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 $\delta z$ (g $\cdot$ cm$^{-2}$) by:

$$\delta z = 1.0197\left( 1013.25 - h\right)$$ (33)

Calculates the sea level scaling factor $S_{sl}$ according to Equation (3) of the source paper:

$$S_{sl} = Y + \frac {A} {\left[ 1 + \exp{\left( - \frac{R_{C}-X}{B} \right)} \right]^{C}}$$ (34)

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 $\Lambda_{atm}$ according to Equation (4) of the source paper:

$$\Lambda_{atm} = y + \frac {a} {\left[ 1 + \exp{\left( - \frac{R_{C}-x}{b} \right)} \right]^{c}}$$ (35)

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

Finally, calculates the scaling factor at the site $S$ according to Equation (5) of the source paper:

$$S = S_{sl}\exp{ \left( \frac{\delta z}{\Lambda_{atm}} \right) }$$ (36)

Accepts either scalars or vectors of equal sizes for all the input arguments. Returns either a scalar or a vector of the appropriate size.