The Earth Surface Mineral Dust Source Investigation (EMIT) Arid Land Imaging Spectroscopy Observations, Analyses, and Initial Results Across Six Continents (Invited Presentation)

NASA’s Earth Surface Mineral dust source Investigation (EMIT) is an Earth Venture Instrument mission located on the International Space Station (ISS). EMIT’s focus is to reduce uncertainty in the mineral dust radiative forcing and related impacts throughout the Earth System by providing improved mineral compositional information for the Earth’s arid lands. The EMIT imaging spectrometer measures spectra from the Visible to Short Wavelength Infrared (VSWIR where important dust minerals have diagnostic spectral absorptions. Surface mineral composition maps from these imaging spectroscopy observations are planned for use in state-of-the-art Earth System Models so that they can better estimate the resulting composition of mineral dust in the atmosphere. Mineral dust aerosol composition, and in particular the fraction of iron oxide, is a major source of uncertainty in the mineral dust-induced radiative forcing. By mapping the mineralogy of dust forming lands, EMIT aims to close this knowledge gap and support improved Earth System Modeling. The EMIT imaging spectrometer acquires spectra from 380 nm to 2500 nm at 7.5 nm sampling and a 75-kilometer swath width at 60 m ground sampling. From the ISS EMIT delivers high signal-to-noise ratio spectral image data sets with accurate radiometric calibration and excellent spectral uniformity. To date, EMIT has delivered more than 40,000 spectral image cube spanning the arid land regions of six continents. Calibration, atmospheric correction and initial mineral composition analyses have been completed for cloud free observations comprising 80% of the grid cells for EMIT’s arid land target regions. All EMIT measurements and products are available from the NASA Land Process Distributed Active Archive Center (LP DAAC). We present the background, current status, and future plans for EMIT.