atmqty: Summary of AtmQty Object Attributes & Quantities

Attributes

All attributes are object attributes, as opposed to class attributes. Thus, if x is an AtmQty object, the latitude attribute is x.lat.

The column "Type" refers to the value of the string returned by the built-in method type on the attribute. All types array are Numeric arrays. If an example is given in the description, it is assumed x is an AtmQty object.

Attribute Type Description
lev array Level vector of the domain, in either units of pressure levels [hPa] or isentropic levels [K]; the units of the levels are specified in the lev_type attribute.
lev_type str The level "type" given in attribute lev, and which can have the following values:
  • "pressure": Vertical levels are in pressure coordinates and lev is in units hPa (this is the default value of lev_type).
  • "isentropic": Vertical levels are in isentropic (constant potential temperature levels) coordinates and lev is in units K.
lat array Latitude vector of the domain.
lon array Longitude vector of the domain.
missing float Missing value value. Scalar. If undefined at object instantiation, is set to None.
p0 float Reference pressure used to calculate potential temperature [hPa]. Scalar. Set by method theta.
qty dict Each key:value pair represents an "atmospheric quantity" and is a rank 3 Numeric array, dimensioned by the tuple made by attributes lat, lon, lev. Example: x.qty['T'] is the rank 3 Numeric array of temperatures in the object domain.


Quantities

All atmospheric quantities are stored as key:value pairs in the object attribute qty. The are added (or overwritten) to qty by the add_qty method, deleted from the dictionary by the del_qty method, and extracted from the dictionary by the get_qty method. The values of the quantities are all rank 3 Numeric floating point (any precision) arrays whose domain is described by the tuple of object attributes (lat, lon, and lev).

Key Units Description
e hPa Vapor pressure (with respect to over water)
eice hPa Saturation vapor pressure over ice
esat hPa Saturation vapor pressure over water
gpot m Geopotential height
p hPa Pressure
q kg/kg Specific humidity
r kg/kg Mixing ratio
RH unitless
fraction
Relative humidity
T K Temperature
theta K Potential temperature
theta_e K Equivalent potential temperature
u m/s Zonal velocity
v m/s Meridional velocity


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Updated: November 20, 2003 by Johnny Lin <email me>. License.