LETTERS Implications of the Recent Trend in the Arctic/North Atlantic Oscillation for the North Atlantic Thermohaline Circulation
نویسندگان
چکیده
Most projections of greenhouse gas–induced climate change indicate a weakening of the thermohaline circulation (THC) in the North Atlantic in response to increased freshening and warming in the subpolar region. These changes reduce high-latitude upper-ocean density and therefore weaken the THC. Using ensembles of numerical experiments with a coupled ocean–atmosphere model, it is found that this weakening could be delayed by several decades in response to a sustained upward trend in the Arctic/North Atlantic oscillation during winter, such as has been observed over the last 30 years. The stronger winds over the North Atlantic associated with this trend extract more heat from the ocean, thereby cooling and increasing the density of the upper ocean and thus opposing the previously described weakening of the THC. This result is of particular importance if the positive trend in the Arctic/North Atlantic oscillation is a response to increasing greenhouse gases, as has been recently suggested.
منابع مشابه
Implications of the recent trend in the Arctic/North Atlantic Oscillation for the North Atlantic thermohaline circulation
Most projections of greenhouse gas-induced climate change indicate a weakening of the thermohaline circulation (THC) in the North Atlantic in response to increased freshening and warming in the subpolar region. These changes reduce high latitude upper ocean density, and therefore weaken the THC. Using ensembles of numerical experiments with a coupled ocean-atmosphere model, it is found that thi...
متن کاملThe influence of Atlantic-Eurasian teleconnection patterns on temperature regimes in South Caspian Sea coastal areas: a study of Golestan Province, North Iran
The main objective of this study was to reveal the impact of nine climate indices on temperature changes and climate oscillations in Golestan Province along the southern coast of the Caspian Sea. Climate indices data from across the Atlantic-Eurasian sector were collected from the NCEP/NCAR, the Climate Prediction Centre (CPC) and the Climatic Research Unit (CRU) over a period of 40 years (1971...
متن کاملThe influence of Atlantic-Eurasian teleconnection patterns on temperature regimes in South Caspian Sea coastal areas: a study of Golestan Province, North Iran
The main objective of this study was to reveal the impact of nine climate indices on temperature changes and climate oscillations in Golestan Province along the southern coast of the Caspian Sea. Climate indices data from across the Atlantic-Eurasian sector were collected from the NCEP/NCAR, the Climate Prediction Centre (CPC) and the Climatic Research Unit (CRU) over a period of 40 years (1971...
متن کاملThe Effects of North Atlantic Oscillation on the atmospheric middle level Anomaly and precipitation of Iran.Case study: west of Iran.
The purpose of this study was to investigate the effects of the North Atlantic Oscillation on the middle levels of Atmosphere and precipitation changes in the West of country. To do this, first monthly rainfall data of 17 synoptic stations of the West Country in period of 30 years from 1984 to 2014 of country were collected from Meteorological Organization. As well as North Atlantic Oscillation...
متن کاملInfluence of atmospheric circulation patterns on dust transport during Harmattan Period in West Africa
This study has used TOMS AI as well as the reanalysis dataset of thirty-four years (1979-2012) to investigate the influence of atmospheric circulation on dust transport during the Harmattan period in West Africa, using Aerosol Index (AI) data, obtained from various satellite sensors. Changes in Inter-Tropical Discontinuity (ITD), Sea Surface Temperature (SST) over the Gulf of Guinea, and North ...
متن کامل