ENSO and Marine Climate Change Lecture Notes

Vocabulary flashcards covering El Niño Southern Oscillation (ENSO), ocean acidification, marine heatwaves, and their ecological impacts based on lecture notes.

ENSO

El Niño Southern Oscillation; natural climate patterns affecting global rain, temperature, and wind.

SST

Sea Surface Temperature.

Upwelling zones

Regions characterized by coastal or equatorial upwelling, often involving Coriolis effect and Ekman flow.

Atmospheric $CO_2$ concentrations

Presently at $430\,ppm$, the highest Earth has experienced in a very long time.

Ocean Acidification

A process where $pH$ dropped $0.1$ in $20$ years, resulting in a less alkaline environment with less $CO_3^{-2}$ and more $HCO_3^{-1}$ and $H^{+}$.

Aragonite

A form of $CaCO_3$ needed for shells and skeletons that is subject to dissolution as a result of $CO_2$ impact.

Weedy marine plants

Carbon-limited plants, such as turf algae, that can grow faster due to increased $HCO_3^{-1}$ as a resource.

Shelford's Law of Tolerance

A law used to explain biological responses to environmental factors, such as poleward range shifts of species.

Poleward range shifts

The movement of species' ranges toward the poles, such as the $0.46^\circ S$ to $1.92^\circ S$ shift in temperate seaweeds observed from $1940\text{-}60$ to $1990\text{-}2009$.

Marine Heatwaves (MHWs)

Events where $SST \ge 5$ days and is $\ge 90th$ percentile of a baseline climate ($30\text{-}year$).

Cumulative Intensity

The sum of $\text{Day} \times \text{Intensity}$ used to measure marine heatwaves.

2010/11 WA MHW

A Western Australian marine heatwave that reached the highest temperature on record in over $140$ years, causing a collapse of Ecklonia kelp forests.

Ecklonia

Cool-water adapted kelp that is up to $15$ times more productive than wheat fields; it experienced extinction along a $100\,km$ coastline during the WA MHW.

Tropicalisation

The proliferation of warm-adapted fish and tropical species into previously temperate areas following a marine heatwave.

Hysteresis

A condition where the kelp forest did not re-establish after the MHW ended due to alternative stable states and regime shifts.

Durvillea

A genus of large bull kelp, reaching up to $10\,m$ and $70\,kg$, which suffered regional extinction in New Zealand following the $2017/18$ MHW.

2017/18 NZ MHW

A marine heatwave in New Zealand where Lyttelton Harbour temperatures reached $>23^\circ C$, leading to the loss of bull kelp at sites like Pile Bay.