Nodaltide
The nodaltide is an astronomical tide that occurs with a period of 18.613 years and affects water levels worldwide over the period. It is caused by the changing declination of the lunar orbit, which, observed from Earth, oscillates once between 28 ° 35 'and 18 ° 19' within the period of 18.613 years. This change arises from the rotation of the system of earth, moon and sun around the common center of gravity.
The influence of the nodal tide in the German Bight is two to four percent of the tidal range and is therefore the only tide with a period> 1 year that has a verifiable influence on tidal events. For the tide on the coast of Heligoland, this means a change in the tide range of approx. 6 cm. Around 2005 the nodal tide reached a minimum. The tidal range will therefore increase again by 2015. The strongest expression of the nodaltide can be observed at the poles.
Individual evidence
- ↑ a b Portal Tideelbe - Glossary. (No longer available online.) Federal Waterways and Shipping Administration (WSV), archived from the original on February 1, 2014 ; Retrieved January 20, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ A b Andrzej Wróblewski: Lunar nodal tide in the Baltic Sea . In: Oceanologia . No. 43 (1) , 2001, p. 109–112 (English, PDF file; 170 kB ).
- ↑ Analysis of the water levels in the Tidal Elbe (1998-2004). (No longer available online.) Federal Institute for Hydraulic Engineering, April 6, 2006, archived from the original on February 1, 2014 ; Retrieved January 20, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
