Be exposure age calculator MATLAB function reference Version 2

2.5 dunai2001sp.m
Syntax:
scalingfactor = dunai2001sp(h,Rc)
Calculates the geographic scaling factor for cosmogenic-nuclide production for particular cutoff rigidity and atmoshperic
pressure according to the scheme in:
Dunai T.J., 2001. Influence of secular variation of the geomagnetic field on production rates of in situ produced
cosmogenic nuclides. Earth and Planetary Science Letters, v. 193, pp. 197-212.
The input arguments are h, atmospheric pressure (hPa) and Rc, cutoff rigidity (GV). Accepts vector arguments.
This function:
Converts atmospheric pressure h (hPa) to atmospheric depth between sea level and the site δz (g · cm −2 ) by:
δz = 1.0197 (1013.25 − h) (34)
Calculates the sea level scaling factor S sl according to Equation (3) of the source paper:
A
S sl = Y + [ ( )]
1 + exp −
R C −X C
(35)
B
where R C is the cutoff rigidity (GV) and the other constants in the equation are:
A 0.5221
B -1.7211
C 0.3345
X 4.2822
Y 0.4952
Calculates the atmospheric attenuation length Λ atm according to Equation (4) of the source paper:
a
Λ atm = y + [ (
1 + exp −
R C
)]
−x c (36)
b
where R C is the cutoff rigidity (GV) and the other constants in the equation are:
a 17.183
b 2.060
c 5.9164
x 2.2964
y 130.11
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