Instruments -> GBMS


The Ground-Based Millimeter-wave Spectrometer (GBMS)

PI: Giovanni Muscari

Since 2009 personnel of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) carries out measurements of stratospheric profiles of O3, CO, HNO3 and tropospheric water vapor content during winter (Jan-Mar) by means of the GBMS. The spectrometer observes rotational emission lines between 230 and 280 GHz with a 600 MHz passband and 50 kHz of spectral resolution, allowing the retrieval of vertical profiles of trace gases from about 20 to 75 km of altitude using an optimal estimation method. The tropospheric sky opacity is also obtained using the balanced-beam observing technique of the GBMS and column water vapor can therefore be accurately estimated. The GBMS was developed at the Stony Brook University (U.S.A.) in the 90's and has been upgraded and maintained by INGV since 2002. It is part of the NDACC.

Which scientific issues can be addressed using GBMS measurements?

CO mixing ratio contour maps to estimate vertical descent of polar vortex air. Di Biagio, C., et al., JGR, doi:10.1029/2010JD014070, 2010

Example of the CO emission line observed by the GBMS at 230 GHz. The upper panel shows the observed line and the lower panel the residual of fit-measurements.

Studies on mesospheric ozone diurnal variations Muscari, G., et al., doi:10.1029/2011JD016863, 2012

Observations of Stratospheric Sudden Warmings (SSW) Muscari, G., et al., doi:10.4401/ag-6382, 2014