year, month, day, hour, minute and second.


Label: source_time
UnitOfMeasure: {sec | hr | day} since YYYY-MM-DD HH:MM:SS.xxx {+/- ZONE}
Abbreviation: source_time
Definition:
Time coordinate of observation based on unit of time (seconds, hours, days) since a defined reference time.


