On long-term variations in the Earth’s surface temperature

We analyze the Earth’s surface temperature recorded at available 7 european meteorological stations with 300 years-long activity. We detect variations at several time scales, present in these recordings, namely decadal, inter-decadal (20-30 years), and sub-centennial (60-90 years). These are corelatable with the solar activity variations at the same time scales, indicating a source - effects relationship between the solar input and the air surface temperatures. First, the decadal variations, of amplitudes of ~1° C, are separated from a trend by a Hodrick and Prescott (1997) type analysis, then the inter-decadal and the sub-centennial variations (of several tenths and, respectively, ~1° C amplitude) are separated from the trend by Butterworth (1930) filtering. The analysis is coroborated with similar ones applied to (1) the Danube river discharge as an integrator of temperature and precipitation in the Central Europe and (2) to solar activity monitored or reconstructed parameters.
The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)