1. Transferability as a Strategy for Researching the Water Cycle and Energy Budget
E. S. Takle1, J. Roads2, W. J. Gutowski, Jr.1, B. Rockel3,
R. W. Arritt1, and I. Meinke2
1Iowa State University, Ames, IA
2Scripps Institution of Oceanography, UCSD,LaJolla, CA
3GKSS Research Centre, Geesthacht , Germany

2. “Transferability” is proposed as the next step beyond “model intercomparison projects” (MIPs) for advancing our understanding of the global energy balance and the global water cycle by use of models

3. Model Intercomparison Projects
ARCMIP
GLIMPSE
BALTIMOS
GKSS/ICTS
PRUDENCE
SGMIP
QUIRCS
RMIP
PIRCS
IRI/ARC
AMMA
LA PLATA

4. Lessons Learned from MIPs
No single model stands out as being best at simulating all variables
Most MIPs have helped individual modelers identify specific shortcomings of their models
Regional models run in climate mode simulate real sequences of events if such events are strongly coupled to the large-scale flow (stratiform precip vs. convective precip)

5. Lessons Learned…
MIP ensemble means frequently are closer to observations than any individual model
MIP ensembles recognize extreme events but fail to capture the magnitude of such extremes
Models generally capture well the diurnal and seasonal cycles of temperature, although with larger error under extreme cold and stably stratified surface conditions (ARCMIP)

6. Lessons Learned…
Most models produce too many high-level clouds, too few mid-level clouds, and too many low clouds
There is wide disagreement on partitioning between convective and stratiform precipitation even when precipitation totals agree
Some but not all models can capture the diurnal cycle of precipitation even with nocturnal convection
All models tend to produce to many light rain events and not enough high-intensity rain events

7. Lessons Learned…
All models (with 50 km resolution) fail to capture the timing between maximum and minimum 3-hourly precipitation accumulation from MCSs
Seasonal cycles of precipitation are captured over a wide range of climate regimes
Precipitation generally is underestimated in both extreme events and very moist climates

8. Transferability Objective
Regional climate model transferability experiments are designed to advance the science of high-resolution climate modeling by taking advantage of continental-scale observations and analyses.

9. Objective
Regional climate model transferability experiments are designed to advance the science of high-resolution climate modeling by taking advantage of continental-scale observations and analyses.
MIPs have helped modelers eliminate major model deficiencies. Coordinated studies with current models can advance scientific understanding of global water and energy cycles.

10. Use of Regional Models to Study Climate
How portable are our models?

11. Use of Regional Models to Study Climate
How portable are our models?
How much does “tuning” limit the general applicability to a range of climatic regions?

12. Use of Regional Models to Study Climate
How portable are our models?
How much does “tuning” limit the general applicability to a range of climatic regions?
Can we recover some of the generality of “first-principles” models by examining their behavior on a wide range of climates?

13. Transferability Working Group (TWG) Overall Objective
To understand physical processes underpinning the global energy budget, the global water cycle, and their predictability through systematic intercomparisons of regional climate simulations on several continents and through comparison of these simulated climates with coordinated continental-scale observations and analyses

14. Types of Experiments Multiple models on multiple domains (MM/MD)
Hold model choices constant for all domains

15. Types of Experiments Multiple models on multiple domains (MM/MD) Not
Hold model choices constant for all domains
Not
Single models on single domains
Single models on multiple domains
Multiple models on single domains

16. TRANSFERABILITY EXPERIMENTS FOR ADDRESSING CHALLENGES TO UNDERSTANDING GLOBAL WATER CYCLE AND ENERGY BUDGET
ARCMIP
GLIMPSE
BALTEX
BALTIMOS
BALTEX
GKSS/ICTS
PRUDENCE
MAGS
SGMIP
QUIRCS
RMIP
PIRCS
CAMP
GAPP
GAPP
GAME
GAME
LBA
LBA
IRI/ARC
AMMA
CATCH
MDB
LA PLATA
MDB

17. Specific Objectives of TWG
Provide a framework for systematic evaluation of simulations of dynamical and climate processes arising in different climatic regions

18. Specific Objectives of TWG
Provide a framework for systematic evaluation of simulations of dynamical and climate processes arising in different climatic regions
Evaluate “transferability”, that is, quality of model simulations in “non-native” regions

19. Specific Objectives of TWG
Provide a framework for systematic evaluation of simulations of dynamical and climate processes arising in different climatic regions
Evaluate “transferability”, that is, quality of model simulations in “non-native” regions
“Meta-comparison” among models and among domains

20. We recognize that…
The water cycle introduces exponential, binary, and other non-linear processes into the climate system

21. We recognize that…
The water cycle introduces exponential, binary, and other non-linear processes into the climate system
Water cycle processes occur on a wide range of scales, many being far too small to simulate in global or regional models

22. We recognize that…
The water cycle introduces exponential, binary, and other non-linear processes into the climate system
Water cycle processes occur on a wide range of scales, many being far too small to simulate in global or regional models
The water cycle creates spatial heterogeneities that feed back strongly on the energy budget and also the circulation system

23. Strategy
Identify key processes relating to the water cycle and energy budget that express themselves to different degrees in different climatic regions

24. Strategy
Identify key processes relating to the water cycle and energy budget that express themselves to different degrees in different climatic regions
Create hypotheses that can be tested by use of MM/MD experiments. Candidate examples:
“Seasonally dependent biases in cloudiness are due primarily to errors relating to soil moisture”
“Physical parameterizations connected with the water cycle are the largest source of error in simulating the diurnal temperature cycle”

25. Expected Outcomes
Improved understanding of the water cycle and its feedbacks on the energy budget and circulation system

26. Expected Outcomes
Improved understanding of the water cycle and its feedbacks on the energy budget and circulation system
Improved capability to model climate processes at regional scales

27. Expected Outcomes
Improved understanding of the water cycle and its feedbacks on the energy budget and circulation system
Improved capability to model climate processes at regional scales
Improved applicability to impacts models

28. Plan of Work
Phase 0: Write an article for BAMS summarizing lessons learned from various “MIPs” and describe how transferability experiments will provide new insight on the global climate system, particularly the water cycle and energy budget, report preliminary results

29. Plan of Work
Phase 0: Write an article for BAMS summarizing lessons learned from various “MIPs” and describe how transferability experiments will provide new insight on the global climate system, particularly the water cycle and energy budget, report preliminary results
Phase 1: Conduct pilot studies

30. Plan of Work
Phase 0: Write an article for BAMS summarizing lessons learned from various “MIPs” and describe how transferability experiments will provide new insight on the global climate system, particularly the water cycle and energy budget, report preliminary results
Phase 1: Conduct pilot studies
Phase 2: Perform sensitivity studies on key processes relating to the water cycle. Create and test hypotheses by MM/MD

31. Plan of Work
Phase 0: Write an article for BAMS summarizing lessons learned from various “MIPs” and describe how transferability experiments will provide new insight on the global climate system, particularly the water cycle and energy budget, report preliminary results
Phase 1: Conduct pilot studies
Phase 2: Perform sensitivity studies on key processes relating to the water cycle. Create and test hypotheses by MM/MD
Phase 3: Prediction, global change, new parameterizations

32. Models: Use experience gained from simulating “home domains”
Transferability Consolidates Lessons Learned from Modeling and Observations
Models: Use experience gained from simulating “home domains”

33. Models: Use experience gained from simulating “home domains”
Transferability Consolidates Lessons Learned from Modeling and Observations
Models: Use experience gained from simulating “home domains”
CEOPS: Use dominant features of the water cycle and energy budget of each CSE to generate testable hypotheses
Review what has been learned
Identify unique climate features

34. Transferability Experiments Meet GEWEX Phase II Objectives:
“Produce consistent descriptions of the Earth’s energy budget and water cycle…”

35. Transferability Experiments Meet GEWEX Phase II Objectives:
“Produce consistent descriptions of the Earth’s energy budget and water cycle…”
“Enhance the understanding of how the energy and water cycle processes contribute to climate feedback”

36. Transferability Experiments Meet GEWEX Phase II Objectives:
“Produce consistent descriptions of the Earth’s energy budget and water cycle…”
“Enhance the understanding of how the energy and water cycle processes contribute to climate feedback”
“Develop parameterizations encapsulating these processes and feedbacks for atmospheric circulation models”

37. Current Status
Three models (RSM/Scripps, Lokalmodell/GKSS, RegCM3/ISU) simulating four domains (GAPP&MAGS - North America, MDB - Australia, LBA - South America, and BALTEX - Europe)

38. Current Status
Three models (RSM/Scripps, Lokalmodell/GKSS, RegCM3/ISU) simulating four domains (GAPP&MAGS - North America, MDB - Australia, LBA - South America, and BALTEX - Europe)
More collaborating modeling groups are being sought

39. Current Status
Three models (RSM/Scripps, Lokalmodell/GKSS, RegCM3/ISU) simulating four domains (GAPP&MAGS - North America, MDB - Australia, LBA - South America, and BALTEX - Europe)
More collaborating modeling groups are being sought
Contact E. S. Takle

40. Transferability Domains and CSE Reference Sites