Thiruvananthapuram: The mean sea level rise has already rung the warning bell for the Indian coastal zone.  The secretary in the Union ministry for earth sciences, Dr Shailesh Nayak informed the audience of the 97th Indian Science Congress here on Tuesday that the Indian Ocean has risen by 9 mm in the period 2004-08.

“We will launch a satellite with French collaboration, next year to monitor sea level rise along India’s coast,” he said.

According to Dr Nayak, the annual sea level rise of Indian Ocean since 2004 was 1.8 mm. The erosion of the coasts of Lakshadweep Islands may be due to the sea level rise of the Indian Ocean. The water level of river Hotly has risen and ingress of saline water into the Sunderbans on the eastern coast has been noticed.

When questioned whether this was due to the effect of Tsunami of December 2004, he said : “This may be the cause. We are trying to find out.”

Experts across the world are concerned over the rise in global mean sea level. They say that the situation is primarily due to fast melting of glaciers on account of the warming effect of climate change.

He said that coral reef was destroyed on account of Tsunami and chlorophyll content has increase in the bay of Bengal following the Aila cyclone. Chlorophyll plays an important role in ocean’s biological productivity and their impact on climate. Hence studies are needed on how much phytoplankton the oceans contain, where they are located, how their distribution is changing with time and how much photosynthesis they perform, he said.

Land and ocean play an important role in influencing climate and weather variability. In this context, Dr Nayak said that the frequency of heavy precipitation has increased over most land areas consistent with warming. An increase in atmospheric water vapour has been noticed. Also more intense and longer droughts have been observed over wider areas since the 1970s, particularly in the tropical and subtropical regions.

He suggested improved monitoring of regional climate and understanding of the regional impact of climate change particularly on the monsoon system. He urged for raising allocation for atmospheric research.