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Sea-Level Trends of the North Indian Ocean
Unnikrishnan, A.S. and Shankar, D. 2007. Are sea-level-rise trends along the coasts of the north Indian Ocean consistent with global estimates? Global and Planetary Change 57: 301-307.

The authors write that "though global sea-level rise has been studied extensively during the last two decades based on tide-gauge data, the same is not true of trends in regional sea level." Hence, they decided to resolve this problem as it pertains to the north Indian Ocean.

What was done
Working with tide-gauge stations having records in excess of 40 years that are located on the coasts of Yemen, Pakistan, India, Bangladesh, Myanmar and Thailand, the two researchers calculated linear trends and applied various checks for regional consistency, after which they made global isostatic adjustments to their results using model-derived data.

What was learned
Unnikrishnan and Shankar report that statistically significant trends obtained from these procedures "yielded sea-level-rise estimates between 1.06-1.75 mm/year, with a regional average of 1.29 mm/year, when corrected for global isostatic adjustment," adding that "the average estimate for the basin is likely to be towards the lower end of this range."

What it means
The Indian researchers say their results are consistent with global tide-gauge estimates, "though somewhat lower," and both sets of numbers are lower than those derived from satellite data available since 1993. With respect to this latter fact, however, they note that "the length of the satellite-based sea-level record is too small ... for estimating long-term sea-level rise." As a result, controversy continues over the current status of the globe's sea level.

Reviewed 30 April 2008