Comparison of ground-based and satellite measurements of water vapour vertical profiles over Ellesmere Island, Nunavut

Weaver, Dan; Strong, Kimberly; Walker, Kaley A.; Sioris, C. E.; Schneider, Mat­thias; McElroy, C. T.; Vömel, H.; Sommer, M.; Weigel, Katja; Rozanov, A.; Burrows, John P.; Read, W. G.; Fishbein, Evan; Stiller, G. P.

doi:10.5194/amt-12-4039-2019

Cited by 7 publications

(6 citation statements)

References 57 publications

(62 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This low bias is further reflected in climatological studies involving MAESTRO ozone, such as that of Hegglin et al (2021), who found low biases of around 50 % in the upper troposphere and 10 %-20 % in the lower stratosphere, except for the tropics where it had a high bias of about 20 % compared to a multi-instrument mean ozone climatology. In terms of water vapour, Weaver et al (2019) found that the previous version of MAESTRO water vapour, v30, was biased low by 6 %-12 % in the upper troposphere and by less than 2 % in the lower stratosphere as compared to measurements from the PEARL FTIR. As compared to radiosondes, MAESTRO had a mean upper tropospheric bias of between 16 % and 64 % but a lower stratosphere bias of less than 3 % (Weaver et al, 2019).…”

Section: Ace-maestromentioning

confidence: 80%

“…In terms of water vapour, Weaver et al (2019) found that the previous version of MAESTRO water vapour, v30, was biased low by 6 %-12 % in the upper troposphere and by less than 2 % in the lower stratosphere as compared to measurements from the PEARL FTIR. As compared to radiosondes, MAESTRO had a mean upper tropospheric bias of between 16 % and 64 % but a lower stratosphere bias of less than 3 % (Weaver et al, 2019). The global comparisons of MAESTRO v31 water vapour against an ensemble of instruments, as performed by Lossow et al (2019), indicate that the MAESTRO bias is roughly parabolic with altitude.…”

Section: Ace-maestromentioning

confidence: 80%

“…Comparisons of coincident measurements made by ACE-FTS v3.6 against the Polar Environment Atmospheric Research Laboratory Fourier transform infrared spectrometer (PEARL FTIR) in the Canadian high Arctic indicated that ACE-FTS has a wet bias compared to this instrument of 7 %-10 % in the UTLS. Further comparisons against in situ radiosondes contrasted this by yielding a slight dry bias in ACE-FTS v3.6, of about 0 %-9 %, in the upper troposphere and a slight wet bias, of less than 2 %, in the lower stratosphere (Weaver et al, 2019). Sheese et al (2017) also examined ACE-FTS v3.5 ozone and found it to be within ±5 % of both Aura-MLS and MI-PAS in the lower stratosphere, while in the upper troposphere these differences reached as high as 30 % for MI-PAS and 40 % for Aura-MLS, with ACE-FTS biased low at these lower altitudes.…”

Section: Ace-ftsmentioning

confidence: 92%

See 2 more Smart Citations

Water vapour and ozone in the upper troposphere–lower stratosphere: global climatologies from three Canadian limb-viewing instruments

et al. 2022

Self Cite

View full text Add to dashboard Cite

Abstract. This study presents upper troposphere–lower stratosphere (UTLS) water vapour and ozone climatologies generated from 14 years (June 2004 to May 2018) of measurements made by three Canadian limb-viewing satellite instruments: the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO), and the Optical Spectrograph and InfraRed Imaging System (OSIRIS; ozone only). This selection of instruments was chosen to explore the capability of these Canadian instruments in representing the UTLS and to enable analysis of the impact of different measurement sampling patterns. The water vapour and ozone climatologies have been constructed using tropopause-relative potential temperature and equivalent-latitude coordinates in an effort to best represent the distribution of these two gases in the UTLS, which is characterized by a high degree of dynamic and geophysical variability. Zonal-mean multiyear-mean climatologies are provided with 5∘ equivalent latitude and 10 K potential temperature spacing and have been constructed on a monthly, seasonal (3-month), and yearly basis. These climatologies are examined in-depth for two 3-month periods, December–January–February and June–July–August, and are compared to reference climatologies constructed from the Canadian Middle Atmosphere Model 39-year specified dynamics (CMAM39-SD) run, subsampled to the times and locations of the satellite measurements, in order to evaluate the consistency of water vapour and ozone between the datasets. Specifically, this method of using a subsampled model addresses the impact of each instrument's measuring pattern and allows for the quantification of the influence of different measurement patterns on multiyear climatologies. This in turn permits a more consistent evaluation of the distributions of these two gas species, as assessed through the differences between the model and measurement climatologies. For water vapour, the average absolute relative difference between CMAM39-SD and ACE-FTS differed between the two versions of ACE-FTS by less than 8 %, while the MAESTRO climatologies were found to differ by 15 %–41 % from ACE-FTS, depending on the version of ACE-FTS and the season. When considering the ozone climatologies, those constructed from the two ACE-FTS versions agreed to within 2 % overall, and the OSIRIS ozone climatologies agreed with these to within 10 %. The MAESTRO ozone climatologies differ from those from ACE-FTS and OSIRIS by 30 %–35 % and 25 %, respectively, albeit with regions of better agreement within the UTLS. These findings indicate that this set of Canadian limb sounders yields generally similar water vapour and ozone distributions in the UTLS, with some exceptions for MAESTRO depending on the season and gas species.

show abstract

Section: Ace-maestromentioning

confidence: 80%

Section: Ace-maestromentioning

confidence: 80%

Section: Ace-ftsmentioning

confidence: 92%

See 1 more Smart Citation

Water vapour and ozone in the upper troposphere–lower stratosphere: global climatologies from three Canadian limb-viewing instruments

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…The PEARL Ridge Lab is a remote site and is minimally influenced by local pollution sources. The PEARL-FTS was installed in July 2006, has been involved in the annual Canadian Arctic ACE-OSIRIS Validation Campaigns held during polar sunrise since spring 2007, and has been previously compared with ACE-FTS and other satellite-borne in-struments: for example, Clerbaux et al (2008), Batchelor et al (2010), Holl et al (2016), Buchholz et al (2017, Griffin et al (2017), Olsen et al (2017), Bognar et al (2019), Weaver et al (2019), andVigouroux et al (2020).…”

Section: Pearl-ftsmentioning

confidence: 99%

Intercomparison of CO measurements from TROPOMI, ACE-FTS, and a high-Arctic ground-based Fourier transform spectrometer

et al. 2021

Self Cite

View full text Add to dashboard Cite

Abstract. The TROPOspheric Monitoring Instrument (TROPOMI) provides a daily, spatially resolved (initially 7×7 km2, upgraded to 7×5.6 km2 in August 2019) global dataset of CO columns; however, due to the relative sparseness of reliable ground-based data sources, it can be challenging to characterize the validity and accuracy of satellite data products in remote regions such as the high Arctic. In these regions, satellite intercomparisons can supplement model- and ground-based validation efforts and serve to verify previously observed differences. In this paper, we compare the CO products from TROPOMI, the Atmospheric Chemistry Experiment (ACE) Fourier transform spectrometer (FTS), and a high-Arctic ground-based FTS located at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Nunavut (80.05∘ N, 86.42∘ W). A global comparison of TROPOMI reference profiles scaled by the retrieved total column with ACE-FTS CO partial columns for the period from 28 November 2017 to 31 May 2020 displays excellent agreement between the two datasets (R=0.93) and a small relative bias of -0.83±0.26% (bias ± standard error of the mean). Additional comparisons were performed within five latitude bands: the north polar region (60 to 90∘ N), northern mid-latitudes (20 to 60∘ N), the equatorial region (20∘ S to 20∘ N), southern mid-latitudes (60 to 20∘ S), and the south polar region (90 to 60∘ S). Latitudinal comparisons of the TROPOMI and ACE-FTS CO datasets show strong correlations ranging from R=0.93 (southern mid-latitudes) to R=0.86 (equatorial region) between the CO products but display a dependence of the mean differences on latitude. Positive mean biases of 7.93±0.61 % and 7.21±0.52 % were found in the northern and southern polar regions, respectively, while a negative bias of -9.41±0.55% was observed in the equatorial region. To investigate whether these differences are introduced by cloud contamination, which is reflected in the TROPOMI averaging kernel shape, the latitudinal comparisons were repeated for cloud-covered pixels and clear-sky pixels only, as well as for the unsmoothed and smoothed cases. Clear-sky pixels were found to be biased higher with poorer correlations on average than clear+cloudy scenes and cloud-covered scenes only. Furthermore, the latitudinal dependence on the biases was observed in both the smoothed and unsmoothed cases. To provide additional context to the global comparisons of TROPOMI with ACE-FTS in the Arctic, both satellite datasets were compared against measurements from the ground-based PEARL-FTS. Comparisons of TROPOMI with smoothed PEARL-FTS total columns in the period of 3 March 2018 to 27 March 2020 display a strong correlation (R=0.88); however, a positive mean bias of 14.7±0.16 % was also found. A partial column comparison of ACE-FTS with the PEARL-FTS in the period from 25 February 2007 to 18 March 2020 shows good agreement (R=0.79) and a mean positive bias of 7.89±0.21 % in the ACE-FTS product relative to the ground-based FTS. The magnitude and sign of the mean relative differences are consistent across all intercomparisons in this work, as well as with recent ground-based validation efforts, suggesting that the current TROPOMI CO product exhibits a positive bias in the high-Arctic region. However, the observed bias is within the TROPOMI mission accuracy requirement of ±15 %, providing further confirmation that the data quality in these remote high-latitude regions meets this specification.

show abstract

“…The ground-based instrument used in this study is a Bruker IFS 125HR Fourier transform spectrometer located at the Polar Environment Atmospheric Research Laboratory Ridge Laboratory (80.05°N, 86.42°W; 610 m ASL) in Eureka, Nunavut, Canada (Batchelor et al, 2009). The PEARL Ridge Laboratory is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC), and is situated approximately 15 km away from the Environment and Climate Change Canada (ECCC) Eureka Weather Station (79.98°N, 85.93°W; 0 m ASL) (Fogal et al, 2013 Batchelor et al (2010), Holl et al (2016), Buchholz et al (2017), Griffin et al (2017), Olsen et al (2017), Bognar et al (2019), Weaver et al (2019), andVigouroux et al (2020).…”

Section: Pearl-ftsmentioning

confidence: 99%

Inter-comparison of CO measurements from TROPOMI, ACE-FTS, and a high-Arctic ground-based FTS

Wizenberg

Strong

Walker

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. ACE/TROPOMI Abstract for AMT submission The TROPOspheric Monitoring Instrument (TROPOMI) provides a daily, spatially-resolved (initially 7 × 7 km2, upgraded to 7 × 5.6 km2 in August 2019) global data set of CO columns, however, due to the relative sparseness of reliable ground-based data sources, it can be challenging to characterize the validity and accuracy of satellite data products in remote regions such as the high Arctic. In these regions, satellite inter-comparisons can supplement model- and ground-based validation efforts and serve to verify previously observed differences. In this paper, we compare the CO products from TROPOMI, the Atmospheric Chemistry Experiment (ACE) Fourier Transform Spectrometer (FTS), and a high-Arctic ground-based FTS located at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Nunavut (80.05° N, 86.42° W). A global comparison of TROPOMI reference profiles scaled by the retrieved total column with ACE-FTS CO partial columns for the period from 10 November 2017 to 31 May 2020 displays excellent agreement between the two data sets (R = 0.93), and a small relative bias of −0.68 ± 0.25 % (bias ± standard error). Additional comparisons were performed within five latitude bands; the north Polar region (60° N to 90° N), northern Mid-latitudes (20° N to 60° N), the Equatorial region (20° S to 20° N), southern Mid-latitudes (60° S to 20° S), and the south Polar region (90° S to 60° S). Latitudinal comparisons of the TROPOMI and ACE-FTS CO datasets show strong correlations ranging from R = 0.93 (southern Mid-latitudes) to R = 0.85 (Equatorial region) between the CO products, but display a dependence of the mean differences on latitude. Positive mean biases of 7.92 ± 0.58 % and 7.98 ± 0.51 % were found in the northern and southern Polar regions, respectively, while a negative bias of −9.16 ± 0.55 % was observed in the Equatorial region. To investigate whether these differences are introduced by cloud contamination which is reflected in the TROPOMI averaging kernel shape, the latitudinal comparisons were repeated for cloud-covered pixels and clear-sky pixels only, and for the unsmoothed and smoothed cases. Clear-sky pixels were found to be biased higher with poorer correlations on average than clear+cloudy scenes and cloud-covered scenes only. Furthermore, the latitudinal dependence on the biases was observed in both the smoothed and unsmoothed cases. To provide additional context to the global comparisons of TROPOMI with ACE-FTS in the Arctic, both satellite data sets were compared against measurements from the ground-based PEARL-FTS. Comparisons of TROPOMI with smoothed PEARL-FTS total columns in the period of 3 March 2018 to 27 March 2020 display a strong correlation (R = 0.88), however a positive mean bias of 14.3 ± 0.16 % was also found. A partial column comparison of ACE-FTS with the PEARL-FTS in the period from 25 February 2007 to 18 March 2020 shows good agreement (R = 0.82), and a mean positive bias of 9.83 ± 0.22 % in the ACE-FTS product relative to the ground-based FTS. The magnitude and sign of the mean relative differences are consistent across all inter-comparisons in this work, as well as with recent ground-based validation efforts, suggesting that current TROPOMI CO product exhibits a positive bias in the high-Arctic region. However, the observed bias is within the TROPOMI mission accuracy requirement of ±15 %, providing further confirmation that the data quality in these remote high-latitude regions meets this specification.

show abstract

Comparison of ground-based and satellite measurements of water vapour vertical profiles over Ellesmere Island, Nunavut

Cited by 7 publications

References 57 publications

Water vapour and ozone in the upper troposphere–lower stratosphere: global climatologies from three Canadian limb-viewing instruments

Water vapour and ozone in the upper troposphere–lower stratosphere: global climatologies from three Canadian limb-viewing instruments

Intercomparison of CO measurements from TROPOMI, ACE-FTS, and a high-Arctic ground-based Fourier transform spectrometer

Inter-comparison of CO measurements from TROPOMI, ACE-FTS, and a high-Arctic ground-based FTS

Contact Info

Product

Resources

About