The Earth Surface Mineral Dust Source Investigation: An Earth Science Imaging Spectroscopy Mission

TLDR

Mineral dust from arid regions strongly influences the Earth system, yet compositional knowledge is limited, prompting the planned EMIT mission aboard the ISS (starting fall 2021) to characterize source dust composition. The study aims to use EMIT’s imaging spectroscopy to map dust source mineralogy and incorporate it into Earth system models to assess the composition‑dependent radiative forcing of mineral aerosols. EMIT employs visible to short‑wavelength infrared imaging spectroscopy to map dust source mineralogy and feed the resulting data into Earth system models. The resulting measurements and products will address EMIT objectives and be released to the scientific community.

Abstract

The Earth Surface Mineral Dust Source Investigation, EMIT, is planned to operate from the International Space Station starting no earlier than the fall of 2021. EMIT will use visible to short wavelength infrared imaging spectroscopy to determine the mineral composition of the arid land dust source regions of the Earth to advance our knowledge of the radiative forcing effect of these aerosols. Mineral dust emitted into the atmosphere under high wind conditions is an element of the Earth system with many impacts to the Earth's energy balance, atmosphere, surface, and oceans. The Earth's mineral dust cycle with source, transport, and deposition phases are studied with advanced Earth System Models. Because the chemical composition, optical and surface properties of soil particles vary strongly with the mineral composition of the source, these models require knowledge of surface soil mineral dust source composition to accurately understand dust impacts on the Earth system now and in the future. At present, compositional knowledge of the Earth's mineral dust source regions from existing data sets is uncertain as a result of limited measurements. EMIT will use spectroscopically-derived surface mineral composition to update the prescribed boundary conditions for state-of-the-art Earth System Models. The EMIT-initialized models will be used to investigate the impact of direct radiative forcing in the Earth system that depends strongly on the composition of the mineral dust aerosols emitted into the atmosphere. These new measurements and related products will be used to address the EMIT science objectives and made available to the science community for additional investigations. An overview of the EMIT science, development, and mission is presented in this paper.