DifferentialDiffusion: Differential firn diffusion

In EarthSystemDiagnostics/TrenchR: Analyse and Plot Trench-like Proxy Records

Differential firn diffusion

Description

Calculate the differential diffusion, as defined in Münch et al. (2007), over a specified depth interval given a diffusion length profile.

Usage

DifferentialDiffusion(
  dat = NULL,
  z00,
  z01,
  z10,
  z11,
  P = 650,
  T = 228.5,
  bdot = 64
)

Arguments

dat	a list providing a firn density profile, in order to calculate diffusion lengths, with two elements: depth, a vector with the depth scale of the density profile in [m]; and density, a vector of firn densities in [kg/m^3]. If NULL (the default), the fitted B41/B42 density profile, provided with the package, is used for the calculation (see Münch et al., 2017).
z00	upper boundary of the first depth interval.
z01	lower boundary of the first depth interval.
z10	upper boundary of the second depth interval.
z11	lower boundary of the second depth interval.
P	atmospheric surface pressure in [mbar] to calculate diffusion lengths; default is 650 mbar for Kohnen Station.
T	annual mean surface air temperature in [K] to calculate diffusion lengths; default is 228.5 K for Kohnen Station.
bdot	annual mean accumulation rate in [kg/m^2/yr] to calculate diffusion lengths; default is 64 kg/m^2/yr for Kohnen Station.

Details

Mean diffusion lengths are calculated for the depth intervals [z00, z01] and [z10, z11], and the differential diffusion length is obtained between these two intervals according to Eq. (2) in Münch et al. (2017).

Value

a named vector with two elements: oxy, the differential diffusion length value for oxygen isotopes; dtr, the differential diffusion length value for deuterium.

Author(s)

Thomas Münch

Source

Eq. (2) in Münch et al. (2017)

References

Münch, T., et al., Constraints on post-depositional isotope modifications in East Antarctic firn from analysing temporal changes of isotope profiles, The Cryosphere, 11(5), 2175-2188, doi:10.5194/tc-11-2175-2017, 2017.

EarthSystemDiagnostics/TrenchR documentation built on Sept. 2, 2023, 3:44 a.m.