Sentences with phrase «ocean oxygen concentrations»

The amount of trace elements in ocean pyrite correspond to ocean oxygen concentrations at different points in geologic time.

The worst - case result is that mean ocean oxygen concentration falls to a low of about 68 % of pre-industrial levels in the next few millennia, while low - oxygen «dead zones» — which don't support fish or many other marine animals such as crabs and clams — spread nearly six-fold to cover 12.8 % of the sea surface area.

Not exact matches

Examining the distribution patterns of microfossils, Shen's Harvard colleagues have discovered that the marine eukaryotic algae of 1.5 billion years ago occupied only the ocean shallows and not the deeper basins, indicating a smaller oxygen concentration in the atmosphere than exists today.

This includes places like parts of the eastern Pacific Ocean where small animals like nematodes and specially adapted fish live on the fringes of habitability, subsisting in waters where oxygen concentrations can be only about 1 % of normal surface water levels.

For each degree of ocean warming, oxygen concentration goes down by 2 percent.

These concentrations could have sustained small, simple animals, just as they do today in the ocean's oxygen - poor zones.

These proxies seemed to indicate that oxygen concentrations in the oceans rose in several steps, approaching today's sea - surface concentrations at the start of the Cambrian, around 541 million years ago — just before more - modern animals suddenly appeared and diversified.

A study published in Geophysical Research Letters in 2011 found widespread declines in oxygen concentration in the upper ocean between the 1970s and the 1990s.

A commonly held belief that global warming will diminish oxygen concentrations in the ocean looks like it may not be entirely true.

And that, the team thinks, is why the oxygen concentrations in the Pacific Ocean so clearly increased from 1950 to 1990.

But for animals to evolve, the concentration of oxygen in the ocean and atmosphere had to be just right.

Thanks to natural warming and cooling, oxygen concentrations at the sea surface are constantly changing — and those changes can linger for years or even decades deeper in the ocean.

«Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it's been challenging to attribute any deoxygenation to climate change.

«Changes in ocean conditions that affect fish stocks, such as temperature and oxygen concentration, are strongly related to atmospheric warming and carbon emissions,» said author Thomas Frölicher, principal investigator at the Nippon Foundation - Nereus Program and senior scientist at ETH Zürich.

With little oxygen available to convert that hydrogen into water, hydrogen gas probably accumulated in the atmosphere and oceans in concentrations as high as hundreds to thousands of parts per million.

Since then, numerous short - lived biotic events — typically marked by significant climatic perturbations — took place when oxygen concentrations in the ocean dipped episodically.

What does it take in terms of climate change / CO2 concentration to trigger a large reduction in the ocean's oxygen production?

This is because hydrate decomposition primarily occurs in the Pacific Ocean, where present - day seawater has low oxygen concentration.

Plots of ocean temperature (left) and salinity will appear (in recent years oxygen concentration is also given).

«Long - Term Changes in Dissolved Oxygen Concentrations in the Ocean Caused by Protracted Global Warming.»

Do you think that the concentration of oxygen in the oceans is in equilibrium with the atmosphere?

As sub-surface oxygen concentrations in the ocean everywhere reflect a balance between supply through circulation and ventilation and consumption by respiratory processes, the absolute amount of oxygen in a given location is therefore very sensitive to changes in either process, more sensitive perhaps as other physical and chemical parameters.

In fact, declining oxygen concentrations in the ocean's interior are currently found to be a near - ubiquitous phenomenon for which the term ocean deoxygenation has been proposed.

The world's climate is way too complex... with way too many significant global and regional variables (e.g., solar, volcanic and geologic activity, variations in the strength and path of the jet stream and major ocean currents, the seasons created by the tilt of the earth, and the concentration of water vapor in the atmosphere, which by the way is many times more effective at holding heat near the surface of the earth than is carbon dioxide, a non-toxic, trace gas that all plant life must have to survive, and that produce the oxygen that WE need to survive) to consider for any so - called climate model to generate a reliable and reproducible predictive model.

Impacts of large - scale and persistent changes in the MOC are likely to include changes to marine ecosystem productivity, fisheries, ocean carbon dioxide uptake, oceanic oxygen concentrations and terrestrial vegetation [Working Group I Fourth Assessment 10.3, 10.7; Working Group II Fourth Assessment 12.6, 19.3].

These changes are resulting in a decrease in pH, carbonate ion concentrations, and dissolved oxygen in the ocean.

«Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it's been challenging to attribute any deoxygenation to climate change.»

In addition, if a hotter ocean were the source of CO2, oxygen would be coming out of solution as well, yet the concentration of oxygen in the atmosphere is actually decreasing, not increasing (sources: Environmental Chemistry.com's CO2 Pollution and Global Warming page and IPCC Working Group 1 Report, Chapter 2, pages 138 - 139).

Monitoring trends in biogeochemical indicators such as chlorophyll, dissolved oxygen, and nutrient concentrations is crucial for evaluating the oceans» response to global climate change and its effects on marine ecosystems.