Polar-to-mid-latitude climate linkage effects on cold air outbreaks

Descripción del proyecto

Examinar el papel del hielo marino en las olas de aire frío

Las olas de aire frío son una característica típica del clima de latitudes medias durante la estación invernal y pueden provocar temperaturas anormalmente bajas que dañen los cultivos o provoquen fuertes nevadas. Sin embargo, el papel de algunos componentes del sistema climático, como el hielo marino, sigue siendo desconocido. El equipo del proyecto Polar2MidLat, financiado con fondos europeos, analizará los mecanismos físicos que vinculan la variabilidad en las latitudes altas (incluida la del hielo marino) con la variabilidad climática en las latitudes medias. El equipo del proyecto también utilizará un conjunto de datos de simulaciones de modelos climáticos mundiales acoplados de muy alta resolución (a unos diez kilómetros) y se espera que esto aporte mejoras significativas a la representación del hielo marino, así como a sus vínculos con otros componentes del sistema climático.

Objetivo

Cold air outbreaks are a typical feature of the mid-latitude climate during the cold season. Their relevance relies on the threat to life caused by the long-lasting periods with abnormally low temperatures as well as on the potential of damage to crops and the occurrence of high-impact weather events such as heavy snow and low visibility during blizzards.
Previous studies have documented the linkages between climate variability at high latitudes with that at mid-latitudes mainly through modulation of the storm tracks, jet streams and patterns of stationary waves which promote blocking events. The role of other components of the climate system, like sea ice, is much less understood and remains an open question. This becomes even more challenging under the current conditions of fast sea ice reduction in the Arctic and the significant trends observed in sea ice around Antarctica, which leads to an increase in uncertainty in the area of sub-seasonal to interannual climate predictions as well as for climate projections for the coming decades. Furthermore, significant biases currently exist in the representation of sea ice in state-of-the-art climate model simulations.
The main objective of this proposal is to analyze the physical mechanisms linking variability at high latitudes (including that of sea ice) with climate variability at mid-latitudes. Special focus will be driven onto the mechanisms promoting cold snaps at mid-latitudes and on their variability. To this aim, this project will make use of a data set of very-high-resolution coupled global climate model simulations (at around 10 km) which is expected to bring significant improvements to the representation of sea ice as well as to its linkages with other components of the climate system. Outcomes of this project are expected to become useful for decision makers and stakeholders, as well as to researchers working in the field of climate predictions and projections.