The Changing Ocean Flashcards
What defines a long term average
The world meteorological association considers 30 years to be the minimum to establish the average climate
How is the ice changing on the globe?
We see from Northern Canada that the ice is freezing slower and later, and has some meltings that occur mid-freeze as well
What affects of climate change have we detected in saanich inlet?
The blob in 2015-2017 elevated temperatures and had cascading effects on oxygen.
From anomaly plots we see that recent years have more anomalies and show both coldest and warmest in same year
Saanich inlet is decreasing oxygen concentration and is becoming more hypoxic/anoxic and for longer
Shallow ocean breaths
These occur frequently for the upper part of worlds oceans exchanging gasses with the surface
Deep ocean breaths
These are very slow circulations of sinking north Atlantic waters that surface in the pacific and indian to provide deep breaths and gas exchange at the surface
How does pH change with depth
pH is highest at the surface and quickly decreases to be most acidic at mid-water depths (~500m). From here the pH increases and plateaus at depth, but never higher than the surface.
Surface has low respiration and net use of CO2 for photosynthesis. Mid water has high resp and low photosyn, but depths has lower resp
What is the closest pH event to today in the last 300 million years
55 mya the Paleocene-Eocene thermal maximum
pH change of 0.45 over 20 thousand years
Today’s pH change has been 0.1 over 150 years
What are the effects of OA on marine organims
They are very diverse
Calcifying organisms likely has negative impact
But photosynthesizers may have increased productivity and growth
But overall community structure will change drastically
Marine carbon dioxide removal
Things such as ocean alkalization, direct CO2 removal and storage and macroalgal culture
The main issue is they aren’t scalable and do not permanently remove CO2 from system
What is the number 1 solution
Net-zero emissions
What can reduce pressures from climate change
Coastal nutrient and organic matter discharge
Habitat restoration/ protection
Fishing pressures
Importance of pterpods
Food source for animals
Biogeochemical – carbonate export to deep waters
Potential indicator due to aragonite shell
Pteropod resiliency to OA
Periostracum is a line of defence that protects shell from short-term exposure to corrosive water
This helped them to survive previous periods of OA in earths history
They may be more resilient to OA than previously thought
Their vertical migration habits make their exposure to acidic waters less
Observed changes at ocean station papa
The waters are freshening and getting warmer
Global observations of sea-surface warming
Ocean warming is slower than on land
warming is widespread
