Commission for Instruments and Methods of Observation Fourteenth Session Geneva, 7 – 14 December 2006 INSTRUMENTS AND METHODS OF OBSERVATION FOR SURFACE MEASUREMENTS (OPAG Surface) surface technology and measurement techniques (ET-ST&MT)

Major topics Automation of visual and subjective observations Information on available instrumentation and instrument development Measurements in harsh environments Design, layout and representativeness of weather stations Urban and road meteorological measurements Cost reduction

Major topics Automation of visual and subjective observations Information on available instrumentation and instrument development Measurements in harsh environments Design, layout and representativeness of weather stations Urban and road meteorological measurements Cost reduction

Automation of visual and subjective observations Automation of manned observations –Low impact on instrument measurements but: quality assurance & siting is critical –Uniform and standardized determination of Present/Past Weather (visual & subjective observations) remains unsolved “Observing the weather is more than measuring a set of variables”

Quality assurance Automation of visual and subjective observations Ref.: World Climate Data and Monitoring Programme, WCDMP-52 (GUIDELINES ON CLIMATE OBSERVATION NETWORKS AND SYSTEMS) (Photo: Meteorological Service of Canada)

Layout of a station Automation of visual and subjective observations Manual on the GOS: Layout of an observing station in the northern hemisphere showing minimum distances between installations (Source: UK Meteorological Office, Observer's Handbook, 4th edition, 1982)

Representativety Automation of visual and subjective observations Ref.: World Climate Data and Monitoring Programme, WCDMP-52 (GUIDELINES ON CLIMATE OBSERVATION NETWORKS AND SYSTEMS) (Photo: Meteorological Service of Canada) Siting & exposure Intercomparing MAN ↔ AUT (Photo: Finnish Meteorological Institute, Finland)

Representativety Layout of a station Siting & exposure Intercomparing Automation of visual and subjective observations Documented in CIMO Guide, IOM reports. Like with instrument measurements to provide the traditional physical variables, like temperature, pressure, wind, etc. In fact increased flexibility

Automation of visual and subjective observations However: Assessment of the state and development of the atmosphere, and of significant weather Remains critical, i.e. Subjective observations or qualitative data has to be converted into quantitative data or variables To be able to generate requested information

Automation of visual and subjective observations How to register quantitatively specific weather phenomena on remote distance, like: ­significant phenomena (thunder, obscuration, showers, fog patches or whirls in the vicinity) ­different mixtures of precipitation types and intensities, inclusive freezing, blowing, drifting ­cloudiness: not only coverage and cloud base, but also cloud type like cumulonimbus to indicate convection (e.g. CB, CTU) How to encode all these phenomena

Automation of visual and subjective observations Introducing appropriate models describing the present state of the atmosphere sophisticated algorithms, linking various variables convert the data into information ‘easy’: uniform ‘complex’: divers

Automation of visual and subjective observations Conversion matrix (example): INPUT: Data Weather Physical Variables via database

ET/AWS-2006 (functional specifications) I: Instantaneous – 1-minute value (instantaneous as defined in WMO-No.8, Part II, paragraph ); V: Variability – Average (mean), Standard Deviation, Maximum, Minimum, Range, Median, etc. of samples – those reported depend upon meteorological variable; T: Total – Integrated value during defined period (over a fixed period(s)); maximum 24 hours for all parameters except radiation which requires a maximum of one hour. A: Average (mean) value.· Automation of visual and subjective observations

Automation of visual and subjective observations Quality evaluation and assurance of automated subjective observations: –‘measurement uncertainty’ of a quantitative variable is not applicable –‘perfomance indicators’, using a contingency matrix detector yesno reality yesab nocd ESS:Equitable Skill Score POD:Probability of Detection FAR:False Alarm Ratio

Automation of visual and subjective observations Quality evaluation and assurance of automated subjective observations: –‘measurement uncertainty’ of a quantitative variable is not applicable –‘perfomance indicators’, using a contingency matrix detector yesno realityyes15%5% no5%80% ESS= 75% POD= 25%acceptable? FAR= 69%

Automation of visual and subjective observations Items to be solved: How to calibrate (up to source) a “multi- parameter followed by algorithm”? What is an appropriate (set of) reference(s) (human observations are subjective)? Can a reference be made traceable to any standard? Is regional climate relevant (arctic, tropic, mountaneous, deserts)?

Information on available instrumentation and instrument development 1.Instrument Development Inquiry (IDI- 7 published, IDI- 8 to be issued) 2.World Meteorological Instrument Catalogue (CMA) on CD 3.HMEI* Members Product Catalogue via the Web (see INF. 9) 4.Web Portal on Development, Maintenance and Operation of Instruments, Observing Methods and AWS (CIMO homepage) 5.Other (CIMO Guide, IOM reports) * HMEI = Association of Hydro-Meteorological Equipment Industry OPAG CB issues

Information on available instrumentation and instrument development Instrument Development (only) Inquiry (now: every 4 years) (IDI- 7 published, IDI- 8 to be issued): IDI-reports published –Like IDI-7 (IOM Report No. 93, WMO/TD No. 1352) Or / and –As Web Portal, updated regularly, to be up-to-date.

Measurements in harsh environments Most instruments are designed for use in moderate climate zones, although requirements are valid for all climate zones. Special attention shall be given to –Harsh environments (arctic, tropic, desert, mountains) –Severe weather Actions: 1.Extend of definitions and requirements on measurements in severe weather conditions. 2.HMEI members are encourage to develop.. 3.Intercomparisons have to be organized for further evaluation

Measurements in harsh environments Source: Eumetnet Severe Weather Sensors Project no. 2

Measurements in harsh environments Extend of definitions and requirements on measurements in severe weather conditions: Rec. 4.1/1: The CIMO Guide be expanded to include: a.A definition of the siting characteristics of the Automatic Weather Station in terms of local icing conditions, and b.The requirements for measurements in severe icing conditions.