While several parts of the world including India reel under heatwaves, worsened by the El Nino phenomenon, oceans are not untouched. Analysis of the dataset has revealed how ocean surface heights continue to rise at faster and faster rates.
The global average sea level increased by 0.76 centimetres in just a year between 2022 and 2023, which experts call a relatively larger jump. The jump is being attributed to a warming climate and the development of a strong El Nino. Nasa’s analysis, based on over 30 years of satellite observations starting with 1992 reveals a significant rise in global sea levels.
The latest data from the Sentinel-6 Michael Freilich mission, launched in November 2020, shows an increase of approximately 4 9.4 centimetres since 1993. This rise has accelerated from 0.18 centimetres per year in 1993 to 0.42 centimetres per year currently. Nadya Vinogradova Shiffer, director of Nasa’s sea level change team, predicts an additional 20 centimetres rise by 2050, doubling the change of the past century and increasing global flood impacts. Sea levels fluctuate due to seasonal climate phenomena like La Nina and El Nino.
La Nina, with cooler Pacific waters, reduces sea levels by shifting rain from the ocean to land. Conversely, El Nino, with warmer Pacific waters, raises sea levels by returning more rain to the ocean. These fluctuations are temporary but overlaid on a long-term trend of rising sea levels due to global warming.
Researchers use radar altimeters to measure sea level, bouncing microwave signals off the ocean surface and refining their data with tide gauges and satellite measurements. This detailed record, enhanced by international cooperation and technological advances, helps scientists understand global sea level changes, combining data on ocean temperature, ice loss, and land movement for comprehensive insights.
