Spatially-Dependent Reactor Kinetics and Supporting Physics Validation Studies at the High Flux
Model validation: flux sites
description
Transcript of Model validation: flux sites
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), plusmeteorological observations and sub-surfacetemperature and soil mositure
- 11 measurement sites across CONUS
- 2+ years of data available (at NCEP)
NOAA/ATDD Surface Flux Network
FP
BV,BP
AZWB,CH
SFBH
MO
GC
CV
NCEP model vs obsMAY 2007
average fluxes
Ft. Peck, MT
H LE
MAY 2007 avg. H, NCEP model vs obs
MAY 2007 avg. LE, NCEP model vs obs
LST verification 07May2006
300
310
LST verification May2006 Mean
For a fully-vegetated surface:
Ch = exchange coefficient (=1/ra)
rs = canopy resistance (inverse canopy cond.)
Using surface fluxes to evaluateland-surface physics formulations
and parametersSensible heat flux (bulk aerodynamic form):
H = cpCh(Tsfc - Tair)Latent heat flux (i.e. Penman-Monteith form):
_______________________LE = (Rn-G) + cp(esfc - eair)/ra
+ (1+rs/ra)
Transpiration processes/parameters:
...e.g., effect of vapor pressure deficit on canopy conductance:
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cano
py c
ondu
ctan
ce (
cm/s
)
Vapor pressure deficit (mb)
soy beans(C3)
corn (C4)
Bondville, Ill. flux siteJULY 2006
T>20C,SWDN>600W/m2
current Noah
test Noah
From Chen et al. 1996
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
To reduce low LH biases during the SummerVapor pressure deficit function
Experimental Design ARM/CART sites • Oklahoma Mesonet sites
• CONTROL• TEST:Seasonal LAI
Root Fraction
Vapor Pressure Deficit Function
SIMULATION PERIOD: OCT 1996 - SEP 1999
ARM/CART
Averaged over 24 ARM/CART sites CONTROL
TEST