Abstract. Atmospheric water vapour has been acknowledged as an essential climate variable. Weather prediction and hazard assessment systems benefit from real-time observations, whereas long-term records contribute to climate studies. Nowadays, ground-based global navigation satellite system (GNSS) products have become widely employed, complementing satellite observations over the oceans. Although the past decade has seen a significant development of the GNSS infrastructure in Central and South America, its potential for atmospheric water vapour monitoring has not been fully exploited. With this in mind, we have performed a regional, 7-year-long and homogeneous analysis, comprising 136 GNSS tracking stations, obtaining high-rate and continuous observations of column-integrated water vapour and troposphere zenith total delay. As a preliminary application for this data set, we have estimated local water vapour trends, their significance, and their relation with specific climate regimes. We have found evidence of drying at temperate regions in South America, at a rate of about 2 % per decade, while a slow moistening of the troposphere over tropical regions is also weakly suggested by our results. Furthermore, we have assessed the regional performance of the empirical model GPT2w to blindly estimate troposphere delays. The model reproduces the observed mean delays fairly well, including their annual and semi-annual variations. Nevertheless, a long-term evaluation has shown systematical biases, up to 20 mm, probably inherited from the underlying atmospheric reanalysis. Additionally, the complete data set has been made openly available as supplementary material.

[1] Our work is focused on the analysis of seasonal and semiannual ionospheric anomalies using vertical total electron content (VTEC) measurements obtained by the International GNSS Service (IGS). For this study we use principal component analysis (PCA) and wavelet transform (WT) because both numerical tools allow us to isolate principal components of the VTEC variability as much spatially as temporally. The IGS VTEC maps are reorganized, and from each daily global data set, two maps were constructed: one at 12:00 LT and the other at 22:00 LT. From these two series of VTEC maps covering the period 1999-2009 for each local time, we found that the semiannual anomaly is globally recorded at noon, especially at mid and low geomagnetic latitudes, and its amplitude has a close relationship with the solar activity, and at night this anomaly is recorded during high solar activity and the larger values are located in the South American region. The values of VTEC at the March equinox exceed that of the September equinox, especially during high solar activity; the winter anomaly is recorded at noon near the geomagnetic poles region, and the effect is more important during high solar activity. At night this anomaly is present during the ascending and descending phases and minimum of the solar cycle. Thus, the night winter anomaly effect is clearly evidenced from our results.

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One of the alternatives to SO2 as an antimicrobial is the use of bioprotection yeasts, which colonize the medium preventing the proliferation of undesirable microorganisms. In this work, the bioprotective effect of a mixed inoculum formed by Torulaspora delbrueckii/Lachancea thermotolerans during fermentation was evaluated. For this purpose, fermentations were carried out using this mixed inoculum and the populations of yeasts, lactic bacteria and acetic bacteria, and the physical–chemical parameters of the wines obtained were studied. The results were compared with those obtained in spontaneous fermentation with and without SO2. The different fermentation strategies caused a differentiation in the yeast species present during fermentation. Regarding populations of lactic acid bacteria, results showed that the effect of the addition of the mixed inoculum was comparable to that exerted by SO2. On the other hand, due to the high sensitivity of acetic acid bacteria to SO2, the sulfite vinifications showed a lower population of acetic acid bacteria in the early stages of fermentation, followed by the vinifications with the mixed inoculum.