Atmospheric memory: How do monsoons ‘remember’ the past?

How do monsoons really work? What makes them plentiful some years, but vanish completely in others, causing drought-like conditions? Climate scientists have been seeking answers to these questions for a long time.

Now a research paper has come up with an intriguing explanatory concept: atmospheric memory. The study was conducted by two scientists -- Anja Katzenberger & Anders Levermann -- from the Potsdam Institute for Climate Impact Research (PIK). Titled ‘Monsoon Hysteresis reveals Atmospheric Memory’, it was published recently in the scientific journal PNAS.

The study showed, for the first time, that the atmosphere can store moisture over extended periods, creating a physical memory effect.  In other words, the atmosphere can ‘remember’ its previous state by storing physical information in the form of water vapour.” The paper also talks about how there is a tipping point in the system that determines monsoon rainfall.

So, how does this discovery change our understanding of how monsoons work? What are its practical applications? What are the risks posed to this system by things like pollution and global warming?

 

Guest: Anders Levermann, Professor of the Dynamics of the Climate System at the Institute for Physics and Astrophysics of the Potsdam University, Germany.

Host: G. Sampath, Social Affairs Editor, The Hindu.

Edited by Sharmada Venkatasubramanian.