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

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

SCIENTIFIC AND TECHNICAL OBJECTIVES

Air

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.

Sea

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.

Land

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.

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

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.

Sea

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.

Land

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.

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.

test title

TEST TEST

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.