Gulf stream why

In fact, England is about the same distance from the equator as cold regions of Canada, yet England enjoys a much warmer climate. The Gulf Stream is caused by a large system of circular currents and powerful winds, called an oceanic gyre. There are five oceanic gyres on Earth. This world map shows the five oceanic gyres and how they impact ocean circulation. Credit: NOAA. The ocean is constantly in motion, moving water from place to place via currents.

As the warm water comes in, colder, denser water sinks and begins moving south—eventually flowing along the bottom of the ocean all the way to Antarctica. Both effects lower the density of sea water, which in turn tend to weaken deep convection. Uncertainties in model projections of future climates are due to three factors: Lack of knowledge of future greenhouse gas emissions, natural variability, and differences among models.

For many years, researchers have been using global climate models to investigate the effects of progressive climate change on the Gulf Stream circulation. The result: The uncertainties in the projections by the end of the 21st century are determined by modeling deficits and less by the uncertain future greenhouse gas emissions. This is in stark contrast to other parameters such as the global surface temperature for which the future emissions are the largest source of uncertainty.

The research team examined how much of the uncertainty was due to different greenhouse gas emission scenarios, which was due to natural variability, and which was due to differences among the models. Mojib Latif, co-author of the study. The circulation will slow with high probability, but by how much remains uncertain.

Reference: Reintges, A. Martin, M. Boers and his colleagues reported in May that a significant part of the Greenland ice sheet is on the brink , threatening a big rise in global sea level.

Others have shown recently that the Amazon rainforest is now emitting more CO2 than it absorbs, and that the Siberian heatwave led to worrying releases of methane. A major report from the Intergovernmental Panel on Climate Change, due on Monday, is expected to set out the worsening state of the climate crisis. Ice-core and other data from the last , years show the AMOC has two states: a fast, strong one, as seen over recent millennia, and a slow, weak one.

The data shows rising temperatures can make the AMOC switch abruptly between states over one to five decades. Pushing a chair alters its position, but does not affect its stability if all four legs remain on the floor. Tilting the chair changes both its position and stability.