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Use of GMD SURFRAD to assess CERES AVG data products (UV Index, PAR, and SW Down).
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For validation we use the 7 NOAA Global Monitoring Division (GMD) Surface Radiation (SURFRAD) observation sites. Each site maintains observations of the ultra-violet, photosynthetically active radiation (PAR), and total surface downward short wave insolation (SWD). The following plots show the monthly mean 3 hourly diurnal cycle values and monthly means of observations and calculations from the CERES AVG data product for all available months from these seven sites.
Site Monthly Mean (RMS) (Click on "Terra" or "Aqua" for scatter plots.)
map of surfrad sites Bondville, IL Terra Bondville, IL Aqua Desert Rock, NV Terra Desert Rock, NV Aqua Fort Peck, MT Terra Fort Peck, MT Aqua Goodwin Creek, MS Terra Goodwin Creek, MS Aqua Penn State, PA Terra Penn State, PA Aqua Sioux Falls, SD Terra Sioux Falls, SD Aqua Boulder (Table Mountain), CO Terra Boulder (Table Mountain), CO Aqua
Surface comparisons, 3 Hourly Monthly Means, Bias, RMS
Results for Terra AVG (Monthly mean diurnal cycles for Apr 2000 through Oct 2005)
SiteUV Index*
Obs Mean,Bias(RMS)N(3hr)		PAR
Obs Mean,Bias(RMS)N(3hr)		SW Down
Obs Mean,Bias(RMS)N(3hr)
BON1.06, -0.14(0.35) 532 73.3, 6.2(16.5) 532176.0, 1.94(15.9) 532
DRA1.61, -0.03(0.21) 536106.0, 1.9( 6.4) 536244.9, 1.21(12.9) 536
FPK0.90, -0.01(0.12) 536 75.1, 1.6( 6.6) 536170.0, 2.15(13.7) 536
GWN1.27, -0.08(0.22) 536 81.9, 5.0(11.6) 536185.7, 6.10(16.7) 536
PSU0.94, -0.04(0.17) 536 67.1, 6.4(12.3) 536158.4, 6.37(17.6) 536
SXF1.06, -0.11(0.29) 229 78.0, 2.5( 9.0) 229180.0, 0.71(18.1) 228
TBL1.26, 0.04(0.17) 536 83.8, 1.7( 7.9) 536194.0, 1.99(17.6) 536
Results for Aqua AVG (Monthly mean diurnal cycles for Jul 2002 through Feb 2005)
SiteUV Index*
Obs Mean,Bias(RMS)N(3hr)		PAR
Obs Mean,Bias(RMS)N(3hr)		SW Down
Obs Mean,Bias(RMS)N(3hr)
BON0.99, -0.13(0.28) 244 71.3, 2.9( 9.0) 244167.3, -0.9(13.6) 244
DRA1.49, -0.05(0.20) 248100.5, 0.2( 5.2) 248233.3, -2.8(11.2) 248
FPK0.82, -0.01(0.14) 248 69.8, 1.8( 6.6) 248158.4, 1.8(13.8) 248
GWN1.17, -0.07(0.20) 248 74.7, 6.7(13.6) 248173.7, 5.2(17.4) 248
PSU0.84, -0.03(0.18) 248 61.3, 6.2(12.3) 248144.9, 5.8(15.1) 248
SXF0.98, -0.12(0.29) 157 72.5, 2.4( 9.2) 157169.0, -0.4(17.6) 156
TBL1.17, 0.01(0.12) 248 79.9, 0.3( 6.1) 248182.6, 1.0(17.0) 248
*Many UV studies employ noontime data. Users expecting values like 10 for UV Index may be jarred by smaller numbers on our monthly maps/statistics, which are averaged for a 24 hour day. Validation plots from the map above use a 3 hour scale and show much of the diurnal range in UV.