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Centre for Atmospheric and Oceanic Sciences

Study identifies new predictors for Indian monsoon through machine learning

A recent collaborative study between the Indian Institute of Science, Bangalore, and the Indian Institute of Technology, Kharagpur, has employed machine-learning techniques to reveal newpredictors for the Indian Monsoon, making monsoon predictions more reliable. The team consisted of Ms. Moumita Saha and Prof. Pabitra Mitra from the Department of Computer Science, IIT–Kharagpur; and Prof. Ravi S. Nanjundiah from the Centre for Atmospheric and Oceanic Sciences as well as Divecha Centre for Climate Change, IISc. Using global climate data from 1948-2000 and machine learning algorithms, the team derived a set of reliable predictors for monsoon rainfall of the sub-continent.

Using soil carbonates to track the journey of the Indian Continent

Around 150 million years ago the Indian subcontinent along with Australia, Africa and Antarctica formed the supercontinent called Gondwanaland. 150 million years ago, however, the Indian subcontinent is said to have drifted north as an isolated land mass until it reached its current position around 55 million years ago. The subsequent collision with the Eurasian subcontinent led to the formation of the spectacular Himalayan-Tibetan system. Although the migration of the Indian plate is widely accepted based on geophysical, biological and geochemical signatures, large discrepancies still exist in its exact position during the transit and the rate of migration. A collaborative effort from researchers from around the globe was required to identify the exact path taken by the Indian subcontinent.

Freshwater affects surface temperature and salinity in the Bay of Bengal, say scientists

River discharge and rainfall differently affect the sea surface temperature, salinity and ocean currents in different parts of the Bay of Bengal, finds a new study from the Indian Institute of Science (IISc), Bangalore. The team headed by Dr. P. N. Vinayachandran at the Centre for Atmospheric and Oceanic Sciences, IISc, has used the Ocean General Circulation Model, a mathematical model to depict the physical and thermodynamical processes involved in oceanic circulation, to study the impact of freshwater inflows on the thermodynamics in different parts of the Bay of Bengal.

Solar installation in the city as good as any others in the country

The performance of a solar plant installed at the Indian Institute of Science campus, Bengaluru has been found to be as good as other well-performing ones in the country, according to a team of researchers at the Divecha Centre for Climate Change. Armed with the data from a solar system they monitored in the IISc campus, the team shows that solar installations can perform reasonably well in the city. They also show that seasonal changes have significant impact on the performance of the system; with a reduced efficiency when the module is too hot.

Submesoscale fronts linked to persistent fresh surface layer in the Bay of Bengal

The persistence of a thin, surface layer of fresh water in the Bay of Bengal (BoB) is known to have a great influence on weather and climate across South Asia. However, the mechanism that sustains this low-salinity layer has remained a puzzle for ocean scientists.
Prof. Debasis Sengupta and his colleagues G. N. Bharath Raj and J. Sree Lekha of the Center for Atmospheric and Oceanic Sciences, Indian Institute of Science (IISc), Bangalore, with M.Ravichandran of the Indian National Center for Ocean Information Services, Hyderabad and Fabrice Papa of the Indo-French Cell for Water Sciences, IISc, have presented the first evidence that submesoscale fronts may be the key to the sustenance of a fresh layer in the north BoB.

Carbon Dioxide more efficient at warming the earth than sunlight, show IISc scientists

Climate is one of the most complex and extensively studied systems and yet one of the most difficult to predict. It has been known for some time now that greenhouse gases (GHGs), especially Carbon Dioxide (CO2), is a major culprit for the increasing temperatures in the recent decades and that sunlight or solar radiation can warm up the atmosphere but not as much as the GHGs do. Scientists at the Indian Institute of Science, Bangalore, have now come up with climate models that offer explanations for these differing inefficiencies in the warming caused by two of the main perpetrators of climate change.

Gangotri’s movements reveal its inner workings

The Gangotri glacier is the largest glacier in the Garhwal Himalaya and the source of the sacred river Ganga. Its snout movements have been tracked for more than a century, but little is known about how the rest of its 30-km length moves and changes over time. A study from the Indian Institute of Science (IISc) has now shed light on the inner workings of the Gangotri glacier by measuring its surface velocity over two decades.

GETTING TO THE “DEPTH” OF THE PROBLEM: NEW INSIGHT ON MAY 21, 2014 BAY OF BENGAL EARTHQUAKE

The Indian subcontinent is among the world’s most disaster-prone areas. It is also very seismically active and hence vulnerable to earthquakes. India has faced many major earthquakes in the past that have caused mass destruction and loss of lives. Earlier, India was vulnerable to earthquakes occurring in the active crust movement in the Himalayan mountains. However, now the crustal movements of the Andaman Sea, the Northern Arabian Sea, and a short segment of Sri-Lanka, along with the resulting tsunamis, also pose a risk to India.

Scientists identify flaws in using plankton shells for climate studies

Scientists at IISc have identified gaps in using certain plankton as a tool for determining the climactic history of a region. These marine plankton of the Foraminifera phylum have calcium carbonate shells. The shells are used for paleoclimactic studies. Studies on these shells found in oceans between 10°N and 40°S have seen a correspondance between the observed and expected values of Carbon and Oxygen isotopes in them. But, south of 40°S in the Southern Ocean, there is a disparity in these values. The research team from the Centre for Atmospheric and Oceanic Sciences led by Prof. Prosenjit Ghosh have studied this phenomenon and have put forth theories to address the inconsistency.

Clouds originating over Indian Ocean cool Bay of Bengal waters

The formation of a pool of cooler water around India and Sri Lanka during summer monsoon, called the Bay of Bengal cold pool, has intrigued many a scientist in the past. Now, a team of researchers at Indian Institute of Science, using computer simulations and satellite data, have discovered the processes that lead to the formation of this extraordinary pool of cold water. As it turns out, clouds originating over the Indian Ocean are to blame for the cold pool in the Bay of Bengal.

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