The Earth Surface Mineral Dust Source Investigation (EMIT) instrument measures surface mineralogy, targeting the Earth’s arid dust source regions. EMIT is installed on the International Space Station (ISS) and uses imaging spectroscopy to take measurements of the sunlit regions of interest between 52° N latitude and 52° S latitude. An interactive map showing the regions being investigated, current and forecasted data coverage, and additional data resources can be found on the VSWIR Imaging Spectroscopy Interface for Open Science (VISIONS) EMIT Open Data Portal.

The EMIT Level 4 Earth System Model (EMITL4ESM) Version 1 data product provides radiative forcing outputs, along with other ancillary outputs generated from different Earth System Models (ESMs). ESMs are complex models that integrate relevant physical, chemical, biological, and human components to simulate multiple aspects of large-scale systems on Earth. Multiple models, input mineral maps, meteorology inputs, and emissions/concentration scenarios are examined for the model runs contained within this data product. Models currently utilized include the Community Earth System Model 2 (CESM2) and the Goddard Institute for Space Studies (GISS) model. Some ESM runs utilize reference surface mineral maps from the literature dating back to 2007; others rely on the EMIT L3 Aggregated Mineral Spectral Abundance and Uncertainty 0.5 Deg (EMITL3ASA) data as inputs.

Each EMITL4ESM granule represents a single ESM run with a Network Common Data Format 4 (netCDF-4) file for each variable. A total of 12 Science Dataset (SDS) layers or variables are provided for each model run. For some SDS layers or variables, multiple layers based on inclusion of model minerology inputs are provided in their netCDF files. The layers/variables table below details which variables contain the extra layers. Metadata flags for Earth System Model, Resolution, Surface Mineral Map, External Meteorology, Time Period, and Emissions/Concentration Scenario indicate the key parameters for each granule. A table outlining each variable in detail can be found in the EMIT Science Data System Level 4 repository.

Known Issues

• Data acquisition gap: From September 13, 2022, through January 6, 2023, a power issue outside of EMIT caused a pause in operations. Due to this shutdown, no data were acquired during that timeframe.