What is decadal climate variability?

What is decadal climate variability?

Decadal climate variability (DCV) – the variations in global and regional climate that distinguish one decade from another – is of relevance to our complex modern society. DCV can arise from internal interactions within the climate system, and in response to external forcing such as clusters of volc.

What is a decadal scale?

The divide between decadal and interannual scales corresponds to a period of 10 years, so that variability due to the El Niño-Southern Oscillation (ENSO) falls into the interannual category, while variability on time scales of 10 years or longer is classified as decadal.

What are examples of climate?

Climate is the average of that weather. For example, you can expect snow in the Northeast in January or for it to be hot and humid in the Southeast in July. This is climate. The climate record also includes extreme values such as record high temperatures or record amounts of rainfall.

How long does the Pacific Decadal Oscillation PDO last?

20 to 30 years
The Pacific Decadal Oscillation (PDO) is a pattern of Pacific climate variability similar to ENSO in character, but which varies over a much longer time scale. The PDO can remain in the same phase for 20 to 30 years, while ENSO cycles typically only last 6 to 18 months.

What is the current status of the PDO?

Discussion: The Pacific decadal oscillation (PDO) shifted into the cool phase in early 2020 remaining in-place into 2022 except stronger during recent months. The 2-year longevity was last observed in 2010-13 when 3+ years of -PDO persisted.

What does the Southern Oscillation Index measure?

The Southern Oscillation Index (SOI) is a measure of the intensity or strength of the Walker Circulation. It is one of the key atmospheric indices for gauging the strength of El Niño and La Niña events and their potential impacts on the Australian region.

What PDO phase are we in now?

“When SSTS are cool in the interior North Pacific and warm along the Pacific Coast, and when sea level pressures are below average over the North Pacific, the PDO has a positive value” (NOAA 2021). This is considered a warm phase.

What are north and south temperate zone?

The north temperate zone extends from the Tropic of Cancer (approximately 23.5° north latitude) to the Arctic Circle (approximately 66.5° north latitude). The south temperate zone extends from the Tropic of Capricorn (approximately 23.5° south latitude) to the Antarctic Circle (at approximately 66.5° south latitude).

What does a negative Southern Oscillation Index mean?

The negative phase of the SOI represents below-normal air pressure at Tahiti and above-normal air pressure at Darwin. Prolonged periods of negative (positive) SOI values coincide with abnormally warm (cold) ocean waters across the eastern tropical Pacific typical of El Niño (La Niña) episodes.

What is a Southern Oscillation?

The Southern Oscillation describes a bimodal variation in sea level barometric pressure between observation stations at Darwin, Australia and Tahiti. It is quantified in the Southern Oscillation Index (SOI), which is a standardized difference between the two barometric pressures.

What are the 5 temperate zones?

The temperate geographical zone is made up of five subzones which are the oceanic, subtropical, continental, Boreal, and Mediterranean subzones.