Diffuse attenuation coefficient for Jerlov optical water types.

Returns Kd(lambda) for the specified Jerlov water type from the bundled jerlov_types dataset (Jerlov 1976; Solonenko & Mobley 2015). Optionally interpolates onto a user-supplied wavelength grid.

Usage

jerlov_Kd(
  type = "IA",
  lambda = NULL,
  interp = c("linear", "spline", "nearest"),
  extrapolation = c("error", "constant")
)

Arguments

type: Jerlov water type. One of "I", "IA", "IB", "II", "III", "C1", "C2", "C3". Case-insensitive.
lambda: Wavelengths in nm to interpolate Kd onto. If NULL (default), returns the full tabulated rows as a data frame.
interp: Interpolation method when lambda is supplied. One of "linear" (default), "spline", or "nearest". Interpolation is applied only within the supported wavelength range.
extrapolation: Out-of-range policy. The default "error" raises a luxR_jerlov_range_error. Set to "constant" to explicitly extend the nearest endpoint value; the choice is recorded in the returned vector's "luxR.jerlov" attribute.

Value

If lambda is NULL: a data frame with columns type, lambda, Kd and dataset metadata attributes. If lambda is supplied: a numeric vector of Kd values (1/m) with a "luxR.jerlov" provenance attribute recording the water type, interpolation and extrapolation policies, supported and requested ranges, source checksum, build commit, and model version.

Details

The bundled Jerlov table supports 350–700 nm. Values outside that domain are not measured by this dataset and therefore fail by default. Constant endpoint extension is available only as an explicit modelling assumption; linear or spline extrapolation is not supported.

References

Jerlov NG (1976) Marine Optics. Elsevier, Amsterdam.

Solonenko MG, Mobley CD (2015) Inherent and apparent optical properties of Jerlov water types. Applied Optics 54(17):5392-5401.

Examples

jerlov_Kd("IA")
#>    type lambda    Kd
#> 16   IA    350 0.076
#> 17   IA    375 0.044
#> 18   IA    400 0.033
#> 19   IA    425 0.023
#> 20   IA    450 0.016
#> 21   IA    475 0.018
#> 22   IA    500 0.024
#> 23   IA    525 0.032
#> 24   IA    550 0.041
#> 25   IA    575 0.068
#> 26   IA    600 0.125
#> 27   IA    625 0.185
#> 28   IA    650 0.257
#> 29   IA    675 0.391
#> 30   IA    700 0.558
Kd_IA <- jerlov_Kd("IA", lambda = c(400, 450, 500, 550, 600))
as.numeric(Kd_IA)
#> [1] 0.033 0.016 0.024 0.041 0.125
attr(Kd_IA, "luxR.jerlov")[c("type", "interp", "extrapolation",
                              "supported_wavelength_range_nm")]
#> $type
#> [1] "IA"
#> 
#> $interp
#> [1] "linear"
#> 
#> $extrapolation
#> [1] "error"
#> 
#> $supported_wavelength_range_nm
#> [1] 350 700
#> 

lam <- seq(400, 700, by = 10)
Kd  <- jerlov_Kd("II", lambda = lam)
attenuate_spectrum(rep(1, length(lam)), Kd, depths = c(10, 25, 50),
                  lambda = lam)
#>    depth lambda            E
#> 1     10    400 3.828929e-01
#> 2     10    410 4.147829e-01
#> 3     10    420 4.493290e-01
#> 4     10    430 4.809461e-01
#> 5     10    440 5.086475e-01
#> 6     10    450 5.379444e-01
#> 7     10    460 5.510113e-01
#> 8     10    470 5.643955e-01
#> 9     10    480 5.769498e-01
#> 10    10    490 5.886050e-01
#> 11    10    500 6.004956e-01
#> 12    10    510 5.862553e-01
#> 13    10    520 5.723526e-01
#> 14    10    530 5.587797e-01
#> 15    10    540 5.455286e-01
#> 16    10    550 5.325918e-01
#> 17    10    560 4.611647e-01
#> 18    10    570 3.993169e-01
#> 19    10    580 3.409566e-01
#> 20    10    590 2.870784e-01
#> 21    10    600 2.417140e-01
#> 22    10    610 1.863740e-01
#> 23    10    620 1.437039e-01
#> 24    10    630 1.110250e-01
#> 25    10    640 8.594910e-02
#> 26    10    650 6.653681e-02
#> 27    10    660 3.815876e-02
#> 28    10    670 2.188399e-02
#> 29    10    680 1.198619e-02
#> 30    10    690 6.269868e-03
#> 31    10    700 3.279711e-03
#> 32    25    400 9.071795e-02
#> 33    25    410 1.108032e-01
#> 34    25    420 1.353353e-01
#> 35    25    430 1.604136e-01
#> 36    25    440 1.845195e-01
#> 37    25    450 2.122480e-01
#> 38    25    460 2.253727e-01
#> 39    25    470 2.393089e-01
#> 40    25    480 2.528396e-01
#> 41    25    490 2.658030e-01
#> 42    25    500 2.794310e-01
#> 43    25    510 2.631582e-01
#> 44    25    520 2.478330e-01
#> 45    25    530 2.334004e-01
#> 46    25    540 2.198082e-01
#> 47    25    550 2.070076e-01
#> 48    25    560 1.444243e-01
#> 49    25    570 1.007614e-01
#> 50    25    580 6.788094e-02
#> 51    25    590 4.415717e-02
#> 52    25    600 2.872464e-02
#> 53    25    610 1.499558e-02
#> 54    25    620 7.828378e-03
#> 55    25    630 4.107256e-03
#> 56    25    640 2.165725e-03
#> 57    25    650 1.141970e-03
#> 58    25    660 2.844367e-04
#> 59    25    670 7.084615e-05
#> 60    25    680 1.572907e-05
#> 61    25    690 3.112762e-06
#> 62    25    700 6.160116e-07
#> 63    50    400 8.229747e-03
#> 64    50    410 1.227734e-02
#> 65    50    420 1.831564e-02
#> 66    50    430 2.573251e-02
#> 67    50    440 3.404745e-02
#> 68    50    450 4.504920e-02
#> 69    50    460 5.079283e-02
#> 70    50    470 5.726876e-02
#> 71    50    480 6.392786e-02
#> 72    50    490 7.065121e-02
#> 73    50    500 7.808167e-02
#> 74    50    510 6.925223e-02
#> 75    50    520 6.142121e-02
#> 76    50    530 5.447573e-02
#> 77    50    540 4.831564e-02
#> 78    50    550 4.285213e-02
#> 79    50    560 2.085837e-02
#> 80    50    570 1.015286e-02
#> 81    50    580 4.607822e-03
#> 82    50    590 1.949856e-03
#> 83    50    600 8.251049e-04
#> 84    50    610 2.248673e-04
#> 85    50    620 6.128350e-05
#> 86    50    630 1.686956e-05
#> 87    50    640 4.690366e-06
#> 88    50    650 1.304097e-06
#> 89    50    660 8.090421e-08
#> 90    50    670 5.019176e-09
#> 91    50    680 2.474036e-10
#> 92    50    690 9.689290e-12
#> 93    50    700 3.794703e-13