1. VARIABLE: CLEAR SKY LAND SURFACE TEMPERATURE (LST)
Observed temporal variations of LST y(t) can be expressed as sum of the time-dependent expected value Y(t), the weather/climate-related anomaly y'(t) and random error of observation δ(t):
y(t) = Y(t) + y'(t) + δ(t) (2)
Expected value Y(t) can be approximated as:
(3)
Where T=1year, H=1day, K=N=2.
Land Surface Temperature (T ) ground truth can be obtained from observation of upward (Uup) and downward (Udw) broadband infrared fluxes over land at Surface Radiation (SURFRAD) stations:
δσT4 = Uup - (1-ε)Udw (1)
Land surface emissivity (ε) is assumed to be known, and σ is the Stefan-Boltzmann constant.
GOES-10 Observed 2001 Diurnal/Seasonal cycle of LST (ºC) at location of SURFRAD stations:
The amplitude of the diurnal cycle of LST is very large, almost twice as large as the amplitude of the diurnal cycle of Surface Air Temperature.

2. Clear sky LST
GOES-8-SURFRAD
GOES-10-SURFRAD
GOES-10-GOES-8
Estimates of seasonal and diurnal variations of cloud free LST (ºC) at SURFRAD stations Y1(t), and systematic differences in expected values Y2(t)-Y1(t), Y3(t)-Y1(t), Y3(t)-Y2(t) of LST observed at SURFRAD stations (1), GOES-8 (2), and GOES-10 (3) satellites. Dashed lines display sunrise and sunset times.
SURFRAD

3. Empirical estimates of Lag-correlation function of weather related component in GOES-10 observed clear sky LST in vicinity of three SURFRAD stations.

4. Systematic Error, Δi,j, ºC
List of selected SURFRAD stations with their coordinates; Numbers of used observations coincided in time at SURFRAD stations, GOES-8 and GOES-10 satellites; Annual mean LST a00; Standard Errors of LST observation δi; Standard Deviation σ of weather related component of LST; Correlation between residuals of LST approximation, COR (yi-Yi,yj-Yj); Mean differences Δi,j between nighttime observed LST. Index i,j=1,2,3 means: 1 - SURFRAD station, 2 - GOES-8, and 3 – GOES-10 satellite observation.
SURFRAD Network
Coordinates
Obser-
vations
Number
Annual Mean, a00ºC
Standard Error SD
COR (yi-Yi,yj-Yj)
Systematic Error, Δi,j, ºC
Station Name
Lat.
º N
Lon.
º W
i=1
i=2
i=3 δ1 ºC δ2 δ3 σ
r1,2
r1,3
r2,3
Δ2,1
Δ3,1
Δ3,2
Goodwin Creek, MS
34.25
89.87
510
14.3
13.0
0.6
0.8
0.7
3.7
.96
.97
-0.2
-0.9.
Desert Rock, NV
36.63
116.02
3190
21.5
19.7
19.9
1.2
3.0
.92
.94
.90
-2.3
-2.0
0.3
Bondville, IL
40.05
88.37
1160
9.5
11.2
9.2
1.3
3.5
-1.2
-1.6
Boulder, CO
40.13
105.24
1350
10.8
10.4
9.6
0.9
1.0
4.3
.95
.93
-0.7
-1.1
-0.4
Fort Peck, MT
48.31
105.10
1360
6.2
5.9
5.1
1.1
-0.5
-0.9