Understanding Arctic amplification of climate change through air-mass transformations

Project Information

A3M-transform

Grant agreement ID: 101076205

DOI

10.3030/101076205

EC signature date 24 March 2023

Start date 1 October 2023

End date 30 September 2028

Funded under

• European Research Council (ERC)

Total cost

€ 1 468 938,00

EU contribution

€ 1 468 938,00

Coordinated by

ALFRED-WEGENER-INSTITUT HELMHOLTZ-ZENTRUM FUR POLAR- UND MEERESFORSCHUNG
Germany

Periodic Reporting for period 1 - A3M-transform (Understanding Arctic amplification of climate change through air-mass transformations)

Reporting period: 2023-10-01 to 2026-03-31

Summary of the context and overall objectives of the project

We want to understand why Arctic climate (temperature and precipitation) change is amplified compared to the global mean, and how the exchange and transformation of air masses couples the Arctic to the global climate system. To achieve this, we link observations and modelling of small-scale processes in Arctic clouds and boundary-layers to a large-scale dynamical and themodynamical understanding of the Arctic's role in the climate system.

In particular, we use drifting balloons that record the evolution of temperature and humidity in air masses that are transported from mid-latitudes to the Arctic. We combine these observations with modelling data to understand the processes that drive changes in temperature and humidity, and to understand how the transport and cooling of these air masses link the Arctic to the global climate system.

As a result of our project, we expect to be able to better understand and constrain Arctic climate change and its amplification compared to lower latitudes.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

We have conducted two balloon campaigns from Svalbard and obtained several valuable case studies of air flow and air mass transformation from the open ocean to the sea-ice covered Arctic. To best use the data, we have developed a scheme to correct the raw data for radiation biases and the instrument time lag.
In parallel, we have analyzed data from land-based observatories to understand changes in the diurnal temperature range, i.e. differences between minimum and maximum temperatures, evaluated the representation of cold and warm Arctic air masses in climate models and investigated air-mass transformation using aircraft campaigns and km-scale atmospheric models.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We have shown that the diurnal temperature range (DTR) is strongly affected by the melting and freezing of snow and moisture on or in the ground, and that this effect is relevant for DTR trends and their representation in climate models. Our results could be used to evaluate the representation of atmosphere-surface coupling over land in further research.
Our evaluation of climate models with data from Svalbard has shown that models with two-moment microphysics, i.e. models that track the evolution of the number of cloud particles over time, better represent the occurence of high moisture content in the air. This needs to be further demonstrated in operational and climate models to make an impact on modelling practices.