Surface Site Validation

Release 4-IP shortwave and longwave downward surface fluxes have been validated against the Baseline Surface Radiation Network (BSRN) data and the Pacific Marine Environmental Laboratory (PMEL) buoy data. At this time, there are 12,116 site-months of BSRN data from 73 sites and 6235 buoy-months of PMEL from 64 buoys.

BSRN

The original BSRN data are 1-, 2-, 3- or 5-minute intervals. Quality-control is first performed on the original data to remove records deemed bad, and then 3-hourly, daily and monthly means are calculated. Note that shortwave 3-hourly validations include only daytime values, which is why their biases are roughly two times larger than their daily and monthly counterparts which, by definition, include nighttime, or zero, values.

Shortwave (January 1992 – June 2017)
Time Ave	Bias	RMS	ρ	σ	μSRB	Number
3-hourly	-2.9	77.6	0.96	77.5	285.4	1280023
Daily	1.3	28.1	0.97	28.1	170.5	154459
3-hourly monthly	-1.1	24.2	1.0	24.2	139.7	62108
Monthly	-1.0	14.7	0.99	14.7	170.1	6097

Longwave (January 1992 – December 2009)
Time Ave	Bias	RMS	ρ	σ	μSRB	Number
3-hourly	1.8	32.7	0.91	32.7	316.0	1307985
Daily	1.5	25.2	0.94	25.1	317.3	156069
3-hourly monthly	0.4	19.0	0.97	19.0	311.0	46962
Monthly	0.9	15.9	0.98	15.9	311.0	5835

PMEL

Shortwave (January 2000 – June 2017)
Time Ave	Bias	RMS	ρ	σ	μSRB	Number
3-hourly	4.9	95.0	0.96	94.9	381.0	648515
Daily	3.1	34.6	0.86	34.4	236.3	126578
3-hourly monthly	2.8	28.3	1.0	28.2	231.2	32159
Monthly	2.9	13.9	0.95	13.6	134.8	4158

Longwave (January 2000 – June 2017)
Time Ave	Bias	RMS	ρ	σ	μSRB	Number
3-hourly	3.4	18.6	0.84	18.3	405.4	343510
Daily	3.4	13.8	0.91	13.3	405.4	43116
3-hourly monthly	4.6	10.3	0.96	9.2	405.2	9047
Monthly	3.2	9.2	0.96	8.7	402.9	1393