Earth System Prediction System: Land Modeling

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NCEP Production Suite Review:
Land-Hydrology at NCEP
Michael Ek and the EMC Land-Hydrology Team
Environmental Modeling Center (EMC)
National Centers for Environmental Prediction (NCEP)
NOAA/NWS
NCEP Production Suite Review, 6-8 December 2011
NOAA Science Center, Camp Springs, Maryland
1
Land model role: Energy Budget
• Noah land model closes the surface energy budget,
& provides surface boundary conditions to NCEP
models.
seasonal storage
2
Land model role: Hydrological Cycle
• Noah land model closes the surface water budget, &
provides surface boundary conditions to NCEP models.
3
NCEPNCAR
unified
Noah
landsurface
model
• Noah model has realistic land physics & is coupled
with NCEP short-range NAM, medium-range
GFS, and seasonal CFS, and run “uncoupled”, i.e.
NLDAS, and GLDAS (in Climate Forecast System).4
Noah Land Model Connections in
NOAA’s NWS Model Production Suite
Climate
CFS
MOM3
Oceans
Hurricane
GFDL
HWRF
HYCOM
WaveWatch III
1.7B Obs/Day
Satellites
99.9%
Global
Forecast
System
Global Data
Assimilation
Regional NAM
Dispersion
WRF NMM
(including NARR)
ARL/HYSPLIT
Severe Weather
Regional Data
Assimilation
North American Ensemble
Forecast System
Short-Range
Ensemble Forecast
WRF: ARW, NMM
ETA, RSM
GFS, Canadian Global Model
NCEPNCAR
unified
NOAH Land Surface Model
WRF NMM/ARW
Workstation WRF
Air Quality
NAM/CMAQ
Uncoupled
“NLDAS”
(drought)
For
eca
st
Rapid Update
for Aviation (ARW-based)
5
Land model validation
• Low-level observations (e.g. 2-m temperature &
humidity, 10-m winds); 10+ year data set.
• Additionally: upper air scores, precipitation threat
& bias scores, specific flux site validation.
www.emc.ncep.noaa.gov/mmb/research/nearsfc/nearsfc.verf.html
5
west
2010
east
4
July monthly diurnal 10-m wind (m/s)
3
3
2011
5
4
obs: solid, NAM: short-dash, GFS: long-dash
3
3
0
24
48
72hr
0
24
00Z Forecast Cycle
48
72hr
6
2011: NMMB & New Land Data Set
• New land-use (vegetation type)
data set based on MODIS used by
Noah land model in NAM.
Land-use type
(1-km, MODIS)
• Better surface
representation
yields better
surface fluxes
and temperature
forecasts in NAM.
7
2011: CFSv2 and Land
• Noah replaced OSU land model in CFS (from GFS).
• Global Land Data Assimilation System (GLDAS):
Daily update of land states via uncoupled Noah
driven by CFS assimilation cycle atmospheric forcing
and blended observations+model precipitation.
• Reasonable soil moisture climatology, and energy
& water budgets closure.
• Reanalysis as initial conditions for reforecasts.
May Soil Moisture
Climatology from 30-year
NCEP Climate Forecast
System Reanalysis (CFSR),
spun up from Noah land
model coupled with CFS.
8
2012: Extend GFS upgrade to NAM
• Surface layer (surface roughness) modifications in
GFS (Xubin Zeng et al, Univ. Arizona) in 2010.
Operational:
Cold bias in skin
temperature
(left), warm bias
in air temperature
(e.g. 48-hr 850mb
fcst, right).
GFS-GOES, 3-day mean: 1-3July2007
00z08Jul2008-00z10Nov2008
New roughness:
Improved skin
temperature
(left), air
temperature
(right).
9
2012: North American Land Data
Assimilation System (NLDAS)
• Noah, SAC, VIC, Mosaic land models run uncoupled,
driven by CPC observed precipitation and atmos.
forcing from NCEP North American Regional Climate
Data Assimilation System; output: 1/8-deg. land &
soil states, surface fluxes, runoff & streamflow.
• Land model runs provide a 30-year climatology.
• Anomalies used for drought monitoring; supports
National Integrated Drought Information System.
www.emc.ncep.noaa.gov/mmb/nldas
July 30-year climo.
July 1988 (drought)
July 1993 (flood)
July 2011
NLDAS four-model ensemble monthly soil moisture anomaly
10
2012: New land data sets
GVF
Green Vegetation Frac. (AVHRR)
• Near realtime
greenness frac.
• LAI (Leaf Area
Index) = veg.
density
June 2007
LAI
Leaf Area Index (MODIS)
• MODIS snowfree albedo
• MODIS max
snow albedo
• Better surface representation should yield better
surface fluxes and T, RH, wind forecasts.
• Update NAM, GFS, and other NCEP systems.
11
Future Land Model/Related Upgrades
• Important for high-res (~downscaling): Lake
model & climatologies in NAM then GFS;
Fire/burned area (account for surface changes);
cycle land in future.
• Assimilation of surface quantities, e.g. soil moisture,
surface temperature, snowpack, vegetation fraction.
• Surface layer turbulent mixing in stable conditions:
affects surface fluxes and night-time temperatures.
• Under NEMS, unify Noah model in NCEP systems.
• River routing/streamflow (discharge to oceans).
• New Noah land model (coop. with NCAR/others): 3layer snowpack, explicit canopy, dynamic
vegetation, CO2-based transpiration, ground-water,
12
air quality, ecosystems & biogeochemical cycles.
Questions?
Physics “Wheel of Pain”
13
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