Guide to Meteorological Instruments and Methods of …

1 To Meteorological Instruments and Methods of ObservationWMO-No. 8 Guide to Meteorological Instruments and Methods of ObservationWMO-No. 8 Seventh edition2008 WMO-No. 8 World Meteorological Organization, 2008 The right of publication in print, electronic and any other form and in any language is reserved by WMO. Short extracts from WMO publications may be reproduced without authorization, provided that the complete source is clearly indicated. Editorial correspondence and requests to publish, reproduce or translate this publication in part or in whole should be addressed to:Chairperson, Publications BoardWorld Meteorological Organization (WMO)7 bis, avenue de la Paix Tel.

2 : +41 (0) 22 730 84 Box No. 2300 Fax: +41 (0) 22 730 80 40CH-1211 Geneva 2, Switzerland E-mail: 978-92-63-100085 NOTEThe designations employed in WMO publications and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of WMO concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or expressed in WMO publications are those of the authors and do not necessarily reflect those of WMO. The mention of specific companies or products does not imply that they are endorsed or recommended by WMO in preference to others of a similar nature which are not mentioned or of the purposes of the World Meteorological Organization (WMO) is to coordinate the activities of its 188 Members in the generation of data and information on weather, climate and water, accord-ing to internationally agreed standards.

3 With this in mind, each session of the World Meteorological Congress adopts Technical Regulations which lay down the Meteorological practices and procedures to be followed by WMO Members. These Technical Regulations are supplemented by a number of Manuals and Guides which describe in more detail the practices, procedures and specifi cations that Members are requested to follow and implement. While Manuals contain mandatory practices, Guides such as this one contain recommended first edition of the Guide to Meteorological Instruments and Methods of Observation was published in 1954 and consisted of twelve chapters.

4 Since then, standardization has remained a key concern of the Commission for Instruments and Methods of Observation (CIMO) activities, and CIMO has peri-odically reviewed the contents of the Guide , making recommendations for additions and amendments whenever present, seventh, edition is a fully revised version which includes additional topics and chapters refl ecting recent technological develop-ments. Its purpose, as with the previous editions, is to give comprehensive and up-to-date guidance on the most effective practices for carrying out Meteorological observations and measurements.

5 This edition was prepared through the collabora-tive efforts of 42 experts from 17 countries and was adopted by the fourteenth session of CIMO (Geneva, December 2006).The Guide describes most Instruments , systems and techniques in regular use, from the simplest to the most complex and sophisticated, but does not attempt to deal with Methods and Instruments used only for research or experimentally. Furthermore, the Guide is not intended to be a detailed instruction manual for use by observers and technicians, but rather, it is intended to provide the basis for the preparation of manuals by National Meteorological and Hydrological Services (NMHSs) or other interested users operating observing systems, to meet their specifi c needs.

6 However, no attempt is made to specify the fully detailed design of Instruments , since to do so might hinder their further development. It was instead considered preferable to restrict standardization to the essential requirements and to confi ne recommendations to those features which are generally most common to various confi gurations of a given instrument or measurement the Guide is written primarily for NMHSs, many other organizations and research and educa-tional institutions taking Meteorological observations have found it useful, so their require-ments have been kept in mind in the preparation of the Guide .

7 Additionally, many instrument manu-facturers have recognized the usefulness of the Guide in the development and production of instru-ments and systems especially suited to Members needs. Because of the considerable demand for this publication, a decision was taken to make it availa-ble on the WMO website to all interested , on behalf of WMO, I wish to express my gratitude to all those NMHSs, technical commis-sions, expert teams and individuals who have contributed to this publication.(M. Jarraud)Secretary-GeneralContentsPart I. MeasureMent of Meteorological VarIaBlesCHAPTER 1.

8 General .. 1 chapter 2. Measurement of temperature .. 1 chapter 3. Measurement of atmospheric pressure .. 1 chapter 4. Measurement of humidity .. 1 chapter 5. Measurement of surface wind .. 1 chapter 6. Measurement of precipitation .. 1 chapter 7. Measurement of radiation .. 1 chapter 8. Measurement of sunshine duration .. 1 chapter 9. Measurement of visibility .. 1 chapter 10. Measurement of evaporation .. 1 chapter 11. Measurement of soil moisture .. 1 chapter 12. Measurement of upper-air pressure, temperature and humidity .. 1 chapter 13. Measurement of upper 1 chapter 14.

9 Present and past weather; state of the ground .. 1 chapter 15. Observation of clouds .. 1 chapter 16. Measurement of ozone .. 1 chapter 17. Measurement of atmospheric composition .. 1 PagePart II. oBserVIng systeMsCHAPTER 1. Measurements at automatic weather stations .. 1 chapter 2. Measurements and observations at aeronautical Meteorological stations .. 1 chapter 3. Aircraft observations .. 1 chapter 4. Marine observations .. 1 chapter 5. Special profiling techniques for the boundary layer and the troposphere .. 1 chapter 6. Rocket measurements in the stratosphere and mesosphere.

10 1 chapter 7. Locating the sources of atmospherics .. 1 chapter 8. Satellite observations .. I 1 chapter 9. Radar measurements .. 1 chapter 10. Balloon techniques .. 1 chapter 11. Urban observations .. 1 chapter 12. Road Meteorological Measurements .. 1 Part III. QualIty assurance anD ManageMent of oBserVIng systeMsCHAPTER 1. Quality management .. 1 chapter 2. Sampling Meteorological variables .. 1 chapter 3. Data reduction .. 1 chapter 4. Testing, calibration and intercomparison .. 1 chapter 5. Taining of instrument specialists .. 1 lIst of contrIButors to tHe Guide .