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GLASS and GABLS workshop on local land-atmosphere coupling


De Bilt, The Netherlands

19-21 september 2005
Last update: 21 Nov 2005

Overview

The GLASS and GABLS panels of GEWEX have  mutually planned a workshop on the importance of local Land-Atmosphere feedbacks for parameterization and data assimilation of land and PBL processes in NWP and climate models. The workshop was held in De Bilt (Netherlands), on 19-21 september 2005. It was  co-sponsored by GEWEX and KNMI. GEWEX reimburses travel costs for a limited number of participants. KNMI sponsors the costs for the meeting room and conference lunches

The main aims of the workshop are
  • to make an inventory of present experience with local land/pbl coupling, including modelling, observation and data assimilation
  • to serve as a platform for interaction between GLASS- and GABLS oriented people
  • to try to kick-off a multi-group organised experiment where models can be systematically evaluated and compared wrt their coupling behaviour on local scale.
The GLASS and GABLS panels, in particular Bert Holtslag and Bart van den Hurk, are putting together a workshop program, which consisted of the following themes
  • Theme 1: stable boundary layers: in particular a review of the results from a coupled land-atmosphere modelling study during CASES99
  • Theme 2: cloud and PBL feedbacks: adressing the synergetic role of land surface processes and PBL processes (entrainment/cloud formation)
  • Theme 3: diagnostics from SCM models: with results from multi-parameter estimation techniques under various degrees of freedom in modelled land-atmosphere coupling
  • Theme 4: coupling diagnosis from large scale models: addressing land-atmosphere feedback diagnosed from large scale models, and
  • Theme 5: data assimilation and coupling aspects: where attention is paid to the role of land-atmosphere coupling in the definition of the "optimal" state achieved by a data assimilation procedure.
The workshop started on Monday morning, September 19, with a special session about the CASES99 model intercomparison study carried out in the context of GABLS. The detailed program is given below and links to the powerpoint files are provided:


Workshop program


day
 time
 speaker
 title
Morning session: GABLS intercomparison meeting concerning CASES99 (Chair: Bert Holtslag)
Monday
 9:30
 Bert Holtslag
 Opening

9:45
 Gunilla Svensson
 Introduction second GABLS 1D Intercomparison case and set up

10:30
 Arnold Moene
 Case set up for LES models

11:00
 break

11:30
 all
 Experiences by participants and discussion on further refinements
Extra presentations given by Geert Lenderink (sensitivity studies with surface temperature and geostrophic forcing) and Vijayant Kumar (LES simulations of multi-day period)
(if needed, the session will be continued on wednesday afternoon)

13:00
 end of session & lunch break
Introduction session mutual GLASS/GABLS workshop
Monday
 14:00
 Bart van den Hurk
 Overview of GLASS issues as relevant for LOCO

14:30
 Bert Holtslag
 Overview of GABLS achievements as relevant for LOCO
Theme 1: Stable boundary layers (Chair: Bart vd Hurk)
  • experience with coupled land/atmosphere models for stable boundary layers in other regions of the world
  • ideas for parameterizations that specifically aim at a proper representation of the land/atmosphere coupling
Monday
 15:00 Gert Jan Steeneveld
 Keynote: Experiences with the (coupled) boundary-layer modelling of the three day-night period in CASES99 (JAS manuscript)

15:30
 Break

16:00
 Zbig Sorbjan Parameterizations of very stable boundary layers, derived from CASES99

16:30
 Joan Cuxart
 Mesoscale simulations of Stable Boundary Layers

17:00
 Bob Beare
 Large Eddy Simulations of an evening transition

...
 ...

18:00
 end of session and day closure (drinks)
Theme 2: Coupled boundary layer experiments and feedbacks (Chair: Bert Holtslag )
  • observational means for diagnosing land-atmosphere interaction
  • SCM experiments with cloud and pbl feedbacks for other places in the world
  • ideas for parameterizations that specifically aim at a proper representation of the land/atmosphere coupling
Tuesday 9:00
 Michael Ek
 Keynote: SCM experiments at Cabauw

9:30
 Anne McCabe
 Modeling the stable boundary layer and the role of land surface heterogeneity

10:00
 Frank Beyrich
 Some recent results on land/atmosphere interaction and ABL structure over the LITFASS area

10:30
 Fred Bosveld en Pieter Baas
 Classification of low level jets at Cabauw

11:00
 break & end of session
Theme 3: diagnostics from offline and SCM models (Chair: Bart vd Hurk)
  • SCM experiments aiming at the determination of the sensitivity of calibration parameters to the degree of coupling between land and atmosphere
  • (Offline) modelling tools to detect the importance of land-atmosphere interaction
Tuesday
 11:30
 Yuqjong Liu and Luis Bastidas
 Keynote: Parameter optimization in coupled and uncoupled models

12:00
 Yonqjiu Dai
 Results from coupling CLM with RegCM3

12:30
 break

13:30
 Eleanor Blyth
 The Joint UK Land Environment Simulator - JULES (abstract)

14:00
 Richard Essery
 Snow modelling in JULES

...
 ...

14:30
 end of session
Theme 4: coupling diagnostics from large scale models (Chair: Bart vd Hurk)
  • Evaluations of land/atmosphere coupling behaviour in reanalysis and GCM simulations
Tuesday
 14:30
 Paul Dirmeyer
 Keynote: GLACE diagnostics

15:00
 break

15:30
 Anton Beljaars
 Keynote: local land/atmosphere coupling diagnosed from the global ECMWF model

16:00
 Pier Luigi Vidale
 Land-atmosphere coupling in the high resolution Earth Simulator

...
 ...

18:00
 day closure & end of session
Evening meal supported by KNMI
Theme 5: data assimilation and coupling aspects (Chair: Bert Holtslag )
  • Comparison between offline and coupled data assimilation systems
  • Overview of data assimilation strategies with respect to their requirements of including/excluding a coupled land/atmosphere system.
Wednesday
 9:00
 Dara Entekhabi, Steven Margulis and David Flagg
 Keynote:  Data assimilation in coupled land-Boundary Layer systems (abstract)

9:30
 Joseph Santanello
 Monitoring PBL and land surface conditions from space (abstract)

10:00
 Bart vd Hurk
 Increments in the TESSEL application of ELDAS (abstract)

...
 ...

11:00
 break & end of session

11:30
Final discussion and conclusions from the workshop (conclusion slides)

13:00
 end of workshop