Transcript Document

Model validation: flux sites
- NOAA/ATDD-Tilden Meyers flux data sets
- Components of the surface energy budget:
(incoming/outgoing short/longwave radiation,
latent, sensible, ground heat flux), plus
meteorological observations and sub-surface
temperature and soil mositure
- 11 measurement sites across CONUS
- 2+ years of data available (at NCEP)
FP
BH
SF
BV,BP
CV
MO
AZ
GC
WB,CH
NOAA/ATDD Surface Flux Network
250
OBS_SH
OBS_SH-e f
200
NLDAS_SH
NDAS_SH
NAM_SH
150
NCEP model vs obs
MAY 2007
average fluxes
NARR_SH
GLDAS_SH
GDAS_SH
100
GFS_SH
50
0
-50
0
3
6
9
12
15
18
21
24
LST
250
OBS_LH
Ft. Peck, MT
H
LE
Ft. Peck, MT
Latent Heat Flux (W m-2)
Sensible Heat Flux (W m-2)
Ft. Peck, MT
OBS_LH-e f
OBS_LH-r es
200
NLDAS_LH
NDAS_LH
NAM_LH
150
NARR_LH
GLDAS_LH
GDAS_LH
100
GFS_LH
50
0
0
3
6
9
12
LST
15
18
21
24
MAY 2007 avg. H, NCEP model vs obs
Bondville, IL-2
OBS_SH
OBS_SH-e f
200
NLDAS_SH
NDAS_SH
150
NAM_SH
NARR_SH
GLDAS_SH
100
GDAS_SH
GFS_SH
50
0
-50
Sensible Heat Flux (W m-2)
Sensible Heat Flux (W m-2)
550
400
Bondville, IL
350
OBS_SH
OBS_SH-e f
Sensible Heat Flux (W m-2)
250
NLDAS_SH
300
NDAS_SH
NAM_SH
250
NARR_SH
200
GLDAS_SH
GDAS_SH
150
GFS_SH
100
50
0
-50
-100
3
6
9
12
15
18
21
24
3
6
9
12
LST
18
21
NLDAS_SH
NDAS_SH
NAM_SH
150
NARR_SH
GLDAS_SH
GDAS_SH
100
GFS_SH
50
0
NAM_SH
NARR_SH
300
GLDAS_SH
250
GDAS_SH
200
GFS_SH
150
100
50
0
0
3
6
9
12
15
18
21
24
350
Black Hills, SD
OBS_SH
OBS_SH-e f
200
NLDAS_SH
NDAS_SH
150
NAM_SH
NARR_SH
GLDAS_SH
100
GDAS_SH
GFS_SH
50
0
-50
Sensible Heat Flux (W m-2)
200
NDAS_SH
350
LST
Brookings, SD
OBS_SH-e f
NLDAS_SH
400
24
250
OBS_SH
Sensible Heat Flux (W m-2)
Sensible Heat Flux (W m-2)
15
LST
Ft. Peck, MT
OBS_SH-e f
450
-100
0
250
OBS_SH
-50
-100
0
Grassland, AZ
500
OBS_SH
300
OBS_SH-e f
NLDAS_SH
250
NDAS_SH
NAM_SH
200
NARR_SH
GLDAS_SH
150
GDAS_SH
GFS_SH
100
50
0
-50
-50
0
3
6
9
12
15
18
21
-100
-100
24
0
3
6
9
LST
15
18
21
0
24
NDAS_SH
NAM_SH
150
NARR_SH
GLDAS_SH
100
GDAS_SH
GFS_SH
50
0
OBS_SH-e f
300
NLDAS_SH
NDAS_SH
250
NAM_SH
NARR_SH
200
GLDAS_SH
GDAS_SH
150
GFS_SH
100
50
0
-50
-50
9
12
LST
15
18
21
24
12
15
18
21
Walker Branch, TN
OBS_SH
Sensible Heat Flux (W m-2)
NLDAS_SH
Sensible Heat Flux (W m-2)
200
6
9
24
350
Chestnut Ridge, TN
OBS_SH
OBS_SH-e f
3
6
LST
350
Columbia, MO
0
3
LST
250
Sensible Heat Flux (W m-2)
12
OBS_SH
300
OBS_SH-e f
NLDAS_SH
250
NDAS_SH
NAM_SH
200
NARR_SH
GLDAS_SH
150
GDAS_SH
GFS_SH
100
50
0
-50
-100
0
3
6
9
12
LST
15
18
21
24
0
3
6
9
12
LST
15
18
21
24
MAY 2007 avg. LE, NCEP model vs obs
350
OBS_LH
300
OBS_LH-r es
NLDAS_LH
250
NDAS_LH
NAM_LH
200
NARR_LH
GLDAS_LH
GDAS_LH
150
GFS_LH
100
50
OBS_LH-e f
300
OBS_LH-r es
NLDAS_LH
250
NDAS_LH
NAM_LH
200
NARR_LH
GLDAS_LH
GDAS_LH
150
GFS_LH
100
50
0
0
0
3
6
9
12
15
18
21
24
OBS_LH-r es
NLDAS_LH
NDAS_LH
NAM_LH
NARR_LH
50
GLDAS_LH
GDAS_LH
GFS_LH
0
3
6
9
12
15
18
21
0
24
3
6
9
350
250
OBS_LH-r es
200
NLDAS_LH
NDAS_LH
NAM_LH
150
NARR_LH
GLDAS_LH
GDAS_LH
100
GFS_LH
50
OBS_LH-e f
300
OBS_LH-r es
NLDAS_LH
250
NDAS_LH
NAM_LH
200
NARR_LH
GLDAS_LH
GDAS_LH
150
GFS_LH
100
50
Latent Heat Flux (W m-2)
Latent Heat Flux (W m-2)
OBS_LH-e f
15
18
21
24
OBS_LH
Black Hills, SD
OBS_LH
Brookings, SD
OBS_LH
Ft. Peck, MT
12
LST
LST
250
OBS_LH-e f
OBS_LH-r es
200
NLDAS_LH
NDAS_LH
NAM_LH
150
NARR_LH
GLDAS_LH
GDAS_LH
100
GFS_LH
50
0
0
0
0
3
6
9
12
15
18
21
24
0
3
6
9
12
LST
15
18
21
0
24
450
NLDAS_LH
NDAS_LH
300
NAM_LH
NARR_LH
250
GLDAS_LH
200
GDAS_LH
GFS_LH
150
100
50
0
Latent Heat Flux (W m-2)
350
6
9
12
LST
15
18
21
24
12
15
18
21
Walker Branch, TN
OBS_LH
400
OBS_LH-e f
OBS_LH-r es
350
NLDAS_LH
NDAS_LH
300
NAM_LH
NARR_LH
250
GLDAS_LH
200
GDAS_LH
GFS_LH
150
100
50
0
3
9
24
450
Chestnut Ridge, TN
OBS_LH-e f
OBS_LH-r es
0
6
LST
450
OBS_LH
Columbia, MO
400
3
LST
Latent Heat Flux (W m-2)
Latent Heat Flux (W m-2)
OBS_LH-e f
100
-50
0
LST
Latent Heat Flux (W m-2)
OBS_LH
Grassland, AZ
OBS_LH
Bondville, IL-2
OBS_LH-e f
Latent Heat Flux (W m-2)
Latent Heat Flux (W m-2)
Bondville, IL
Latent Heat Flux (W m-2)
350
OBS_LH
400
OBS_LH-e f
OBS_LH-r es
350
NLDAS_LH
NDAS_LH
300
NAM_LH
NARR_LH
250
GLDAS_LH
200
GDAS_LH
GFS_LH
150
100
50
0
0
3
6
9
12
LST
15
18
21
24
0
3
6
9
12
LST
15
18
21
24
LST verification 07May2006
310
300
LST verification May2006 Mean
Using surface fluxes to evaluate
land-surface physics formulations
and parameters
Sensible heat flux (bulk aerodynamic form):
H = rcpCh(Tsfc - Tair)
Latent heat flux (i.e. Penman-Monteith form):
LE = _______________________
D(Rn-G) + rcp(esfc - eair)/ra
D + g(1+rs/ra)
For a fully-vegetated surface:
Ch = exchange coefficient (=1/ra)
rs = canopy resistance (inverse canopy cond.)
Transpiration
processes/parameters:
canopy conductance (cm/s)
...e.g., effect of vapor pressure deficit on canopy conductance:
Bondville, Ill. flux site
JULY 2006
soy beans(C3)
corn (C4)
current Noah
test Noah
Vapor pressure deficit (mb)
T>20C,SWDN>600W/m2
· Better NLDAS results with new VPD option (next pages)
To reduce low LH biases during the Summer
Vapor pressure deficit function
Using a narrow range of this
tends to overestimate the
evaporation during wet
periods (spring) and
underestimate the
evaporation during dry
periods (summer).
SMHIGH and SMLOW
BXEXP
From Chen et al. 1996
Experimental Design
ARM/CART sites
•
Oklahoma Mesonet sites
ARM/CART
• CONTROL
• TEST:
Seasonal LAI
Root Fraction
Vapor Pressure Deficit Function
SIMULATION PERIOD: OCT 1996 - SEP 1999
Averaged
over 24
ARM/CART
sites
CONTROL
TEST