Modeling regional sea level rise using local tide gauge data

Abstract

Currently regional mean sea level trends and variations are inferred from the analysis of several individual local tide gauge data that spanonly a long period of time at a given region. In this study, we propose using a model to merge various tide gauge data, regardless of theirtime span, in a single solution, to estimate parameters representative of regional mean sea level trends. The proposed model can accountfor the geographical correlations among the local tide gauge stations as well as serial correlations, if needed, for individual stations’ data.Such a vigorous regional solution enables statistically optimal uncertainties for estimated and projected trends. The proposed formulationalso unifies all the local reference levels by modeling their offsets from a predefined station’s reference level. To test its effectiveness, theproposed model was used to investigate the regional mean sea level variations for the coastal areas of the Florida Panhandle using 26 localtide gauge stations that span approximately 830 years of monthly averages from the Permanent Service for Mean Sea Level repository. Thenew estimate for the regional trend is 2.14 mm/yr with a ±0.03 mm/yr standard error, which is an order of magnitude improvement overthe most recent mean sea level trend estimates and projections for the Florida region obtained from simple averages of local solutions.