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lifton2006sp.m

Syntax:

scalingfactor = lifton2006sp(h,Rc,S);

Calculates the geographic scaling factor for cosmogenic-nuclide production for particular cutoff rigidity and altitude according to the scheme in:

Lifton N.A., Bieber J.W., Clem J.M., Duldig M.L., Evenson P., Humble J.E., Pyle R., 2005. Addressing solar modulation and long-term uncertainties in scaling secondary cosmic rays for in situ cosmogenic nuclide applications. Earth and Planetary Science Letters, v. 239, pp. 140-161.

The input arguments are h, atmospheric pressure (hPa), Rc, cutoff rigidity (GV), and S, the solar modulation factor (nondimensional; see the source paper for details). Accepts vector arguments.

This function:

Converts atmospheric pressure $ h$ (hPa) to atmospheric depth $ x$ (g $ \cdot$ cm$ ^{-2}$) by multiplying by 1.0197.

Assigns cutoff rigidities below 1.907 GV a value of 1.907.

Calculates the scaling factor $ I$ (Lifton's nomenclature) using Equation (4) in the source paper:

$\displaystyle \ln{(I)} = c_{1}\ln{\left( XS \right)} - S\exp{\left[ \frac{c_{2}...
...ft( R_{C} + 4S \right) X \right]^{c_{6}} +c_{7} \left(R_{C} + 4S\right)^{c_{8}}$ (40)

where $ R_{C}$ is the cutoff rigidity, $ S$ is the solar modulation factor, and the constants $ c_{i}$ are:

$ c_{1}$ 1.8399
$ c_{2}$ $ -1.1854 \times 10^{2}$
$ c_{3}$ $ -4.9420 \times 10^{-2}$
$ c_{4}$ $ 8.0139 \times 10^{-1}$
$ c_{5}$ $ 1.2708 \times 10^{-4}$
$ c_{6}$ $ 9.4647 \times 10^{-1}$
$ c_{7}$ $ -3.2208 \times 10^{-2}$
$ c_{8}$ 1.2688

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


next up previous contents
Next: NCEPatm_2.m Up: Subsidiary calculation functions Previous: ET_objective.m   Contents
2007-11-13