Dynamics-aerosol-chemistry-cloud interactions in West Africa
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University of Leeds, UK. Met Office Unified Model (UM-UKCA)

Staff & Students: John Marsham (PI), Paul Field, Alan Blyth, Barbara Brooks, Phil Rosenberg (PDRA), Geoffrey Bessardon (PhD)

Regional runs for WP4 (interacting especially with WPs 6 & 7). Mar 2015-Mar 2018

Resolution: ‘continental’~100km & 24km & 4km, ‘regional’~1km ‘local’~200m for DACCIWA observing period. Hourly diagnostics (some more frequent). 
Initial and boundary conditions: Met Office analyses, or ERA 
Aerosol and Chemistry: UKCA modal aerosol scheme with online or offline chemistry, and/or idealised aerosol
Cloud-aerosol coupling: Yes – bulk, multi-moment 
Main Science objectives: WP4, Tasks 4.4 & 4.5 
  1. Evaluation of modelled aerosols & clouds as a function of model complexity
  2. Assessment of two-way cloud-aerosol interactions and their representation as a function of model complexity: implications for radiation & rainfall, WPs 6 & 7
  3. Assessment of chemical transport & processing: implications for other WPs

Karlsruhe Institute of Technology (KIT), Germany COSMO-ART (link)

Staff & Students: Dr. Bernhard Vogel, Konrad Deetz (PhD, split WP3/WP4) Regional runs for WP3 and WP4 (interacting with WP 6). Jun 2014-Jun 2017

Domains, resolutions and durations: ‘CONTINENTAL:’ 25°W-40°E, 20°S-35°N, 28 km, 8 May – 31 July 2016 ‘SWA’: 18°W-26.6°E, 20°S-24.6°N, 5 km, 25 June – 3 July 2016 ‘REGIONAL’: 10°W-12°E, 0°-15°N, 2.5km, 2 July – 3 July 2016 (nested in ‘SWA’)

Initial and boundary conditions: ICON, MOZART

Aerosol and Chemistry: COSMO-ART with modal aerosol scheme and online coupled chemistry

Cloud-aerosol-radiation coupling: Yes, two-moment scheme and interaction with prognostic aerosol for ’REGIONAL’.

Main Science objectives: WP3
  1. Assessment of the impact of atmospheric composition on radiative forcing in particular that of aerosols.
Main Science objectives: WP4, Tasks 4.5 & 4.2 
  1. Quantification of the two-way coupling between aerosols and cloud and raindrops, focusing on the distribution and characteristics of CCN and IN, their impact on cloud characteristics and the removal of aerosol by precipitation.
  2. Quantification of cloud microphysical and dynamical behaviour across the SWA, with particular emphasis on the influence the variety of aerosol sources across the region have on stratus, cumulus and congestus clouds and their transition.
COSMO-ART forecasts: Chemistry forecast runs realized for IOP in June/July 2016 with COSMO-ART (‘CONTINENTAL’ setup). Dispersion simulations of aerosols and trace gases from natural and anthropogenic sources to support the planning of the flight routes during IOP.
Quick looks are available at: Sedoo_COSMO-ART

EUROPEAN CENTRE FOR MEDIUM-RANGE WEATHER FORECASTS/Copernicus Atmosphere Monitoring Service (ECMWF/CAMS) Composition-Integrated Forecasting System (C-IFS) model (link)

Staff: Angela Benedetti (Scientific Contact)

Provisions of boundary conditions for regional runs (relevant for WP6):

Domains, resolutions and durations: Global. 9 km (operational NWP run, no online aerosols). ~80km (CAMS run operational at the time of the DACCIWA campaign), ~40 km (CAMS current resolution) Hourly diagnostics. Duration to be decided based on partners needs.
Initial and boundary conditions: IFS analysis/C-IFS analysis.
Aerosol and Chemistry: IFS, no online aerosols/chemistry/ C-IFS including online chemistry and aerosols.
Aerosol interaction with the radiation: can be activated.
Cloud-aerosol coupling: Not working at the moment. Could be reintroduced for the DACCIWA runs, but not the focus of the global model runs.
Emissions: existing emission inventories. Can be re-run with DACCIWA emissions.

Other global runs (WP7):

Domains, resolutions and durations: same as above but for the ECMWF’s Ensemble Prediction System coupled with ocean model (80 km), monthly run, with interactive aerosols.
Aerosol and Chemistry: same as C-IFS
Aerosol interaction with the radiation: same as C-IFS
Cloud-aerosol coupling: same as above.
Emissions: existing emissions
Reanalysis: To be discussed.  

ETH Zurich, Switzerland Global climate-aerosol model ECHAM6-HAM2 (link)

Persons involved: Tanja Stanelle

Global runs for WP3, WP4, and WP7

Resolution: horizontal resolution T63 (approx. 200 km * 200 km)
Aerosol and Chemistry: HAM (aerosol model)
Anthropogenic aerosol emissions: prescribed from ACCMIP, HTAPv.2 regional emission scenarios for Africa compiled in WP2 will be used  Natural aerosol emissions (dust, sea salt, SOA) are calculated
Biomass burning aerosol emissions: prescribed from ACCMIP, GFAS
Cloud-aerosol coupling: yes (but not included for convective clouds yet)
Simulations for present (e.g., 1996-2010; (AMIP SST)) and future (e.g., 2040-2060,  SST, SIC taken from ECHAM6 CMIP5 simulations) conditions
Nudged simulation of 2016 (until October)

Main objectives:
  • WP3: (1) Evaluation of impacts of present day emissions on atmospheric composition, radiative forcing, regional public and ecosystem health in SWA (3.5) (2) Same as (1) but for future conditions (3.6)
  • WP4: Global modelling of clouds and aerosols interactions with analysis focusing on SWA (4.5)
  • WP7: Model control and sensitivity experiments (7.4) and Scenario experiments (7.5)

Karlsruhe Institute of Technology, Germany. Regional NWP-Model WRF 3.3.1 (link)

Staff & Students: Andreas Fink, Marlon Maranan (PhD)
Domains, resolutions and durations: Two-way-nested simulations encompassing the domain from 4°N to 12°N and 10°W to 15°E. WRF is conducted in convection permitting mode with a grid spacing of 3 km. The model is initialized daily at 12 UTC during the rainy season of 2016 (April to October) and is integrated for 54 hours.

Initial and boundary conditions: ECMWF analysis
Aerosol and Chemistry: Aerosol and Chemistry Model of WRF is deactivated
Cloud-aerosol coupling: Yes, Morrison two-moment scheme
Main Science objectives: WP6, Tasks 6.2 & 6.5
  1. Investigation of model's ability to simulate life cycle of different rainfall types during the rainy season in West Africa. Comparison will be made both with satellite retrievals and ground-based observations (amongst others in cooperation with WP1)
  2. Analysis of (thermo-) dynamic tendencies related to nocturnal and daytime PBL evolution during peak monsoon.
  3. Part of multi-model assessment of spatio-temporal PBL cloud development and its influence on rainfall amounts.

UPMC, Paris, France CHIMERE Model (link)

Staff & Students: Flamant Cyrille, Menut Laurent, Deroubaix Adrien (Postdoc)

Regional runs for WP3 
Domains, resolutions and durations: continental domain at ~60km and nested regional domain at ~20km ; for the AMMA period, April-July 2006 (and later for DACCIWA observational period).
Initial and boundary conditions: LMDZ

Main Science objectives: WP3, Task 3.2, 3.4, 3.5
  1. Models assessment, validation and inter-comparison of spatial scales
  2. Venting and loss of pollutants from the boundary layer, especially along the coast (sea-breeze)
  3. Impacts of emissions on radiative forcing and forecast impact of future emissions
Development of the two-way coupling aerosol-meteorology for WP4
WRF-CHIMERE development, evaluation in the SWA with DACCIWA datasets

Main Science objectives: WP4, Tasks 4.1, 4.2, 4.4, 4.5 
  1. Quantify the two-way coupling between aerosols and cloud and raindrops 
  2. Assessment of two-way cloud-aerosol interactions for predicting cloud behavior
  3. Improve the predictive capability for cloud-aerosol interactions across the region

University of York, GEOS-Chem Model

Staff & Students: Mat Evans, Eleanor Morris (PhD)

Regional runs for WP3 
Domains, resolutions and durations: Global domain at 250km and regional domain at 25km. Probably initially look at the AMMA period and then the DACCIWA observational period. 
Initial and boundary conditions: GEOS-Chem

Main Science objectives: WP3, Task 3.1, 3.4, 3.5

  1. Models assessment, validation and inter-comparison of spatial scales
  2. Impacts of emissions on radiative forcing and forecast impact of future emissions

Karlsruhe Institute of Technology (KIT), Germany ICON (link)

Staff & Students: Peter Knippertz, Anke Kniffka (Postdoc)

Sensitivity studies for WP7

Domains, resolutions and durations: Global runs with nested circular domains including continental domain 25°W–40°E, 20°S–35°N, 28 km and regional domain: 12°W–12°E, 0°–15°N, 14 km, period covered: July–September 2006, June–July 2016.
Initial and boundary conditions:
 ERA-Interim re-analysis
Aerosol and Chemistry:
climatology (Tegen, 1997)
Cloud-aerosol-radiation coupling: could be activated for individual sensitivity experiment
Main Science objectives: WP7, Tasks 7.3, 7.4, 7.5

  1. Models assessment and inter-comparison of nested and global runs.
  2. Evaluation of the forecasts produced for the campaign period, including models used in WP3 and WP7, based on campaign measurements and satellite-derived parameters.
  3. Evaluation of models in a larger temporal range to assess the representation of the WAM system based on widely used global and regional model datasets, operational products and DACCIWA specific runs.
  4. Sensitivity simulations with special emphasis on low-level cloud cover and low-level jet formation, precipitation and monsoon circulation.

Tegen, I., Hollrig, P., Chin, M., Fung, I., Jacob, D., and Penner, J.: Contribution of different aerosol species to the global aerosol extinction optical thickness: Estimates from model results, J. Geophys. Res., 102, 23895–23915, 1997.

University of Toulouse, UPS, France Meso-NH (link)

Staff & Students: Celine Mari, Jean-Pierre Chaboureau, Maud Leriche, Flore Tocquer (PDRA) , Fabien Brosse (PhD), Irene Reinares Martinez (PhD)

Regional, Cloud-resolving Model (CRM) and LES simulations for WP3 and WP6

Resolution: ‘continental’~20km & 5km, ‘regional/CRM'~2.5km ‘local’~250m for AMMA and DACCIWA observing periods.
Initial and boundary conditions: ECMWF analysis for meteorology, MOZART or GEOS-CHEM for chemistry
Aerosol and Chemistry: tracers, prognostic modal aerosol scheme with online chemistry (NOx, VOC, ozone and SOA chemistry), dust scheme
Cloud-aerosol coupling: Yes – bulk, multi-moment

Main Science objectives:


  1. To estimate the impact of convective boundary layer (thermals) on the oxidation capacity of the atmosphere in SWA
  2. To quantify the ageing and mixing of polluted plumes from major WA cities (priority on Accra, Lomé, Cotonou – case study 06-07-08 July 2016)
  1. to identify dynamical controls on precipitation related to planetary-boundary layer development and transition from stratus to convective clouds
  2. Determine the relationships between cloud dynamics, entrainment & detrainment, and the development of warm rain in warm layered and deeper congestus clouds