Changes in Physical Properties of Inland Streamwaters Induced by Earth and Atmospheric Tides

Abstract

Earth and atmospheric tides create oscillations in water parameters of inland rivers, mainly due to the similar behavior of groundwaters. Tidal oscillations of inland rivers were termed orthotides and were detected in fluctuations of water level and specific conductivity of some rivers. However, few things are understood about orthotides because of their recent discovery. Here, we show that orthotidal signals exist in streamwater temperature too. Wavelet and T_TIDE analyses are used to study streamwater temperature and specific conductivity. We found solar and lunar semidiurnal orthotides (S2 and M2) in Alapaha River (USA) water temperature and Wybong River (Australia) water specific conductivity with amplitudes of up to 0.6 °C and 11.3 µS/cm. We demonstrate that the tidal semidiurnal cycles have statistical significance and are caused by similar cycles in groundwater. Oscillations found in water temperature time series for some new moon time intervals have shapes that correlate with the gravitational tides. Diurnal and fortnightly tidal cycles were found and overlapped with other natural cycles with similar periodicities. The inclusion of more water parameters to the list of orthotidally sensitive parameters indicates the wider than expected environmental impact of the small periodic natural changes.

Changes in the Water Temperature of Rivers Impacted by the Urban Heat Island: Case Study of Suceava City

“…The wavelet coherence analysis used the methodology of Grinsted et al [30], which continued to implement the Morlet mother wavelet in the study of hydrological time series. For a detailed description of the wavelet analysis and equations, see our complementary studies [31,32].…”

Combined Multilevel Monitoring and Wavelet Transform Analysis Approach for the Inspection of Ground and Surface Water Dynamics in Shallow Coastal Aquifer

“…The wavelet type can be chosen to best match the characteristics of the observed signals. The Morlet wavelet has been shown to be most suitable for geophysical time series [32,[40][41][42]. The Morlet wavelet function is defined as:…”

“…Scalogram is a useful way to express periodicity features of time series with reference to characteristic frequencies or periods [40,41]. Hereby, we select and present six scalograms respectively, seawater level, precipitation, PS Modric intake water level, P1 groundwater level, EC G probe as observed in P1 and EC D probe as observed in P1 (Figure 7a-f).…”