Temporal changes of near-surface air temperature in Poland for 1781-2016 and in Tbilisi (Georgia) for 1881-2016

TL;DR

This study analyzes long-term temperature data from Poland and Tbilisi, revealing a centenary warming trend mainly driven by solar activity, with seasonal and solar cycle variations, and distinguishes between natural and anthropogenic influences over two centuries.

Contribution

It provides a comparative analysis of temperature changes in Poland and Tbilisi over two centuries, highlighting solar activity's role in centenary warming and identifying natural climate fluctuations.

Findings

Centenary warming of about 1.08°C in Poland and Tbilisi.

Warming is more pronounced in winter (~1.15°C).

Solar activity correlates strongly with temperature variations, especially 1890-1960.

Abstract

Analyses of near-surface air temperature T in Poland for 1781-2016 and in Tbilisi (Georgia) for 1881-2016 have been carried out. We show that the centenary warming effect in Poland and in Tbilisi has almost the same peculiarities. An average centenary warming effect deltaT = (1.08+/-0.29) C is observed in Poland and in Tbilisi for 1881-2016. A warming effect is larger in winter season (deltaT = ~1.15 C) than in other seasons (average warming effect for these seasons deltaT = ~0.95 C). We show that a centenary warming is mainly related to the change of solar activity (estimated by sunspot numbers (SSN) and total solar irradiance (TSI)); particularly, a time interval about ~70 years (1890-1960), when a correlation coefficients between 11 years smoothed SSN and T, and TSI and T are high, r = 0.66+/-0.07 and r = 0.73+/-0.07 for Poland and r = 0.82+/-0.05 and r = 0.90+/-0.05 for Tbilisi, respectively; in this period solar activity contributes decisively in the global warming. We show that a global warming effect equals zero based on the temperature T data in Poland for period 1781-1880, when human activities were relatively less than in 1881-2016. We recognize a few feeble ~20+/-3 years disturbances in the temperature changes for period 1885-1980, most likely related with the fluctuations of solar magnetic cycles. We distinguish the fluctuations of ~7-8 years in Poland's T data, possibly connected with local effects of the North Atlantic Oscillation.