Multi-Angle Aerosol Remote Sensing: From Research Algorithm to Applications

In addition to aerosol optical depth, under favorable observing conditions multi-angle remote sensing offers constraints on near-source aerosol plume height, e.g., from volcanoes, wildfires, and dust storms, as well as aerosol type, which represents constraints on particle size, shape, and single-scattering albedo. We have developed algorithms to derive plume height and particle type information from the NASA Earth Observing System’s Multi-angle Imaging SpectroRadiometer (MISR) instrument. Recent work has included further refinement and extension of the MISR Research Aerosol Retrieval algorithm to better constrain sensor radiometric calibration, to better represent the ocean surface, to better account for the range of natural and anthropogenic aerosol types, and to implement a number of more subtle changes to radiance handling, cloud screening, uncertainty estimation, etc. These changes have resulted in improved aerosol optical depth (AOD) and greatly improved aerosol type retrievals, compared to the Standard algorithm and to aerosol products from other passive remote-sensing instruments.

Importantly, as the retrieval algorithm refinements have advanced, the focus of our efforts under NASA’s ACMAP program is increasingly toward the application of these tools. This includes providing constraints to climate and air quality modeling, and contributing to NASA’s Disaster Response efforts. Specifically, we are generating a global climatology of smoke plume injection heights as part of the AeroCom climate-modeling Biomass Burning experiment, aimed at providing a satellite-based constraint on climate models. Also as part of the AeroCom experiment, we are testing both the widely used GFED smoke emissions inventory and the implied smoke source strength in 14 individual AeroCom models with AOD snapshots primarily from MODIS and to some extent from MISR. Our MISR-derived maps of plume height and aerosol type for recent eruptions at Kilauea volcano were used to initialize regional air quality modeling for the Hawaii region. We have demonstrated a physical approach for constraining air quality modeling outputs with MISR aerosol type results from the Research Algorithm, and are now applying it to a range of urban areas in different parts of the world. And we have developed a multi-sensor approach to observing and interpreting volcanic activity from space, including plume dispersion, plume property evolution, as well as some aspects of the underlying geology. This presentation will highlight the key applications to which we are contributing with the 18+ years of MISR and MODIS data, in the context of the underlying tools that make this work possible.

References

Limbacher, J.A., and R.A. Kahn, 2017. Updated MISR dark water research aerosol retrieval algorithm – Coupled 1.1 km ocean surface Chlorophyll-a retrievals with empirical calibration corrections. Atmos. Meas. Tech. 10, doi:10.5194/amt-10-1539-2017

Limbacher, J. A. and R.A. Kahn, 2018. Updated MISR dark water research aerosol retrieval algorithm – Part 2: Aerosol and surface-reflectance retrievals over shallow, turbid, and eutrophic water. Atmos. Meas. Tech. (submitted)

Flower, V.J.B., and R.A. Kahn, 2017b. Distinguishing remobilized ash from erupted volcanic plumes using space-borne multi-angle imaging.Geophys. Res. Lett.. 44, doi:10.1002/2017GL074740.

Flower, V., and R.A. Kahn, 2018. Tracking microphysical variations in emissions from Karymsky volcano, using MISR multi-angle imagery. Atmosph. Chem. Phys. 18, doi:10.5194/acp-18-1-2018

Friberg, M.D., R.A. Kahn, J.A. Limbacher, K.W. Appel, and J.A. Mulholland, 2018. Constraining chemical transport PM2.5 modeling outputs using surface station measurements and satellite retrievals: Application over San Joaquin valley. Atmosph. Chem. Phys. (in press)

Petrenko, M., R.A. Kahn, M. Chin, J.A. Limbacher, 2017. Refined use of satellite aerosol optical depth snapshots to constrain biomass burning emissions in the GOCART model. J. Geophys. Res.,doi:10.1002/2017JD026693.

Val Martin, M. and R.A. Kahn, 2018. A Global Climatology of Wildfire Smoke Injection Height Derived from Space-based Multi-angle Imaging. (in preparation)

Zamora, L.M., R.A. Kahn, A. Stohl, K. Huebert, and S. Eckhardt, 2018. Aerosol microphysical effects on cloud fraction over the nighttime Arctic Ocean. Atmosph. Chem. Phys. Discuss. doi.org/10.5194/acp-2018-514.