Diagnosing Changes in Earth's Top-Of Radiation Budget Since 2000
Abstract
Earth's radiation budget (ERB) is a key indicator of the climate system as it describes the delicate balance between how much of the sun's energy reaching Earth is absorbed and how much thermal infrared radiation is emitted back to space. It is now well established that there is a positive net imbalance in ERB of 0.5-1 Wm-2. This imbalance, referred to as Earth's Energy Imbalance (EEI), is shaped by natural and anthropogenic climate forcings and the climate system's response to the forcing. When averaged over a long period, a positive EEI leads to an increase in surface temperature, sea level rise, ocean heat content, melting of snow and sea-ice, and an acceleration of the hydrological cycle. EEI is also influenced by internal climate variability at interanual (e.g., El Niño/Southern Oscillation (ENSO)) and longer timescales (e.g., Pacific Decadal Oscillation (PDO)). Here we use CERES data to show that since 2000, EEI has been increasing at a rate of 0.04± 0.03 Wm- 2 per yr, corresponding to 0.8 Wm-1 over the 20-year CERES record. To understand the underlying causes for this increase, we analyze the CERES data in the context of internal climate variability indices and regional pattern changes. We also perform a partial radiative perturbation analysis that decomposes the TOA SW and LW radiation variations in terms of contributions by clouds, aerosols, surface albedo, temperature, water vapor and other gases (e.g., ozone, carbon dioxide, methane, etc.).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMGC133..02L
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3339 Ocean/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 3359 Radiative processes;
- ATMOSPHERIC PROCESSES