The Full Picture

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The INM’s Izaña Atmospheric

Research Centre, a GEO-oriented experience

Emilio Cuevas, Director, Izaña Atmospheric Research Center,

Instituto Nacional de Meteorología (INM), Spain

n 2004, IGOS/IGACO made the following statement:

“Observations have clearly shown that human activity is

changing the composition of the Earth’s atmosphere.

Research has demonstrated that there are important conse-

quences of such changes for the climate, human health, and

the balance of ecosystems.” This statement has been made

possible, in part, thanks to the observational and research

activities performed by a few selected stations around the

world which are part of the World Meteorological Organization

(WMO) Global Atmospheric Watch (GAW) programme.

GAW provides data for scientific assessments and for early warn-

ings of changes in the chemical composition and related physical

characteristics of the atmosphere that may have adverse effects on

our environment. Monitoring priorities have been given to green-

house gases for possible climate change, ozone and ultraviolet

radiation for both climate and biological concerns, certain reac-

tive gases and the chemistry of precipitation for a multitude of

roles in pollution chemistry, and aerosols for their impact on both

air quality and climate.

The Izaña-ARC manages one of the GAW stations situated on

Tenerife’s Izaña mountain, where an important number of atmos-

pheric measurement programs are performed on a long-term basis.

The current emphasis of GAW is mainly on surface monitoring of

the atmospheric composition. However, the GAW mandate

includes the integration of satellite and aircraft observations with

surface measurements, as well as the integration of chemical data

and numerical models.

Increasing standardization and interoperability

Efforts on the coordination of ground-based networks for the moni-

toring of the atmosphere continue in Europe. The building of

integrated (ground and space) systems is supported by the WMO as

a contribution to IGACO and GEOSS. In the case of ozone, there are

two world ground-based networks, formed by Dobson and Brewer

spectrophotometers, respectively. The Izaña observatory was offi-

cially acknowledged by the WMO-GAW as the Regional Brewer

Calibration Centre for Europe (RBCC-E)

in November 2003. A set

of three MK III Brewer spectrophotometers has been set up as the

regional reference triad (RRT) to transfer the calibration scale of the

World Brewer Triad (WBT) to the regional network.

The main goal of the RBCC-E is to transfer the absolute cali-

bration to the European Brewer spectrophotometer network.

Intercomparability with the Dobson network is assured by peri-

odical joint exercises with the Regional Dobson

Calibration Centre, located at the GAW

Hohenpeissenberg Observatory (DWD, Germany).

However, the role played by the regional centres goes

beyond maintaining a quality assurance system of

ground-based networks. An important activity is to

carry out the calibration of satellite sensors and to act

as a link between the ground-based and space-based

ozone observations.

During the last few years, emphasis has been given

to the issue of interconnections between ozone deple-

tion and climate change. Future increases in greenhouse

gas concentrations will contribute to the average

cooling rates of the stratosphere, which leads to greater

ozone destruction, which may in turn slow down the

recovery of the ozone layer. Twenty years after the

Montreal Protocol was signed, precision observation

systems are needed to detect signs of recovery.

In the study of aerosols, which play an important

role in climate, the IZAÑA-ARC has been contributing

to the global observation system as a Cimel master-

sun calibration site for PHOtométrie pour le

Traitement Opérationnel de Normalisation Satellitaire

(PHOTONS) network

since June 2004. This network

is part of the AErosol RObotic NETwork (AERONET)

Cimel sunphotometer network.

Increasing the capacity of observational tools

The Network for the Detection of Atmospheric

Composition Change (NDACC) is a major component

of the international upper atmosphere research effort

and has been endorsed by national and international

scientific agencies, including WMO. NDACC provides

an independent calibration of satellite sensors of the

atmosphere. The four ongoing programmes at Izaña

within NDACC are:

• Total column ozone with Brewer spectrophotometer

• Vertical ozone profiles with ECC ozonesondes

• FTIR (managed by IMK-Germany)

• DOAS/UV-VIS (managed by INTA-Spain).

All the programmes have, as a high-priority goal, the

validation of satellite sensors. Validation of ESA

GOME and SCIAMACHY/ENVISAT, NASA/KNMI and

ATIONAL

& R

EGIONAL

EPORTS