Intercomparison of total column ozone data from the Pandora spectrophotometer with Dobson, Brewer, and OMI measurements over Seoul, Korea

Abstract

Abstract. Daily total column ozone (TCO) measured using the Pandora spectrophotometer (no. 19) was compared with data from the Dobson (no. 124) and Brewer (no. 148) spectrophotometers, as well as from the Ozone Monitoring Instrument (OMI) (with two different algorithms, Total Ozone Mapping Spectrometer (TOMS) TOMS and differential optical absorption spectroscopy (DOAS) methods), over the 2-year period between March 2012 and March 2014 at Yonsei University, Seoul, Korea. Based on the linearregression method, the TCO from Pandora is closely correlated with those from other instruments with regression coefficients (slopes) of 0.95 (Dobson), 1.00 (Brewer), 0.98 (OMI-TOMS), and 0.97 (OMI-DOAS), and determination coefficients (R2) of 0.95 (Dobson), 0.97 (Brewer), 0.96 (OMI-TOMS), and 0.95 (OMI-DOAS). The daily averaged TCO from Pandora has within 3 % differences compared to TCO values from other instruments. For the Dobson measurements in particular, the difference caused by the inconsistency in observation times when compared with the Pandora measurements was up to 12.5 % because of diurnal variations in the TCO values. However, the comparison with Brewer after matching the observation time shows agreement with large R 2 and small biases. The TCO ratio between Brewer and Pandora shows the 0.98 ± 0.03, and the distributions for relative differences between two instruments are 89.2 and 57.1 % of the total data within the error ranges of 3 and 5 %, respectively. The TCO ratio between Brewer and Pandora also is partially dependent on solar zenith angle. The error dependence by the observation geometry is essential to the further analysis focusing on the sensitivity of aerosol and the stray-light effect in the instruments.

Updated and validated solar irradiance reference spectra for estimating environmental photodegradation rates

“…Additionally, higher temporal resolution measurements have shown large variations in ozone concentrations throughout the day. 34 Because of this bias at wavelengths <310 nm, the comparison of UVB broadband irradiances were worse for the NOAA data than the NREL data with modeled irradiances being 0-35% higher than the measurements (Fig. 5B).…”

Simulation of Threshold UV Exposure Time for Vitamin D Synthesis in South Korea

“…252, location: 37.57°N, 126.95°E, 84 m above sea level). e quality of the Dobson data was validated using a dataset from the Brewer spectrophotometer at Pohang [41], overpass data from TOMS [41,43,44,45], and data from OMI [41,46,47]. From the intercomparison studies, the total ozone from the other instruments agreed within 2% with that from the Dobson spectrophotometer.…”

Retrieval of NO2 Column Amounts from Ground-Based Hyperspectral Imaging Sensor Measurements

“…Pandora at Yonsei University has been operated since 2012 [18,20]. From the direct sun measurements, the TCN from Pandora is calculated by radiance fitting using the spectral window of 370 to 500 nm [7].…”

“…Korea has various emission sources of NO 2 and a distinct diurnal variation due to anthropogenic emissions and photochemical reactions [18]. Campaigns have been executed to understand the distribution and variation of total column amounts of trace gases, including NO 2 , in Korea using the Pandora spectrophotometer during the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-North East Asia [19,20], Megacity Air Pollution Studies-Seoul (MAPS-Seoul) [18,21], and Korea-US Air quality study (KORUS-AQ) [22,23] in 2012, 2015, and 2016, respectively. Since the conclusion of the KORUS-AQ campaign, two of the Pandora spectrophotometers have been in operation in Seoul and Busan.…”