Swedish Meteorological and Hydrological Institute
The Swedish Meteorological and Hydrological Institute (Swedish: Sveriges Meteorologiska och Hydrologiska Institut, abbreviated SMHI) is a Government agency in Sweden and operates under the Ministry of the Environment.  SMHI has expertise within the areas of meteorology, hydrology and oceanography, and has extensive service and business operations within these areas.
SMHI's head office is located in Norrköping. Prior to 1975 it was located in Stockholm but after a decision taken in the Riksdag in 1971 it was relocated to Norrköping in 1975. SMHI also has offices in Göteborg, Malmö, Sundsvall and Upplands Väsby. To the Swedish public SMHI is mostly known for the weather forecasts in the public-service radio provided by Sveriges Radio. Many of the other major media companies in Sweden also buy weather forecasts from SMHI.
Staff and organisation
SMHI has about 650 employees. The research staff includes some 100 scientists at the Research Unit, where the Rossby Centre is part of. The research division is divided into six units: 
- Meteorological prediction and analysis
- Air quality
- Rossby Centre (Regional and Global Climate Modelling)
- Atmospheric Remote Sensing
The regional and global climate modelling is at the Rossby Centre, which was established at SMHI in 1997. 
Environmental research spans all six research units. There is also a project for providing contributions to the HIRLAM (High Resolution Limited Area Model) project.
The main goal of the research division is to support the Institute and the society with research and development. The scientists participate in many national and international research projects.
Air quality research
Some of the atmospheric pollution dispersion models developed by the air quality research unit are:
The air quality consultancy department develops and use the Airviro Air Quality Management (AQM) system.  This an integrated, web-based system for collection of meteorological and environmental data, handling of emission databases, dispersion models, etc.
Typical users are national environmental institutes, large to small city authorities , industries, environmental organizations, consultancy firms and meteorological institutes.
The most important modules of Airviro are
- EDB: emission databases, including dynamic emissions from shipping obtained from AIS data.
- Dispersion: atmospheric dispersion calculations, with the choice of several models:
- Airviro Wind Model: (SMHI) Danard diagnostic model
- Airviro Gauss: (SMHI) gaussian model
- Airviro Grid: (SMHI) simplified eulerian model
- AERMOD: (US-EPA) gaussian model
- CALPUFF: (US-EPA) puff model
- Dispersion: (SMHI) gaussian model
- OSPM: street canyon and open road model. SMHI implementation of the model by the National_Environmental_Research_Institute_of_Denmark
- MATCH: (SMHI) advanced eulerian model
- AUSTAL2000: (German Federal Environmental Agency) lagrangean model 
- Airviro Receptor model: (SMHI) inverse dispersion model.
- Airviro Heavy Gas: (SMHI) simple model for heavy gases
- Aircast: air quality forecasts
- Indico Presentation: presentation and analysis of time-series data
- Indico Validation: Validation of time-series data
- Indico Administration: handling of monitoring stations and data collection
- Indico Report: automated reports for environmental data
- Alarm: setup and handling of automated alarms
- APUB: web publishing tool
- Air pollution dispersion terminology
- List of atmospheric dispersion models
- National Environmental Research Institute of Denmark
- North West Shelf Operational Oceanographic System
- Royal Meteorological Society
- SMHI web site (in English)
- The Model Documententation System (MDS) of the European Topic Centre on Air and Climate Change (part of the European Environment Agency)
- Airviro web page
- Airviro page on Westlakes web site