Impact of Hurricane Ida on Nitrogen Oxide Emissions in Southwestern Louisiana Detected from Space

Hurricane Ida made landfall on August 29, 2021, in southwestern Louisiana and devastated the region's industrial landscape. Its disruptions to atmospheric composition were detected by the TROPOspheric Monitoring Instrument (TROPOMI). This study quantifies NO₂spatial changes and estimates top-down NO_xemissions for two cities impacted by Hurricane Ida, New Orleans and Baton Rouge. Considering the difference in NO₂lifetime pre- and post-Ida, top-down derived NO_xemissions for each impacted city saw decreases in NO_xemissions of ∼40% and ∼80% for New Orleans and Baton Rouge, respectively. However, a significant increase in the TROPOMI NO₂level was seen during the posthurricane period, occurring only on September 2, 2021, where potential causes of such deviation are attributed to hurricane recovery actions. When this date is excluded from post-Ida averages, the NO_xemission estimates are further decreased by ∼80% and ∼92% for New Orleans and Baton Rouge, respectively. Short-lived extreme weather events and their accompanying preparatory and recovery actions are unique drivers of change in NO_xemissions. This study demonstrates the use of satellite products to provide a quick emission analysis of areas affected by such events and illustrates the necessity of understanding their influence on atmospheric pollutants.