POLAR AMPLIFICATION

Polar amplification can be defined as the climate models that predict amplified warming in Polar Regions due to climate feedbacks. 

 other words, when climate change near the pole compared to the rest of the hemisphere or globe in response to a change in global climate forcing, such as the concentration of greenhouse gases (GHGs) is called Polar amplification.

Reasons:

Change in Albedo:

• Albedo is a measure of how much light that hits a surface is reflected without being absorbed.

• When bright and reflective ice (with more albedo) melts, it gives way to a darker ocean (lowering albedo); this amplifies the warming trend because the ocean surface absorbs more heat from the Sun than the surface of snow and ice.

Changing Ocean currents:

• Ocean currents normally bring in warmer water from the Pacific, and colder water exits out of the Arctic into the Atlantic.

• But those currents may be changing because more melting ice is injecting the Arctic Ocean with freshwater. The missing ice also exposes the surface waters to more wind. This mixes up colder freshwater at the surface and warmer saltwater below, raising surface temperatures and further melting ice.

Changing Weather

• Ocean currents drive the powerful polar jet stream, which moves hot and cold air masses around the Northern Hemisphere. This is a product of the temperature differences between the Arctic and the tropics.

• But as the Arctic warms, the jet stream now undulates wildly north and south. This has been injecting the Arctic with warm air.

• Thunderstorms are also much more likely to occur in the tropics than the higher latitudes. The storms transport heat from the surface to higher levels of the atmosphere, where global wind patterns sweep it toward higher latitudes.

• The abundance of thunderstorms in tropics creates a near-constant flow of heat away from the tropics towards the Arctic

Impact in the Arctic:

1- The floating sea ice cover of the Arctic Ocean is shrinking, especially during summer.

2- Snow cover over land in the Arctic has decreased, notably in spring.

3- In addition, frozen ground in the Arctic, known as permafrost, is warming and in many areas thawing.

Effects Worldwide:

1- Higher temperature will cause a Sea-Level Rise globally that in turn has impacts like the destruction of ecosystems, displacement, loss of life and property etc.

2- Arctic permafrost thaw is also releasing the potent greenhouse gas methane causing profound global warming effects.

3- Arctic wildfire, called Zombie Fire intensity is also increasing each year as thawing ground dries out.