From NoTricksZone

By Kenneth Richard on 7. October 2024

The radiation budget changes shaping trends in global dimming (cooling) and global brightening (warming) are driven by cloud cover changes, which are themselves modulated by internal deep ocean processes.

A new study assesses the associated factors in North Atlantic climate variations, noting how critical clouds are in modulating Earth’s Energy Imbalance (EEI).

“Cloudiness is the most important meteorological factor shaping the amount of solar energy reaching Earth’s surface.”

The authors find cloud changes are seemingly driven by variations in the intensity of the ocean’s internal thermohaline circulation, which is itself associated with AMO, PDO indices.

“…strong correlations between cloudiness and AMO (Atlantic Multidecadal Oscillation) variability. … AMO is a manifestation of thermohaline circulation.”

In turn, cloud changes predominantly determine how much solar energy is absorbed by the Earth’s surface, driving warming or cooling trends.

“…changes in cloudiness…are the cause of changes in the accumulated solar energy and related increase in air temperature”

While this is a regional study using climate data from Krakow (Poland) spanning the last 150 years, especially the 1950-2020 period, the authors point out that the cloud variations and their driving factors are aligned with changes across the European continent, and on a global scale too.

“Such changes in the extent structure of cloudiness…largely explain the variations in sunshine duration in Europe associated with changes in NA THC [North Atlantic thermohaline circulation] phases. Additionally, these changes are linked to global processes of dimming and brightening.”