Contact
Sustainable Energy Research Group
School of Civil Engineering and the Environment
University of Southampton

Address
Highfield
Southampton
SO17 1BJ, UK

Telephone
+44 (0)23 8059 2051

Fax
+44 (0)23 8067 7519

Email
serg@soton.ac.uk

more details
a


Climate Change World Weather File Generator for
World-Wide Weather Data - CCWorldWeatherGen

June to August 2009 - IMPORTANT UPDATES

Important updates have been made to CCWorldWeatherGen. If you have been using previous versions of the tool please download the current version (V 1.4) and replace your existing version. For more information on the updates please view the update notes.

What is CCWorldWeatherGen?

The climate change world weather file generator (CCWorldWeatherGen) allows you to generate climate change weather files for world-wide locations ready for use in building performance simulation programs. It uses Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report model summary data of the HadCM3 A2 experiment ensemble which is available from the IPCC Data Distribution Centre (IPCC DDC) (1,2). The tool is Microsoft® Excel based and transforms 'present-day' EPW weather files into climate change EPW or TMY2 weather files which are compatible with the majority of building performance simulation programs.

The underlying weather file generation routines of this tool are based on the so-called ‘morphing’ methodology for climate change transformation of weather data, which was developed by Belcher, Hacker and Powell (3). It builds on previous work by the Sustainable Energy Research Group on climate change transformation of UK weather data (4) (see also the web pages on the CCWeatherGen tool).

The CCWorldWeatherGen tool allows you to generate climate change weather files with a few mouse clicks. You can produce ‘morphed’ EPW and TMY2 files as well as present-day TMY2 files from the original EPW format files. The tool is made available free of charge. However, it is solely distributed WITHOUT the required baseline weather files and/or climate change scenario data! (Please view sections 2.1 and 2.2 of the CCWorldWeatherGen user manual for information on where to obtain the required baseline data.)

A journal publication detailing the underlying climate change data generation methodology used for the CCWorldWeatherGen tool is currently in preparation.

Important - please note:
The CCWorldWeatherGen tool uses coarse General Circulation Model (GCM) data. Therefore, CCWorldWeatherGen users are requested to familiarise themselves with the IPCC assessment reports to appreciate limitations and handle uncertainties of the climate change weather data generated with this tool. For sites in the UK it is recommended to use the CCWeatherGen tool instead, as this uses more detailed Regional Climate Model (RCM) data.

Copyright and Licensing Notes

The original weather files used for generating climate change adapted weather data may be copyrighted material. Therefore, generated weather files can only be used by persons or entities who possess the corresponding licensed weather files. The user of this tool takes the sole responsibility of complying with the terms and conditions of the original weather data as well as the climate change scenario data used within this tool. Files generated with this tool may not be distributed to a third party.

Disclaimer of Warranties

The entire risk as to the quality, accuracy and performance of the climate change weather data calculated with this tool is with you. In no event will the authors of the weather file generation tool be liable to you for any damages, including without limitation any lost profits, lost savings, or other incidental or consequential damages arising out of the use or inability to use this tool and/or its generated data.

Acknowledgements

The authors gratefully acknowledge the HadCM3 general circulation model (GCM) data by the UK Met Office Hadley Centre (1) which is required for this tool and can be downloaded from the IPCC Data Distribution Centre website (2). The morphing methodology for generating climate change weather data bases on the methods developed by Belcher, Hacker and Powell (3). Special thanks go to Linda Lawrie and Drury Crawley for providing guidance on the appropriate ground temperature equations for generating EPW files.

Furthermore the work of the following people / institutions that was key to compiling this weather file generator tool is also gratefully acknowledged: the ASHRAE psychrometric formulae (5), the TMY2 weather file manual by Marion and Urban (6), the EPW weather data description by Crawley, Hand and Lawrie (7), the all sky model for calculating downwelling longwave radiation by Crawford and Duchon (8), the models for calculating illuminance and sky luminance parameters from radiation data by Perez, Ineichen, Seals, Michalsky and Stewart (9), the ground temperature equation by Kusuda and Achenbach (10), the optical air mass tables provided by Kasten and Young which were used for calculating illuminance and sky luminance parameters (11) and CIBSE Guide J which was used for calculating direct normal solar radiation (12).

The self extracting download file was generated using FreeExtractor v1.44 (13).

This work has been undertaken within the project ‘Climate change implications for buildings and their technical services in tropical and moderate climates’ under the PMI2 Connect research programme funded by the British Council. This project is a joint project between the Sustainable Energy Research Group at the University of Southampton and the Department of Mechanical Engineering at the University of Malaya in Kuala Lumpur. Special thanks go to Dr Yau Yat Huang, Choo Khean Chang and Muhammad Hafiz Azizan for testing the climate change data under tropical climates. This tool represents a further development of previous work conducted under the UK Government Engineering and Physical Sciences Research Council (EPSRC) funded research programme ‘Innovation in Design, Construction & Operation of Buildings for People’ (IDCOP).

References

(1) Met Office Hadley Centre, Exeter, UK, http://www.metoffice.gov.uk
(2) IPCC Data Distribution Centre, HadCM3 climate scenario data download page, http://www.ipcc-data.org/sres/hadcm3_download.html
(3) Belcher SE, Hacker JN, Powell DS. Constructing design weather data for future climates. Building Services Engineering Research and Technology 2005; 26 (1): 49-61.
(4) Jentsch MF, Bahaj AS, James PAB. Climate change future proofing of buildings - Generation and assessment of building simulation weather files. Energy and Buildings 2008; 40 (12): 2148-2168. view paper
(5) ASHRAE. Chapter 6 - Psychrometrics. ASHRAE Handbook - Fundamentals. Atlanta: American Society of Heating Refrigerating and Air-Conditioning Engineers, 2005.
(6) Marion W, Urban K. User’s Manual for TMY2s - Typical Meteorological Years. Golden, Colorado, USA: National Renewable Energy Laboratory 1995.
(7) Crawley DB, Hand JW, Lawrie LK. Improving the weather information available to simulation programs. Building Simulation ‘99 Conference. Kyoto, Japan; 1999.
(8) Crawford TM, Duchon CE. An improved parameterization for estimating effective atmospheric emissivity for use in calculating daytime downwelling longwave radiation. Journal of Applied Meteorology 1999; 38 (4): 474-480.
(9) Perez R, Ineichen P, Seals R, Michalsky J, Stewart R. Modelling Daylight Availability and Irradiance Components from Direct and Global Irradiance. Solar Energy 1990; 44 (5): 271-289.
(10) Kusuda T, Achenbach PR. Earth temperature and thermal diffusivity at selected stations in the United States. ASHRAE Transactions 1965; 71 (1): 61-74.
(11) Kasten F, Young AT. Revised optical air mass tables and approximation formula. Applied Optics 1989; 28 (22): 4735-4738.
(12) CIBSE. CIBSE Guide J - Weather, solar and illuminance data. London: The Chartered Institution of Building Services Engineers, 2002.
(13) FreeExtractor v1.44. Disoriented Labs. http://www.disoriented.com

Download CCWorldWeatherGen V 1.4


Requirements for the CCWorldWeatherGen Tool

(a) A valid installation of Microsoft® Excel on your local hard drive. CCWorldWeatherGen was tested with the 2003 and 2007 versions. (However, the authors do not take responsibility for any compatibility issues on these or other platforms.)
(b) A ‘present-day’ EPW file. (see section 2.1 of the CCWorldWeatherGen manual)
(c) Summary data of the HadCM3 A2 climate change model predictions, which can be downloaded free of charge from the IPCC Data Distribution Centre. (see section 2.2 of the CCWorldWeatherGen manual)

CCWorldWeatherGen is provided as a self-extracting file. Please click the link below and follow the instructions on the screen.

download CCWorldWeatherGen tool and user manual

CCWorldWeatherGen Manual

All instructions required for CCWorldWeatherGen are given in the user manual. It is highly recommended to read the manual before using the tool.

view CCWorldWeatherGen manual

Feedback Wanted

Please send us your feedback and comments on the weather file generation tool. This will help us to improve its functionality in future versions.

Email mj3@soton.ac.uk or serg@soton.ac.uk

Update History
April 2009 - V 1.0
CCWorldWeatherGen available online.

May 2009 - V 1.1
'Overflow Error' on morphing of selected EPW weather files resolved.

June 2009 - V 1.2
IMPORTANT UPDATE -
A major error was resolved within the equation of time (EOT) calculations. The routines for determining the day of the year which is needed for the EOT were missing and have now been added. As a result extraterrestrial direct normal radiation, direct normal radiation and the lighting parameters were not calculated correctly in previous releases of the tool. Error with weather station ID's shorter than 5 digits causing incorrect headers in TMY2 files resolved.

July 2009 - V 1.3
IMPORTANT UPDATE - Incorrect writing of negative dry bulb and dew point temperatures in TMY2 files resolved. (EPW files were not affected by this error.) Issues with incorrect year format resolved when converting selected original EPW files into present-day TMY2 files. Error when loading HadCM3 precipitation data for sites with no rainfall for selected months fixed. Ground temperatures in EPW files provided for three depths rather than one. Ground temperature equation corrected.

August 2009 - V 1.4
Morphing error for sites with very low relative humidity fixed. Ground temperature equation improved to achieve more accurate results and to make the results more consistent with the outputs of the EnergyPlus Weather Converter. Editorial updates to the manual and the tool.
SERG 2009 last update - 13/08/2009 by mj