“Major changes in northeast Pacific marine ecosystems have been correlated with phase changes in the PDO; warm eras have seen enhanced coastal ocean biological productivity in Alaska and inhibited productivity off the west coast of the contiguous United States, while cold PDO eras have seen the opposite north-south pattern of marine ecosystem productivity.”http://research.jisao.washington.edu/pdo/
I had to check a claim made in the video – but they are right. There are different biological markers in Alaska and the US west coast. The difference is the relative change in cold, nutrient rich deep ocean upwelling. In the cool phase there is a vast blue “V” swathe across the Pacific.
Coupled winds and current push surface water west to pile up against Australia and Indonesia in a vast pool of potential and thermal energy. When conditions are ripe – and in the flick of a Madden-Julian Oscillation – the energy surges back east to crash against the eastern Pacific margin. Although the flows are vastly more complex than I make out – the vast area of warmer surface water warms the atmosphere. Ocean heat dissipates north and south at it hits the coastline. In the evolution of ENSO – the energy once stored in the western Pacific has dissipated and the next phase is inevitably recharge – in La Nina – of energy in the Pacific warm pool.
The cool phase starts with upwelling which starts with flows in the Peruvian and Californian Currents spinning up with the Pacific gyres. Cooler higher latitude water is pushed toward the equator diluting residual warm surfaces. Turbulent deep ocean flows surface and set up wind and current responses that again extend the cold tongue and piles warm surface water up against Australia and Indonesia. The vast area of cool surface absorbs heat from the atmosphere. The ocean warms and the atmosphere cools. There are as well cloud effects.
More cloud with the cooler ocean – and vice versa. In temperature/cloud coupling -clouds are lower and denser in cooler temps. There are large satellite observed changes in the energy dynamic of the planet from changing patterns in ocean and atmospheric flows – and the aperiodic changes in the Pacific are a big part of it. But more than that – all of the global flows are coupled in Earth’s spatio/temporal chaotic flow field. It is has implications for how and why aperiodic regimes form. The idea seems like random words to many – but is a relatively precise description of a reality you can actually see in near real time – given the wonders of modern technology and big data. Here I have the Earth Null School site showing total precipitable water in the atmosphere. It is an interesting field to view because it shows where the heat is in both oceans and atmosphere and where the atmospheric moisture is.
I play on the Earth Null School site for hours – it is fascinating what you can see in near real time in a super-computer visualization. From the stratosphere to the oceans. What this view is showing is cooler, drier air pushing up from Antarctica – and down from the Arctic – deep into the Australian continent. I have been feeling this for months on the Tropic of Capricorn – cooler temps with subtle changes in winds and dramatic biological responses. Not quite the biggest Trichodesmium bloom I can remember but up there. We are entering drought territory with risks of summer fires in store. Remnants of the 2014-16 El Niño ocean heat and atmospheric moisture are still spilling over into hurricane alley in the south-west Atlantic.
Winds and great ocean gyres spin up in negative phases of the polar annual modes. This graphic shows the familiar blocking pattern in the Northern Hemisphere where the troughs are cold and stormy air pushing into lower latitudes.
As gryes spin up and dilute the thermocline with cooler water – more turbulent deep ocean flow push to the surface. This sets up wind and current responses – in a resonant ocean – that influence global temps, hydrology and biology.
Both ENSO and the PDO have 20 to 30 years regimes. Moreover the cool PDO is associated with more frequent and intense La Niña – and a warm phase with frequent El Niño. The puzzle of a shared 20 to 30 year pulse in both hemispheres is traced mechanistically back to changing polar surface pressure fields – influencing storm tracks in high latitudes. At the same time – research is showing a solar UV/ozone chemistry influence in modulating atmospheric flows and polar pressure fields.
There is a recent study that wonders at the potential for the ~22 year Hale cycle of solar magnetic reversal to be the trigger for the 20 to 30 year regimes. As I did some months ago now. It supplies a plausible mechanistic link for solar variability amplification in the terrestrial system. With intriguing possibilities for the evolution of climate.
There are opinions that the Pacific state has shifted over the past few years to a warmer phase again. I am intrigued. The wishy washy neutral looking regime we have seen since the last shift at the turn on the century has been punctuated by long and intense surface warmth following relatively intense cooling. My bet is that the transition is happening now and that this a dragon-king.
“We emphasize the importance of understanding dragon-kings as being often associated with a neighborhood of what can be called equivalently a phase transition, a bifurcation, a catastrophe (in the sense of Rene Thom), or a tipping point. The presence of a phase transition is crucial to learn how to diagnose in advance the symptoms associated with a coming dragon-king.” https://arxiv.org/abs/0907.4290
Dragon Kings live in coral castles guarded by crab generals and shrimp soldiers. They bring us flood and drought at their whim. A solar connection suggests the potential for a shift to a yet cooler state in the Pacific on a centennial scale.
Salt content in a Law Dome, Antarctica, ice core has implications for coupling modes globally and northeast Australian rainfall especially. More salt is La Niña as wind and currents spin up gyres and upwelling increases…