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History 1991 In 1991 the Environment Department of ENEA started a collaboration with the Institute of Atmospheric Physics at the National Reasearch Council (CNR-IFA) of Italy to develop a system for the measurement of atmospheric carbon dioxide, as a support to similar measurements carried out in Antarctica. The laboratory was established at the ENEA Casaccia Research Center in Rome. The Laboratory participated already in 1991 in the first international round robin test, an intercalibration experiment organized by the World Meteorological Organization (WMO) that involves most of the measuring sites all over the world. 1992 In 1992 the island of Lampedusa was identified as a suitable site for long-term measurements of greenhouse gas concentration in the atmosphere. The program was activated in early 1992, and the first air sampling was performed on 8 May 1992 from the lighthouse at Capo Grecale, on the North-Eastern coast of Lampedusa. Flasks of ambient air are collected since then on a weekly basis, every friday morning. Analyses aimed at determining the concentration of CO2 were performed at the ENEA Casaccia Laboratory in Rome. The first measurements were referred to the WMO X85 concentration scale, at that time maintained in Italy by the Servizio Meteorologico dell’Aeronautica (the Air Force Met Service). Mesurements of methane concentration were also started by providing air samples at a national laboratory. 1993 The Laboratory was equipped with eight standards of CO2 concentration prepared at the Scripps Institute of Oceanography (SIO, USA). SIO maintained an absolute primary scale of CO2 concentration, recognized as WMO reference (scale X93).The measurements prior to 1994 were reported, after an intercalibration against the previously used standards, on the X93 WMO scale. 1996 A measurement line for the determination of CH4, N2O, CFC-11 and CFC-12 concentration in the atmosphere was developed at the Laboratory of ENEA Casaccia. Starting from 1996, measurements of the concentration of these gases, in addition to CO2, were carried out using the air samples from Lampedusa. National standards were used as reference scale for CH4, N2O, CFC-11 and CFC-12. In 1996 a small building close to the lighthouse of Capo Grecale was identified as a possible site for a measurement station at Lampedusa. 1997 ENEA acquired the small building at Capo Grecale, and constituted the Station for Climate Observations. The Station is entitled to Roberto Sarao, who dedicated part of his activities to the creation of this laboratory, and died after a tragic accident in 1996. 1998 The Station for Climate Observations “Roberto Sarao” at Lampedusa became operational as a permanent scientific facility for climate observations with the installation of a Brewer spectrophotometer, an instrument dedicated to the measurement of ultraviolet radiation and total ozone. Later in the year, the system for the measurement of CO2 concentration was moved from Rome to Lampedusa. 1999 The meteorological station was installed at Lampedusa. It includes a 10-m tower,and sensors for the measurement of atmospheric pressure, humidity, temperature, wind direction and speed, and total solar radiation. Continuous measurements of CO2 concentration were started. Weekly flask sampling was continued, to guarantee the comparability of data obtained with different sampling methodologies. The Laboratory at Lampedusa participated in the WMO Round robin test on CO2 measurements. An aerosol backscatter/depolarization lidar was installed by the University of Rome during the Photochemical Activity and Ultraviolet Radiation Modulating Factors II (PAUR II) Campaign, that took place in May and June. During the Campaign radiometers for the measurement of the solar and ultraviolet radiation, and a Sun photometer for the measurement of aerosol properties, were installed by the Surface Radiation Research Branch of he National Oceanic and Atmospheric Administration (SRRB/NOAA; USA); measurements from an ultralight aircraft were performed at Lampedusa by the Forschungszentrum Karlsruhe, Institute for Meteorology and Climate Research (Garmisch-Partenkirchen, Germany). A visible spectrometer (ENEA) and a Sun photometer (IFA/CNR) were also operational during the campaign. In July 1999 the lidar was housed in a container. 2000 A new set of standards of CO2 concentration was acquired from the Carbon Cycle Group at the Climate Monitoring and Diagnostic Laboratory (CMDL/NOAA, USA), that is actually the WMO reference Laboratory for CO2 measurements where a primary absolute carbon dioxide concentration scale is maintained. Similarly, reference standards of CH4, N2O, CFC-11 and CFC-12 concentrations were acquired from the HATS (halocarbon abd other atmospheric trace species) Group at CMDL/NOAA (USA). Measurements prior to 2000 were scaled to the new standards after an extensive intercomparison against the previously used national standards. 2001 The gas chromatograph HP 5890, used to measure the atmospheric concentration of CH4, N2O, CFC-11, CFC-12, was moved to Lampedusa. Two Sun photometers (Multi Filter Rotating Shadowband Radiometers), one operating in the visible-near infrared, and one operating in the ultraviolet spectral range, were installed for continuous measurements. These instruments, that provide observations of aerosol optical depth at several wavelength, total water vapour amounts, and global and diffuse irradiances at several bands, are useful to monitor the aerosol distribution and the radiation at the surface. 2002 In September 2002 the HP 5890 gaschromatograph was replaced by a GC 6890. The new gaschromatograph is equipped with an innovative hardware system through which it is possible to electronically control all GC functions. Moreover the instrument can be automated for in-situ measurements by an upgraded software. A GC 6890 coupled with an Agilent 5973 N mass spectrometer,dedicated to the detection of hydrochlorofluorocarbons (HCFCs), was installed in the laboratory of Casaccia in Rome. These compounds are used since 1995 to replace CFCs in refrigerators and air conditioning systems, and are powerful greenhouse gases. They are present in the atmosphere at extremely low concentrations (few parts per trillion), and thus are very difficult to be detected. For this reason the analizer is equipped with a preconcentration system (Markes Air server). The measurement line will be dedicated to the analysis of air samples collected at Lampedusa. 2003 A system for the absolute calibration of spectroradiometers, based on 1000 W FEL lamps, developed at SRRB/NOAA, was acquired. The system is used in the periodic absolute calibration of the Brewer spectrophotometer, MFRSR, actinic radiation spectrometer, etc. A GASCOD (gas absorption spectrometer correlating optical differences ) spectrometer, designed by the Institute for Sciences of the Atmosphere and Climate (ISAC/CNR), acquired by ENEA, was installed at Lampedusa in June. The spectrometer operates in the ultraviolet and visible spectral regions and measures several trace gases (vertical distribution of O3, NO2, SO2, and, for high amounts, BrO and ClO). In July 2003 a Total Sky Imager (TSI) was installed. The TSI records digital images of the sky under a wide filed of view, allowing the determination of the cloud cover. The Laboratory at Lampedusa participated in a new WMO round robin test on CO2 measurements. Toward the end of the year, new sets of standards for the greenhouse gases were provided by the CMDL/NOAA. A spectrometer for actinic radiation measurement was operated during a small campaign in the summer of 2003. This instrument, to be used during periods of intensive observations, measures actinic radiation (i.e. the amount of radiaton that may produce photochemical reactions) in the 250-700 nm spectral range. Precision Spectral Pyranometers, that measure solar shortwave irradiance, and Precision Infrared Radiometers, that measure longwave irradiance, are used during campaign periods and for intercalibration purpose. These measurements are used in connection with the other observations to determine the radiative budget of the atmosphere. Future activities Within a project funded by the Ministry for Education and Research of Italy the following instruments were developed: a system for ozone-soundings, and a water vapour Raman lidar. The lidar has been developed jointly with the University of Rome, and will complement the system dedicated to aerosols, already operational at Lampedusa. The two new instruments, that will be installed at Lampedusa in 2004, will allow the measurement of vertical profiles of pressure, temperature, ozone, water vapour, and aerosol extinction. Measurement of chemical compounds at the surface (ozone, SO2, CO, NOx) will be also added. In 2002 a research project, called SNUMMAS (in italian “Sviluppo di Nuove Metodologie di Misura in continuo e ad elevata sensibilità di Anidride Solforosa in aree a bassa antropizzazione”) involving the climate ENEA division of Palermo and a private company (SE.PR.AM.) was approved by the Italian Ministry of Environment. The SNUMMAS project is intended to develop innovative technologies to measure low SO2 concentrations. The project also includes the study of several important chemical species involved in the sulphur cycle. For this purpose the following activities will be carried out from ENEA: · Lampedusa : air sampling in stainless steel canisters for dymethilsulphide (DMS) measurement; sampling of particulate for the analysis of methane sulphonic acid (MSA) and other sulphates (the analysis will be performed at the University of Florence); water sampling for the detection of DMS in the sea and at the air/sea boundary. · Palermo: a gaschromatografic system for the measurement of DMS is under development. The apparatus will be equipped with a preconcentration system for trace gases analysis, a permeation tubes calibrator, and an Agilent HP 6890 gaschromatograph with a PFPD (Pulsed Flame Photometric Detector) detector (O.I. analytical). |
