PlumeRise
Documentation
Data export

The Data export tab allows model data to be exported from PlumeRise for further analysis.

Data export box

The PDF report contains the text output from the Model outputs tab (read more) together with the currently active plots (read more)

Raw data from the PlumeRise calculations can be exported as plain text. The table below gives details of the data provided.

Variable Unit Description
x m

The position of the centreline trajectory along the East–West coordinate axis, with positive values corresponding to positions East of the vent and negative values corresponding to positions West of the vent.

y m

The position of the centreline trajectory along the North–South coordinate axis, with positive values corresponding to positions North of the vent and negative values corresponding to positions South of the vent.

z m

The altitude of the centreline trajectory above sea level.

Q kg/s

The mass flux along the centreline trajectory in the plume.

M kg m/s^2

The momentum flux along the centreline trajectory in the plume.

E J/s

The energy flux along the centreline trajectory in the plume.

L m

The Gaussian radius of the plume.

U m/s

The top-hat speed of the plume along the centreline trajectory.

T K

The temperature of the plume.

beta kg/m^3

The bulk density of the plume.

n

The mass fraction of gas in the plume.

phi

The mass fraction of liquid water and water vapour in the plume.

phiv

The mass fraction of water vapour in the plume.

phiw

The mass fraction of liquid water in the plume.

w

The mass fraction of gas in the plume that is composed of water vapour.

Cp J/K/kg

The bulk specific heat capacity in the plume.

Rg J/K/kg

The bulk gas constant in the plume.

theta deg

The local angle of the plume centreline to the horizontal plane.

psi deg

The local angle of the projection of the plume centreline onto the horizontal plane, from the East–West coordinate axis.

V m/s

The atmospheric wind speed.

Vx m/s

The component of the wind velocity in the East–West direction.

Vy m/s

The component of the wind velocity in the North–South direction.

psia deg

The local angle of the projection of the wind velocity vector onto the horizontal plane, from the East–West coordinate axis.

P Pa

The atmospheric pressure.

Ta K

The atmospheric temperature.

Rga J/K/kg

The gas constant of the atmosphere.

alpha kg/m^3

The density of the atmosphere.

phia

The atmospheric specific humidity (i.e. mass fraction of water vapour in the atmosphere).

File headers (produced on request by selecting the 'Include file header' checkbox) provide details of the run parameters used in the PlumeRise calculation.

Header Description
PlumeRise output file

Output file title

Generated at yyyy/mm/dd hh:mm:ss

The date and time at which model output was generated.

Source velocity (m/s):xx

The (top-hat) centreline velocity of the plume at the source.

Vent mass fraction: xxxx

The mass fraction of gas at the vent.

Vent radius (m): xxx

The (top-hat) radius of the plume at the source, assumed to be the vent radius.

Vent elevation (m asl): xxxx

The altitude of the vent above sea level.

Source temperature (K): xxxx

The temperature of the plume at the vent.

Solid pyroclast density (kg/m^3): xxxx

The density of solid pyroclasts.

No-wind entrainment coefficient: xxxx The entrainment coefficient for a turbulent plume rising in a quiescent ambient.
Wind entrainment coefficient: xxxx The entrainment coefficient due to a cross wind.

The following header lines appear if the parameter set uses a model atmosphere (by selecting the 'Use modelled standard atmosphere' button in the 'Atmospheric model parameters' tab)

Standard atmosphere air temperature at sea level (deg C): xx

The air temperature at sea level.

Standard atmosphere pressure at vent (hPa): xxxx The pressure of the atmosphere at the altitude of the vent.
Standard atmosphere stratospheric wind speed (m/s): xx

The wind speed in the stratosphere.

For the model atmosphere, the wind profile is taken to be linearly increasing in the lower atmosphere (up to the top of the troposphere) and a uniform wind speed above.

Standard atmosphere wind direction (degrees): xxx

Wind direction is the angle that the wind originates from (the bearing), in degrees, with 0° corresponding to North, 90° corresponding to East, etc.

For a model atmosphere, the wind direction is assumed to be constant through the atmosphere.

Standard atmosphere tropopause height (km asl): xx

The height above sea level of the troposphere–tropopause transition.

There is a discontinuous change in the atmospheric temperature gradient at this altitude.

Standard atmosphere stratosphere height (km asl): xx

The height above sea level at which the stratosphere begins.

There is a discontinuous change in the atmospheric temperature gradient at this altitude.

Standard atmosphere temperature gradient in troposphere (K/km): xxx

The atmospheric temperature gradient (lapse rate of temperature) in the troposphere.

Standard atmosphere temperature gradient in stratosphere (K/km): xxx

The atmospheric temperature gradient (lapse rate of temperature) in the stratosphere.

The following header line appears if the parameter set uses tabulated atmospheric data (by selecting the 'Use atmospheric data' button in the 'Atmospheric data' tab)

Used custom atmospheric data Specifies that tabulated atmospheric data was used in the PlumeRise calculation.