Use of GNSS Tropospheric Products for Climate Monitoring (Working Group 3)

Bock, Olivier; Pacione, R.; Ahmed, Furqan; Araszkiewicz, Andrzej; Baldysz, Zofia; Balidakis, Kyriakos; Barroso, C.; Beirle, Steffen; Berckmans, Julie; Böhm, Johannes; Bogusz, Janusz; Bos, M. S.; Bröckmann, E.; Cadeddu, Maria; Chimani, Barbara; Douša, Jan; Elgered, Gunnar; Elias, Michal; Fernandes, Rui; Figurski, Mariusz; Fionda, E.; Gruszczyńska, M; Guerova, Guergana; Guijarro, J. A.; Hackman, Christine; Heinkelmann, Robert; Jones, Jonathan; Kazancı, S. Zengin; Kłos, Anna; Landskron, Daniel; Martins, João Paulo; Mattioli, V.; Mircheva, Biliana; Nahmani, S.; Nilsson, Ricky; Ning, Tong; Nykiel, Grzegorz; Parracho, Ana C.; Pottiaux, Eric; Ramos, Alzira; Rebischung, Paul; Sá, André; Dorigo, Wouter; Schuh, Harald; Stankūnavičius, Gintautas; Stępniak, Katarzyna; Valentim, H.; Malderen, Roeland Van; Viterbo, Pedro; Willis, Pascal; Xaver, Angelika

doi:10.1007/978-3-030-13901-8_5

Cited by 10 publications

(8 citation statements)

References 140 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Station position repeatability was in general good both in the horizontal (≤ 0.005 m) and vertical (≤ 0.015 m) except for two stations (BOUL, OLVN). In a second step, a tighter range check completed with an outlier check were applied following the recommendations of Bock (2020a). The range check limits were [0.5, 3.0 m] on ZTD values and 0.01 m on formal errors.…”

Section: Gnss Data Quality Checkingmentioning

confidence: 99%

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC4A

Bock

Bosser

Flamant

et al. 2021

Earth Syst. Sci. Data

View full text Add to dashboard Cite

Abstract. Ground-based Global Navigation Satellite System (GNSS) measurements from nearly 50 stations distributed over the Caribbean arc have been analysed for the period 1 January–29 February 2020 in the framework of the EUREC4A (Elucidate the Couplings Between Clouds, Convection and Circulation) field campaign. The aim of this effort is to deliver high-quality integrated water vapour (IWV) estimates to investigate the moisture environment of mesoscale cloud patterns in the trade winds and their feedback on the large-scale circulation and energy budget. This paper describes the GNSS data processing procedures and assesses the quality of the GNSS IWV retrievals from four operational streams and one reprocessed research stream which is the main data set used for offline scientific applications. The uncertainties associated with each of the data sets, including the zenith tropospheric delay (ZTD)-to-IWV conversion methods and auxiliary data, are quantified and discussed. The IWV estimates from the reprocessed data set are compared to the Vaisala RS41 radiosonde measurements operated from the Barbados Cloud Observatory (BCO) and to the measurements from the operational radiosonde station at Grantley Adams International Airport (GAIA), Bridgetown, Barbados. A significant dry bias is found in the GAIA humidity observations with respect to the BCO sondes (−2.9 kg m−2) and the GNSS results (−1.2 kg m−2). A systematic bias between the BCO sondes and GNSS is also observed (1.7 kg m−2), where the Vaisala RS41 measurements are moister than the GNSS retrievals. The IWV estimates from a collocated microwave radiometer agree with the BCO soundings after an instrumental update on 27 January, while they exhibit a dry bias compared to the soundings and to GNSS before that date. IWV estimates from the ECMWF fifth-generation reanalysis (ERA5) are overall close to the GAIA observations, probably due to the assimilation of these observations in the reanalysis. However, during several events where strong peaks in IWV occurred, ERA5 is shown to significantly underestimate the GNSS-derived IWV peaks. Two successive peaks are observed on 22 January and 23–24 January which were associated with heavy rain and deep moist layers extending from the surface up to altitudes of 3.5 and 5 km, respectively. ERA5 significantly underestimates the moisture content in the upper part of these layers. The origins of the various moisture biases are currently being investigated. We classified the cloud organization for five representative GNSS stations across the Caribbean arc using visible satellite images. A statistically significant link was found between the cloud patterns and the local IWV observations from the GNSS sites as well as the larger-scale IWV patterns from the ECMWF ERA5 reanalysis. The reprocessed ZTD and IWV data sets from 49 GNSS stations used in this study are available from the French data and service centre for atmosphere (AERIS) (https://doi.org/10.25326/79; Bock, 2020b).

show abstract

Section: Gnss Data Quality Checkingmentioning

confidence: 99%

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC4A

Bock

Bosser

Flamant

et al. 2021

Earth Syst. Sci. Data

View full text Add to dashboard Cite

show abstract

“…The analysis of the distribution of formal errors helped to set the range limits for the post-processing data screening in order to reject outliers in the ZTD and position estimates (Bock, 2020). Due to the different statistical properties observed in the results discussed above, different thresholds were adopted for the two software packages and the three R/Vs:…”

Section: Data Screeningmentioning

confidence: 99%

“…where h ERA5 and h GNSS are the geoid heights of the ERA5 grid point and of the GNSS antenna, respectively; T (h ERA5 ) and P (h ERA5 ) are the temperature and pressure from ERA5 at the model surface; g(h ERA5 ) = 9.8062 m s −2 is the gravity at the model surface; g atm = 9.7840 m s −2 is the approximated gravity of the centre of mass of the atmosphere (Nilson et al, 2013); and k 1 = 0.77643 K Pa −1 is a refractivity constant for dry air updated by Bock et al (2021) for the EUREC 4 A period. In the case that larger height differences are considered, a more accurate formulation of height correction should be applied such as that proposed in Bock (2020).…”

Section: Gnss Iwv Retrievalmentioning

confidence: 99%

Integrated water vapour content retrievals from ship-borne GNSS receivers during EUREC4A

Bosser

Bock

Flamant

et al. 2021

Earth Syst. Sci. Data

View full text Add to dashboard Cite

Abstract. In the framework of the EUREC4A (Elucidating the role of clouds–circulation coupling in climate) campaign that took place in January and February 2020, integrated water vapour (IWV) contents were retrieved over the open tropical Atlantic Ocean using Global Navigation Satellite System (GNSS) data acquired from three research vessels (R/Vs): R/V Atalante, R/V Maria S. Merian and R/V Meteor. This paper describes the GNSS processing method and compares the GNSS IWV retrievals with IWV estimates from the European Centre for Medium-range Weather Forecasts (ECMWF) fifth reanalysis (ERA5), from the Moderate Resolution Imaging Spectroradiometer (MODIS) infrared products and from terrestrial GNSS stations located along the tracks of the ships. The ship-borne GNSS IWV retrievals from R/V Atalante and R/V Meteor compare well with ERA5, with small biases (−1.62 kg m−2 for R/V Atalante and +0.65 kg m−2 for R/V Meteor) and a root mean square (rms) difference of about 2.3 kg m−2. The results for the R/V Maria S. Merian are found to be of poorer quality, with an rms difference of 6 kg m−2, which is very likely due to the location of the GNSS antenna on this R/V prone to multipath effects. The comparisons with ground-based GNSS data confirm these results. The comparisons of all three R/V IWV retrievals with MODIS infrared products show large rms differences of 5–7 kg m−2, reflecting the enhanced uncertainties in these satellite products in the tropics. These ship-borne IWV retrievals are intended to be used for the description and understanding of meteorological phenomena that occurred during the campaign, east of Barbados, Guyana and northern Brazil. Both the raw GNSS measurements and the IWV estimates are available through the AERIS data centre (https://en.aeris-data.fr/, last access: 20 September 2020). The digital object identifiers (DOIs) for R/V Atalante IWV and raw datasets are https://doi.org/10.25326/71 (Bosser et al., 2020a) and https://doi.org/10.25326/74 (Bosser et al., 2020d), respectively. The DOIs for the R/V Maria S. Merian IWV and raw datasets are https://doi.org/10.25326/72 (Bosser et al., 2020b) and https://doi.org/10.25326/75 (Bosser et al., 2020e), respectively. The DOIs for the R/V Meteor IWV and raw datasets are https://doi.org/10.25326/73 (Bosser et al., 2020c) and https://doi.org/10.25326/76 (Bosser et al., 2020f), respectively.

show abstract

“…The ERA5 fields were used with the highest temporal and spatial resolutions: 1-hourly and 0.25°x 0.25°, respectively. The refractivity coefficients and thermodynamics constants were updated from Bock (2020a) to account for the global CO 2 content for January 2020 (see the Appendix). The g m formula proposed by Bosser et al (2007) was used instead of the Saastamoinen (1972) one.…”

Section: Gipsy Repro1 Resultsmentioning

confidence: 99%

Comment on essd-2021-50

Bock¹

2021

View full text Add to dashboard Cite

Use of GNSS Tropospheric Products for Climate Monitoring (Working Group 3)

Cited by 10 publications

References 140 publications

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC<sup>4</sup>A

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC<sup>4</sup>A

Integrated water vapour content retrievals from ship-borne GNSS receivers during EUREC<sup>4</sup>A

Comment on essd-2021-50

Contact Info

Product

Resources

About

Use of GNSS Tropospheric Products for Climate Monitoring (Working Group 3)

Cited by 10 publications

References 140 publications

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC&lt;sup&gt;4&lt;/sup&gt;A

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC&lt;sup&gt;4&lt;/sup&gt;A

Integrated water vapour content retrievals from ship-borne GNSS receivers during EUREC&lt;sup&gt;4&lt;/sup&gt;A

Comment on essd-2021-50

Contact Info

Product

Resources

About

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC<sup>4</sup>A

Integrated water vapour observations in the Caribbean arc from a network of ground-based GNSS receivers during EUREC<sup>4</sup>A

Integrated water vapour content retrievals from ship-borne GNSS receivers during EUREC<sup>4</sup>A