In 1990 the scientific community recognized, that a summer smog problem exists in Switzerland. The national scientific project POLLUMET (POLLUtion and METeorology), therefore was started. From the beginning on people felt, that numerical modeling would be an indispensable method for the investigation of this complex phenomenon. Already at that time it was well known, that the complex alpine topography in Switzerland lead to very complicated wind patterns and there was no doubt, that these would have an impact onto the transport of the pollutants. It was therefore the idea of Heinz Wanner at the geographical Institute of the University of Bern, to create a software which would equally account for meteorological and photochemical phenomena. Together with Martin Beniston he launched a project for the creation of such a tool. Beniston's mesoscale model "DREAMS" which used cartesian coordinates was used as a bases for the meteorological part. The project was able to pay the work my Ph.D. From 1990 to 1995 I created the first version of MetPhoMod (at that time called BerPhoMod, the BERnese PHOtochemical MODel). The modules included in this first version are listed in Table 1.
Table 1: Modules and techniques implemented in the first version of MetPhoMod
|
Module for |
applied techniques |
|---|---|
|
atmospheric flow and transport |
MPDATA transport scheme (Smolarkievicz, 1984), hydrostatic pressure solver. |
|
atmospheric turbulence |
Transilient turbulence module (Stull, 1988), Surface boundary layer parameterisation according to Monin-Obukhov (1954)/Businger (1971). |
|
Solar radiation |
Parameterisation according to Paltridge and Platt (1976). |
|
soil - atmosphere interface |
solving the energy balance at the soil surface and at the level of a "big leaf". |
|
atmospheric gas phase chemistry |
Implementation of a chemical interpreter, using the Gong & Cho (1993) numerical scheme to solve the equations. |
|
deposition of chemical species |
three resistors model. |
This first version was applied to and evaluated with the POLLUMET '93 field campaign. The model and the evaluation results have been published in a book ("Ein numerisches Modell zur Simulation des Sommersmogs, Geographica Bernensia, G47, 1996, ISBN-3-906151-05-0, see documentation).
After my Ph.D. I spent some more months at the Geographical Institute of the University of Bern. There we applied MetPhoMod in a project which intended to derive total nitrogen deposition in the rural "Seeland" region in Switzerland. At the same time I created a parallel version of the program.
In August 1996 I went to the private Met-office "Meteotest" at Bern. There we set up an environment to calculated local wind field on a daily bases with MetPhoMod. To do this, we used the freely available previsions of the American AVN model and nested MetPhoMod in the AVN domain. The daily prediction can be viewed here and here. The MetPhoMod stratus cloud model was implemented at that time.
From april 1997 until February 1999 I have worked at LPAS/EPFL. There we applied MetPhoMod to several air pollution projects. At the same time I was able to prepare version 2.0 of the model, which included a new transport scheme, a new turbulence scheme, a non-hydrostatic pressure solver, as well as a mechanism for elevated point emission sources.
MetPhoMod mainly has been developed by me (Silvan Perego), but many people at many helped me with this project:
Heinz Wanner (GIUB) and Martin Beniston had the original idea to develop MetPhoMod. They convinced the funding institutions to spend money on the project.
Beat Ihly checked the physical soundness of the model and its concept in an early phase.
Werner Eugster wrote the sunpos (sun's position) module, and discussed turbulence and deposition matters with me.
Markus Reinhardt, Alex Leuenberger, Matthias Liechti (GIUB), Thomas Kuenzle, Erich Lerch, Ueli Joss (Meteotest), Olivier Couach, Cedric Besson, Martin Junier, Vijay Sathya and Frank Kirchner (LPAS/EPFL) carried out applications with MetPhoMod in many different projects and in many contexts. Their feedback has been the major motivation for the continuous development of MetPhoMod.
Marion Gempeler and Chris Sidle (GIUB) assisted me in preparing the MetPhoMod documentation.
Frank Kirchner (LPAS/EPFL) assisted me in preparing the RACM chemistry input file.
Alain Clappier and Alberto Martilli (LPAS/EPFL) have provided excellent suggestions and have been part of many an interesting discussion which helped me improving the dynamic part of the model.
The Swiss national science foundation, the Swiss environmental office have funded the development process of MetPhoMod.
Table2 : Institutions
|
Geographical Institute of the University of Bern, group for climate and meteorology |
|
|
a private met office in Bern |
|
|
Laboratory for air pollution, Swiss federal institute of technology, Lausanne |
At the moment MetPhoMod version 2.1 is in the process of development. Its main new features will be:
The code has been changed to be C++ compatible. Some modules will be programmed in C++.
A new standardized way to incorporate new models will be integrated. All major parts of the model, such as modules, variables, input sections etc. are defined with object classes. The user can easily introduce new classes without having to change to code already existing.
A new multi-scattering radiation module will be incorporated. This module will be able to calculate atmospheric radiation with spectral radiation much more precicely.
Furthermore, there are Projects to incorporate an aerosol module. A new soil module with higher spatial resolution and accuracy is being developed.
Silvan Perego, March 1999
