Title: Evaluating Diurnal Ozone Emissions: A Comparative Analysis of DSCOVR EPIC, PANDORA, and TOLNet Data for Space-Based Monitoring Assessment: A Case Study by ASDC

Monitoring diurnal ozone emissions is crucial for understanding the atmospheric composition and its impacts on air quality and climate. This study aims to evaluate the effectiveness of using various data sources, including Earth Polychromatic Imaging Camera (EPIC) aboard Deep Space Climate Observatory (DSCOVR), Pandora spectrometers, and Tropospheric Ozone Lidar Network (TOLNet), to assess diurnal ozone emissions and identify the strengths and weaknesses of space-based emissions monitoring.

DSCOVR EPIC provides valuable global measurements of ozone column from space. It has wider spatial coverage and higher temporal resolution compared with polar-orbiting sensors thus providing an opportunity to capture diurnal variations in ozone emissions. Level 2 and level 4 ozone data from EPIC stored at the Atmospheric Data Center (ASDC) at the NASA Langley research Center are used in this study. Pandora sun-spectrometer instruments measure ozone column from the ground by means of the differential optical absorption spectroscopy. TOLNet measures ozone profiles at several locations across the USA. Comparisons between ground-based and space-based observations of total ozone columns made over major metropolitan areas of the USA showed good correlations. This study uses both HIRES and CLIM TOLNet data. Environmental Protection Agency’s monitoring stations provide localized measurements of ground-level ozone concentration with high accuracy and reliability while measuring neither total nor tropospheric column. For this reason, EPA data are not used in this study.

By comparing the diurnal ozone emissions derived from these different data sources, the strengths and weaknesses of each approach are identified. This evaluation considers factors such as spatial and temporal coverage, accuracy, sensitivity, and limitations associated with each dataset. Additionally, the impact of factors like cloud cover and atmospheric conditions on the measurements are assessed.

The findings of this study will contribute to the understanding of the reliability and applicability of space-based ozone monitoring for studying diurnal variations. It will provide insights into the potential of DSCOVR EPIC data for characterizing diurnal ozone emissions and its complementarity with ground-based measurements from the TOLNet and PANDORA instruments. The results will enhance our understanding of ozone-related processes in the atmosphere and improve ozone monitoring capabilities by providing better information to air quality management.