Global warming changing old concepts of weather understanding: Experts

According to global scientists, the reason for this anomaly is the change in old concepts of weather understanding brought about by global warming

Despite the concern over India experiencing a ‘below normal’ monsoon in an El Niño year, the rain in July has been 15% ‘above normal’. According to global scientists, the reason for this anomaly is the change in old concepts of weather understanding brought about by global warming and the consequent need for adoption of new mechanisms driving weather.

Despite the concern over India experiencing a ‘below normal’ monsoon in an El Niño year, the rain in July has been 15% ‘above normal’. (REPRESENTATIVE PHOTO)

In a recent observation, weather expert, Emily Becker, University of Miami/CIMAS, said that in general, stronger the sea surface temperature (SST) anomaly, stronger the atmospheric response and more consistent the pattern of El Niño’s remote impact on rain and temperature patterns. However, the warm global ocean may complicate this relationship.

Vineet Kumar, former scientist, Indian Institute of Tropical Meteorology (IITM), said, “Due to record warm global SSTs, the ocean temperature gradients are not the same as they used to be in classical El Niño conditions. As a result, despite ocean state in the El Niño condition, the atmospheric response to El Niño is weak, resulting in negligible influence of El Niño on the monsoon till date.”

Swapna Panickal, scientist, IITM, said that the recent IPCC (Intergovernmental Panel on Climate Change) report shows that with an increase in global surface temperature, moisture availability increases and hence, summer monsoon precipitation is projected to increase, albeit with more variability. Extreme El Niños are projected to increase with warming. Therefore, summer monsoon rainfall will be more variable in the coming decades.

The seasonal monsoon forecast issued by the India Meteorological Department (IMD) indicated normal (96-104% of Long Period Average/LPA) monsoon conditions over the Indian region. El Niño is one of the dominant external drivers of the monsoon, which can lead to below normal rainfall over India. However, other factors like positive Indian Ocean Dipole (IOD) and snow cover over the Eurasian region also influence summer monsoon rainfall. Positive IOD can lead to above normal rainfall over the Indian region and Eurasian snow cover has an inverse relationship with the Indian summer monsoon rainfall, said Panickal. A weak El Niño condition developed during June with above average SSTs across the equatorial Pacific Ocean. The El Niño forecast indicates continued growth of El Niño through the fall, peaking this winter with moderate-to-strong intensity, Panickal said.