A new American study claims that atmospheric changes over the ocean can impact the timing of influenza outbreaks, reports BBC News.

Tracing the timeline of the previous four major flu outbreaks, scientists from New York-based Columbia University suggest that the respiratory illness might be linked to La Nina – a weather condition in which temperature over the eastern Pacific drops significantly, chilling the surface of the waters. The study report has been published in Proceedings of the National Academy of Sciences (PNAS), BBC notes.

It is just a prediction based on anecdotal evidence and one should not rely entirely on it to foretell a flu outbreak, the researchers warn, reminding that not all flu outbreaks in the last century were preceded by El Nina.

The El Nino Southern Oscillation, abbreviated as ENSO, comprises La Nina and El Nino, informs the news source.

"Certainly ENSO affects weather and precipitation and humidity around the world", BBC quotes study author Jeffrey Shaman as saying. Mr Shaman also assures that the impact of this climatic change on flu is inconsistent around the globe, implying that no definite conclusion can be drawn from it.

The news channel says previous four major outbreaks – the 1918 Spanish Flu, the 1957 Asian Flu, the 1958 Hong Kong Flu, and the 2009 Swine Flu – occurred in the aftermath of La Nina.