17 June 2016

Evaluation of the Vertical Distribution of Aerosols in Global Transport Models

Scientists used a space-borne lidar to evaluate the vertical distribution of aerosols simulated by a suite of global models.

Science

The vertical distribution of aerosols is important because it affects the likelihood that aerosols will be removed from the atmosphere by clouds and because it affects the impact of the aerosols on the global energy balance. Particles high in the atmosphere generally reside in the atmosphere longer, prolonging their ability to affect the global energy balance. Absorbing particles produce a much stronger radiative impact if they absorb sunlight above clouds rather than below them.

Impact

This evaluation of the latest generation of global aerosol models shows that most models simulate the vertical distribution of the aerosol more realistically than the previous generation.

Summary

Climate scientists at the Pacific Northwest National Laboratory and at twenty other climate centers have developed models of the emission, transport and removal of aerosol particles in the atmosphere.  Eleven such AeroCom models were evaluated in this study by comparing a measure of the mean height of the aerosol with observations from a lidar orbiting the Earth. The study found that most models underestimated the mean height over land, but that the latest generation of models simulated the height better than the previous generation.

Contact
Steven J. Ghan
Pacific Northwest National Laboratory (PNNL)
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