Enviro-HIRLAM

ENVIRO-HIRLAM Gas phase, aerosol and heterogeneous chemistry Each HIRLAM time step Yes... 

Status and Evaluation of Enviro-HIRLAM Differences Between Online and Offline Models... 

The purpose of this study is to illustrate some important differences between online and offline model systems and to evaluate transport, dispersion and deposition of the online coupled meteorological and chemical transport and dispersion model Enviro-HIRLAM (High Resolution Limited Area Model), which is developed at the Danish Meteorological Institute (DM1). 

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). 

The current version of Enviro-HIRLAM has not previously been evaluated against ETEX-1 measurements. The ETX domain (Eig. 5.1) was used with at time-step fixed at 10 min, and initial and boundary conditions were post-processed from the European Centre for Medium-Range Weather Eorecasts operational model, IFS (Integrated Forecast System). No surface or upper air data assimilation was employed and the model was integrated 80 h into the future. The start time was on 23 October 1994 at 12 00 UTC, 4 h before the start of the release. Output was interpolated to measurement stations in order to compare to the observations and produce statistical measures. 

The online coupled model system, Enviro-HIRLAM, which integrates a meteorological model and an atmospheric chemical transport model has been described and evaluated. 

Enviro-HIRLAM performs satisfactory with regards to transport and dispersion when simulating the ETEX-1 controlled release. 

Enviro-HIRLAM performs satisfactorily with regards to deposition when simulating the Chernobyl accident. 

The Enviro-HIRLAM is an on-line (Korsholm et al. 2008) it is also used for pollen modelling (Mahura et al. 2006 Rasmussen et al. 2006)... 

Enviro-HIRLAM (Environment-High Resolution Limited Area Model)... 

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. 

Enviro-HIRLAM includes two-way feedbacks between air pollutants and meteorological processes. Atmospheric chemical transport equations are implemented inside the meteorological comer on each time step (Chenevez et al. 2004). To make... 

At the current stage the Enviro-HIRLAM model is used as the baseline system for the HIRLAM chemical branch, and additionally to the HIRLAM community the following groups join the development team University of Copenhagen, Tartu University (Estonia), Russian State Hydro-Meteorological University and Tomsk State University, Odessa State Environmental University (Ukraine), etc. 

Fig. 16.4 Schematic description of the Integrated (On-line Coupled) Modelling System for Predicting Atmospheric Composition Enviro-HIRLAM (Environment - High Resolution Limited Area Model)...

Enviro-HIRLAM Status and Evaluation of Differences between On-line and Off-line Models Korsholm et al. 

DMI is actively working with development of the fully on-line integrated system Enviro-HIRLAM, that considers chemistry, aerosol forcing mechanisms, etc. 

Improvement of NWP itself by implementation of ACTMs and aerosol/gases forcing/feedback mechanisms into HIRLAM (mostly by online integration, like in Enviro-HIRLAM) as well as by further development of the radiation and cloud microphysics modules to introduce feedback mechanisms. 

The Enviro-HIRLAM (see its description and validation in a separate paper by Korsholm et al. in this volume) is a fully online NWP-ACT integrated system. The following steps towards Enviro-HIRLAM are being incorporated or have already been achieved (1) nesting of models for high resolutions, (2) improved resolution of boundary and surface layer characteristics and structures, (3) urbanisation of the model, (4) improvement of advection schemes, (5) implementation of chemical mechanisms, (6) implementation of aerosol dynamics, (7) realisation of feedback mechanisms, (8) assimilation of monitoring data (ongoing). 

The Enviro-HIRLAM 10-year development history is outlined as the follows ... 

Tests of new advection schemes in Enviro-HIRLAM (Univ. Copenhagen, PhD and MSc studies)... 

Decision to build HIRLAM Chemical Branch (HCB) with the Enviro-HIRLAM as a baseline system... 

Enviro-HIRLAM becomes the international project 2009 Opening of the HCB at http //hirlam.org... 

Integrated version of Enviro-HIRLAM based on the HIRLAM reference version 7.2... 

Within the completely online Enviro-HIRLAM (Baklanov et al. 2008a Korsholm et al. 2008b) the transport of chemical species is achieved in the same way like for other variables in HIRLAM (actually it was performed via the Tracer subroutine inside HIRLAM like for other scalars) on the same time steps and with the same grid. There is no need for any interface in Enviro-HIRLAM, because ACT is inside the HIRLAM model, so all the HIRLAM parameters are available for ACT. The model is designed to be used for operational as well as research purposes and comprises aerosol and gas transport, dispersion and deposition, aerosol physics and chemistry, as well as gas-phase chemistry. A Climate version Enviro-HIRHAM is also planned and will be developed in the near future. 

Several steps in implementation of specific urban dynamics and energetics have already been achieved by the HIRLAM/HARMONIE community. Enviro-HIRLAM considers a surface improved description for urban areas roughness, albedo, urban heat sources (Eaklanov et al. 2008). Properties of urban aerosol used to modify the albedo characteristics and the effective radius of cloud droplets for the SW radiation (in the HIRLAM radiation scheme). In FUMAPEX two other more sophisticated urban schemes EEP (Martilli et al. 2002) and SM2-U modules (Dupont and Mestayer 2006) were tested. They are more expensive computationally. Town energy balance (TEE) module (Masson 2000) is a part of SURFEX, available in the HARMONIE framework. Handling of the finest-scale details of momentum fluxes in town (forest) canopy could be developed. 

Sensitivity studies are needed to understand the relative importance of different feedbacks. First experience of Enviro-HIRLAM indicates some sensitivity to effective droplet size modification in radiation and cloud characteristics (Korsholm et al. in this volume). 

For simulation of the aerosol (especially anthropogenic) effects more detailed microphysics in HIRLAM is needed, in the former version it is very difficult to consider all the aerosol indirect effects. The current STRACO (Soft TRAnsition condensation) scheme in HIRLAM (Sass 2002) needs modifications and gives a possibility of developing simpler indirect mechanisms. One of such feedback semi-empirical model was developed in Enviro-HIRLAM by Korsholm et al. (2008b). The new AROMA/HARMONIE cloud scheme (Pinty and Jabouille 1998 Caniaux et al. 1994) is more suitable for implementation of aerosol dynamics and indirect effects of aerosols (CCN) models, but will be more expensive computationally. So, the main focus of our collaboration in this field should be in the improvement of the cloud/microphysics and radiation schemes in HIRLAM. 

The choice of the chemical and aerosol models for using with or implementation into HIRLAM/HARMONIE depends on specific tasks (e.g. for atmospheric pollution or for improvement of NWP). Current ACTMs of HIRLAM institutes (e.g. DACFOS, EMEP, MATCH, SELAM, etc.) are problem-oriented (air quality) and not very flexible for simple modifications. In CAC and Enviro-HIRLAM different... 

The path towards a coupled meso-scale HARMONIE-chemistry model is not clear yet. There is a possibility to use chemical components that have recently been included in AROME, but they have proved to be quite difficult to use. The Enviro-HIRLAM community is considering two different options for the development of a mesoscale coupled system either the present HARMONIE chemistry code is used and extended with the chemistry and aerosol modules and feedback mechanisms that are already included in Enviro-HIRLAM, or Enviro-HIRLAM can be extended with an updated non-hydrostatic core NH-HIRLAM from Estonia (Room et al. 2007). 

The vertical structure of PBL and SL is very important for ACTMs, so increasing the vertical resolution and improved parameterizations of BL are necessary. The meteorological improvements are already worked out for some aspects (stable PBL) and the urban characteristics should be included in the new surface scheme. In the meso-scale model the urban parametrization is already available (TEB Town Energy Budget in SURFEX and BEP Building Effect Parameter-isation in Enviro-HIRLAM). 

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