• MeteoMet

  • Metrology

  • for Essential

  • Climate

  • Variables


Meteomet News

You're welcome to check out our new Youtube channel with videos and the image gallery from MMC 2016, Madrid.



Metrology for Essential Climate Variables

project background

Starting from the experience achieved during the previous JRP ENV07 MeteoMet on the traceability to SI of some essential climate variables...read more


need for the project

High-quality observations are possible only if they are based on a sustained traceability to SI and with uncertainties associated to the measured essential climate variables... read more

scientific and technical objectives

    radiosonde tests           permafrost temperature
deep-sea thermometers           absolute salinometer
optic-fibre based sea profiling... read more

expected results

The project will deliver advances to an international science area of critical importance to future global sustainability...read more

Meteomet 1 & 2 in numbers

- 65 contributors
- 11 budget in M€
- 960 work months (90 years!)
- 300 scientific & technical deliverables

Project implementation

MeteoMet aims to develop metrological traceability for the measurement of main essential climate variables (ECV) defined by GCOS.
It is structured in 3 technical work packages (WP), each covering a different area of observation, the Impact WP and Managment WP.

WP 1


Provision of suitable calibration facilities and procedures for humidity sensors working under actual measurements conditions

WP 2


Improvement of traceability to the SI of temperature and absolute salinity measurements performed by both surface and sub-surface ocean observing networks

WP 3


Provision of traceable procedures for sensor calibration, sensor characterisation and measurements of several of the terrestrial and surface ECVs with a consistent, realistic and reliable uncertainty calculation







The Consortium

Istituto Nazionale di Ricerca Metrologica
(CP) A Merlone, coordinator
Phys.-Techn. Pruefdienst des Bundesamt fuer Eich- und Vermessungswesen
Centro Español de Metrología
(CP) C García-Izquierdo
Centre Technique des Industries Aérauliques et Thermiques
(CP) Eric Georgin
Cesky Metrologicky Institut Brno
(CP) Radek Strnad
Conservatoire national des arts et metiers
(CP) Fernando Sparasci
Agencia Estatal Consejo Superior de Investigaciones Cientificas
(CP) Pedro Corredera
Danish Technological Institute
(CP) Jan Nielsen
Institut za mjeriteljstvo Bosne i Hercegovine
(CP) Nedzadeta Hodzic
NPL Management Limited
(CP) Stephanie Bell
Physikalisch-Technische Bundesanstalt
(CP) Volker Ebert
Federale Overheidsdienst Economie, KMO, Middenstand en Energie
(CP) Miruna Dobre
Turkiye Bilimsel ve Teknolojik Arastirma Kurumu
(CP) Murat Kalemci
University of Ljubljana
(CP) Gaber Begeš
(CP) Andrea Peruzzi
Teknologian Tutkimuskeskus
(CP) Martti Heinonen
Service hydrographique et océanographique de la Marine
unfunded partner
Universitat Politècnica de Catalunya
(EG) Joaquín del Río

The Collaborators

ARPA Valle d’Aosta

Permafrost dynamics and degradation

3a, Srl.

Agro-meteorological data management

ARPA Piemonte

Permafrost monitoring

Università di Napoli 2

Environmental Physics

Dpt. of Meteorology, Univ. of Reading

Meteo. measurements and instrumentation

Cal Power

Instrumentations provider

Centro en Cambio Climático, Univ.Rovira i Virgili
New Tarragona, Spain

Climate data restoration

New Zealand

Upper-air measurements

Environmental Agency of the republic of Slovenia

Environmental Agency

Univ.di Torino - Dip.di Scienze della Terra

Climate variables

Federal Hydrometeorological Institute

Meteorology and environment quality

CNR, Unità di Torino

Earthmoving machinery and soil

Institut für Umweltphysik
Heidelberg, Germany

Remote sensing

Internationales Zentrum für Nachhaltige Entwicklung

Meteorology for renewable energy production

Laboratoire de Météorologie Dynamique

Climate processes and change


Upper air instruments manufacturer


Instrumentations provider

Società Meteorologica Italiana

Meteorological and climate information and research


Instrumentations provider

World Meteorological Organization

State and behaviour of the Earth's atmosphere

Meteo Swiss

National weather service

Alfred Wegener Institut

Ocean methods and instruments validation

Korea research institute of standards and science
South Korea

Special chambers for radiosonde calibration

Climate Consulting

Meteorological and climatological fields

Finnish Meteorological Institute

Radiosondes and cryogenic frost point hygrometers

GCOS Reference Upper Air Network

Traceability for radiosondes measurements

Extreme Energy Events Project, E. Fermi, INFN

Extreme Energy Events

Istituto di Ricerca per la Protezione Idrogeologica - CNR

Temperatures at high-elevation sites

International Surface Temperatures Initiative

Uncertainties in historical series


Designer and manufacturer meteorological sensors

NK Electronics

Designer and manufacturer of density sensor

Osservatorio Meteo Duomo

General meteorology and climatology at the urban environment

Università IUAV di Venezia

Env.control, acoustics, lighting, comfort and thermal properties of materials

Lombard & Marozzini

Instruments supplier for industry and research in meteorology, agronomy and plant science







Upcoming Events

Currently no events schedulled.

Past Events

September 26 to 29, 2016, Madrid, Spain

Metrology for meteorology and climate, MMC 2016 conference

MMC logo

September 27, 2016, Madrid, Spain

ENVRIPlus meeting

September 28, 2016, Madrid, Spain

Soil moisture workshop

September 29, 2016, CEM, Madrid, Spain

METEOMET 2 plenary meeting

September 2015, Torino, Italy

Meeting of participants to siting experiment

September 23 to 25, 2015, Tromsø, Norway

MeteoMet Arctic activities presented at the Ny-Ålesund Seminar

October 1 to 18, 2015, Reykjavik, Iceland

Breakout session on Arctic Metrology organised by
MeteoMet, EURAMET and BIPB-CCT at the Arctic Circle Assembly

November 3 & 4, 2015, Ljubljana, Slovenia

Meteomet WP3 meeting and ARSO visit

April 23, 2015, Torino, Italy

Arctic Metrology Workshop

April, 2015, Czech Republic

Škola měření teploty a vlhkosti

March 11-12, 2015, Tortosa, Spain

MeteoMet 2 Rainfall Meeting

March 11-13, 2015, Tortosa, Spain

International symposium Climate-ES 2015

February 11-12, 2015, Italy

Training course /workshop for JRP-Consortium

February 6, 2015, Madrid, Spain

CEM activities in MeteoMet2 project

January, 2015, Madrid, Spain

Consortium meeting

October 31 to November 3, 2014, Reykjavik, Iceland

MeteoMet at Arctic Circle

January 13-14, 2015, Bologna, Italy

Meeting on Arctic activities

December 14-18, 2014, San Francisco, USA

AGU Fall Meeting 2014

September 18, 2014, Brdo, Slovenia

Meteomet 2 kick-off meeting







Project background

Starting from the experience achieved during the previous JRP ENV07 MeteoMet on the traceability to SI of some Essential Climate Variables (ECVs) and the evaluation of calibration uncertainties, this joint research project, JRP (ENV58 MeteoMet2) aims to extend the investigations to other variables and at evaluating further aspects and contributions to the uncertainty.

The aim is to make a further step towards the final goal: the evaluation of the overall measurements uncertainties for the quantities involved in the meteorological observations and climate change evaluations. The improvement of quality of ECVs recorded data through the inclusion of measurement uncertainty budget will bring to possible strategies for the reduction of the uncertainty.

This JRP, which aims to develop metrological traceability for the measurement of main ECVs defined by GCOS1 , is structured in 3 work packages each covering a different area of observation: Air, Sea and Land. The ECVs considered are: water vapour in upper-air and surface atmosphere, surface and deep sea temperature, salinity, air temperature, precipitation, albedo, permafrost temperature and soil moisture.

Need for project

As stated by GCOS “Long-term, high-quality and uninterrupted observations of the atmosphere, land and ocean are vital for all countries, as their economies and societies become increasingly affected by climate variability and change”. High-quality observations are possible only if they are based on a sustained traceability to SI and with uncertainties associated to the measured ECVs.


Air humidity is a key parameter in climate processes. A big challenge, for humidity sensors, is the wide dynamic range with a factor of more than 10000 of water content in the atmosphere. Reliable measurements require sensitive and fast responding sensors to quantify dynamic changes characterizing the phenomenon. Radiosondes sensors calibration protocols need to be improved and validated, to cover real conditions.


Two of the key oceanic ECVs, for monitoring and understanding decadal changes in heat content and transport, are temperature and salinity. A comprehensive study of the effect of the main quantities of influence (water pressure and temperature) on thermometers and salinometers is needed, for reducing measurement uncertainty, and validating their characterization.


For land ECVs consistent measurement uncertainties calculations need complete knowledge of the measurement system: its intrinsic behaviour, other parameters of influence, siting etc.

WMO/CIMO2 notices the “importance of instrument intercomparison as a tool to improve the data traceability and the uncertainty calculation and to improve operational and maintenance procedures”. Although at present meteorological calibration laboratory intercomparisons are not satisfactory to guarantee full traceability and data comparability, and a well-defined protocol is missing.

Though the permafrost temperature is classified as a parameter to investigate climate changes, at present few or none are the measurement procedures reporting fully detailed uncertainty budget.

Calibration and measurements standards for precipitation and soil moisture are not yet well enough developed to solve differences between laboratory setup and natural conditions.

Scientific and technical objectives


To investigate the performance of humidity sensors in real working conditions, reference systems will be developed to validate reference instruments and test facilities for radiosonde and airborne sensors. Two types of sensors for fast changing ECVs will be improved: a microwave hygrometer, and a reference free space instrument for temperature and humidity detection. To improve the reliability of humidity measurements a facility to quantify the enhancement factors for measurements under atmospheric conditions will be built.


A comprehensive study of the pressure dependence of the most widespread deep-sea thermometers will be carried out, as well as an analysis of the temperature-resistance linearization model. A facility for determining temperature and pressure effects on a new generation of absolute salinometers – based on the measurement of seawater refraction index – will be manufactured. Optic-fibers based on Bragg grating will be conceived, studied and metrologically characterized as distributed temperature sensors for sea-surface and sea-profile temperature traceable measurements.


Metrological procedures to evaluate intrinsic characteristics of air thermometers and humidity sensors plus radiation shield will be developed. The effect of influence parameters, such as: sensors siting, rain, and albedo on air temperature measurements, will be analyzed.

Procedures for comparison of laboratories and instruments will be defined in order to give consistency and coherence at the meteorological measurements taken in different places.

Procedures for traceable dynamic calibrations of hygrometers for the air humidity near Earth surface will be developed. New fast step change humidity generators will be manufactured and validated using traceable spectroscopic methods like as TDLAS3 or CRDS4.

A laboratory facility will be constructed to carry out a metrological comparison of the two current methods to measure permafrost temperature (buried or in pipe thermometers along the well drilled in the soil) and to develop calibration procedure, measurements technique, and uncertainty evaluation methods associated with the best technique.

Expected results

The project will deliver advances to an international science area of critical importance to future global sustainability. The dissemination and impact will be based on the network of collaborators, established during the previous JRP ENV07 MeteoMet. The vision of this JRP is to establish a permanent collaboration between metrology and meteorology communities, for the benefit of the future generations of climatologists. The impact effort is demonstrated also by the involvement of key international stakeholders such as GRUAN5, ISTI6, IAPWS7, main manufacturers and several others.

Direct impact

The improvement of calibration procedures and measurement techniques for some ECVs, the improvement of measurement devices and their use in field activities, the investigations on sensor characteristics in this project have a common objective: improve the data quality for more reliable climate considerations.

Economical Impact

The high quality data will have numerous applications in economic sectors as agriculture, energy, transport, forestry and tourism. Furthermore, the characterization of meteorological sensors will give an important feedback for the construction of improved instruments and sensors with a large impact on European market competitiveness.

Social Impact

Climate change is also a significant and emerging threat to public health. The inclusion of uncertainties in climate data will strongly reduce controversies on trends and consequently reduce the mitigation actions upon purely political decisions.

Impact on EC Directives and other relevant standards

The project results are expected to contribute to the improvement of:

   - Sensor characteristics - ISO 17714:2007 and CCT8 WG2 and WG6 guide on secondary thermometry and humidity - Soil moisture

   - ISO/TS 17892-1:2004, and ISO 11271:2002

   - Siting uncertainty evaluation - CIMO-XV/Doc. 4 and CIMO Expert team on standardisation documents

   - Oceanic sensors - European Earth Observation Programme “Copernicus” 9

   - Permafrost temperature measurements techniques - EU funded PermaNET network 10







WP1 Objectives


  • development of metrological procedures to calibrate radiosondes under atmospheric conditions including reduced pressures and temperatures

  • improvement atmospheric water vapour level measurements by measuring enhancement factors under atmospheric conditions i.e. reduced pressure and temperature

  • further development of spectroscopic techniques (TDLAS, CRDS) as possible basic standard for traceable atmospheric measurements and as on-site reference

  • development of a traceable calibration source capable to provide on-site calibration of airborne instruments

  • development of a reference instrument for measurement of rapid transients of temperature and humidity in free space

  • development of a new generation of traceable humidity sensors based on microwave resonators with low response time and small size

WP2 Objectives


  • development of facilities to study the pressure dependence of the most widespread deep-sea thermometers, in order to determine metrologically validated pressure-correction models

  • performing thermodynamic calibration of deep-sea standard thermometers and carry out an analysis of the temperature-resistance linearisation models, to define uncertainties related to linearisation or to determine improved linearisation relationships

  • development of a facility for determining temperature and pressure effects on a new generation of salinometers, based on the measurement of seawater refraction index, to make progress with the metrological characterisation of such new-generation salinometers

  • development of distributed temperature sensors based on optical fibre Bragg gratings to improve the traceability of sea-surface and sea-profile temperature measurements and to monitor time-related temperature drifts in thermometers currently under use in underwater observatories




WP3 Objectives


  • development of metrological procedures to evaluate intrinsic characteristics of the systems air thermometers plus radiation shield and humidity sensors plus radiation shield; the objective is a better sensor characterisation in order to define suitable calibration procedures and methods of evaluation of measurement and calibration uncertainties; the possibility to improve the ISO Guide 17714:2007 will be explored

  • measurement and analysis of the influence of the siting on air temperature measurements in terms of uncertainty components

  • study of the influence of rain and albedo on air temperature measurements from a metrological point of view

  • performing procedures for comparison of laboratories and instruments in order to give consistency and coherence at the meteorological measurements taken in different places

  • development of procedures for traceable dynamic calibrations of hygrometers which measure the air humidity near Earth surface with a reliable uncertainty calculation

  • development of a fast step change humidity generator to study the air humidity sensor behaviour under fast changes in humidity levels near Earth' surface. The humidity generators will be validated using traceable spectroscopic methods like as TDLAS or CRDS

  • development of laboratory facility in order to carry out a metrological comparison of the two current methods to measure permafrost temperature and, as a consequence, to develop calibration and measurements procedures and uncertainty evaluation methods associated with the best technique to measure permafrost temperature

  • theoretical research on precipitation and on soil moisture in order to provide a review of the state of the art and to highlight the needs and the requirements to perform traceable measurements of such ECVs with a reliable uncertainty calculation. Initial experimental trials of calibration approaches for soil moisture will also be included

  • application of a consistent measurement uncertainty to meteorological humidity data sheets










Contact us

To contact MeteoMet coordinator, please fill in the form.