The warming trend in the Arctic is almost twice as large as the global average in recent decades. This is known as Arctic amplification. Changes in cloud cover, increases in atmospheric water vapour, more atmospheric heat transport from lower latitudes and declining sea ice have all been suggested as contributing factors.
- The Arctic/Polar Amplification Effect is mainly caused by a combination of a few things. The chief components include the magnitude of change regarding ice extent and snow cover loss allows for a more dramatic change in climate architecture of the polar region. This also relates to the amount of land in the northern hemisphere verses the southern hemisphere. In a warming world, it is expected that the Arctic would heat faster for these reasons.
- Potential contributor to amplified warming that’s investigated is changes in cloud cover. Spring is the only season that exhibits significant trends in Arctic average cloudiness and the trend is negative. However, decreased cloud cover is expected to cause surface cooling because clouds have a warming influence in spring. Thus no evidence is found of cloud cover changes contributing to recent near-surface Arctic warming.
- Changes in atmospheric water vapour content may amplify Arctic warming. However, specific humidity trends are found only during summer and early autumn. The pronounced warming in winter and spring are not accompanied by increases in humidity. In fact, the evidence suggests part of the humidity increase is driven by enhanced surface moisture fluxes associated with sea ice reductions.
- Declining sea ice cover and thickness have been great enough to enhance Arctic warming during most of the year.Loss of the Arctic Ice cap in summer melt season. The polar ice is on the water, while the Antarctic ice is sitting on land. As the oceans warm, warmer water helps melt the Arctic ice. This cannot happen at the South Pole since it is sitting on land.
- The resulting accelerating warming will increase the latitudinal shift of the jet-stream, thus drying out areas of land further to the north resulting in changes to vegetation and land albedo as well as increased fire risk (all of which translate to increased CO2 and increased warming). Dryer regions moving north will severely impact existing crop growth infrastructure.
- Colder dense air over the Antarctic prevents some degree of mixing with air mass from other regions, thus helping this region retain cold air mass longer than the in Arctic region which is subject to many factors that can move heat or cold energy in and out of the polar region through the ocean or the atmosphere.