NOAA-16 AVHRR Day and Night SST Equations
=========================================

The NOAA/NESDIS equations to be used for NOAA-16 sea surface temperature 
computation are given below. These equations are those being used for NOAA
operational products.

definition of Terms:
--------------------
MCSST = linear Multi-Channel Sea Surface Temperature (SST) algorithm.

NLSST = non-linear SST algorithm.

T3.7, T11, T12 = AVHRR channels 3, 4, 5 brightness temperatures in 
degrees Kelvin.

Sec   = secant of satellite zenith angle.

Tsfc = an a priori estimate of surface temperature in degrees Celsius.  
The NOAA/NESDIS one- degree latitude/longitude objectively analyzed 
global SST field was used to generate these equations and will be used in 
the operational generation of global SST.  One can also use for Tsfc a 
satellite-only, blended, or climatological SST analysis or an SST derived 
from AVHRR data with one of the MCSST equations.

X Coefficients = the coefficients to use with the Features indicated.

Constant = the constant to use in the SST equation.



NIGHTIME EQUATION - LINEAR SPLIT WINDOW ******************************
  
A1+ A2*T4 + A3*T5+ A4*(T4-T5)*(SEC (ZA)-1)

A1=-273.15 
A2=3.5316
A3=-2.53655
A4=0.753291

ZA - Satellite Zenith Angle

OPERATIONAL DAYTIME EQUATION - LINEAR SPLIT WINDOW ********************

A1 + A2*T4 + A3*T5+ A4*(T4 - T5)*(SEC (ZA) - 1)

A1=-273.77
A2=3.301267
A3=-2.30195
A4=0.628966


NIGHTTIME OPERATIONAL EQUATION - MCSST Triple ***************************

SST = A1*T3 + A2*T4 + A3*T5 + A4*(T3 - T5)*(sec (ZA) - 1) + A5

A1= 1.01684
A2= 0.733532
A3= -0.753123
A4= 0.344182
A5= -271.763


DAY NLSST Split *********************************************************

SST = A1*T4 + A2*Tsfc*(T4 - T5) + A3*(T4 - T5)*(sec (ZA) - 1) + A4

A1= 0.914471
A2= 0.0776118
A3= 0.668532
A4= -248.116


Night MCSST Dual *********************************************************

SST = A1*T4 + A2*(T3 - T4) + A3*(sec (ZA) - 1) + A4
 
A1= 1.00413
A2= 1.50825
A3= 1.52452
A4= -273.082

Night NLSST Dual **********************************************************

SST = A1*T4 + A2*Tsfc*(T3 - T4) + A3*(sec (ZA) - 1) + A4

A1= 1.00079
A2= 0.0526707
A3= 1.64982
A4= -271.895

Night NLSST Triple ********************************************************

SST = A1*T4 + A2*Tsfc*(T3 - T5)+ A3*(sec (ZA) - 1) + A4

A1= 0.955816
A2= 0.0335850
A3= 1.57899
A4= -259.583


Night NLSST Split **********************************************************

SST = A1*T4 + A2*Tsfc*(T4 - T5) + A3*(T4 - T5)*(sec (ZA) - 1) + A4

A1= 0.898887
A2= 0.0839331
A3= 0.755283
A4= -244.006