Heat extremes are becoming more frequent and intense in southern South America. This study uses a storyline approach to explore how different climate drivers shape future summer temperature extremes. Using climate model simulations, we identified key drivers, such as soil moisture, sea surface temperature and atmospheric circulation, to build physically consistent scenarios that explain the sources of uncertainty in regional warming projections in southern South America.

In 2023, Rio de Janeiro experienced record-breaking heat waves linked to climate change and El Niño. Our study shows that global warming made these extreme temperatures at least 2 °C hotter than in pre-industrial times. Heat-related deaths surged, with climate change contributing to one in three fatalities during the peak event. Without adaptation, future heat waves will claim even more lives. This underscores the urgent need for policies to mitigate climate impacts from escalating heat threats.

Ozone (discovered in 1837) was first measured in 1847 using paper strips that reacted with ozone, providing an indication of its concentration based on colour changes. Here, we present the data, covering over 60 years of daily observations conducted along the eastern Atlantic coast, spanning from the tropics to the northern extratropics.

Variability in the extratropical stratosphere and troposphere is coupled, and because of the longer timescales characteristic of the stratosphere, this allows for a window of opportunity for surface prediction. This paper assesses whether models used for operational prediction capture these coupling processes accurately. We find that most processes are too weak; however downward coupling from the lower stratosphere to the near surface is too strong.

During February–March (FM) 2020–2022, unusually intense dust storms from northern Africa hit the western Euro-Mediterranean (WEM). Using dust products from satellites and atmospheric reanalysis for 2003–2022, results show that cut-off lows and European blocking are key drivers of FM dust intrusions over the WEM. A higher frequency of cut-off lows associated with subtropical ridges is observed in the late 2020–2022 period.

Tropospheric and stratospheric aerosol extinction profiles observations from a searchlight at New Mexico, US, were rescued and re-calibrated. Spanning between December 1963 and 1964, they measured the volcanic aerosols from the 1963 Agung eruption. Contemporary and state of the art information were used in the re-calibration. A unique and until the present forgotten/ignored dataset, it contributes current observational and modelling research on the impact of major volcanic eruptions on climate.

Forecast models that are used to predict weather often struggle to represent the Earth’s stratosphere. This may impact their ability to predict surface weather weeks in advance, on subseasonal-to-seasonal (S2S) timescales. We use data from many S2S forecast systems to characterize and compare the stratospheric biases present in such forecast models. These models have many similar stratospheric biases, but they tend to be worse in systems with low model tops located within the stratosphere.

The first multi-year stratospheric aerosol lidar dataset was recovered and recalibrated. The vertical profile dataset, January 1964 to August 1965 at Lexington, MA, and July to August 1964 at Fairbanks, AK, provides info on volcanic forcing after the 1963 Agung eruption. Applying two-way transmittance correction to the original dataset reveals data variations, with corrected stratospheric aerosol optical depth (sAOD) highest in 1965 with the highest 532 nm sAOD peak at 0.07 in March 1965.

In this review we describe the factors leading to the extreme water heights producing the floods of Venice. We discuss the different contributions, their relative importance, and the resulting compound events. We highlight the role of relative sea level rise and the observed past and very likely future increase in extreme water heights, showing that they might be up to 160 % higher at the end of the 21st century than presently.

Air stagnation occurs when an air mass becomes settled over a region and precipitation is suppressed. Pollutant levels can rise during stagnation. The synoptic- to large-scale influence on European air stagnation and pollution is explored here. We show that around 60 % of the monthly variability in air stagnation and pollutants can be explained by dynamical indices describing the atmospheric circulation. The weather systems most related to stagnation are different for regions across Europe.