EXERCISE 2:

The Primary Bio-aerosol Pollution (The Emission and Transport)

Model used: Enviro-HIRLAM and SILAM
        (Enviro-HIRLAM is based on the DMI version of the HIRLAM - HIgh Resolution Limited Area Model)

Teachers: Mikhail Sofiev (FMI, Finland),

Group 2.1
:
Laura Veriankaite (Lithuania), Sara Ortega Jimenez (Spain), Anton Svetlov (Russia), Anastasia Gernega (Ukraine), Elena Filatova (Russia)    

Group 2.2:
Pilvi Siljamo
(Finland), Lukasz Grewling (Poland), Ekaterina Yakovleva (Russia), Ekaterina Khoreva (Russia)

Introduction & Background:
Release of many species into the atmosphere is not controlled by the anthropogenic activity (or controlled indirectly). These species can originate from physical processes, such as wind-driven soil erosion or sea-salt production (so-called natural components), biological processes in vegetation (biogenic species), wild-land fires (partly natural, partly human-induced), etc. Release of such type of pollutants into the atmosphere and their subsequent transport are largely driven by meteorology. Usually, such species are parameterized in the atmospheric composition models via various emission models. In rare cases, fixed time-dependent emission fluxes are prescribed. Meteorology-driven transport of the non-anthropogenic species follows the same principles but the source areas evidently differ from those for anthropogenic pollutants. Therefore, depending on specific transport conditions, distribution patterns of anthropogenic and non-anthropogenic species can be both very similar and very diverse.
The considered case is an example of meteorology-promoted synchronous release and transport of anthropogenic pollutants, smoke from wild-land fires, and birch pollen.

Main Goal:
The goal of the exercise is to study how the meteorological forcing affects the non-anthropogenic emissions, first of by driving the biogenic processes, how the inter-action of anthropogenic and natural phenomena determines the large-scale atmospheric composition changes, and how the selection of meteorological driver for transport model influences the predicted dispersion patterns of various pollutants.

Specific Objectives:  
We consider simulations of two-week period in 2006 where plumes from anthropogenic sources, wild-land fires in Russia and birch forests in the Eastern Europe and Russia were synchronized by continental-scale meteorological developments and transported over Central and Northern Europe together causing strong degradation of air quality. For the case simulations group 2.1 will use the SILAM model with the ECMWF input meteorological data, group 2.2 will utilize the HIRLAM/EnviroHIRLAM fields. Both groups will perform the same set of the model simulations and compare the results.
1)  General description of emission processes. Write down and discuss the main meteorological processes determining the emission intensity from (i) anthropogenic sources, (ii) wild-land fires, (iii) vegetation flowering.
2)  Perform three independent SILAM simulations with the prescribed meteorological datasets. Simulations should include: pollen emission and transport, anthropogenic-emission driven chemical simulations and anthropogenic plus fire chemical simulations. Compare the output between the groups with regard to (i) pollen emission fields, (ii) concentrations of main chemicals and pollen, (iii) meteorological parameters provided by the drivers.
3)  perform comparison with observations and try to identify the root causes of specific performance characteristics of each model setup. The validation shall include a calculation of normalized mean square error, bias, and correlation coefficient.
4)    Summarise the results of the simulations in a form of oral presentation (max. 15 min.).

Literature List:
The students in both groups shall read these papers before the Summer School.

REQUIRED READINGS:

SILAM user’s guide.
Sofiev, M., Siljamo, P., Ranta, H., Rantio-Lehtimäki, A. (2006) Towards numerical forecasting of long-range air transport of birch pollen: theoretical considerations and a feasibility study. Int J. on Biometeorology, DOI 10 1007/s00484-006-0027-x, 50, 392-402
Hidalgo, P.J., Mangin, A., Galan, C., Hembise, O., V´azquez, L.M.,  Sanchez, O. An automated system for surveying and forecasting Olea pollen dispersion. Aerobiologia 18: 23–31, 2002.
Saarikoski, S., Sillanpää, M., Sofiev, M., Timonen, H., Saarnio, K., Teinilä, K., Karppinen, A., Kukkonen, J., Hillamo, R. (2007) Chemical composition of aerosols during a major biomass burning episode over northern Europe in spring 2006: experimental and modelling assessments. Atmosph. Environ., 41, 3577-3589
A. Stohl, T. Berg, J. F. Burkhart, A. M. Fjǽraa, C. Forster, A. Herber, Ø. Hov, C. Lunder, W. W. McMillan, S. Oltmans, M. Shiobara, D. Simpson, S. Solberg, K. Stebel, J. Ström, K. Tørseth, R. Treffeisen, K. Virkkunen, and K. E. Yttri. Arctic smoke – record high air pollution levels in the European Arctic due to agricultural fires in Eastern Europe in spring 2006. Atmos. Chem. Phys., 7, 511-534, 2007

ADDITIONAL READINGS:

Sofiev M., Siljamo, P., Valkama, I., Ilvonen, M., Kukkonen, J. (2006) A dispersion modelling system SILAM and its evaluation against ETEX data. Atmosph.Environ. , 40, 674-685, DOI:10.1016/j.atmosenv.2005.09.069
Pasken, R., Pietrowicz, J.A. Using dispersion and mesoscale meteorological models to forecast pollen concentrations. Atmospheric Environment 39 (2005) 7689–7701