Scientific Advisory Committee Meeting, November 25-26, 2002
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Scientific Progress through Interdepartmental Co-operation
Hartmut Grassl
Max Planck Institute for Meteorology
Meteorological Institute, University Hamburg
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
OutlineMotivation
Results (Examples)
• Improving GCM parameterizations by LES modelling
• Complex planetary boundary layers measured and modelled
• Global distribution of semi-volatile organic compounds
Plans (Examples)
• Tropospheric aerosols and the climate of the North Atlantic region
• Persistent organic substances in and above the North Sea and
the Baltic Sea
• Evaluation of all MPI Met models by ENVISAT data
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Motivation
•Most scientific progress originates from new data that falsify and subsequently improve models
•The experimental groups and the modellers have to co-operate
•In addition corporate identity is strengthened
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
LES for GCM Parameterizations (I)Chlond/Bäuml/Roeckner
Method:
1. Determine reduction factor for different cloud types using Large-Eddy Simulations and radiative transfer calculations
2. Implement correction factor into standard two-stream scheme, diagnosing cloud type from phase and cloud thickness
Goal:
Development of a radiative transfer parameterization in the ECHAM5 model which accounts for the effect of horizontal sub-grid scale cloud variability
Basis:
Effective Thickness Approach (Cahalan, 1994): Optical thickness of clouds is reduced by a correction factor
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Geographical distribution of the mean winter albedo bias due to cloud inhomogeneity
Results:
• Albedo is reduced by 1.8 % in the global annual mean (corres-ponding to an increase of net SW radiation by 6.2 W/m2)
• Correction factors are in the range 0.4 1 for water clouds (depending on LWP), = 0.9 for ice clouds
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
LES for GCM Parameterizations (II)Chlond/Müller/Roeckner
Goals:
• advance the understanding of the physical processes that determine the thermal and dynamical state of the cloud-topped boundary layer
• evaluate and improve methods of representing shallow cloud systems in global climate models of the atmosphere
• produce comprehensive 4-D data sets using LESs
• use of LES data sets to investigate deficiencies in ECHAM using the Single Column Model (SCM) version as a test bed
• correct and improve parameterizations in ECHAM
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
LES vs SCM: Diurnal variation of LWP (FIRE)
Result: ECHAM-SCM produces a too shallow boundary layer and predicts a too low liquid water path but with a timing in phase compared with the observations
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Observation and simulation of a double boundary layer over the Baltic Sea
Bösenberg/Jacob/Hennemuth
• During PEP in BALTEX a double-layered PBL was observed over the central Baltic Sea (Gotland) by lidar and other sensors
• REMO in the BALTEX version with 1/6° horizontal resolution is capable to simulate such structures
• The model results indicate that the upper layer is the advected PBL over land
• The occurrence of an elevated layer over the marine PBL further suppresses the vertical transport of sensible and latent heat from the surface layer into the free atmosphere
• Concerning PBL structure the Baltic Sea is rather a big lake than an ocean
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Observation of the phenomenon
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Simulation of the phenomenon
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Profiles of Latent Heat Flux through Combination of an H2O-DIAL and a RADAR-RASS
Bösenberg/Peters/Wulfmeyer
Objective: Determine the vertical transport of water vapourin the boundary layer.
Approach: Eddy correlation technique using high resolution retrievals of vertical wind and water vapour.
Advantages: No assumptions on turbulence structure. Representative for large area.
Technique: RASS for vertical wind.DIAL for water vapour.
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Profiles of Latent Heat Flux through Combination of an H2O-DIAL and a RADAR-RASS
Bösenberg/Peters/Wulfmeyer
P1 P2 P3 P4From Wulfmeyer, Atmos. Sci.
Gotland 12/13 September 1996
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Vertical Structure of Aerosol Optical Properties over Europe
Bösenberg/Feichter
EARLINET• Systematic measurements of aerosol profiles at 22 stations in Europe• Quantitative lidar methods (Raman lidar, multi-angle method) applied• Quality controlled• Products: backscatter and extinction profiles, optical depth• Special measurements for diurnal cycle, Saharan dust, forest fires• 2.5 years of measurements • More than 10000 profiles
MODEL SIMULATIONS• Relaxation of the GCM towards
observed meteorology
• Calculation of the distribution of
the aerosol physical, chemical and
optical properties
• Atmospheric GCM ECHAM5-T63
(2ox2o horizontal resolution)
including aerosol microphysics
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Intercomparison Observations - Model resultsRequirements for future cooperation
• Realistic intercomparison requires:
• Modelling of observable parameters:• Backscatter and extinction, optical depth• Calculation of statistical distribution• Improved representation of the PBL• Detailed comparison for typical situations
• Improved microphysical retrievals• Improved temporal coverage
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Environmental fate of semivolatile organic compounds (SOCs), in particular persistent organic pollutants (POPs)
Lammel/Feichter
Scientific objectives: • Understanding the fate of those substances which migrate between compartments on large spatial scales• Validation of model tools used in decision making (national and international chemicals legislation / conventions)
Methodological achievements:• Multicompartment chemistry-transport model• Characterization of environmental fate by novel and appropriate indicators
Results obtained:• The persistence and long-range transport potential of SOCs are strongly (and more than expected) dependent on the location and the time of entry into the environment.
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Environmental Fate as a Function of Location of Entry DDT emission from China (overall persistence Poverall = 10 years, effective spatial spreading SSeff = 750 km)
Ocean Atmosphere
Turkey (Poverall = 13 years, SSeff = 1900 km)
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
HOAPS
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Direct and Indirect Aerosol EffectsOlaf Krüger, Johann Feichter
• Emissions: Africa (Sahara), USA, Europe
• Influence on ITCZ, NAO
• Correlations between cloud water/precipitation and
cloud albedo
• Evaluation of coupled global models with long satellite
time series (AVHRR, MODIS)
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
EXPOSURE TO PERSISTENT ORGANIC SUBSTANCES AND EFFECTS IN THE NORTH SEA AND BALTIC SEA ATMOSPHERIC AND AQUATIC ENVIRONMENTS
• INTERDISCIPLINARY:
• INTEGRATED: exposure (environmental) and effects (wildlife, humans) or: P+S+I #• GEOGRAPHIC FOCUS: German Bight (during the 1st phase)• PROCESS FOCUS: air-sea exchange (1st phase)• SUBSTANCE FOCUS: exploratory (1st phase)
Field Laboratory Modelling Atmospheric Sciences (MPI/MI) * * Oceanic Sciences (IfM) * * Chemical Analysis (IBM/FB13) *
Biological Analysis and Epidemiology (IHF)
* *
Public Health - Epidemiology (FB4) *
#D = driverP = pressureS = stateI = impactR = response
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
Conclusions
• Development of new remote sensing tools (sensors + algorithms) and LES modelling has reached a level that allows global and regional model evaluation and improvement
• Co-operation within the ZMAW will give us the capability of ecosystem model evaluation
• Our hypothesis: There is a connection between NH anthropogenic aerosol load and ITCZ as well as NAO
Scientific Advisory Committee Meeting, November 25-26, 2002
Hartmut Grassl et al.: Interdepartmental Co-operation
THE END