|
CIMO ET on Meteorological Radiation and Atmospheric Composition Measurements,
6-10 February 2006, Davos, Switzerland
The WMO report of this meeting is available at:
http://www.wmo.ch/web/www/IMOP/reports.html
Attendees:
Mr Klaus BEHRENS, ET Chair - Deutscher Wetterdienst, Germany
Mr Osvaldo Marcelo BARTUREN - Servicio Meteorologico Nacional, Buenos Aires
Dr L.J. Bruce McARTHUR - Meteorological Service of Canada (MSC)
Dr Wolfgang FINSTERLE - Physikalisch-Meteorologisches Observatorium Davos (PMOD), World Radiation Center (WRC), Switzerland
Mr Ibrahim REDA - National Renewable Energy Laboratory (NREL), USA
Dr Bruce FORGAN - Bureau of Meteorology, Australia
Dr Julian Gröbner - PMOD, WRC, Switzerland
Prof. Werner SCHMUTZ, Representative of BIPM, PMOD, WRC, Switzerland
Dr Nigel FOX, Representative of BIPM, National Physical Laboratory, UK
Mr Kees HOOGENDIJK, Representative of HMEI, Kipp & Zonen, Netherlands
Ms Christine CHARSTONE -Administrator HMEI
Mr Bruce SUMNER - Executive Secretary HMEI
Dr Miroslav ONDRÁŠ - WMO Secretariat, Senior Scientific Officer, OSD, WWW
Item 1.1 – Opening of the session
Klaus Behrens welcomed the team experts
and guests, and opened the meeting.
Item 1.2 - Adoption of the Agenda
Agenda was adopted with some extra additions to be put into Item 6 –
Other Business.
Item 2 - Report of the Chairman
The Chairman presented his report of ET’s activities since its establishment in 2002. He
outlined ET's responsiblity for a range of important tasks, such as the Tenth International Pyrheliometer Comparison and the establishment of the
World Infrared Radiometer Calibration Centre (IRC). Mr Behrens indicated that a major objective of this meeting was to evaluate the IRC and the World
Standard Group of absolute long-wave radiometers and to provide guidance for future IRC operations.
Comments:
1) Question: “What is the time-scale
for the work to be submitted to the “Update for the CIMO Guide”?
Considerations:
a) There
needs to be at least three people working on this, as there are at least three tasks to be done. Also there needs to be a higher priority for this task.
b) CAS
is also doing some of this work. So they need to be collaborated with.
c) Terms
of reference in CIMO Guide need to be defined for next CIMO-XIV.
2) The issue of the traceability in
the way Regional Centers measure, in comparison with the World International Standards for radiation measurements, was noted as an important point to be
discussed.
Item 3 - Work Plan
The
meeting reviewed the Work Plan and discussed possible revisions necessary for the wording of tasks and deadline dates.
The
work plan was also further reviewed in light of the discussions throughout the meeting.
Action:
Some deadlines of the work plan were revised and further matters added to the work plan.
Item 4.1 - 10th International
Pyrheliometer Comparison And Regional Pyrheliometer Comparisons (IPC–X)
 Draft Final Report of the IPC-X
Wolfgang Finisterle presented the draft final report of this IPC.
Questions were asked regarding the
variation of instrument measurements from the World Radiation Reference (WRR). The possibility that this meeting should recommend that only centers, whose measurements had
tractability proving that they fell within a defined variation from the WRR, be included in the World Standard Group.
The meeting asked Wolfgang Finisterle
to make some revisions and additions to the measurement data and the meeting will then re-look at the final report.
Please see the report at: ftp://ftp.pmodwrc.ch/stealth/ipc-x/IPC_REPORT
Report on the Ad Hoc Meeting held at the beginning of
IPC-X
This was presented by Dr Bruce Forgan,
who explained that an AD Hoc was held during the IPCs in order to ensure that the IPC is carried our in accordance with CIMO
guidelines. These meetings also define the selection criteria for observations and measurements of the IPC. Tractability for the measurements of those centers
constituting the World Standard Group, also for tractability for Regional Radiation Centers and National Radiation Centers, were an issue raised by the AD
Hoc meeting.
Item
4.2 - Infrared Radiometer Calibration Center (IRC)
The ET considered comments contributed by Mr Ibrahim Reda on the IPC and IRC.
Action:
Discussion
resulted in a recommendation to Baseline Surface Radiation Network (BSRN) requesting cooperation regarding coordination of various center’s research on pyrgeometer body radiation
coefficients.
Operating
Procedure at the Infrared Radiation Centre (IRC) of the
Physikalisch Meteorologisches Observatorium Davos, World Radiation Centre. This paper by Julian Gröbner, was the basis of
his Power Point presentation to the meeting. This PowerPoint presentation is available as a pdf at: http://www.wmo.ch/web/www/IMOP/reports/2003-2007/Infrared
Radiometer Centre.pdf
Discussion:
Traceability of instruments and measurements again became an issue in
regard to this.
ASR - All Sky Scanning Radiometer
Julian Gröbner presented information about this instrument, which is the absolute reference for
infrared pyrgeometer measurement in conjunction with World Infrared Standard Group of pyrgeometers (WISG).
Standard calibration procedures have not yet been established for
infrared instruments. Different laboratories do not agree with calibration coefficients (C, k1, k2, k3).
Dr Gröbner talked of the achievements of IRC and the various “to
do” and “in progress” tasks for the IRC, including design and build of extra newly designed instrumentation for testing procedure.
Mr Kees Hoogendijk the HMEI expert representative from Kipp
and Zonen was able to offer a potential new approach to ASR.
HMEI suggested that perhaps the WRC should like to approach
manufacturers with a view to collaborative work, as has in the past sometimes happened.
Actions:
The ET will formulate a recommendation to CIMO in regard to the IRC.
Item 5.1 - Matters related to Baseline Surface Radiation Network
Klaus Behrens presented a short paper outlining the task of
liaising with the World Climate Research Programme on matters related to the Baseline Surface Radiation Network BSRN) and informing members of developments.
Action:
The meeting agreed that the linkage between CIMO and BSRN should be strongly recognized. This will allow a clear path of traceability of both long wave
and short wave radiation calibration to world references rather than via transfers through national and region references.
Item 5.2 - Operational Practices Related to Total Ozone, UV and Aerosol Optical Depth Measurements
Mr. Osvaldo Marcelo Barturen presented the paper Report
to the Commission on Instruments and Methods of Observation OPAG on Surface Observation Technology (OPAG-Surface) Expert Team on
ATMOSPHERIC OZONE MEASUREMENTS, which outlined developments in Argentina and collaborative work worldwide in the Ozone area. It include a report
of the CAS Scientific Advisory Group for Ozone (SAG Ozone) and their recommendations to CIMO.
Discussion:
It was noted that, outside of the prevalent instruments,
Brewer, Dobson and the Russian filter instrument, used in the World Ozone and UV Data Centre (WOUDC), there existed other instruments, including some that do multiple radiation
measurements including ozone. These now needed also to be looked at to see if they are of comparable quality with the dedicated, currently accepted, ozone
instruments.
Dr.
Bruce McArthur presented the Report to the CIMO - OPAG-Surface Expert Team on Meteorological Radiation and Atmospheric Composition Measurements On
Ultra-Violet Radiation Measurements to the meeting.
The
2005 report Instruments
to Measure Solar Ultraviolet Radiation, Part 2: Broadband
Instruments
Measuring Erythemally Weighted Solar Irradiance (WMO
GAW No. 164) is available to view and download at: http://www.wmo.ch/web/arep/reports/gaw164_final_dratf.pdf
Although
significantly later than anticipated, this report was considered far more useful to the NMHS’s than the first report on spectral instruments. There are two main
chapters, one on recommended specifications and the other on calibration and characterization. The report also contains a number of annexes that may be
helpful to NMHS’s in quality assuring any data obtained from these instruments.
The meeting discussed recommendations on UV Radiation issues to
be submitted to CIMO.
The meeting also considered the Report - to the CIMO OPAG-Surface Expert Team on Meteorological
Radiation and Atmospheric Composition Measurements - on Aerosol Optical Measurements.
Item 6.1- Issues related to standardization
The meeting discussed interaction between CIMO and ISO. In order
that the CIMO Guide references could be useful updating the ISO standards on radiation measurements.
Action:
It was decided that CIMO ET recommends that WMO approach ISO to request that the standards linked to TC180/SC1 be reviewed and if
necessary updated to reflect current best practice in solar energy measurement.
HMEI noted to the meeting that it would be pleased to also work with ISO on this update.
Item 6.2 -
World, Regional and National Radiation Centres
Problems with the hierarchy traceability of radiation data to the WRR were noted
and problems of no-attendance of some RRCs at IPC-X.
Actions:
*
The ET some made recommendations for changes to the Terms of Reference for the World, Regional and National Radiation Centres.
*
In the Terms of Reference, the World Infrared Radiometer Calibration Centre will be recommended to be renamed the Infrared Radiometer Center (IRC).
*
Text to be made for revising chapter 7 Annex7C of the CIMO Guide.
Item 6.3 - The CIMO Guide
Changes to chapters 7 and 8 of the CIMO Guide where discussed.
Revisions
were proposed and discussed by the meeting, for defining the requirements of measurements of direct solar irradiance in this chapter of the CIMO Guide.
The
aim of these changes was to more precisely define the requirements such that the traceability of the measurements would be clarified.
Action:
*
The ET some made recommendations for changes to the Terms of Reference, regarding the World Infrared Radiometer Calibration Centre, including that it be
renamed as the Infrared Radiometer Center (IRC).
Revision CIMO Guide - Chapter
7 “Measurement
of radiation”.
Actions:
*
Perhaps
the most significant recommendation, for manufacturers, that the ET made was that the seventh edition of the CIMO Guide should be available on the WMO
website.
* The
ET decided on some recommendations for changes to Chapter 7 of the Guide, including revisions to the selection criteria for IPCs, in Annex 7C, in order to
create in this annex Rules describing targets to be fulfilled at IPCs.
* The
HMEI expert representative, Mr Kees
Hoogendijk from Kipp
& Zonen, also had suggestions for amendments to Chapter 7. These will be valuable contributions, giving a
manufacturers viewpoint to these changes. He has been invited to pass his comments to Dr Bruce Forgan, so that he can included them in the revision.
Revision
CIMO Guide - Chapter 8, “Measurement of sunshine duration”
Action:
Revisions
for Chapter 8 will also be written and recommended for CIMO approval.
Revision CIMO Guide -
Chapters 16, “Measurement of ozone” and Chapter 17, “Measurement of atmospheric composition”
Action:
Recommendations to CIMO, for some revisions to
these chapters, where
also agreed to.
Item
7 - Recommendations to CIMO-XIV
The
ET, from its discussions, made recommendations for CIMO-XIV, which can be seen in Annex VII of the Final Report of this Session.
Item
8 - Draft Report of the Session
The
meeting considered the draft of this meeting's Report by the CIMO Secretary and made adjustments as necessary for the final version.
Item
9 - Closing of the Session
The
chairman closed the meeting at 3.30pm, Friday 10th February 2006.
|
