Philippine Volcano Hid Evidences of Accelerating Sea Level Rise, Study Shows
A new study led by National Center for Atmospheric Research (NCAR) revealed that data from the altimeter satellite recording the global average sea level rise have been biased in the past decade due to the happenstance eruption of Mount Pinatubo in the Philippines in 1991.
Climate scientists believe that there is acceleration in the rise of sea level due to the increasing amount of Greenhouse gases, resulting to climate change. However, past data indicate that the rate of sea level rise remained at three millimeters per year.
The study, published in the journal Scientific Reports, suggests that eruption of Mt. Pinatubo in 1991 temporarily cooled the planet, causing the sea levels to drop. Two years after the cataclysmic eruption, the first altimeter satellite TOPEX/Poseidon was launched.
Researchers believe that the data gathered by the satellite during its early years were not the reliable primarily because the ocean temperature is recovering from the temporary cooling caused by the sunlight-blocking aerosols from Mt. Pinatubo.
Computer simulation showed that temporary cooling of the ocean caused the sea level to drop by about six milliliters immediately before the TOPEX/Poseidon began recording observations.
The recovery of the Earth's oceans caused the sea levels to rise in higher-than-normal rate in the early days of monitoring the sea levels from space, making the sea level to appear at a higher point in the early 1990s. As a result, the apparent acceleration in the sea level rise was masked and may actually appear like its decreasing.
"When we used climate model runs designed to remove the effect of the Pinatubo eruption, we saw the rate of sea level rise accelerating in our simulations," said NCAR scientist John Fasullo, who led the study, in a statement.
"Now that the impacts of Pinatubo have faded, this acceleration should become evident in the satellite measurements in the coming decade, barring another major volcanic eruption."