The paper is currently in press at the Journal of Coastal Research and is provided with open access to the full publication. The results are stunning for their contradiction to AGW theories which suggest global warming would accelerate sea level rise during the last century.
“Our first analysis determined the acceleration, a2, for each of the 57 records with results tabulated in Table 1 and shown in Figure 4. There is almost a balance with 30 gauge records showing deceleration and 27 showing acceleration, clustering around 0.0 mm/y2.”
The near balance of accelerations and decelerations is mirrored in worldwidegauge records as shown in Miller and Douglas (2006)
Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses
‡Professor Emeritus, Department of Civil and Coastal Civil Engineering, University of Florida, Gainesville, FL 32611, U.S.A. firstname.lastname@example.org
Without sea-level acceleration, the 20th-century sea-level trend of 1.7 mm/y would produce a rise of only approximately 0.15 m from 2010 to 2100; therefore, sea-level acceleration is a critical component of projected sea-level rise. To determine this acceleration, we analyze monthly-averaged records for 57 U.S. tide gauges in the Permanent Service for Mean Sea Level (PSMSL) data base that have lengths of 60–156 years. Least-squares quadratic analysis of each of the 57 records are performed to quantify accelerations, and 25 gauge records having data spanning from 1930 to 2010 are analyzed. In both cases we obtain small average sea-level decelerations. To compare these results with worldwide data, we extend the analysis of Douglas (1992) by an additional 25 years and analyze revised data of Church and White (2006) from 1930 to 2007 and also obtain small sea-level decelerations similar to those we obtain from U.S. gauge records.
Received: October 5, 2010; Accepted: November 26, 2010; Published Online: February 23, 2011
Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses, J. R. Houston and R. G. Dean
We analyzed the complete records of 57 U.S. tide gauges that had average record lengths of 82 years and records from1930 to 2010 for 25 gauges, and we obtained small decelerations of 20.0014 and20.0123 mm/y2, respectively. We obtained similar decelerations using worldwide-gauge records in the original data set of Church andWhite (2006) and a 2009 revision (for the periods of 1930–2001 and 1930–2007) and by extending Douglas’s (1992) analyses of worldwide gauges by 25 years.
The extension of the Douglas (1992) data from 1905 to 1985 for 25 years to 2010 included the period from 1993 to 2010 when satellite altimeters recorded a sea-level trend greater than that of the 20th century, yet the addition of the 25 years resulted in a slightly greater deceleration.
Our analyses do not indicate acceleration in sea level in U.S. tide gauge records during the 20th century. Instead, for each time period we consider, the records show small decelerations that are consistent with a number of earlier studies of worldwide-gauge records. The decelerations that we obtain are opposite in sign and one to two orders of magnitude less than the +0.07 to +0.28 mm/y2 accelerations that are required to reach sea levels predicted for 2100 by Vermeer and Rahmsdorf (2009), Jevrejeva, Moore, and Grinsted (2010), and Grinsted, Moore, and Jevrejeva (2010). Bindoff et al. (2007) note an increase in worldwide temperature from 1906 to 2005 of 0.74uC.
It is essential that investigations continue to address why this worldwide-temperature increase has not produced acceleration of global sea level over the past 100 years, and indeed why global sea level has possibly decelerated for at least the last 80 years.
h/t to John Droz and to Dr. Willem de Lange