The results demonstrate that the new reprocessing significantly improves the accuracy and consistency of the life-time SNPP OMPS NM and NP SDR data sets. Finally, this study compares the v2 reprocessed OMPS data sets with the operational and the v1 reprocessed data sets. This study further analyzes the impact of each improvement on the quality of the OMPS SDR data by taking advantage of the existing OMPS SDR calibration/validation studies. Compared with a previous (v1) reprocessing, this new reprocessing includes the improvements associated with the following updated tables or error correction: an updated stray light correction table for the NM, an off-nadir geolocation error correction for the NM, an artificial offset error correction in the NM dark processing code, and biweekly solar wavelength LUTs for the NP. In this study, we present results for the newly (v2) reprocessed SNPP OMPS NM and NP SDR data prior to 30 June 2021, which uses consistent calibration tables with improved accuracy. However, the discrepancies of quality remain in the operational OMPS SDR data prior to 28 June 2021 due to changes in calibration algorithms associated with the calibration coefficient look-up tables (LUTs) during this period. The OMPS NM and NP instruments flying on the Suomi-NPP (SNPP) satellite have provided over ten years of operational Sensor Data Records (SDRs) data sets to support a variety of OMPS Environmental Data Record (EDR) applications. The Nadir Mapper (NM) and Nadir Profiler (NP) within the Ozone Mapping and Profiler Suites (OMPS) are ultraviolet spectrometers to measure Earth radiance and Solar irradiance spectra from 300–380 nm and 250–310 nm, respectively. Therefore, it can be concluded that the measures that have been taken by the Quito city council over the last few years are yielding good results.
In this paper, it was shown that the air pollution at the Belisario station due to the concentration of SO2 in the last 12 years is not harmful to humans, with the measurement precision provided by robust statistical methods. In addition, the trend in the level of SO2 concentration decreased over the years studied, with a sharp drop from 2008 to 2012, then a small rise in 2013 and another fall until 2019, presenting decreasing oscillations that tend toward a desirable level of pollution. The results showed that the level of air pollution at the Belisario station due to the SO2 concentration is acceptable. For the analysis, classic, nonparametric and robust statistical methods were used, and the data were classified based on criteria established by the Quiteño Air Quality Index, taking confidence intervals into account. In addition, this set of measurements was decomposed into variables that represent each year, month, day of the week, and hour of the day in groups of two hours.
The analyzed data contain 12 years of measurements, from January 2008 to December 2019. In this paper, a robust analysis of SO2 concentration measurements taken at the Belisario air quality monitoring station, Quito, Ecuador is carried out. Similar SO₂ total mass estimates over the region are obtained from the two products. Results for a volcanic cloud over Colombia for the updated LFSO2 for OMPS and a Differential Optical Absorption Spectroscopy (DOAS) algorithm for the Tropospheric Monitoring Instrument (TROPOMI) measurements are also examined. The minimum detectable values for all three SO₂ layer products and the planetary boundary layer (PBL) products are estimated with the updated LFSO2 algorithm. Using the new retrieval logic, the discontinuity in LFSO2 retrievals and the saturation appearance in comparisons vanished and a close to a linear relationship with the matchup data from the PCA retrieval products is demonstrated. We found that the operational LFSO2 retrievals at lower troposphere (TRL), mid-troposphere (TRM), and lower stratosphere (STL) exhibited a discontinuity and have a saturation-like relationship if compared with PCA results. More than three months of Kilauea volcanic activity in 2018 are monitored and are included in this evaluation and comparison. Twenty independent volcanic scenarios and one environmental disaster scenario spread over eight years are selected for this comparison.
We evaluate the LFSO2 and compare the results to those from a principal component analysis (PCA) offline algorithm. The LFSO2 is used to create estimates from measurements made by the Suomi NPP (S-NPP) Ozone Mapping and Profiler Suite (OMPS). Changing a logic switch threshold in the linear fit sulfur dioxide (LFSO2) algorithm improves the performance based on the evaluation of the NOAA operational atmospheric SO₂ near-real-time (NRT) retrieval.