vocals_vis_loop

UK - VOCALS Meeting Manchester 10 th March 2009 Leeds Activities and Plans Mirek Andrejczuk, Alan Blyth, Ralph Burton, Alan Gadian, Patricia Krecl, Jim McQuaid, Ben Parkes & Laura Stevens Progress Report: 1. Data analysis with the VACC (Patricia; see earlier separate slides) 2. High resolution lagrangian modelling ( Mirek; see later separate slides) 3. WRF modelling (Mirek & Ralph) Domain plots WRF model activities and plans 4. Sc and UM (Ben) and LEM (Laura) 5. WRF_UM climate interaction (WRF viewpoint contribution) 6. Summary of next stages.

WRF Ocean Domain Domains 500 * 500 or 400*400, nz dependent Outer domain dx=4.5km A second inner domain, dx=1.5km has so far been defined. For higher resolution simulations, a 3rd inner domain with dx=0.5km. Uses ECMWF input (a) Morrison microphysics (1 and 2 moment): (b) Basic Kessler microphysics Aim:- To produce stratocumulus

WRF Land Domain Domains of 500*500 or 400*400, nz dependent Outer domain dx=4.5km A second inner domain, dx=1.5km has so far been defined. For higher resolution simulations, a 3rd inner domain with dx=0.5km Uses ECMWF input (a) Morrison microphysics (1 and 2 moment): (b) Basic Kessler microphysics Aim:- Land Wave & Stratocumulus interactions

Current and planned modelling activities:- To take the initial base study of November 13th a. To simulate the ocean domains and land domains b. Evidence of land forcing over a 48 hour period c. Use inner domain structure to focus on the structure d. Adjust microphysical parameters for sensitivity e. Insert a hole in the cloud where qc is zero f. How does the “hole” advect over a 48 hour cycle. What is the consequences on precipitation? g. With 3rd domain, is there evidence of size circulations and entrainment in the structure.

Current and planned modelling activities:- To take the initial base study of November 13th a. To use the LEM in a study of SC in and near the Rin Brown using the LEM (100*100*100) at 20 m resolution b. Evidence of sensitivity of cloud droplet concentrations with N using LEM microphysics schemes. c. Insert a hole in the cloud d. What is the consequences on precipitation? e. Is there evidence of size circulations and entrainment in the structures produced, and the role of drizzle reaching the surface

UM and related studies (Ben) Look at the climate runs (Laura Stephen and replicate on Hector) Check the effects of No variations and seasonal results. Check long wave forcings in the model for different No values Examine flights where cloud Physics and radiometer measurements are available. Take vocals data from Eagle / Hawk. Radiometer measurements. Geos 10 measurements of albedo and SW emissivities. Compare with albedo from Geos 10 data.

CLIMATE - MODEL - UM interactions Result of meetings with Thomas, Ralph, Mirek, Len & Alan. Agreed format. Take nc data from UM in NC format and use it to produce meta data. (see details from Len) Code identified to convert directly from netcdf to “intermediate data format” Data arrived from Len on Thursday. Plan is to implement over the next few weeks. There are no impediments in principle.

CLIMATE - MODEL - UM interactions Outstanding concerns. 1. Skin temperature on different grid to the rest of the model 2. 2m (WRF) and 1.5m (UM) temperatures. 3. Concerns over hydrostatic balance of the atmosphere in the WRF data, using UM input. 4. The outer domain will nudge the WRF domain, and this may initiate perturbations at boundaries. 5. Different soil temperature levels, now not of concern. Aim: To have some results to discuss by the next 3 monthly meeting

Observational / Modelling data issues. WHAT DATA IS THERE AND WHAT DO WE NEED?

Summary and Issues We need to clarify data position on microphysics. Some data will be good and other data not so good. This needs to be clarified for the modellers. We need to ensure that we have the data required for the cloud modelling We need to ensure that there are no overlap, but also complement for specific case studies. We need to focus on the processes to be examined before the July meeting, and how we are going ro achieve the objectives. We need to examine the work we said we would complete in the relevant Work Packages. Is it wise to prioritise which data is work up first?

Summary and Issues Clarify data needed for modelling details below. Identify key processes necessary to improve the skill in simulations of SC over the SEP region Assess the progress of treating Stratocumulus clouds in regional and global climate models. Case studies of aerosol transformation and cloud interactions Simulations of cloud dynamical process, drizzle formation and open cell formation (What about entrainment and mixing) Aerosol and thermodynamics in WRF-CHEM in the prediction of the activation process. How do marine stratocumulus clouds influence climate

Work Plan. To clarify data needed for modelling activities. To obtain a “result” about the feasibility of WRF-UM climate interaction. To produce some idealised SC study results (Mirek), November 12 th 2008 To produce some first assessment of Stratocumulus representation using WRF & ECMWF initialisation LEM simulations for SC on November 13th Climate simulation studies and variation of No. Inter-comparison with radiation observations. To produce abstracts for July meeting