stratoIMPACT · The downward impact of the stratosphere in current and future climates

The downward impact of the stratosphere in current and future climates

One of the most striking long-lived influences on the weather in Europe comes from the stratosphere, a highly stratified, stable layer of the atmosphere at 10 to 50 km above the surface. Extreme stratospheric events, such as sudden stratospheric warmings (SSW), can have a prolonged downward impact on the large-scale atmospheric circulation, including an equatorward shift of the tropospheric jet stream over the North Atlantic, cold spells over Scandinavia and increased rainfall over the Mediterranean. Future climate projections demonstrate great uncertainty when it comes to the stratospheric response to climate change. the model spread is considerable, particularly in winter, when the stratospheric influence is strongest. Furthermore, midlatitude storms are expected to become more intense as the storm tracks shift poleward or extend to Europe. It is therefore unclear how these changes in both the stratosphere and the troposphere may alter the tropospheric response to stratospheric forcing under climate change. The main goal of the stratoIMPACT project is to understand the physical processes that are responsible for the impact of the stratosphere (a layer of the atmosphere, above 10 km) on surface weather and climate, and how this coupling will be modified under climate change. The specific scientific objectives for the project are to: 1. Identify and characterize the role of the storm tracks in the downward response to stratospheric forcing in observations. 2. Investigate the mechanisms through which stratospheric anomalies reach the surface using a series of modeling experiments and state-of-the-art climate model projections. 3. Combine the results of (1) and (2) to resolve how the downward response to stratospheric forcing will be affected by climate change. This project has addressed societal needs at regional level by two aspects: First, understanding the downward impact of the stratosphere and its influence on surface weather (e.g., the jet stream and the storm track) helps to shed light on ongoing processes in Earth’s atmosphere that affect our day-to-day weather, and reduces the uncertainty of future climate projections. Second, this work helps to quantify the risk and the uncertainty of extreme storms under climate change, thus providing an essential step forward and a solid scientific basis for advanced early warning systems (more than 1 week in advance) for extratropical cyclones and windstorms in a changing climate.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз