The seasonal cycle of sea level in Sri Lanka and Southern India

Abstract

Mean sea level (MSL) data recorded at tide gauge stations in Sri Lanka and southern India, some previously unpublished, have been used in order to determine the main characteristics of the seasonal cycle of MSL in the region, concentrating on the annual component. Altimetric, meteorological and hydrographic information, together with results from numerical modelling, have been employed to try to understand the main factors which contribute to the observed MSL changes. Success in obtaining understanding has been relatively modest, especially for the southern Indian coastline, but proposals are put forward for further work in order to derive greater insight into the seasonal variability. With regard to Sri Lanka, it is evident that change in steric sea level (or dynamic height) is the main factor leading to seasonal MSL change. However, even in this case, there are apparent systematic differences between the various data sets, indicating scope for further research