Improving ECC Ozonesonde Data Quality: Assessment of Current Methods and Outstanding Issues

Tarasick, D. W.; Smit, H. G. J.; Thompson, A. M.; Morris, Gary A.; Witte, J. C.; Davies, J.; Nakano, Tatsumi; Malderen, Roeland Van; Stauffer, Ryan M.; Johnson, B. J.; Stübi, René; Oltmans, S. J.; Vömel, H.

doi:10.1029/2019ea000914

“…Instrument performance has been evaluated through laboratory experiments (Smit & ASOPOS, 2014; Smit et al., 2007, 2021; Thompson et al., 2019), field campaigns (Boyd et al., 1998; Deshler et al., 2008; Komhyr et al., 1995), and analysis of historical records (Tarasick et al., 2019). Uncertainties associated with ECC ozonesonde measurements have decreased from >10% in the late 1990s, to near 5% today (Smit et al., 2021; Tarasick et al., 2021; Witte et al., 2018). The satellite instrument community has requested even more stable and reliable data to detect and quantify drift in satellite measurements that span a decade or more (Hubert et al., 2016).…”

Section: Ecc Ozonesondes and Data Quality Assurancementioning

confidence: 99%

“…Always paired with a meteorological radiosonde, the ECC provides continuous, high‐quality, in‐situ measurements of ozone with high vertical resolution (100–150 m) from the surface to over 30‐km altitude, characteristics that no other instrument, remote‐sensing or otherwise, can match. The measurement principle of the ECC is based on the wet chemical reaction of ozone in a neutral‐buffered potassium iodide (KI) solution, such that approximately two electrons flow in an external circuit in the ECC for each ozone molecule absorbed into the solution (Smit et al., 2021; Tarasick et al., 2021). The magnitude of the resulting current is transmitted via the radiosonde to a receiving station and converted into ozone partial pressure.…”

Section: Ecc Ozonesondes and Data Quality Assurancementioning

confidence: 99%

An Examination of the Recent Stability of Ozonesonde Global Network Data

Stauffer¹,

Thompson

²

,

Vömel

³

et al. 2022

Earth and Space Science

Self Cite

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The recent Assessment of Standard Operating Procedures for Ozonesondes 2.0 (WMO/ GAW Report #268) addressed questions of homogeneity and long-term stability in global electrochemical concentration cell (ECC) ozone sounding network time series. Among its recommendations was adoption of a standard for evaluating data quality in ozonesonde time series. Total column ozone (TCO) derived from the sondes compared to TCO from Aura's Ozone Monitoring Instrument (OMI) is a primary quality indicator. Comparisons of sonde ozone with Aura's Microwave Limb Sounder (MLS) are used to assess the stability of stratospheric ozone. This paper provides a comprehensive examination of global ozonesonde network data stability and accuracy since 2004 in light of the sudden post-2013 TCO "dropoff" of ∼3%-4% that was reported previously at select stations (Stauffer et al., 2020, https://doi.org/10.1029/2019GL086791). Comparisons with Aura OMI TCO averaged across the network of 60 stations are stable within about ±2% over the past 18 years. Sonde TCO has similar stability compared to three other TCO satellite instruments, and the stratospheric ozone measurements average to within ±5% of MLS from 50 to 10 hPa. Thus, sonde data are reliable for trends, but with a caveat applied for a subset of dropoff stations in the tropics and subtropics. The dropoff is associated with only one of two major ECC instrument types. A detailed examination of ECC serial numbers pinpoints the timing of the dropoff. However, we find that overall, ozonesonde data are stable and accurate compared to independent measurements over the past two decades.Plain Language Summary Ozonesondes provide accurate ozone measurements from the surface to ∼30-km altitude and are used as a reference for studies of satellite data, trends, pollution, and climate. Updated guidelines for sonde preparation and adoption of sonde total column ozone (TCO) comparisons with satellite TCO as a "data quality" reference were published in 2021 by the Assessment of Standard Operating Procedures for Ozonesondes (ASOPOS) 2.0 panel in WMO/GAW Report 268. We report the first application of the ASOPOS 2.0 protocol to TCO evaluation from the 60-station global ozonesonde network (42,042 profiles total). With Aura OMI TCO as the satellite reference (October 2004 to mid-2021), we find that TCO readings from the global ozonesonde network are remarkably stable, consistently within ±2% of the satellite. An exception occurs at only a small subset of tropical and subtropical locations that use one type of ozonesonde instrument. The latter result confirms our earlier report that a sudden TCO drop occurs at selected sites after 2013. The timing and magnitude of the dropoff are revisited. The hypothesis that ozonesonde production changes are a contributor remains, with station-specific factors possibly affecting the magnitude of the bias. Overall, global ozonesonde network data are of high quality and stability.

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“…ECC Ozonesondes measure the vertical distribution of ozone at very high vertical resolution (∼100–150 m) based on the principle of iodometric titration (Komhyr, 1969). The accuracy of the ozone measurement is within 15% up to 30 km altitude (D. W. Tarasick et al., 2021; Witte et al., 2018). The detailed description of the measurement technique of ECC ozonesonde and their measurement uncertainty can be found in Smit and ASOPOS‐panel (2014) and Smit and ASOPOS 2.0‐panel (2021).…”

Section: The Cruise Track General Meteorology and Experimentsmentioning

confidence: 99%

Effect of Synoptic‐Scale Dynamics on the Vertical Distribution of Tropospheric Ozone Over the Arabian Sea and the Indian Ocean During the Boreal Winter of 2018

Chandran

¹

,

Sunilkumar

²

,

Muhsin

³

et al. 2022

JGR Atmospheres

2

0

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Ozone (O3) and relative humidity profiles obtained from in situ electrochemical concentration cell ozonesonde‐radiosonde observations over the Arabian Sea and the Indian Ocean from 16 January to 14 February 2018 during the Integrated Campaign for Aerosols gases and Radiation Budget cruise were analyzed. On the basis of the prevailing synoptic conditions during the cruise period, the cruise track was divided into three legs which were studied separately. The main objective of this study was to investigate the influence of prevailing synoptic scale dynamics and transport on the vertical distribution of ozone in the troposphere, especially in the tropical tropopause layer (TTL) region. Tropospheric ozone exhibits pronounced latitude variations over the Arabian Sea and the Indian Ocean with very high values (∼60–70 ppbv) above the marine boundary layer near the Indian landmass. Distinct ozone‐rich plume‐like structures are observed in the free troposphere around 1–3 and 4–5 km. At around 1–3 km, the ozone plume was maintained by the continental outflows from the Indian sub‐continent. The mid‐tropospheric (4–5 km) high ozone‐low water vapor layer is hypothesized to be associated with the equatorward return flow of the Hadley circulation. Enhanced (declined) ozone is observed below 12 km altitude in the descending (ascending) branch of Hadley circulation. The ozone distribution in the TTL shows distinct structures associated with the prevailing synoptic dynamics and transport during respective legs. Evidences of stratospheric intrusion and air mass transport from biomass burning locations are seen regarding upper tropospheric ozone enhancements.

show abstract

“…Always paired with a meteorological radiosonde, the ECC provides continuous, high-quality, in-situ measurements of ozone with high vertical resolution (100-150 m) from the surface to over 30-km altitude, characteristics that no other instrument, remote-sensing or otherwise, can match. The measurement principle of the ECC is based on the wet chemical reaction of ozone in a neutral-buffered potassium iodide (KI) solution, such that approximately two electrons flow in an external circuit in the ECC for each ozone molecule absorbed into the solution (Smit et al, 2021;Tarasick et al, 2021). The magnitude of the resulting current is transmitted via the radiosonde to a receiving station and converted into ozone partial pressure.…”

mentioning

confidence: 99%

“…Instrument performance has been evaluated through laboratory experiments (Smit & ASOPOS, 2014;Smit et al, 2007Smit et al, , 2021Thompson et al, 2019), field campaigns (Boyd et al, 1998;Deshler et al, 2008;Komhyr et al, 1995), and analysis of historical records (Tarasick et al, 2019). Uncertainties associated with ECC ozonesonde measurements have decreased from >10% in the late 1990s, to near 5% today (Smit et al, 2021;Tarasick et al, 2021;Witte et al, 2018). The satellite instrument community has requested even more stable and reliable data to detect and quantify drift in satellite measurements that span a decade or more (Hubert et al, 2016).…”

mentioning

confidence: 99%

An Examination of the Recent Stability of Ozonesonde Global Network Data

Stauffer

¹

,

Thompson

²

,

Kollonige

³

et al. 2022

Preprint

View full text Add to dashboard Cite

The recent Assessment of Standard Operating Procedures for Ozonesondes 2.0 (WMO/ GAW Report #268) addressed questions of homogeneity and long-term stability in global electrochemical concentration cell (ECC) ozone sounding network time series. Among its recommendations was adoption of a standard for evaluating data quality in ozonesonde time series. Total column ozone (TCO) derived from the sondes compared to TCO from Aura's Ozone Monitoring Instrument (OMI) is a primary quality indicator. Comparisons of sonde ozone with Aura's Microwave Limb Sounder (MLS) are used to assess the stability of stratospheric ozone. This paper provides a comprehensive examination of global ozonesonde network data stability and accuracy since 2004 in light of the sudden post-2013 TCO "dropoff" of ∼3%-4% that was reported previously at select stations (Stauffer et al., 2020, https://doi.org/10.1029/2019GL086791). Comparisons with Aura OMI TCO averaged across the network of 60 stations are stable within about ±2% over the past 18 years. Sonde TCO has similar stability compared to three other TCO satellite instruments, and the stratospheric ozone measurements average to within ±5% of MLS from 50 to 10 hPa. Thus, sonde data are reliable for trends, but with a caveat applied for a subset of dropoff stations in the tropics and subtropics. The dropoff is associated with only one of two major ECC instrument types. A detailed examination of ECC serial numbers pinpoints the timing of the dropoff. However, we find that overall, ozonesonde data are stable and accurate compared to independent measurements over the past two decades.Plain Language Summary Ozonesondes provide accurate ozone measurements from the surface to ∼30-km altitude and are used as a reference for studies of satellite data, trends, pollution, and climate. Updated guidelines for sonde preparation and adoption of sonde total column ozone (TCO) comparisons with satellite TCO as a "data quality" reference were published in 2021 by the Assessment of Standard Operating Procedures for Ozonesondes (ASOPOS) 2.0 panel in WMO/GAW Report 268. We report the first application of the ASOPOS 2.0 protocol to TCO evaluation from the 60-station global ozonesonde network (42,042 profiles total). With Aura OMI TCO as the satellite reference (October 2004 to mid-2021), we find that TCO readings from the global ozonesonde network are remarkably stable, consistently within ±2% of the satellite. An exception occurs at only a small subset of tropical and subtropical locations that use one type of ozonesonde instrument. The latter result confirms our earlier report that a sudden TCO drop occurs at selected sites after 2013. The timing and magnitude of the dropoff are revisited. The hypothesis that ozonesonde production changes are a contributor remains, with station-specific factors possibly affecting the magnitude of the bias. Overall, global ozonesonde network data are of high quality and stability.

show abstract

Improving ECC Ozonesonde Data Quality: Assessment of Current Methods and Outstanding Issues

Cited by 43 publications

References 151 publications

An Examination of the Recent Stability of Ozonesonde Global Network Data

An Examination of the Recent Stability of Ozonesonde Global Network Data

Effect of Synoptic‐Scale Dynamics on the Vertical Distribution of Tropospheric Ozone Over the Arabian Sea and the Indian Ocean During the Boreal Winter of 2018

An Examination of the Recent Stability of Ozonesonde Global Network Data

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