DSpace Community: 01. Atmosphere

Measurements of low amounts of precipitable water vapor by millimeter wave spectroscopy: An intercomparison with radiosonde, Raman lidar, and Fourier transform infrared data

Sat, 28 Jun 2008 22:58:59 GMT

Title: Measurements of low amounts of precipitable water vapor by millimeter wave spectroscopy: An intercomparison with radiosonde, Raman lidar, and Fourier transform infrared data

Authors: Fiorucci, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Muscari, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Bianchi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Di Girolamo, P.; Università della Basilicata; Esposito, F.; Università della Basilicata; Grieco, G.; Università della Basilicata; Summa, D.; Università della Basilicata; Bianchini, G.; Istituto di Fisica Applicata, CNR; Palchetti, L.; Istituto di Fisica Applicata, CNR; Cacciani, M.; Università di Roma "La Sapienza"; Di Iorio, T.; Università di Roma "La Sapienza"; Pavese, G.; Istituto di Metodologie per l'Analisi Ambientale, CNR; Cimini, D.; Università di L'Aquila; de Zafra, R.; State University of New York at Stony Brook

Abstract: Observations of very low amounts of precipitable water vapor (PWV) by means of the Ground-Based Millimeter wave Spectrometer (GBMS) are discussed. Low amounts of column water vapor (between 0.5 and 4 mm) are typical of high mountain sites and polar regions, especially during winter, and are difficult to measure accurately because of the lack of sensitivity of conventional instruments to such low PWV contents. The technique used involves the measurement of atmospheric opacity in the range between 230 and 280 GHz with a spectral resolution of 4 GHz, followed by the conversion to precipitable water vapor using a linear relationship. We present the intercomparison of this data set with simultaneous PWV observations obtained with Vaisala RS92k radiosondes, a Raman lidar, and an IR Fourier transform spectrometer. These sets of measurements were carried out during the primary field campaign of the Earth Cooling by Water vapor Radiation (ECOWAR) project which took place at Breuil-Cervinia (45.9N, 7.6E, elevation 1990 m) and Plateau Rosa (45.9N, 7.7E, elevation 3490 m), Italy, from 3 to 16 March 2007. GBMS PWV measurements show a good agreement with the other three data sets exhibiting a mean difference between observations of 9%. The considerable number of data points available for the GBMS versus lidar PWV correlation allows an additional analysis which indicates negligible systematic differences between the two data sets.

Biomonitoring of traffic air pollution in Rome using magnetic properties of tree leaves

Sat, 28 Jun 2003 22:58:59 GMT

Title: Biomonitoring of traffic air pollution in Rome using magnetic properties of tree leaves

Authors: Moreno, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Sagnotti, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Winkler, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Cascella, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia

Abstract: We report a biomonitoring study of air pollution in Rome based on the magnetic properties of tree leaves. In a first step, magnetic properties of leaves from different tree species from the same location were compared. It was observed that leaves of evergreen species, like Quercus ilex, present much higher magnetic intensities than those of deciduous species, like Platanus sp., suggesting that leaves accumulate magnetic pollutants during their whole lifespan. In a second step, leaves from Q. ilex and Platanus sp. trees, both very common in Rome, have been used to monitor traffic emission pollution in two different periods. A Platanus sp. sampling campaign was undertaken in October 2001, at the end of the seasonal vegetational cycle, and 5 Q. ilex monthly sampling campaigns from April to August 2002. The strong difference observed in the magnetic susceptibility from leaves collected in green areas and roads allowed the realization of detailed pollution distribution maps from the south of Rome. Magnetic properties indicate that high concentrations and relatively larger grain-sizes of magnetic particles are observed in trees located along roads with high vehicle traffic and in the vicinity of railways. The decrease in concentration and grain size of magnetic particles with distance from the roadside confirms that magnetic properties of leaves are related to air pollution from vehicle emissions. The results indicate that a magnetic survey of tree leaves, which is relatively rapid and inexpensive, may be used in addition to the classical air quality monitoring systems to identify and delineate high-polluted areas in urban environments.

Long period geomagnetic field fluctuations at Terra Nova Bay (Antarctica)

Sat, 14 Jun 1997 22:58:59 GMT

Title: Long period geomagnetic field fluctuations at Terra Nova Bay (Antarctica)

Authors: Villante, U.; Dipartimento di Fisica, Università dell'Aquila, L’Aquila, Italy; Lepidi, S.; Dipartimento di Fisica, Università dell'Aquila, L’Aquila, Italy; Francia, P.; Dipartimento di Fisica, Università dell'Aquila, L’Aquila, Italy; Meloni, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia

Abstract: A statistical analysis of the power spectra (0.7 - 5 mHz) of the geomagnetic field components H and D recorded at Terra Nova Bay (Antarctica) during three austral summers close to the maximum of solar activity reveals power enhancements in the H componenta t = 3.3, 3.9 and 4.5 mHz, which become more evident during daytime intervals. During intervals characterized by higher solar wind speeds these spectral features more clearly emerge and are also accompanied by other enhancements at lower frequencies (= 1.2, 1.9 and 2.7 mHz). The observed frequencies are close to the ones detected both at auroral and low latitudes.

Long period geomagnetic field fluctuations at Terra Nova Bay (Antarctica)

Sat, 14 Jun 1997 22:58:59 GMT