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heat_apptemp

Compute apparent temperature.

Available in version 6.4.0 and later.

Prototype

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/heat_stress.ncl"  ; This library is automatically loaded
                                                             ; from NCL V6.5.0 onward.
                                                             ; No need for user to explicitly load.

	function heat_apptemp (
		t          : numeric,  
		vp         : numeric,  
		w10        : numeric,  
		iounit [3] : integer,  
		opt        : integer   
	)

	return_val [dimsizes(t)] :  float or double

Arguments

t

Scalar or array containing temperature(s) [ units see iounit ].

vp

Scalar or array containing vapor pressure (Pa).

w10

Scalar or array containing 10-meter winds (m/s).

iounit

An integer array of length 2 which specifies the units of the input t and returned heat_index:

  • iounit(0)=0 input t (degC)
  • iounit(0)=1 input t (degK)
  • iounit(0)=2 input t (Farenheit)

  • iounit(1)=0 input vp (hPa)
  • iounit(1)=1 input vp (Pa)
  • iounit(1)=2 input vp (kPa)

  • iounit(2)=0 returns units degC
  • iounit(2)=1 returns units degK
  • iounit(2)=2 returns units Farenheit

opt

Currently not used. Set to False.

Return value

A scalar or an array of the same size and shape as t. The output will be double if t or rh is of type double. The units are specified by iounit(1).

Description

Wikipedia: Apparent temperature is the general term for the perceived outdoor temperature, caused by the combined effects of air temperature, relative humidity and wind speed. 



REFERENCES: 
    Australian Bureau of Meteorology
    
    http://www.bom.gov.au/info/thermal_stress/#atapproximation

    Steadman, R.G., 1994: Norms of apparent temperature
             in Australia, Aust. Met. Mag., 43, 1-16. 

    Buzan, J.R. et al (2015): 
           Implementation and comparison of a suite of heat stress metrics
              within the Community Land Model version 4.5
           Geosci. Model Dev., 8, 151-170, 2015
           www.geosci-model-dev.net/8/151/2015/    doi:10.5194/gmd-8-151-2015

See Also

Heat and Stress functions

Examples

Example 1: 

   t   = 30.5      ; C
   vp  = 20.0      ; Pa
   w10 = 10.0      ; m/s
   at  = heat_apptemp(t, vp, w10, (/0,1,0/), 0)
   print(at)
The output is: 

    Variable: at
    Type: float
    Total Size: 4 bytes
                1 values
    Number of Dimensions: 1
    Dimensions and sizes:	[1]
    Coordinates: 
    Number Of Attributes: 5
      long_name :	apparent temperature
      units :	degC
      reference_1 :	Steadman, R.G., 1994: Norms of apparent temperature in Australia, Aust. Met. Mag., 43, 1-16
      reference_2 :	Buzan et al (2015): eq (1)
      NCL :	heat_apptemp
    (0)	19.566