Atmospheric Radiation

Atmospheric radiation encompasses the processes by which solar and terrestrial electromagnetic energy are exchanged, transformed and redistributed within Earth’s atmosphere. Incoming short-wave radiation is scattered and absorbed by gases, aerosol particles and cloud droplets, warming the air and driving photochemical reactions. Simultaneously, the surface and atmosphere emit long-wave infrared energy, which is modulated by greenhouse gases and clouds before escaping to space or being re-absorbed. Accurate description of these exchanges relies on the radiative-transfer equation, which balances extinction (absorption and scattering) against emission sources. Solutions underpin our understanding of Earth’s energy budget, the greenhouse effect and feedbacks that govern climate sensitivity. They also guide remote-sensing of trace constituents, cloud properties and surface temperature, and inform air-quality forecasts. Advances in spectroscopy, in situ measurement and radiative-transfer modelling continue to reduce uncertainties in how radiation interacts across scales from nanometre-sized aerosols to global circulation patterns.

Research from Nature Portfolio

New experimental–modelling work has demonstrated that the hygroscopic phase transitions of salt and organic nanoparticles depend critically on particle diameter, with sub-20 nm particles remaining liquid at ambient conditions. Incorporation of size-dependent solute activities into global-model parameterisations has resolved long-standing mismatches between observed aerosol optical properties and simulations. A second study has shown that black-carbon (BC) light absorption in climate models is highly sensitive to emitted particle size and internal mixing-state diversity. By resolving a distribution of BC core diameters and coating fractions, models now predict a five- to seven-fold wider range of radiative forcing and align more closely with field observations. In complementary work, a unified theoretical framework for BC mixing-state evolution links coating-growth dynamics to observed coating-thickness distributions. Implemented in global aerosol models, it substantially tightens estimates of BC’s direct radiative effect and supports more robust projections of aerosol–radiation interactions.

Atmospheric Radiation publication trend

The graph below shows the total number of articles in atmospheric radiation across all publications each year (not limited to Nature Index journals).

Technical terms

Radiative-Transfer Equation: Governs the change in radiance along a path due to absorption, emission and scattering in a medium.

Single-Scattering Albedo (ω): The ratio of scattering to total extinction (absorption + scattering) by particles or gases.

Aerosol Optical Depth (AOD): Vertical integral of extinction by aerosol particles; a measure of columnar aerosol load.

Köhler Theory: Describes the activation of aerosol particles into cloud droplets by combining solute-dilution and curvature effects.

Mass Absorption Coefficient (MAC): The absorption cross-section of a substance per unit mass, used to quantify black-carbon warming efficiency.

Wien’s Displacement Law: Relates the temperature of a blackbody to the wavelength at peak emission (λmax ∝ T⁻¹).

Stefan–Boltzmann Law: The total radiative power emitted per unit area of a blackbody scales as T⁴.

Greenhouse Effect: Warming of Earth’s surface due to atmospheric gases absorbing and re-emitting long-wave infrared radiation.

References

1. Size dependence of phase transitions in aerosol nanoparticles. Nature Communications (2015).
2. Black carbon radiative effects highly sensitive to emitted particle size when resolving mixing-state diversity. Nature Communications (2018).
3. Unified theoretical framework for black carbon mixing state allows greater accuracy of climate effect estimation. Nature Communications (2023).
4. Spherical Harmonics for the 1D Radiative Transfer Equation. I. Reflected Light. The Astrophysical Journal (2023).
5. Improved Chebyshev Spectral Method Modeling for Vector Radiative Transfer in Atmospheric Propagation. IEEE Transactions on Antennas and Propagation (2024).
6. Application of a PCA‐Based Fast Radiative Transfer Model to XCO2 Retrievals in the Shortwave Infrared. Journal of Geophysical Research: Atmospheres (2017).
7. The water vapour self-continuum absorption in the infrared atmospheric windows: new laser measurements near 3.3 and 2.0 µm. Atmospheric Measurement Techniques (2018).
8. Atmospheric observations of the water vapour continuum in the near-infrared windows between 2500 and 6600 cm-1. Atmospheric Measurement Techniques (2020).
9. Introduction to Atmospheric Radiation.