1. Land surface key issues and GLASS progress Land-surface and the key issues Bart van den Hurk co-chair GLASS

2. Land surface key issues and GLASS progress Overview of key-issues Model development (parameterization and model structure) Surface characteristics/parameters Land-atmosphere interaction, feedbacks and climate change attribution Data assimilation

3. Land surface key issues and GLASS progress General developments in the past decades Increases in –number of key components ’80s: surface energy ’90s: surface hydrology ’00s: surface biochemistry ’10s: surface feedbacks (?) –spatial detail more surface types become relevant (urban, lakes) more types of land-atm interaction become relevant –contribution to predictability at various time scales

4. Land surface key issues and GLASS progress Outstanding parameterization issues (1) Hydrology P-E > 0 Often it’s not! We need: –groundwater redistribution –overland flow (river routing) and wetland formation –dynamic calibration procedures Snow Okavanga river Botswana: floodplain extent  f(local P) rms of basin discharge old scheme new scheme snow dominated basins

5. Land surface key issues and GLASS progress Outstanding parameterization issues (2) Biogeochemistry –Photosynthesis and carbon allocation used to be a “climate application”, but… –phenology (LAI) and dependence on nutrients and droughts –(temperature sensitivity of) soil respiration –releases CH 4 from wetlands, BVOC from forest, aerosol from arid or urban areas anomaly fAPAR summer 2003 (obs and modelled); Ciais et al 2005

6. Land surface key issues and GLASS progress Outstanding parameterization issues (3) Human land use and hydrology management –urban “tiles” –lakes –irrigation Siebert et al, 2005

7. Land surface key issues and GLASS progress Outstanding issues in land- atmosphere interaction To what extent is land responsible for land-atm.coupling variability? Studies with CRM and LES underway –sign of soilm-precip.feedback depends on convective parameterization P CTL (P wet -P dry ) P CTL positive feedback negative feedback Hohenegger et al, in press

8. Land surface key issues and GLASS progress Outstanding Land Data Assimilation issues (1) Multiple systems around (GLDAS, NWP systems) or coming up (Land Flux) Offline systems rely heavily on precip/rad forcing, coupled (“nudging”) systems on assumed dSM/dRH Land Flux from GRP maybe should merge concepts Science question: will DA reduce the spread in current ET estimates?

9. Land surface key issues and GLASS progress Outstanding Land Data Assimilation issues (2) Data assimilation is also developing into new observational types –(SMOS) soil moisture –LAI from NDVI (requires long assimilation window) Data assimilation and parameter estimation become increasingly intertwined –parameterization is increasingly relying on calibration rather than model structure The suite of systems requires a coordinated Land Data Assimilation Intercomparison Project (LDAIP)

10. Land surface key issues and GLASS progress Outstanding feedback/ attribution issues (1) Diagnostics for land atmosphere coupling vary widely –(Koster’s ,  P/  sm,  LCL/  sm, diurnal T/RH) …but refer to different processes …and are not always observable Integrated framework is being developed in GLASS

11. Land surface key issues and GLASS progress Outstanding feedback/ attribution issues (2) Experiments address land use in climate signal –Land use 1870 and 1992 provided to 7 GCMs …but LUCID learns that parameter transfer is far from straightforward –GCMs have different tile structures and model philosophies (e.g. yes/no phenology, yes/no prognostic albedo, …) JJA temp response of land use change

12. Land surface key issues and GLASS progress Outstanding application/ operation issues (1) Surface Tile structure –debate on “types of heterogeneity” is not as active anymore, but will increase again when spatial resolution increases (land param. in LES) –some land surface types demand complex tiling structure (e.g. floodplains/wetlands with coupling to groundwater) –tile structure determines interpretation of land use data to a large extent (see LUCID example) Coupled/offline operation –e.g. routing/groundwater need horizontal network –data assimilation of LAI needs long time window

13. Land surface key issues and GLASS progress Outstanding application/ operation issues (2) Land Information System (LIS) –LIS is increasingly suited for complex modelling/data assimilation experiments multiple LSMs coupled to WRF or using offline forcings data data assimilation capabilities –but its portability can probably be improved Also ECMWF is integrating offline surface driver into Integrated Forecasting System

14. Land surface key issues and GLASS progress Conclusions on outstanding issues Parameterization –new components (groundwater, lakes, urban, …) –new diagnostics and/or experimental set-up: Data assimilation –combination of scheme structures desired –trade-off data assimilation/parameter calibration revisited Infrastructure –need for flexible LIS-type systems will increase “What is the true contribution of the land component to the climate system?” “Does my land surface model describe this contribution sufficiently well?”

15. Land surface key issues and GLASS progress Progress report of GLASS The current structure

16. Land surface key issues and GLASS progress Some issues concerning GLASS structure PILPS-type studies are still quite active (Urban, Snow, Radiation) but does not answer the question: how good should a model be? What benchmark should be considered? Data-assimilation is not well visible in structure Difference between local and global coupling is artificial

17. Land surface key issues and GLASS progress Proposal for new structure (under discussion) benchmarking land-atmosphere coupling model data fusion metrics GLACE2 LandFlux LoCo current projects new projects PILPS-Urban SnowMIP LUCID Coordinated LDAIP RAMI4PILPS PILPS-Carbon 2

18. Land surface key issues and GLASS progress Proposal for new structure (under discussion) benchmarking land-atmosphere coupling model data fusion metrics GLACE2 LoCo PILPS-Urban SnowMIP LUCID

19. Land surface key issues and GLASS progress { Global Land Atmosphere Coupling Exp 2: GLACE2 Adressing potential seasonal predictability from land surface state Integration into WCRP/TFSP project

20. Land surface key issues and GLASS progress Perform ensembles of retrospective seasonal forecasts Initialize land states with “observations”, using GSWP approach Prescribed SSTs or the use of a coupled ocean model Initialize atmosphere with “observations”, via reanalysis Evaluate forecasts against observations Step 1: Experiment overview

21. Land surface key issues and GLASS progress Perform ensembles of retrospective seasonal forecasts Initialize land states with “observations”, using GSWP approach Initialize atmosphere with “observations”, via reanalysis Evaluate forecasts against observations Step 2: “Randomize” land initialization! Experiment overview Prescribed SSTs or the use of a coupled ocean model

22. Land surface key issues and GLASS progress Step 3: Compare skill; isolate contribution of realistic land initialization. Forecast skill obtain in experiment using realistic land initialization Forecast skill obtained in identical experiment, except that land is not initialized to realistic values Forecast skill due to land initialization Experiment overview

23. Land surface key issues and GLASS progress Group/ModelPoints of Contact 1. NASA/GSFC (USA): GMAO seasonal forecast system (old and new) 2. COLA (USA): COLA GCM, NCAR/CAM GCM 3. Princeton (USA): NCEP GCM 4. IACS (Switzerland): ECHAM GCM 5. KNMI (Netherlands): ECMWF 6. GFDL (USA): GFDL system 7. U. Gothenburg (Sweden): NCAR 8. CCSR/NIES/FRCGC (Japan): CCSR GCM # models S. Seneviratne, R. Andreas E. Wood, L. Luo P. Dirmeyer, Z. Guo R. Koster, T. Yamada2 B. van den Hurk, H. Camargo, G. Balsamo T. Gordon J.-H. Jeong T. Yamada 2 1 1 2 1 1 1 11 models Confirmed participant list

24. Land surface key issues and GLASS progress Generation of SST Boundary Conditions Needed: SST conditions for forecasts that do not include measurements of SSTs during the forecast period. Approach: Determine persistence timescales from observational record (with data exclusion) and reduce initial (measured) SST anomalies with time into the forecast, using those timescales.

25. Land surface key issues and GLASS progress “Persisted” SST boundary conditions have been constructed and are now available online. (T. Yamada)

26. Land surface key issues and GLASS progress Results for Precipitation 4. Extended forecast techniques with GSFC model (Will apply to GLACE-2 models…)

27. Land surface key issues and GLASS progress Results for Air Temperature

28. Land surface key issues and GLASS progress GSWP2 Princeton June 1988 Soil Moisture Anomaly (against 1986-1995) 5. Examined forcing datasets (T. Yamada)

29. Land surface key issues and GLASS progress Many groups started simulations

30. Land surface key issues and GLASS progress Forecast ModelPoints of ContactProgress to Date NASA/GSFC, USA (GEOS-5 GCM) (NSIPP GCM) Randal Koster, Tomohito Yamada -- Simulated 50 years of land surface conditions for initialization -- Initial trial forecasts underway. COLA, USA (COLA GCM) (NCAR/CAM GCM) Paul Dirmeyer, Zhichang Guo -- Forcing data interpolated to proper resolution; offline land simulations proceeding. NCEP (via Princeton, USA) Eric Wood, Lifeng Luo -- Simulated 50 years of land surface conditions for initialization. -- Ready to go; waiting for time on NCEP machine. ECHAM (via IACS, Switzerland) Sonia Seneviratne, Roesch Andreas -- Series 2 simulations for GSWP2 period have begun (306 2-month simulations already performed). 7. Monitored, helped groups as needed…

31. Land surface key issues and GLASS progress Forecast ModelPoints of ContactProgress to Date ECMWF (via KNMI, the Netherlands) Bart van den Hurk, Helio Camargo, Gianpaolo Balsamo -- GSWP2 forcings regridded to their GCM’s resolution. -- 10-yr climatology run with the GCM, to allow for soil moisture scaling. -- Land model incorporated into LIS, for efficient offline simulation. GFDL (USA)Tony Gordon-- AMIP style control run performed for atmospheric initial conditions and for scaling of land variables. -- Experiments will start this summer. NCAR (USA, via U. Gothenburg, Sweden) Jee-Hoon Jeong-- GLACE-2 experiment prepared: the base set of simulations for the period 1986-1995 is currently being run. CCSR/NIES/FRCGC (Japan) Tomohito Yamada-- Simulated 50 years of land surface conditions for initialization.

32. Land surface key issues and GLASS progress Original timeline Summer 2007: –Finish identifying interested modeling groups Summer 2007 –Provide data to participants (meteorological forcing data, atmospheric initialization, SST conditions) Summer/Fall 2008 –Simulations due Fall/Winter 2008 –First analyses performed

33. Land surface key issues and GLASS progress New timeline Summer 2007: –Finish identifying interested modeling groups Summer 2007 –Provide data to participants (meteorological forcing data, atmospheric initialization, SST conditions) Summer/Fall 2008 –Simulations due Fall/Winter 2008 –First analyses performed Spring 2008 Fall/Winter 2008 First Spring 2009

34. Land surface key issues and GLASS progress http://gmao.gsfc.nasa.gov/research/GLACE-2/

35. Land surface key issues and GLASS progress Proposal for new structure (under discussion) benchmarking land-atmosphere coupling model data fusion metrics GLACE2 LoCo PILPS-Urban SnowMIP LUCID

36. Land surface key issues and GLASS progress Land Use and Climate – IDentification of robust impacts (LUCID) Designed to separate land use change and GHG signal Multiple phases (prescribed SST  coupled models) Phase 1: –Fixed SSTs –4 ensembles (30 yrs, 5 members) pre-industrial/present-day vegetation pre-industrial/present-day GHG & SST –7 GCMs –First results presented during sep 2008 Paris w/s

37. Land surface key issues and GLASS progress Major outcome Transfer of common landuse maps to model parameters quite variable –tiling structure –assignment of PFTs –parameter treatment (fixed/prognostic albedo, z 0 ) –phenology (prescribed/prognostic LAI) Result –Response between models not very uniform –No reason to suspect significant teleconnection patterns from land use –GRL paper (Pitman et al) being drafted

38. Land surface key issues and GLASS progress LUCID JJA LHF phenology of LAI Small difference between forest/crop LAI

39. Land surface key issues and GLASS progress Proposal for new structure (under discussion) benchmarking land-atmosphere coupling model data fusion metrics GLACE2 LoCo PILPS-Urban SnowMIP LUCID

40. Land surface key issues and GLASS progress LoCo Multiple processes Multiple diagnostics being explored Proposal for hierarchy of land-atm coupling maps (see GEWEX News November’08) Proof of concept to be applied to SGP with LIS direct PBL feedback on surface fluxes Triggering of convection Fueling convection remembering anomalies PBL cloud formation

41. Land surface key issues and GLASS progress Proposal for new structure (under discussion) benchmarking land-atmosphere coupling model data fusion metrics GLACE2 LoCo PILPS-Urban SnowMIP LUCID

42. Land surface key issues and GLASS progress PILPS-Urban (Sue Grimmond, KCL) http://geography.kcl.ac.uk/micromet/ModelComparison Aimed at evaluation of urban models –range in structure (simple plane parallel canopies  complex multicomponent canyon models) Big group (22 models!) Initial data-set (Vancouver) released for testing Presently: models are running an anonymous city –hierarchy of data releases (characteristics, calibration, validation)

43. Land surface key issues and GLASS progress Proposal for new structure (under discussion) benchmarking land-atmosphere coupling model data fusion metrics GLACE2 LoCo PILPS-Urban SnowMIP LUCID

44. Land surface key issues and GLASS progress SnowMIP (Richard Essery) BAMS overview paper submitted Main results: –focus on forest –33 models, 11 countries –sites Canada, US, Switzerland –results: accumulation and ablation ~ ok albedo ~ ok mass and difference forest/open land vary widely soil temperatures too low

45. Land surface key issues and GLASS progress SWE accumulation at open sites

46. Land surface key issues and GLASS progress Soil Temperature

47. Land surface key issues and GLASS progress Final remarks Parameterization focuses on new components Systematic benchmarking of both models and data is not well embedded but needs attention Data assimilation will benefit from LDAIC New infrastructure inspired on LIS should combine offline modelling, data fusion and benchmarking GLASS panel will get new membership