Millimeter wave spectroscopic measurements of stratospheric and mesospheric constituents over the Italian Alps: stratospheric ozone

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Muscari, G., Cesaroni, C., Bianchi, C., de Zafra, R. L., Di Iorio, T., Fiorucci, I., Fuà, D., Romaniello, V., Zuccheretti, E.
• Other Authors: Muscari, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Cesaroni, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Bianchi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, de Zafra, R. L.; Department of Physics and Astronomy and Institute for Terrestrial and Planetary Atmospheres, Di Iorio, T.; Dipartimento di Fisica, Università degli Studi di Roma «La Sapienza», Roma, Italy, Fiorucci, I.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Fuà, D.; Dipartimento di Fisica, Università degli Studi di Roma «La Sapienza», Roma, Italy, Romaniello, V.; Dipartimento di Fisica, Università degli Studi di Roma «La Sapienza», Roma, Italy, Zuccheretti, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, Department of Physics and Astronomy and Institute for Terrestrial and Planetary Atmospheres, Dipartimento di Fisica, Università degli Studi di Roma «La Sapienza», Roma, Italy
• Format: Article in Journal/Newspaper
• Language: English
• Published: Editrice Compositori 2007
• Subjects: millimeter-wave spectroscopy; stratospheric ozone; isentropic transport; 01. Atmosphere::01.01. Atmosphere::01.01.99. General or miscellaneous; Arctic
• Online Access: http://hdl.handle.net/2122/3678

Measurements of rotational lines emitted by middle atmospheric trace gases have been carried out from the Alpine station of Testa Grigia (45.9°N, 7.7°E, elev. 3500 m) by means of a Ground-Based Millimeter-wave Spectrometer (GBMS). Observations of species such as O3, HNO3, CO, N2O, HCN, and HDO took place during 4 winter periods, from February 2004 to March 2007, for a total of 116 days of measurements grouped in about 18 field campaigns. By studying the pressure-broadened shape of emission lines the vertical distribution of the observed constituents is retrieved within an altitude range of ∼17-75 km, constrained by the 600 MHz pass band and the 65 kHz spectral resolution of the back-end spectrometer. This work discusses the behavior of stratospheric O3 during the entire period of operation at Testa Grigia. Mid-latitude O3 columnar content as estimated using GBMS measurements can vary by large amounts over a period of very few days, with the largest variations observed in December 2005, February 2006, and March 2006, confirming that the northern winter of 2005-2006 was characterized by a particularly intense planetary wave activity. The largest rapid variation from maximum to minimum O3 column values over Testa Grigia took place in December 2006 and reached a relative value of 72% with respect to the average column content for that period. During most GBMS observation times much of the variability is concentrated in the column below 20 km, with tropospheric weather systems and advection of tropical tropospheric air into the lower stratosphere over Testa Grigia having a large impact on the observed variations in column contents. Nonetheless, a wide variability is also found in middle stratospheric GBMS O3 measurements, as expected for mid-latitude ozone. We find that O3 mixing ratios at ∼32 km are very well correlated with the solar illumination experienced by air masses over the previous ∼15 days, showing that already at 32 km altitude ozone photochemistry dominates over transport processes. The correlation of ...