NSLOT_v2

MATLAB

[cnsq,ustar,tstar,qstar,l,data_flag] = NSLOT_v2(zref,u,tair, ...
                          tsea,rh,pr,zu,zt,zq,zp,lambda)

Description

Bulk model for computing surface-layer scaling parameters, and the refractive index structure parameter from mean values of meteorological quantities measured near the ocean surface. The wind speed, air temperature and air humidity must be measured between 1 and 50 m above the ocean surface. The model will still run if either the pressure or pressure measurement height inputs are bad (data_flag <= 3). In such cases the pressure is defaulted to 1013.25 mb and the pressure measurement height is defaulted to 10 m. The model will not run if any other inputs besides the pressure and/or pressure measurement height are bad (data_flag > 3). All output parameters (except data_flag) are set to -99 if any input data besides pressure or pressure height are bad. All output parameters (except data_flag) are set to -98 if the bulk model (bulk_params subroutine) does not converge.

Parameters

Parameters	Description
zref [vector]	Reference height above surface to compute cnsq (m). Returns -99 if zref < 1m or zref > 50m.
u [vector]	Wind speed (m/s). Returns -99 if u < 0.1m/s or u > 30m/s.
tair [vector]	Air temperature (deg C). Returns -99 if tair < -60C or tair > 60C.
tsea [vector]	Sea surface temperature (deg C). Returns -99 if tsea < -2C or tsea > 40C.
rh [vector]	Air relative humidity (%). Returns -99 if rh < 0% or rh > 100%.
pr [vector]	Atmospheric pressure (mb) (default is 1013.25). Resets to 1013.25 if pr < 940mb or pr > 1050mb.
zu [vector]	Wind speed measurement height (m). Returns -99 if zu < 1m or zu > 50m.
zt [vector]	Air temperature measurement height (m). Returns -99 if zt < 1m or zt > 50m.
zq [vector]	Relative humidity measurement height (m). Returns -99 if zq < 1m or zq > 50m.
zp [vector]	Atmospheric pressure measurement height (m) (default is 10). Resets to 10m if zp < 1m or zp > 50m.
lambda [scalar]	Optical wavelength for computing cnsq (microns). Must be in the range 0.36 to 4.0 or 7.8 to 19.0 microns, returns -99 if lambda outside this range.

Return Values

Return Values	Description
cnsq [vector]	Refractive index structure parameter at zref (m^-2/3)
ustar [vector]	Bulk wind speed scaling parameter (m/s)
tstar [vector]	Bulk potential temperature scaling parameter (K)
qstar [vector]	Bulk specific humidity scaling parameter (g/g)
l [vector]	Obukhov length (m)
data_flag [vector]	0 if all input data are good, 1 if input pressure is bad, 2 if input pressure height is bad, 3 if input pressure and height are both bad, 4 or more if any input data other than pressure/height are bad

References

P. A. Frederickson, K. L. Davidson, C. R. Zeisse, and C. S. Bendall, "Estimating the Refractive Index Structure Parameter (Cn2) over the Ocean Using Bulk Methods," J. Appl. Meteorol., vol. 39, pp. 1770-1783, 2000.