Multiple Choice Questions

With reference to the Pacific Decadal Oscillation PDO consider the following statements It is a cycl...........

Geography and Environment (RAS) World climates

With reference to the Pacific Decadal Oscillation (PDO), consider the following statements

It is a cyclical event that repeats every 20-30 years and just like ENSO, has a ‘cool’ and ‘warm’ phase.
El Nino Southern Oscillation (ENSO) with a positive PDO is generally not good, however, ENSO with a negative PDO brings more rain to India.
A warmer (positive-phased) PDO implies fewer equatorial-origin cyclones.

How many of the statements given above are correct?

Only One

Only Two

All Three

None of the above

Pacific Decadal Oscillation

The Pacific Decadal Oscillation (PDO) is a long-term ocean fluctuation of the Pacific Ocean. It is a cyclical event that repeats every 20-30 years and just like ENSO, has a ‘cool’ and ‘warm’ phase.
Positive (warm) PDO = cooler west Pacific Ocean and warmer eastern side (vice versa for negative PDO).
The term PDO was coined in about 1996 by Steven Hare.

Impact of PDO

On Global Climate: PDO phase can have significant implications for the global climate, affecting Pacific and Atlantic hurricane activity, droughts and flooding around the Pacific basin, the productivity of marine ecosystems, and global land temperature patterns.
On Cyclones: A warmer (positive-phased) PDO implies fewer equatorial-origin cyclones.
In 2019, the PDO entered a cooler, negative phase and which if continues, could mean more such cyclones in post-monsoon months.

ENSO and PDO

ENSO with a positive PDO is generally not good, however, ENSO with a negative PDO brings more rain to India.
If both ENSO and the PDO are in the same phase, it is believed that El Niño/La Nina impacts may be magnified.

Hence option 3rd is correct.