Work

CO2 Dependence in Global Estimation of All‐Sky Downwelling Longwave: Parameterization and Model Comparison

Year: 2024

Type: article

Abstract: The downwelling longwave radiation at the surface (DLR) is a key component of the Earth's surface energy budget. We present a novel set of equations that explicitly account for both clouds and the effect to calculate the all‐sky DLR. This paper first extends the clear‐sky DLR model of Shakespeare and Roderick (2021, https://doi.org/10.1002/qj.4176 ) to include temperature inversions and clouds. We parameterize relevant cloud properties through theoretical and empirical considerations to formulate an all‐sky model. Our model is more accurate than existing methods (reduces Root Mean Squared Error by 2.1–8.7 and 1.2–10.1 compared to ERA5 reanalysis and in‐situ data respectively), and provides a strong physical basis for the estimation of the downwelling longwave from near‐surface information. We highlight the important role of dependence by showing our model largely captures the change in atmospheric emissivity purely due to (i.e., the instantaneous radiative forcing) in CMIP6 models.

Source: Geophysical Research Letters

DOI: 10.1029/2024gl110384

Authors: Koh Kawaguchi, Callum J. Shakespeare, Michael L. Roderick

Institutions: Australian National University, ARC Centre of Excellence for Climate Extremes

Language: English

Topic: Meteorological Phenomena and Simulations

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Climate action

Open Access status: gold

Estimated APC paid: $2,900