Chemical weather forecasting

In perspective, integrated NWP-ACTM modelling may be a promising way for future atmospheric simulation systems leading to a new generation of models for improved meteorological, environmental and chemical weather forecasting. 

The on-line implementation of environmental processes in the GEM model allows running in global uniform, global variable, and limited area configurations, allowing for multiscale chemical weather forecasting (CWF) modelling. This approach provides access to all required dynamics and physics fields for chemistry at every time step. The on-line implementation of chemistry and aerosol processes... 

The Atmospheric Chemistry Transport modelling system used is based on the off-line coupled CAMx and HIRLAM models has been developed to simulate particulate and gas-phase air pollution on different scales. It has been used to simulate short and longterm releases of different chemical species and air pollution episodes. At present it is run in a pre-operational mode 4 times per day based on 3D meteorological fields produced by the HIRLAM NWP model. Currently this modelling system is setup to perform chemical weather forecasts for a series of chemical species (such as O3, NO, NO2, CO and SO2) and forecasted 2D fields at surface are available for each model as well as an ensemble of models (based on 12 European regional air quality models). The simulated output is publicly available and it is placed at the ECMWF website (http //gems.ecmwf.int/d/products/raq/forecasts/) of the EC FP6 GEMS project. 

Fig. 17.1 Comparison between PEACE G-II airborne meteorological parameters and global chemical weather forecasting system output fields along the flight paths. Colors denote altitudes...

There are several shortcomings of the current HIRLAM and other NWP models for use in air pollution modelling and Chemical Weather Forecasting (CWF), including the following ... 

Modeling (chemical weather forecasting air quality and human health dispersion of chemicals aerosol and cloud physics)... 

Lawrence, M.G. Rasch, P.J. von Kuhlmann, R. Williams, J. Fischer, H. de Reus, M. Lelieveld, J. Cmtzen, P.J. Schultz, M. Stier, P. Huntrieser, H. Helans, J. Stohl, A. Forster, C. Elbem, H. Jakobs, H. Dickerson, R.R., 2003 Global Chemical Weather Forecasts for Field Campaign Planning Predictions and Observations of Large-Scale Features During MINOS, CONTRACE, and INDOEX , in Atmospheric Chemistry and Physics, 3 267-289. 

The advent of fast computers and the availability of detailed data on the occurrence of certain chemical species have made it possible to construct meaningful cycle models with a much smaller and faster spatial and temporal resolution. These spatial and time scales correspond to those in weather forecast models, i.e. down to 100 km and 1 h. Transport processes (e.g., for CO2 and sulfur compounds) in the oceans and atmosphere can be explicitly described in such models. These are often referred to as "tracer transport models." This type of model will also be discussed briefly in this chapter. 

Development of methods to forecast chemical weather and to assess the air quality over Europe, which also takes the impact of global climate change into account. 

Enviro-HIRLAM is an online coupled meteorological, chemical transport and dispersion model. It is based on a previous version HlRLAM-tracer and at its core lies DMI-HIRLAM, version 6.3.7 employed for limited area short range operational weather forecasting at DM1 (Chenevez et al. 2004). Eor a detailed description of the features in HIRLAM the reader is referred to the HIRLAM reference guide (Unden et al. 2002). 

As TAPM was being developed, the opportunity arose to integrate its chemical transport component with Australian Bureau of Meteorology s weather forecasting system to provide real-time weather and air pollution forecasts. TAPM already had been using historical 6-hourly BoM global analyses to initialise that model so, the... 

The Enviro-HIRLAM is an online coupled NWP and ACT model for research and forecasting of both meteorological and chemical weather (Fig. 16.4). The integrated modelling system is developed by DMI and other collaborators (Chenevez et al. 2004 Baklanov et al. 2004, 2008a Korsholm et al. 2008a, Korsholm 2009) and included by the European HIRLAM consortium as the baseline system in the HIR-LAM Chemical Branch (https //hirlam.org/trac/wiki), it is used in several countries. 

The infamous smog of Los Angeles and Tokyo (and of many large cities) is caused mainly by the existence of a vast number of motor cars whose emissions are trapped in a relatively small area. The cars emit NO2 which (in the presence of sunlight and unburned petrol) produces ozone and other chemical irritants. The NO2 often gives the air a hazy brown coloration. Some cities give the predicted daily ozone levels with the daily weather forecast The ozone is purely destructive it cannot reach the ozone layer sufficiently fast to reduce ozone depletion. 

Weather elements instruments effect on chemical agents forecasting. 

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