probability_of_mass_concentration_of_volcanic_ash_in_air_above_threshold 1 [UUUU] "probability_of_X_above_threshold" means the chance that X is above the threshold.
Space and time coordinates must be used to indicate the area and time to which a probability applies. "Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Volcanic ash" means the fine-grained products of explosive volcanic eruptions, such as minerals or crystals, older fragmented rock (e.g. andesite) and glass. Particles within a volcanic ash cloud have diameters less than 2 mm. "Volcanic ash" does not include non-volcanic dust.
Change Date: 13 Apr 2026, 10:57 a.m.
probability_of_mass_concentration_of_volcanic_ash_in_air_above_threshold 1 [UUUU] "probability_of_X_above_threshold" means the chance that X is above the threshold.
Space and time coordinates must be used to indicate the area and time to which a probability applies. "Mass concentration" means mass per unit volume and is used in the construction "mass_concentration_of_X_in_Y", where X is a material constituent of Y. A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". "Volcanic ash" means the fine-grained products of explosive volcanic eruptions, such as minerals or crystals, older fragmented rock (e.g. andesite) and glass. Particles within a volcanic ash cloud have diameters less than 2 mm. "Volcanic ash" does not include non-volcanic dust. To specify the threshold, provide a coordinate variable with the standard name mass_concentration_of_volcanic_ash_in_air.