Kolmogorov Complexity Analysis and Prediction Horizon of the Daily Erythemal Dose Time Series

Abstract

Influenced by stratospheric total ozone column (TOC), cloud cover, aerosols, albedo, and other factors, levels of daily erythemal dose (Her) in a specific geographic region show significant variability in time and space. To investigate the degree of randomness and predictability of Her time series from ground-based observations in Novi Sad, Serbia, during the 2003–2012 time period, we used a set of information measures: Kolmogorov complexity, Kolmogorov complexity spectrum, running Kolmogorov complexity, the largest Lyapunov exponent, Lyapunov time, and Kolmogorov time. The result reveals that fluctuations in daily Her are moderately random and exhibit low levels of chaotic behavior. We found a larger number of occurrences of deviation from the mean in the time series during the years with lower values of Her (2007–2009, 2011–2012), which explains the higher complexity. Our analysis indicated that the time series of daily values of Her show a tendency to increase the randomness when the randomness of cloud cover and TOC increases, which affects the short-term predictability. The prediction horizon of daily Her values in Novi Sad given by the Lyapunov time corrected for randomness by Kolmogorov is between 1.5 and 3.5 days.

Diffuse and Direct UV Index Experimental Values

“…The mean daily erythemal dose for global UVER is 2333 J/m 2 . This value is on the order of 2000 J/m 2 of that obtained for Novi Sad (Serbia) (45 • 33" N, 19 • 85" E, 84 m.a.s.l) in the period 2004-2012 [23]. These results, with 17% more erythemal dose than in BASS (39 • 350" N; 0 • 250" W, 30 m.a.s.l.…”

Reconstruction and variability of high daily erythemal ultraviolet doses and relationship with total ozone, cloud cover, and albedo in Novi Sad (Serbia)

“…In Vienna, 81.40% of high daily UV doses occur in low cloud cover conditions in comparison to 77.3% occurred in low TOC conditions. These results are consistent with the results presented in several other studies, which reveal that the impact of changes in TOC on the level of UV radiation reaching the Earth's surface is more pronounced at higher latitudes, whilst in mid‐latitudes, besides the TOC levels, the effects of other parameters such as cloud cover, aerosols, and albedo can be very high and can even primarily control UV levels (EEAP, 2019; Malinović‐Milićević et al ., 2022a).…”