Quantifying the Role of Atmospheric and Surface Albedo on Polar Amplification Using Satellite Observations and CMIP6 Model Output

Abstract

Polar amplification (PA) refers to the phenomenon where an external radiative forcing, such as changes in greenhouse gases (GHGs) and solar variability (Collins et al., 2013;Gregory & Webb, 2007;Gregory et al., 2004) causes a stronger warming effect in the polar regions than the rest of the Earth (Manabe & Wetherald, 1975;Trenberth et al., 2007). PA can be quantified by the PA factor (fPA) which is the ratio between temperature change in the high latitudes to the temperature change in the low-to mid-latitudes. PA is a key aspect of climate change, but its causes and effects are still not fully understood. Fundamentally, PA depends on variations in the temperature sensitivity to external forcings across different regions of the Earth. An amplified warming in high latitudes results in a smaller meridional temperature gradient between the equator and the poles. The meridional temperature gradient between low and high latitudes governs many features of the dynamics in the atmosphere, such as the meridional heat transport associated with large scale circulations, atmospheric winds via the thermal

An Ensemble Learning Model Reveals Accelerated Reductions in Snow Depth Over Arctic Sea Ice Under High‐Emission Scenarios

“…The models used and their corresponding variables are shown in Table S1 in Supporting Information S1. According to Donohoe and Battisti (2011) and Södergren and McDonald (2022), the surface albedo can be calculated using a simplified equation based on a simple radiation model, that is, the albedo is equal to the ratio of surface downwelling shortwave radiation (rsds) to surface upwelling shortwave radiation (rsus).…”

Assessment of Antarctic Amplification Based on a Reconstruction of Near-Surface Air Temperature

“…Previous studies found asymmetry in polar amplification, with the Antarctic amplification (AnA) weaker than Arctic amplification [7,8]. Variations in albedo are closely coupled to the strength of polar amplification, and changes in surface albedo are more important relative to changes in the atmosphere, and the opposite sign can be captured in the Arctic [9]. Moreover, changes in surface albedo, cloud cover and atmospheric absorbed shortwave radiation are greater in the Arctic, which is associated with the strong Arctic amplification [9].…”

“…Variations in albedo are closely coupled to the strength of polar amplification, and changes in surface albedo are more important relative to changes in the atmosphere, and the opposite sign can be captured in the Arctic [9]. Moreover, changes in surface albedo, cloud cover and atmospheric absorbed shortwave radiation are greater in the Arctic, which is associated with the strong Arctic amplification [9]. The role of stratospheric ozone depletion contributes to the asymmetry, and increased greenhouse gases (GHG) and ozone depletion cause dramatic changes in Southern Hemisphere circulation; the anticipated recovery from ozone depletion may offset the changes that respond to the increasing GHG [10].…”

Broadband radiometric measurements from GPS satellites reveal summertime Arctic Ocean Albedo decreases more rapidly than sea ice recedes

“…Climate model-based analysis drives interpretation and hypotheses of causes behind Arctic Amplification. Several analyses have found sea ice albedo feedbacks are likely driving Arctic Amplification 7 – 12 . The albedo feedback is due to (1) sea ice melting that leads to recession of the ice pack as well as (2) decreasing reflectivity or albedo of the remaining ice due to surface melt 13 – 18 that changes the snow and ice surface reflectivity as well as forming poorly reflecting melt ponds.…”