A recipe for simulating the observed interhemispheric albedo symmetry and constraining cloud radiative feedbacks

• Earth’s albedo has remained symmetric between the northern and southern hemispheres over the satellite record, a feature that climate models have difficulty capturing. We investigate causes of these biases using a perturbed parameter ensemble of atmospheric simulations to probe the sensitivity of the albedo symmetry to cloud properties and the processes that control them. We find that the most significant parameters to simulated albedo symmetry impact precipitation, turbulent dissipation, and sea salt aerosol emissions. Constraining shortwave cloud feedbacks using the observed albedo symmetry leads to a range of +0.61±0.24 W m-2 K-1 (66% confidence). These are stronger than the model’s control settings due to greater loss of subtropical low clouds and weaker negative cloud phase feedback. Comparing the constrained and control parameter settings shows a preference towards settings that would reduce the control simulation’s biases, indicating that the constraint can select for representations that capture the observed cloud cover.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Meteorologi och atmosfärforskning (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Meteorology and Atmospheric Sciences (hsv//eng)

Nyckelord

Albedo symmetry

Albedo

Cloud feedbacks

Model bias

atmosfärvetenskap och oceanografi

Atmospheric Sciences and Oceanography

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)