NOAA-15 AVHRR Day and Night SST Equations ========================================= The NOAA/NESDIS equations to be used for NOAA-15 sea surface temperature computation are given below. All nighttime equations are based on August 1998 drifting buoy matchups (plus tropical Pacific TOGA moored buoys). All daytime equations were based on matchups from August 1, 1998 to September 24, 1998. 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. For NOAA-15 global SST processing, the Night NLSST Triple and Day NLSST Split will be used operationally (indicated by asterisks). For CoastWatch, these equations will also be used except in the Great Lakes during the day for which the Day MCSST Split equation will be used. For CoastWatch, Tsfc is obtained with the Night MCSST Split equation at night and the Day MCSST Split equation during the day. Example of Use: --------------- The Night NLSST Triple equation, returning Celsius SST is: SST = 0.998871 * T11 + 0.0345648375 * Tsfc * (T3.7-T12) + 1.399856 * (SecO -1) - 271.4493793 Regression Output: Night NLSST Triple ******** Constant -271.4493793 Std Err of Y Est 0.5177705748 R Squared 0.9951056245 No. of Observations 1400 Degrees of Freedom 1396 X Coefficient(s) 0.998871 0.0345648375 1.399856 Std Err of Coef. 0.003328 0.0003356545 0.078066 Feature T11 Tsfc*(T3.7-T12) SecO -1 Regression Output: Night NLSST Dual Constant -281.6478518 Std Err of Y Est 0.5557999176 R Squared 0.9943602544 No. of Observations 1400 Degrees of Freedom 1396 X Coefficient(s) 1.035572 0.0533349597 1.628825 Std Err of Coef. 0.00333 0.000561628 0.083411 Feature T11 Tsfc*(T3.7-T11) SecO -1 Regression Output: Night MCSST Triple Constant -276.7558563 Std Err of Y Est 0.5088054612 R Squared 0.9952736478 No. of Observations 1400 Degrees of Freedom 1396 X Coefficient(s) 1.015354 1.0635723508 1.294955 Std Err of Coef. 0.003159 0.0101265218 0.076899 Feature T11 T3.7-T12 SecO -1 Regression Output: Night MCSST Dual Constant -283.5117285 Std Err of Y Est 0.5476636059 R Squared 0.9945241654 No. of Observations 1400 Degrees of Freedom 1396 X Coefficient(s) 1.041037 1.5875819344 1.67743 Std Err of Coef. 0.003242 0.0164359039 0.082107 Feature T11 T3.7-T11 SecO -1 Regression Output: Night MCSST Split Constant -271.3969724 Std Err of Y Est 0.5998438097 R Squared 0.9934310052 No. of Observations 1400 Degrees of Freedom 1396 X Coefficient(s) 0.993892 2.7523466369 0.662999 Std Err of Coef. 0.004036 0.038939438 0.059175 Feature T11 T11-T12 (T11-T12)*(secO -1) Regression Output: Night NLSST Split Constant -258.8020646 Std Err of Y Est 0.5448917347 R Squared 0.9945794545 No. of Observations 1400 Degrees of Freedom 1396 X Coefficient(s) 0.953493 0.0877621139 0.740922 Std Err of Coef. 0.003994 0.001101308 0.05285 Feature T11 Tsfc*(T11-T12) (T11-T12)*(secO -1) Regression Output: Day NLSST Split ************* Constant -240.244409 Std Err of Y Est 0.468095827 R Squared 0.988967076 No. of Observations 1318 Degrees of Freedom 1314 X Coefficient(s) 0.890887 0.088739642 0.557058 Std Err of Coef. 0.004598 0.000795317 0.046308 Feature T11 Tsfc*(T11-T12) (T11-T12)*(secO -1) Regression Output: Day MCSST Split Constant -261.029735 Std Err of Y Est 0.471157391 R Squared 0.988822284 No. of Observations 1318 Degrees of Freedom 1314 X Coefficient(s) 0.959456 2.663579879 0.570613 Std Err of Coef. 0.004305 0.024044759 0.046566 Feature T11 (T11-T12) (T11-T12)*(secO -1)