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The results of ground-based microwave measurements of the stratospheric ozone profiles over Moscow during the cold half-years of 2014–2015 and 2015–2016 are presented. The causes of the observed changes in the ozone in the upper stratosphere are considered. Increased planetary wave activity, strong temperature decreases in the beginning of winter, and decreased temperatures from January to March were detected during the winter of 2014–2015. The polar vortex was long-lived but not deep; the cold air of the vortex was over Moscow in February–March. This led to a strong negative correlation of the measured ozone content with the temperature. The highest ozone content at the 2-mb level was observed in mid-March. Conversely, an intense polar vortex formed in November–December 2015 under lower planetary wave activity; it was completely destroyed by the major final warming in the beginning of March 2016. The ozone variations in the upper stratosphere over Moscow in December 2015 and January 2016 were related to the alternation of air masses of the vortex and regions outside the vortex. Higher temperatures (as compared to those in the beginning of 2015) led to a decreased ozone content in the beginning of 2016. The interannual difference in the ozone content in the first half of March exceeded 40% of the monthly mean value. [ABSTRACT FROM AUTHOR]

Performance of 142-and 204-GHz radio spectrometers is optimized for remote sensing of ozone and chlorine monoxide in the Earth’s atmosphere by means of computer simulation. Versions of spectrometers with one broadband acousto-optical and two filtering spectrum analyzers optimized in frequency resolution are considered. A brief description of the spectrometers and their basic units is given. [ABSTRACT FROM AUTHOR]

Trends in the ozone layer remain among the major problems of the atmosphere physics; thus, results of measurements of the ozone altitude distribution (profile), carried out in the same place and via the same method, are very important. This paper presents the results of the statistical analysis of ensembles of ozone profiles obtained from ground-based microwave radiometry data acquired at the P.N. Lebedev Physical Institute over a period of two decades (1996–2017). The data collected show the significant difference between monthly mean statistical parameters of ozone profiles of the decades 1996–2006 and 2007–2017. The main and unexpected result is the drastic decrease in monthly root-mean-square (rms) variances of ozone profiles over Moscow above 30 km in cold months of the decade 2007–2017 (if compared to the variances in the decade 1996–2006) with the maximum fall by 46% at 39 km in February monthly mean variances. The decade change of variances obtained by averaging over all nine months in the analysis (from September to May) has the same decrease with maximum fall by 25% at 38 km. Additionally, significant decade changes were revealed in other monthly mean statistical parameters: probability density of ozone profile variances, inter-altitude covariance and correlation functions, and time covariance and correlation—as well as their frequency spectra. The decade change of the ozone profile obtained by averaging over the nine months appeared much less significant: the decrease by 5.7% at the altitude of 19 km (with 1.5% sampling error), minor decrease by 2.6% (with sampling error 1.5%) in the profile maximum at 37 km, and increases of 1.7% at 28 km and 2.5% at 47 km (with sampling errors 1.7%)—lower and higher of this maximum. In addition to that, the corresponding averaged mean total column (integral) ozone content above 20 km remained practically unchanged: 4.61 g/m2 for decade 1996–2006 as compared to 4.58 g/m2 for 2007–2017. Possible explanations of revealed offsets are proposed and discussed. [ABSTRACT FROM AUTHOR]