About

The STRÅNG model system produces instantaneous fields of global radiation, photosynthetically active radiation, UV radiation CIE weighted and direct radiation at a horizontal resolution of about 2.5 x 2.5 km and a temporal resolution of one hour. Sunshine duration is available with daily resolution. The model covers the Nordic countries with a grid of size 630 x 779. Information about direct solar radiation and global radiation from the radiation network of SMHI has been used for tuning and validation.

The resolution and model area has changed during the years: between January 1999 and May 2006 the horizontal resolution was about 22 x 22 km. Then it changed to 11 x 11 km and from March 29 2017 it changed again and is now 2.5 x 2.5 km. Also, at this time the photosynthetically active radiation changed entity from PPFD in micro moles per square meter and second to irradiance in watts per square meter.

The input and output fields that are produced by the system are adapted to the mesoscale analysis system at SMHI called MESAN. Input data also comes from the numerical weather prediction system at SMHI. It uses the AROME model within the HARMONIE script system coupled to the external SURFEX scheme, see the HIRLAM project for more informaton. Ozone fields are retrieved from the European Centre for Medium-Range Weather Forecasts (ECMWF).

The model development was financed by SMHI, the Swedish Radiation Safety Authority (Strålsäkerhetsmyndigheten, SSM) and the Swedish Environmental Protection Agency (Naturvårdsverket). The STRÅNG model is run at SMHI with financial contributions from The Swedish Environment Protection Agency (Miljövervakningen).

For more information see the STRÅNG website.

Parameters

This API supports retrieving historical model data. Different types of radiation data can be retrieved. The type is identified by it's parameter. The supported parameters are:

Parameter Meaning Availability
116 CIE UV irradiance [mW/m²] 1999-01-01 - present
117 Global irradiance [W/m²] 1999-01-01 - present
118 Direct normal irradiance [W/m²] 1999-01-01 - present
120 PAR [W/m²] 1999-01-01 - present
121 Direct horizontal irradiance [W/m²] 2017-04-18 - present
122 Diffuse irradiance [W/m²] 2017-04-18 - present

Point and Multipoint Requests

This api supports two types of requests, point requests and multipoint requests.

A point request returns historical data for a single latitude-longitude coordinate. See Get Point for more information and examples.

A multipoint request returns all data in the entire field for a given point in time. See Get Multipoint for more information and examples.

To get an analys, eg. https://opendata-download-metanalys.smhi.se/api/category/strang1g/version/1/geotype/point/lon/16.158/lat/58.5812/parameter/118/data.json, can be used to get an meteorological analys at a point near SMHI, Norrköping. To get started with the API, see Examples and Point Demo.

Licence

SMHI Open Data API is published under these Terms and conditions.