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<p style='margin-top:0px; margin-bottom:1.5rem; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;'><b>Date of Image: </b></p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;'>4/10/2021</p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;'><b>Date of Next Image: </b><br /></p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;'>Unknown</p><div style='font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;'><b>Summary:</b></div><div><b><br /></b><div><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'>The Active Aersolol Plume (AAP) Project Team provided this map of volcanic plume heights for the La Soufriere eruption on St. Vincent, derived from data acquired by the Multi-angle Imaging SpectroRadiometer (MISR) instrument, on board the NASA Terra satellite, on April 10, 2020. MISR carries nine fixed cameras, each of which views a scene from different angles over a period of about seven minutes. After accounting for true motion of the clouds due to wind, the angular parallax of the plume features (i.e., the change in apparent feature position relative to the surface between different views) is used to derive the height of the volcanic plume. Plume height gives an indication of plume intensity, and is also important as an input to air quality models that predict where the smoke and ash will go, and who might be affected downwind.</p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'><b>Suggested Use: </b></p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'>In this visualization, MISR-retrieved plume heights are represented as circles with progressively lighter colors for higher elevation, reaching <span style='font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif;'>more than 20,000 meters (20 kilometers) above the surface. </span></p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'>Plume height gives an indication of injection intensity and helps determine where the particles will affect air quality at ground-level. As such, observations of plume height are an important input to air quality models that predict where the smoke or ash will go, and who might be affected downwind. </p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'><b>Satellite/Sensor: </b></p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'>Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra Satellite</p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'><b>Resolution: </b></p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'>Horizontal Resolution: 1.1km</p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'>Vertical Resolution: 250-500 m</p><p style='margin-top:0px; margin-bottom:1.5rem; font-family:inherit; font-size:16px;'><b>Credits: </b><br /></p><p style='margin-top:0px; margin-bottom:1.5rem;'><span style='font-size:16px;'>Active Aerosol Plume (AAP) Project, V. Flower, R. Kahn, K. Junghenn-Noyes, visualized by Garrett Layne, NASA Disasters Program.</span><br /></p><p style='margin-top:0px; margin-bottom:1.5rem;'><span style='font-size:16px;'>The volcanic plume height calculation was performed using the MISR INteractive eXplorer (MINX) software tool, which is publicly available at </span><a href='https://github.com/nasa/MINX' rel='nofollow ugc' style='font-family:inherit; font-size:16px; color:rgb(0, 121, 193); text-decoration-line:none;'>https://github.com/nasa/MINX</a><span style='font-size:16px;'> (Reference: Nelson, D.L., M.J. Garay, R.A. Kahn, and B.A. Dunst, 2013. Stereoscopic Height and Wind Retrievals for Aerosol Plumes with the MISR INteractive eXplorer (MINX). Remote Sens. 5, 4593-4628, doi:10.3390/rs5094593.)</span></p></div></div>
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