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GEWEX Global Land-Atmosphere System Study (GLASS):
Updates and WGNE Connections
Joseph A. Santanello, Jr. NASA-GSFC
Co-chair: Martin Best (UK Met Office)
WGNE 27th Meeting 20 October 2011
GLASS Status and Activities - 2011 • The GLASS Mission Statement is formulated as follows: Support improved estimates
and representation of land states and fluxes in models, the interaction with the overlying atmosphere, and maximize the utilized fraction of inherent predictability.
• For the next 3 years our contribution will be based on the inertia of developments that comprise the present structure (Model Data Fusion – Benchmarking – Coupling), introduced in 2009.
Ongoing Projects (POCs):
-GLACE2 (Bart vd Hurk)
-LoCo (Joe Santanello)
-PILDAS (Rolf Reichle)
-GSWP-3 (Hyungjun Kim)
-PALS (Gab Abramowitz)
-ALMIP2 (Aaron Boone)
-GLASS-GHP Links (Mike Ek)
• LAC: Addressing land-atmosphere interaction/coupling/feedbacks in models
• MDF: Incorporates data assimilation and parameter estimation/calibration studies
• Benchmarking: Standardized way to evaluate models and their ‘goodness’
• Metrics: Diagnostics and quantification at the heart of each component
GLASS Role in GEWEX Imperatives 3. Processes: Develop diagnos.c approaches to improve process-‐level understanding of energy and water cycles in support of improved land and atmosphere models.
► Extend diagnostics of stand-alone modules or model components and establish metrics that quantify the strength of interactions and feedbacks in the coupled land-atmosphere system
GLASS Role/Actions (2013-18)
• Identify feedbacks and interactions among different processes, and build confidence in their replication in models (GLACE2, LoCo).
• Spin-up activities in advanced diagnostics through a joint pan-GEWEX effort/workshop (GRP, GLASS, GHP, and others).
• Develop metrics to aid benchmarking activities for both un-coupled and coupled modeling activities.
• With the current and expected increasing complexity of land models in terms of various hydrologic and vegetation treatments, model optimization (i.e., parameter estimation approaches) will continue to be relevant to GLASS efforts (through Model Data Fusion).
• Investigate alternative representations of sub-grid processes in land surface schemes (heterogeneity).
• Develop improved understanding of climate variability and change on land surface properties, including soils, vegetation and hydrological processes, and an associated modeling capability (GSWP3).
• Investigate the scope for development of next generation land surface models with improved representation of subsurface hydrology, including groundwater processes; identify suitable areas for their evaluation.
GLASS Role in GEWEX Imperatives 4. Modeling: Improve global and regional simula.ons and predic.ons of precipita.on, clouds, and land hydrology, and thus the en.re climate system, through accelerated development of models of the land and atmosphere. ► Target model development with a goal of improved weather and climate prediction on the global and regional scales, focusing on the core components of the land and its coupling to the atmosphere while acting as a facilitating group who supports model development and helps the community to progress.
GLASS Role/Actions (2013-18)
• Coordinate the construction of a global land reanalysis system, building on ongoing and preparatory activities in Landflux, GSWP3, GLDAS and operational weather centers.
• Develop a framework and infrastructure for evaluation of land-atmosphere feedbacks. This should include the development of more quantitative estimates of uncertainty in the land condition and how this uncertainty propagates through to the atmosphere (e.g., PBL, convection, water and energy). This objective will be advanced in conjunction with the Processes Imperative in developing diagnostics.
• Organize coordinated intercomparison experiments for a range of model components in state of the art land models, especially with regard to: groundwater hydrology; surface water treatment (snow, river routing, lakes, irrigation, and dynamic wetlands); vegetation phonology and links between carbon and water; and Land Data Assimilation systems (follow-up the PILDAS initiative).
• Evaluation of these land model components will also have to be considered in their interactive (coupled) context with the PBL, while taking into account and developing more quantitative measures of uncertainty in the land parameters and states will enable more robust evaluation of data assimilation systems.
Review of WGNE 2010
• Data assimilation is being discussed a lot more now in WGNE, and also the idea to combine the land and atmospheric data assimilation into one suite is discussed.
– This is at the heart of PILDAS, which should provide an assessment of offline LDAS in current system, and ultimately the impact of atmospheric feedback on DA approaches.
• Previously, there have not been very tight links between GLASS and WGNE.
– However - the land surface is an emerging topic in WGNE, and certainly via this data assimilation subject we should be able to have more mutual feedbacks as well.
Project for the Intercomparison of Land Data Assimila.on Systems (PILDAS)
PILDAS-‐1 Experiment Plan
Rolf Reichle* (NASA/GSFC) and
Jean-‐François Mahfouf (Météo-‐France)
*Email: [email protected] Phone: +1-‐301-‐614-‐5693
• Enable beQer communica.on among developers of land data assimilaSon systems (LDAS).
• Develop and test a framework for LDAS comparison and evaluaSon.
• Compare land assimilaSon methods.
• Conduct sensiSvity studies of assimila.on input parameters (such as model and observaSon errors).
• Provide guidance and priori.es for future land assimilaSon research and applicaSons.
• UlSmately, produce enhanced global data sets of land surface fields.
The first experiment (PILDAS-‐1) will focus on • systems targeted for weather and seasonal forecasSng at operaSonal centers and research insStuSons
• soil moisture assimilaSon • development of a framework for LDAS comparison.
PILDAS-‐1 will use • various assimilaSon approaches (EnKF, EKF, …) • “off-‐line” land model (not coupled to atmosphere) • syntheSc observaSons.
PILDAS-‐1 provides a first assessment of the capability of different assimilaSon systems to extract the useful informaSon from current and future soil moisture missions (SMOS, SMAP).
“Core group”:
• Disseminates LDAS input data (forcing, syntheSc obs).
• Collects and post-‐processes LDAS output. • Coordinates analysis of results and publicaSons.
“Par.cipants”:
• Generate syntheSc truth data and LDAS output. • Contribute to analysis of results.
TentaSve experiment setup (details TBD!):
• Domain: Red-‐Arkansas river basin
• Exchange grid: 0.25 deg lat/lon • DuraSon: 2002-‐2008
Forcing data will be provided and LDAS output is expected on the exchange grid.
ParScipaSng systems may run on their na.ve grids. ParScipaSng systems use na.ve model parameters (land cover, soil texture, …).
“TRUTH” FORCING
LSM_i
SFSM_i RZSM_i FLUX_i (truth)
Phase A
SFSM_i (obs)
NOISE
Phase B
LDAS_k
“LDAS” FORCING
SFSM_k,i RZSM_k,i FLUX_k,i (assim)
Phase C
compare
Skill_k,i Phase D
Phase A: Generate truth for i=1:NT land models (parScipants).
Phase B: Generate i=1:NT sets of syntheSc observaSons (core).
Phase C: Generate NA open loop and NA ·∙NT assim. runs (parScipants). Phase D: Analyze results (all).
Phase C:
• ParScipants must assimilate all NT sets of syntheSc observaSons at least once into their default LDAS.
• ParScipants may addiSonally use LDAS variants (different model, different assimilaSon method, different assimilaSon parameters,…).
• ParScipants choose assimilaSon algorithm and assimilaSon parameters
• LDAS output must include assimilaSon diagnosScs (O-‐F, increments, error parameters, …)
Phase D:
• Core group computes skill metrics, including
• “Normalized InformaSon ContribuSon” (Kumar et al. 2009) • “VerScal Coupling Strength” (Kumar et al. 2009)
• AssimilaSon diagnosScs (O-‐F mean, O-‐F variance etc.)
Sep 2011: Disseminate experiment plan to potenSal parScipants.
Oct 2011: Refine experiment plan (GLASS panel meeSng)
Dec 2011: Finalize domain and exchange grid. Prepare forcing data. Jan 2012: Conduct dry-‐run of enSre experiment with 2 insStuSons.
Mar 2012: Phase A – Truth integra.ons (par.cipants).
Jun 2012: Phase B – Genera.on of synthe.c observa.ons (core).
Aug 2012: Phase C – Data assimila.on experiments (par.cipants).
Oct 20112 Phase D – Analysis of experiments (all). Dec 2012: Drao publicaSons.
Which of these groups have an assimila?on system ready?
Are we missing anyone?
Institution POC Email NASA/GMAO Rolf Reichle [email protected] Meteo-France Jean-Francois Mahfouf [email protected] ECMWF Patricia de Rosnay, Gianpaolo
Balsamo [email protected], [email protected]
Environment Canada Stephane Belair [email protected] UK Met Office Martin Best, Sam Pullen [email protected] KNMI Bart van den Hurk [email protected] University of Colorado Andrew Slater [email protected] Princeton University Eric Wood [email protected] Ghent University Valentijn Pauwels, Niko Verhoest [email protected], [email protected]
Observatoire de Paris Carlos Jimenez [email protected] University of Tokyo Toshio Koike [email protected] Monash University Jeff Walker [email protected] NASA/HSB Sujay Kumar, Christa Peters-Lidard [email protected],
[email protected] Argentina Homero Lozza [email protected] MIT Dara Entekhabi, Dennis McLaughlin [email protected], [email protected]
UCLA Steve Margulis [email protected] NCEP Mike Ek [email protected] NESDIS Xiwu Zhan [email protected] Colorado State University Andrew Jones [email protected] USDA Wade Crow [email protected] CESBIO/SMOS Yann Kerr [email protected] US Air Force Weather Agency John Eylander
University of Tokyo Taikan Oki [email protected] NILU William Lahoz [email protected] SMHI Magnus Lindskog [email protected] ??? ???
Follow-‐on experiments (PILDAS-‐x) will focus on:
• AssimilaSng satellite observaSons (non-‐syntheSc) • Soil Moisture (AMSR, SMOS, SMAP) • Land Surface Temperature (MODIS) • SNOW (MODIS, AMSR)
• Uncoupled vs. Coupled assimilaSon • Current systems vary
Global Soil Wetness Project – Phase 3 • A follow-up project to the Global Soil Wetness Project 2 (1986-95) is
currently being planned. The new components being considered for this project are:
– Provide a comprehensive set of land surface states for the period including entire 20th century and recent years (~1901 – recent) that can serve as a long-term land surface reanalysis suite.
– Include carbon models, to explore/attribute a possible carbon-related effect or changes in Hydro-Energy-Eco functioning.
– Explore uncertainties of input datasets and their propagation through different schemes (LSMs) and super-ensembles (multi-input and multi-model).
– Build a robust evaluation framework through component-wise verification (e.g. routing scheme for a validation of discharge (flux); GRACE for a validation of terrestrial water storage variation (storage)).
– Includes engagement of the carbon community and inclusion of a suite of LSMs in varying hydrological and carbon treatments.
GSWP3 Design
Experiment Timespan T. Res. S. Res. Base Sim. Reference Data
EXP 1 1901 – 2008 (1987 – 2008)
3 h 0.5° 20th Century Reanalysis
GPCC, CRU, SRB
EXP 2 2001 – 2100 (2080 – 2100)
3 h 0.5° CMIP5 with 2 scenarios
GPCC, CRU, SRB
EXP 3 1998 – present 3 h 0.5° ERA Interim & MERRA
*MulTple Prcp, CRU, SRB
GSWP3 Design
Benchmarking
• PALS – The development of a beta version of the Protocol for the Analysis of Land Surface Models
(PALS, http://pals.unsw.edu. au) is underway. – PALS is a web application for evaluating land surface models and the observed data sets used
to test them (e.g. FLUXNET, CEOP). – The PALS website is designed to analyze in a standard way uploaded single site model
simulations with FLUXNET and other observations. – A related activity is that of a joint GHP-GLASS project to demonstrate benchmarking
approaches using PALS, and establishing empirical benchmarks in PALS from which to evaluate a suite a models.
• ALMIP2 (2nd AMMA Land MIP) – Experiments on a much higher spatial resolution (5km) and covers a 4 year period. – Focus on the hydrology and vegetation processes that dominate there, using high-res satellite – The project will give recommendations on the parameterization of runoff scaling. – As this project has regional hydrological aspects, it will likely serve as a collaborative project
between GLASS and GHP.
• Coupled (L-A) Benchmarking – Point of discussion for GLASS-WGNE?
Global Land-Atmosphere Coupling Experiment
- 2!
The 2nd phase of the Global Land-Atmosphere Coupling Experiment
Overall goal: Determine the degree to which realistic land surface (soil moisture) initialization contributes to forecast skill (rainfall, temperature) at 1-2 month leads
GLACE-2
• 10 GCMs
• 100 start dates (1 Apr 1986 … 15 Aug 1995)
• 10 members of 2 months runs
• 2 series – series 1: initial soil from pseudo obs – series 2: random initial soil
• Main Diagnostics: – difference in R2 relative to obs series 1 – series 2, averaged for
15-day lead periods
GRL-paper
Wet/dry quantiles
GLACE-2 Conclusions
• Skill improvement in US better than in Europe (also potential predictability in US larger)
• Skill in temperature and precipitation increases mainly in areas where: – the precipitation forcing quality is high (high station density gives better
initial soil moisture data) – soil moisture is relatively extreme – where potential predictability is high.
• Ongoing GLACE2 experiments from KNMI, ECMWF and ETH are being performed for 2000-2010 in order to check possible signals emerging from known strong droughts in this period.
• Also yet to be carried out are possible studies involving hydrological forecast models fed by the GLACE2 GCMs (Eric Wood).
GLACE-2 Publications
• Koster, R.D., S. P. P. Mahanama, T. J. Yamada, Gianpaolo Balsamo, A. A. Berg, M. Boisserie, P. A. Dirmeyer, F. J. Doblas-Reyes, G. Drewitt, C. T. Gordon, Z. Guo, J.-H. Jeong, W.-S. Lee, Z. Li, L. Luo, S. Malyshev, W. J. Merryfield, S. I. Seneviratne, T. Stanelle, B. J. J. M. van den Hurk, F. Vitart, and E. F. Wood (2011): The Second Phase of the Global Land-Atmosphere Coupling Experiment: Soil Moisture Contributions to Subseasonal Forecast Skill; J.Hydrometeorol., in press.
• Hurk, B.J.J.M. van den, F. Doblas-Reyes, G. Balsamo, R.D. Koster, S.I. Seneviratne en H. Camargo Jr, Soil moisture effects on seasonal temperature and precipitation forecast scores in Europe; Clim. Dyn., 2010, doi:10.1007/s00382-010-0956-2.
• Koster , R. D., S. Mahanama, T. Yamada, G. Balsamo, A.A. Berg, M. Boisserie, P. Dirmeyer, F. Doblas-Reyes, G. Drewitt, C.T. Gordon, Z. Guo, J.H. Jeong, D.M. Lawrence, W.-S. Lee, Z. Li, L. Luo, S. Maleyshev, W.J. Merryfield, S.I. Seneviratne, T. Stanelle, B.J.J.M. van den Hurk, F. Vitart and E.F. Wood (2010), Contribution of land surface initialization to subseasonal forecast skill: First results from a multi-model experiment, Geophys. Res. Lett., 37, L02402, doi:10.1029/2009GL041677.
Local Land-Atmosphere Coupling (LoCo)
Motivation:
• Land-atmosphere interactions (L-A) play a critical role in supporting and modulating extreme dry and wet regimes, and must therefore be quantified and simulated correctly in coupled models.
Objectives:
• Address deficiencies in NWP and climate models by developing diagnostics to quantify the strength and accuracy of the Local L-A Coupling (‘LoCo’) at the process-level.
• Develop NASA’s Land Information System coupled to the WRF mesoscale model (LIS-WRF) as a testbed to diagnose the behavior and impact of land surface (LSM) and boundary layer (PBL) coupling during dry/wet extremes in the SGP.
Deliverables:
• Diagnostics that can be applied to any model, scale, or observation (in-situ or satellite).
• Assessment of coupled model components and their integration through the land-PBL ‘process-chain’ linking the soil to precipitation.
• LIS-WRF system as a testbed for GEWEX-GLASS directed studies of LoCo and model intercomparisons.
GEWEX Global Land-Atmosphere System Study
GLACE
LoCo
Benchmarking
Land-‐Atmosphere Coupling (LAC)
Model Data Fusion (MDF)
Metrics
• LAC: Combines the global (GLACE) and local (LoCo) studies • MDF: Incorporates data assimilation and parameter estimation/calibration studies • Benchmarking: Standardized way to evaluate models and their ‘goodness’ • Metrics: Diagnostics and quantification at the heart of each component
New structure of GLASS (circa 2009)
Perspectives on Past Workshops
Sept. 2005: GLASS/GABLS workshop on local L-A coupling
Overarching Goals of LoCo
• Are the results of PILPS, GSWP, or data assimilation experiments affected by the lack of L-A coupling?
• Can we explain the physical mechanisms leading to the coupling strength differences found in GLACE or other coupled NWP/climate experiments?
• Is there an observable diagnostic that quantifies the role of local land-atmosphere coupling?
Perspectives on Past Workshops
June 2008: GLASS-WATCH LoCo Workshop
Challenges of LoCo
• Land-atmosphere coupling takes place at many different spatial and temporal scale and involves many physical processes simultaneously.
• The multi-scale and multi-process phenomenon makes a proper definition of “local” land-atmosphere coupling not easy.
• Defining the ‘Realm of LoCo’ is certainly useful for: – identifying where L-A interaction has a significant impact on the local climate – defining proper diagnostics expressing the strength of coupling – designing model intercomparison experiments in order to evaluate the coupling
(GEWEX Newsletter; van den Hurk and Blyth, 2008)
Complexity of L-A Interactions
Ek, M. B., and A. A. M. Holtslag, 2004: Influence of Soil Moisture on Boundary Layer Cloud Development. J Hydrometeorol., 5, 86-99.
Perspectives on Past Workshops
• Direct moistening/drying and heating/cooling of the PBL, and the feedback exerted by this PBL change on the surface fluxes.
• Impact of the change of the PBL depth or thermodynamic state on the formation/disappearance of PBL clouds (shallow cumulus) induced by land surface fluxes.
• Triggering and fueling of shallow or deep convection.
• The accumulation of hydrological anomalies in the soil water or snow reservoir, and the subsequent impacts of these surface states on the surface energy balance.
‘Realm of LoCo’
The temporal and spatial scale of all land-surface related processes that have a direct influence on the state of the PBL
LoCo Diagnostic Approach 2008-11 GLASS Collaborations
- Diagnose the components of GLACE at the diurnal process level:
- Our focus: Evaluate the ‘links in the chain’ and their sensitivities to land and PBL perturbations:
ΔSM → ΔEFsm → ΔPBL → ΔENT → ΔEFpbl ► ΔP/Clouds
(a) (b) (c) (d)
SM: Soil Moisture EF: Evaporative Fraction PBL: Mixed-layer quantities ENT: Entrainment fluxes at PBL top P/Cloud: Moist processes
‘LoCo Process-Chain’ defined by non-linear series of
interactions and feedbacks
LoCo Diagnostic Connections
• GLASS-LoCo Working Group - Craig Ferguson (Princeton/UTokyo)
- L-A coupling in global reanalysis (MERRA) and satellite products (AIRS, MODIS, AMSR-E)
- Obbe Tuinenburg and Cor Jacobs (Wageningen) - Global and regional reanalysis (ERA, MERRA) and Indian monsoon
- Paul Dirmeyer (COLA) - Global climate models (IFS)
- Kirsten Findell (GFDL) - Regional reanalysis (NARR) and CTP-HIlow extension
- Michael Ek (NCEP) - EF/SM analytic development with in-situ data
- Chiel van Heerwaarden (MPI) w/Bart vd Hurk (Wageningen) - Single-column and LES studies
→ WCRP OSC poster cluster in Denver, CO (October), GEWEX-NEWS review (December), and U.S. SGP targeted/synthesis study (TBD)
L-A Coupling in NU-WRF
Coupled LIS-‐WRF 1-‐km resoluSon NARR init/bdy condiSons 43 verScal levels (~42m sfc) 3 PBL + 3 LSM schemes
Land Informa.on System (LIS) Suite of LSMs w/flexible
resoluSon, forcing, parameters Provides spinup capability for
improved iniSalizaSon of land surface states
Plug-‐in design supports model calibraSon and data assimil.
LIS VerificaSon Toolkit (LVT) for intra-‐ and inter-‐model evaluaSon
PBLs in WRF YSU (Yonsei University) MYJ (Mellor-‐Yamada) • Counter-‐gradient fluxes • Level 2.5 closure
• Explicit entrainment • TKE MRF
• Based on YSU scheme • Implicit verScal diffusion
LSMs in LIS Noah (NCEP) CLM (Community Land Model) • 4 soil layers • 10 soil layers (2 cm upper)
• NCEP operaSonal • Extensive canopy/veg H-‐TESSEL (ECMWF)
• 4 soil layers • Tiled soil, canopy, snow surfaces
Impact of LIS Spinup on WRF Initialization
LIS Spinup – Noah LSM
Vol %
WRF Initial SWC
Vol %
Summary of IHOP-2002 Study
- Soil moisture differences lead to significantly different signatures of heat and moisture evolution.
- The sensitivity of the L-A coupling is thus reflected in the balance between PBL and surface fluxes.
Dry Soils
Entrainment Fluxes
7am
Sfc Fluxes
7pm
7am
- - - Observations
7pm
Model Range
Wet Soils
Dry Soils
Wet Dry
Soil Moisture (m3/m3)
Fig. 2: Daytime evolution of specific humidity vs. potential temperature for the dry and wet soil moisture locations in Fig. 1
Fig. 1: Near-surface soil moisture map of the Southern Great Plains as simulated by LIS-WRF.
Vector length = Flux Vector slope = Bowen Ratio
Santanello, J. A., C. Peters-Lidard, and S. Kumar, C. Alonge, and W.-K. Tao, 2009: A modeling and observational framework for diagnosing local land-atmosphere coupling on diurnal time scales. J. Hydrometeor., 10, 577-599.
Dry Soil Site IHOP02 – Noah + 3 PBLs
Theta-‐e (θe) and Rela.ve Humidity θe – Measure of Moist StaSc Energy and convecSve potenSal (LFC)
-‐ Entrainment dominant in drying out the PBL
• = YSU • = MYJ • = MRF
Ah
βsfc
βent
Ale
320 K
330 K 340 K
350 K 360 K 370 K
25%
100% 75%
50%
7am
7pm
Wet Soil Site IHOP02 – Noah + 3 PBLs
Theta-‐e and Rela.ve Humidity -‐ Surface fluxes and limited PBL growth support buildup of MSE and near saturated RH
• = YSU • = MYJ • = MRF
Ah βsfc
βent
Ale
320 K 330 K
340 K 350 K 360 K 370 K 25%
100% 75%
50%
7am
7pm
2006 & 2007 Soil Moisture Initialization
ARM-SGP Domain
%vol
LIS-WRF w/ 9 LSM-PBL combinations were run for case studies over the SGP region:
a) 14-20 July 2006
b) 14-20 June 2007
Each LSM was spun-up offline for 4 years prior to LIS-WRF initialization w/NLDAS forcing.
Evaluation performed using LIS’ Land surface Verification Toolkit (LVT)
%vol
Initial SM for LIS-WRF simulations
4 year spinup of the Noah LSM
2006 Land Surface Energy Balance
Dry Regime (2006)
All runs underestimate the Evaporative Fraction (EF)
TESSEL performs best overall and is unbiased
CLM performs worst for all fluxes
Coupling tends to improve the energy balance in Noah and TESS
Sensitivity to LSM >> Sensitivity to PBL scheme
2007 Land Surface Energy Balance
Wet Regime (2007)
All runs overestimate EF due to very high net radiation vs. obs
TESSEL performs worst overall, especially for Qle
Coupling produces larger RMSE/Bias is all runs, and often reverses the sign
Noah exhibits very low sensitivity to soil type or parameters (e.g. Czil)
2006 Mean Diurnal Cycles
TESSEL + YSU Domain Avg. Confirms RMSE/Bias stats
2006 Noah Spinup Domain Avg. Rnet low; Qle suffers
Noah + YSU Domain Avg. EF too low; LSM too dry
2007 Mean Diurnal Cycles
Noah + YSU Domain Avg. Rnet very high; all fluxes suffer
CLM + YSU Domain Avg. Rnet very high, but Qle is very good and Qg suffers
2007 Noah Spinup Domain Avg. Rnet low; highlights NLDAS vs. WRF difference
2006 & 2007 Sites of Interest
TESSEL + MYJ Site E4 Best Rnet, Qle, Qh, but Qg worst; best LoCo!
Noah + YSU Site E4 Bowen ratio high; see LoCo plots at this site
TESSEL + YSU Site E13 Rnet too high and manifested in Qle
Noah + YSU Site E13 Rnet high and spread out thru all 3 fluxes; best LoCo!
2006 Mixing Diagrams
Noah – Site E4 TESSEL – Site E4 CLM – Site E4 YSU MYJ MRF OBS
YSU MYJ MRF OBS
YSU MYJ MRF OBS
q*sat βsfc
βent
ΑH ΑLE
7-‐day Composites at Site E4:
Noah+ YSU
Noah+ MYJ
Noah+ MRF
TESS+ YSU
TESS+ MYJ
TESS+ MRF
CLM+ YSU
CLM+ MYJ
CLM+ MRF
RMSE T2
7676.35 4010.32 7541.49 5374.09 2260.11 5095.88 3328.06 4118.45 4494.36
Q2 4286.08 4955.41 3690.39 4033.14 2141.18 3467.70 4821.05 4238.01 4705.49 BIAS
T2 -‐7573.25 -‐3809.71 -‐7386.57 -‐4993.44 -‐2137.12 -‐4763.65 -‐3239.87 -‐4075.62 -‐4432.84
Q2 3679.64 4909.45 3108.82 3611.82 2076.45 3082.27 4777.64 3898.18 4628.91 Total
Energy -‐1946.81 549.87 -‐2138.88 -‐690.81 -‐30.33 -‐840.69 768.88 -‐88.72 98.04
Statistics based on evolution of T2m and Q2m vs. observations, derived from the mixing diagrams above.
2007 Mixing Diagrams
Noah – Site E13 TESSEL – Site E13 CLM – Site E13 YSU MYJ MRF OBS
YSU MYJ MRF OBS
YSU MYJ MRF OBS
q*sat
βsfc
βent
ΑH ΑLE
7-‐day Composites at Site E13:
Noah+ YSU
Noah+ MYJ
Noah+ MRF
TESS+ YSU
TESS+ MYJ
TESS+ MRF
CLM+ YSU
CLM+ MYJ
CLM+ MRF
RMSE T2
2002.19 1931.68 2191.51 3100.40 2479.13 3178.33 4700.82 2087.73 5499.77
Q2 2174.83 3907.56 2197.26 1305.83 1565.65 1350.86 3384.12 3029.64 3246.01 BIAS
T2 -‐1948.28 1311.79 -‐2130.07 -‐2797.02 -‐1936.05 -‐2825.40 3994.71 1312.28 4750.65
Q2 1655.55 3314.64 1705.91 640.82 277.45 786.45 2667.00 1710.91 2455.45 Total
Energy -‐146.37 2313.21 -‐212.08 -‐1078.10 -‐829.30 -‐1019.47 3330.85 1511.60 3603.05
Statistics based on evolution of T2m and Q2m vs. observations, derived from the mixing diagrams above.
PBL Heat and Moisture Budgets
Heat and moisture budgets (SFC, ENT, and TOTAL) from the LIS-WRF simulations vs. observed, derived from the mixing diagrams above.
EF vs. PBL Height
E4 and E13 Composites
14-20 July 2006
14-20 June 2007
YSU MYJ MRF ● = Noah ○ = TESS □ = CLM X = Obs
----- Diurnal Std Deviation
Evaporative Fraction vs. PBL Height for each simulation vs. observed, along with the diurnal standard deviation through the 7-day period
LCL Deficit - Timeseries
LCL Deficit = P(pbl) -‐ P(lcl) + = LCL not reached -‐ = LCL reached
Measure of how close the PBL gets to Clouds/Precip
Larger posiSve (+) indicates drying regime
Integrated measure of the diurnal land-‐PBL coupling
◘
LCL Deficit time series from each LIS-WRF run at the E4 and E13 sites.
◘
◘ = Obs
LCL Deficit - Spatial
LCL Deficit calculated spatially at 21Z on 19 June 2007 for the Noah-YSU and TESSEL-MRF simulations.
E13
LCL Deficit (mb)
E13
LoCo: Key Findings
• Significant errors exist in land surface energy balance simulations that depend on LSM and dry/wet regime.
• Noah exhibits large insensitivity to soil and flux parameters during wet conditions.
• LoCo Diagnostics can be used to evaluate LSM and PBL scheme behavior simultaneously in the context of their diurnal co-evolution.
• The sensitivity of L-A coupling is stronger towards the land during dry conditions.
• MYJ produces best total energy and PBL budgets in dry regime for all LSMs.
• CLM overestimates and TESSEL underestimates total energy in both regimes.
• PBL height is largely insensitive to surface fluxes during wet regime.
LoCo Conclusions
• The governing processes and feedbacks involved are explicitly integrated by the diurnal evolution of heat and moisture in the PBL, and therefore can be quantified using integrative diagnostic approaches.
• Mixing diagram diagnostics offer a robust methodology that requires little input and can be applied equally to observations and any modeling system.
Santanello, J. A., C. Peters-Lidard, S. Kumar, C. Alonge, and W.-K. Tao, 2009: A modeling and observational framework for diagnosing local land-atmosphere coupling on diurnal time scales. J. Hydrometeor., 10, 577-599.
Santanello, J. A., C. Peters-Lidard, and S. Kumar, 2011: Diagnosing the Sensitivity of Local Land-Atmosphere Coupling via the Soil Moisture-Boundary Layer Interaction. J. Hydromet., in press.
Santanello, J. A., C. Peters-Lidard, and S. Kumar, C. Alonge, and W.-K. Tao, 2012: Diagnosing the Nature of Land-Atmosphere Coupling During the 2006-7 Dry/Wet Extremes in the U. S. Southern Great Plains. J. Hydrometeor., in prep.
• This type of quantitative yet practical approach is a crucial first step towards a broader investigation of L-A coupling that will have implications for modeling and applications across a range of scales.
GLASS Relevance • “Committee on Assessment of Intraseasonal to Interannual Climate Prediction and
Predictability“ (NAS BASC) reported last year:
"The realistic initialization of soil moisture in models can increase the accuracy of precipitation and temperature predictions at intraseasonal timescales…. To maximize the impact of land feedbacks on prediction quality, the mechanisms underlying the land-atmosphere coupling (e.g., evaporation, boundary layer dynamics, convection) need to be better understood and better represented in forecast systems."
Recommendations in that report include: • Systematic errors in dynamical models should be identified. • The representation of physical processes should be improved to reduce errors in dynamical models. • Many sources of predictability remain to be fully exploited by ISI forecast systems.
Two bullets from recent GLASS research:
• GLACE-2 has shown that intraseasonal-seasonal prediction skill of temperature and precipitation over the U.S. can be significantly improved by realistic initialization of the land surface (soil moisture) in forecast models.
• LoCo is significantly improving our understanding of the mechanisms by which soil moisture anomalies impact weather prediction via surface fluxes and atmospheric boundary layer processes, which can inform design of a real-time monitoring network to initialize those forecasts.
GLASS-WGNE: Past
• “Land topics” don’t seem to be at the heart of WGNE
• Added value of strong links not entirely clear
• PILPS was originally co-sponsored by WGNE (?) – What has been mutually gained – Do we need another large intercomparison project?
GLASS-WGNE: Present
• Offline projects are producing improved global estimates of land surface states (GSWP) and techniques (PILDAS).
• Coupled projects show how the land impacts prediction (GLACE), and is dependent on coupling that can be diagnosed at the process-level (LoCo).
• Benchmarking both offline and coupled systems is essential for translating understanding to model development.
• GLASS panel meeting: Updates on all projects
• WCRP OSC: Project leads and posters
GLASS-WGNE: Future?
• Mutual Interests – Involvement in projects like PILDAS, GSWP3, LoCo – Coupled L-A benchmarking
• Discussion…..