TCfA Humidity Counts Till 2015

Fig. 1: Seasonal relative counts of humidity measured above 97 % and equal to 100 % in the period from mid 2000 till 6 April 2015. Seasons are here defined as periods of 92 days, Winter starting with 1st December. Usually there were more than 700 000 measurements in a season. The rate of these high values of humidity are seen here to gradually rise till Winter of 2011. Then, after the meteo station was replaced, the rate drops to very low values, but soon begins to rise again.

Fig. 2: Same as Fig. 1 but red bars here show the relative count of measurements below 75 %. Interestingly, for the old station these bars do not seem to systematically decrease with passage of time, at least for the first 7 or 8 years of its operation. There is slight indication that the new station might have these bars somewhat above the average in the first two years of operation (since Spring of 2011). However it could be that this station will continue higher counts also in the future.

These diagrams lead to the conclusion that the new station has similarly faulty humidity sensor in that high humidities (especially above 97 %) are gradually becoming more frequent. On the other hand both stations seem to be quite stable for smaller humidities (say below 75 % or 65 %). The higher counts seen in Fig. 2 since 2011 might be related to the fact that the old sensor was giving systematically higher values, by about 10-15 %, than values in Koniczynka station (see this figure of the earlier report, where the green line lies more than 10 % above the red line).