Inhomogeneity introduced to the climate data series by instrumentation changes of the thermometer shields and rain gauges

Abstract

Abstract Recently we can see the trend of introducing a new instrumentation and automatization in the field of information and monitoring systems for the meteorology, hydrology and crisis centers. Nowadays a great number of sensors are used in projects in many countries of various climates. Therefore it is crucial to deeply understand how the change of sensor types will affect the accuracy of measurements and how is accuracy of individual sensor type affected by different weather conditions. We analyzed several screen/shields and rain gauges at the premises of faculty of Meteorology and Climatology of FMFI UK. On the basis of our results we can recommend as a most accurate and not depending on weather condition artificially ventilated screen although it is the most expensive. Our second choice would be a large naturally ventilated shield. In case of Stevenson screens we would recommend painting it with a high gloss coating. Our last choice would be a small naturally ventilated screen because of its high sensitivity to the global radiation. Our first choice of the participating rain gauges would be the weighing rain gauge because of its best results in both cases, of rainfalls up to 2 mm and also over 2 mm. The tipping bucket rain gauge gave also agreeable result in both cases. The optical sensor gave very good results in rainfalls over 2 mm but it is unsuitable for rainfalls up to 2 mm. The radar sensor is also completely unsuitable for low intensity rainfalls and his performance for rainfalls over 2 mm was just average.