As per recent studies, some meteorologists claim that 2016 will be among hottest years on record due to "Pacific Decadal Oscillation (PDO)". With this reference, consider the following statements:
- PDO is a temperature pattern observed primarily in southern Pacific Ocean.
- While during “warm" phase of PDO, south-west pacific becomes cooler, during “cold" phase south east pacific becomes cooler.
Which of the above statements is/are correct?
First statement is incorrect because the Pacific Decadal Oscillation (PDO) is a temperature pattern in the North Pacific Ocean, north of 20° N that spends roughly 20-30 years in the cool phase or the warm phase. Second statement is incorrect because during a "warm", or "positive", phase, the north-west Pacific becomes cooler and part of the north-eastern ocean warms; during a "cool" or "negative" phase, the opposite pattern occurs. The Pacific Decadal Oscillation (PDO) has also been described by some as a long-lived El Nino-like pattern of Pacific climate variability, and by others as a blend of two sometimes independent modes having distinct spatial and temporal characteristics of North Pacific sea surface temperature (SST) variability. PDO “events" persist for 20-to-30 years, while typical ENSO events persist for 6 to 18 months. PDO is currently under its “warm" phase, which has lasted almost for 20 years and now about to transit to “cooler" phase within upcoming few years.
Impacts of PDO
Warm phases of the PDO coincide with anomalously dry periods in eastern Australia, Korea, Japan, the Russian Far East, interior Alaska, in a zonally elongated belt from the Pacific Northwest to the Great Lakes, the Ohio Valley, and in much of Central America and northern South America; warm PDO phases also tend to coincide with anomalously wet periods in the coastal Gulf of Alaska, the southwest US and Mexico, southeast Brazil, south central South America, and western Australia, while just opposite happens during cooler phase of PDO.
The causes for Pacific Decadal Oscillation (PDO) are still not clear, but the primary effects seem to be changes in northeast Pacific marine ecosystems and a changing jet stream path.
This question is a part of GKToday's Integrated IAS General Studies Module