The CNR4 Kipp & Zonen net radiometer measures the energy balance between incoming short-wave and long-wave Far Infrared (FIR) radiation versus surface-reflected short-wave and outgoing long-wave radiation. The CNR 4 net radiometer consists of a pyranometer pair, one facing upward, the other facing downward, and a pyrgeometer pair in a similar configuration. The pyranometer pair measures the short-wave radiation. And the pyrgeometer pair measures long-wave radiation. The upper long-wave detector of CNR 4 has a meniscus dome. This ensures that water droplets role off easily and improves the field of view to nearly 180°, compared with a 150° for a flat window. All 4 sensors are integrated directly into the instrument body, instead of separate modules mounted onto the housing. But are each calibrated individually for optimal accuracy. Two temperature sensors, a Pt-100 and Thermistor, are integrated for compatibility with every data logger. The temperature sensor is used to provide information to correct the infrared readings for the temperature of the instrument housing. Care has been taken to place the long-wave sensors close to each other and close to the temperature sensors. This assures that the temperatures of the measurement surfaces are the same and accurately known. Which improves the quality of the long-wave measurements.

I parametri meteorologici (temperatura dell’aria, pressione atmosferica, umidità relativa, precipitazione, velocità e direzione del vento) sono misurati con una stazione meteorologica automatica Vaisala WXT520. Meteorological parameters (air-temperature, atmospheric pressure, relative humidity, rain precipitation, wind speed and direction) are measured by an automatic weather station (Vaisala WXT520). Technical details: Wind Speed (range: 0 - 60 m/s, response time: 250 ms, accuracy (0 - 35 m/s): ±0.3 m/s or ±3%, accuracy (35 - 60 m/s): ±5%; output resolutions: 0.1 m/s) units 0.1 mph, 0.1 knots Wind Direction (response time: 250 ms; accuracy ±3°; output resolution and unit 1°) Rainfall (output resolutions and units 0.01 mm, accuracy: 5%, Due to the nature of the phenomenon, deviations caused by spatial variations may exist in precipitation readings, specially in a short time scale. The accuracy specification does not include possible wind induced errors) Relative Humidity (Range: 0 - 100 %RH; Accuracy (0-90%): ±3 %. accuracu (90-100%):±5, output resolution and unit 0.1 %R) Barometric Pressure (Range: 600 - 1100 hPa; Accuracy (0 - +30 °C): ±0.5 hPa, accuracy (-52 - +60 °C ): ±1 hPa, Output resolutions and units: 0.1 hPa) Air Temperature (Range: -52 - +60 °C; Accuracy for sensor at +20 °C: ±0.3 °C)

Le concentrazioni di CO, CO2, CH4 e la percentuale di H2O sono misurate utilizzando l’analizzatore PICARRO G2401; tale strumento si basa sulla tecnologia Cavity-Ring-Down Spectroscopy (CRDS) che, dall’analisi dell’attenuazione di un segnale laser su un cammino ottico di 20 km, permette di valutare in modo accurato e selettivo le concentrazione dei gas. Lo strumento è stato tarato sulla base di miscele di taratura fornite dal World Calibration Center (NOAA-GMDL) della rete WMO/GAW. Ogni 48 ore vengono eseguite tarature di routine utilizzando working standard commerciali. Instrument (Picarro G2401) is connected by a Synflex 1300 (OD: ¼”) to the air intake manifold. Antiparticulate filter (Svagelock) are present at the instrument inlet. Scale and calibration: WMO-CH4-X2004, WMO-CO-X2014, WMO-CO2-X2007. Once the implementation phase will be ended (end of summer 2015), for each gas, two working standards (6 working standards in total) will be used for automatic calibration every 48h. These working standard will be calibrated every month against two travelling/secondary standards (6 travelling standards in total) which, on turn, will be calibrated, every six months against NOAA – GMDL reference cylinders (CB11039, CB11164, CB10928) hosted at the twin station “Lamezia Terme” and representing the laboratory primary standard. The working and secondary standards have CO2, CH4 and CO mole fractions representing upper and lower ranges of the expected ambient variability. Working standard (50 lt, Alluminum tanks at 150bar) and travelling standards (10 lt, Aluminum tanks at 150 bar) are provided by RIVOIRA (Praxair). Two-stage stainless steel pressure regulators for high purity gas are used (Praxiar RSD2SX). Currently and until the end of the implementation phase, manual calibration against the two working standard is carried out every 14days/1month by ISAC-CNR operators. The link to the NOAA-GMDL standard at Lamezia Terme is still not effective, thus currently the instrument is running with factory calibration parameter. Data are recorded on a 5sec basis by the Picarro internal PC and mirrored to a station server , then delivered in NRT mode to ISAC-CNR HQs in Bologna, where 1-minute average were calculated. Final aggregation to hourly average will be executed by using validated 1-min data. On hourly basis data will be flagged to identify “background” observations. This can be done both by considering wind sector (with the aim of selecting observations under sea breeze conditions, thus neglecting influence from in-land contributions) as well as by using de-spiking procedures as proposed by Thoning et al. [1989] . Information about instrument functioning and intervention are stored within an e-logbook. Instrument manual are present at the station. SOP are extracted by the: GAW Report No. 185 “Guidelines for the Measurement of Methane and Nitrous Oxide and their Quality Assurance”, GAW Report No. 192 “Guidelines for the Measurement of Atmospheric Carbon Monoxide”; GAW Report No. 213 “17th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques”.

Gli ossidi di azoto (NOx=NO+NO2) sono misurati utilizzando un analizzatore a chemioluminescenza (Thermo 42i-TL), dotato di convertitore al molibdeno per la determinazione della NO2. A regime, ogni 24 ore viene eseguito un controllo di zero per la NO usando un generatore di aria zero e diluendo una miscela certificata di NO. In futuro la tecnica della GPT verrà utilizzata per verificare l’efficienza del convertitore di NO2. Instrument (Thermo 42iTL) is connected by a Teflon pipe (OD: ¼”) to the air intake manifold. Antiparticulate filter (Teflon material) are present at the instrument inlet (changed every 30 days). Currently only zero check are performed at the station by using an external zero air generator (Thermo 1160). A gas dilution/GPT system is available at the station (Thermo 160i). Once the implementation phase will be ended, this system will be used for executing every 48h span and zero checks for NO, as well as GPT test for evaluating the NO2 -> NO converter efficiency. A substitution of the analyser Molybdenum converter with a photolytic converter (e.g. BLC) is foreseen. Data are recorded on a 1-minute basis by a station server and delivered in NRT mode to ISAC-CNR HQs in Bologna for publication on the web (http://www.i-amica.it/i-amica/?page_id=868). Information about instrument functioning and intervention are stored within an e-logbook. Instrument manual are present at the station. SOP are extracted by the ACTRIS “Draft for standardized operating procedures (SOPs) for NOxy measurements (Version: 2012/04/02)”