The L-Band solar flux retrieval from the Soil Moisture and Ocean Salinity (SMOS) mission: Theoretical algorithm and its validation | Journal of Space Weather and Space Climate

Open Access

Issue		J. Space Weather Space Clim. Volume 15, 2025


Article Number		47
Number of page(s)		22
DOI		https://doi.org/10.1051/swsc/2025042
Published online		31 October 2025

Achard, F, G D’Souza. 1994. Collection and pre-processing of NOAA-AVHRR 1 km resolution data for tropical forest resource assessment. In: Tech. Rep. Report EUR 16055 EN.European Commission, ECSC-EC-EAEC, Brussels. https://op.europa.eu/en/publication-detail/-/publication/15b97b3e-cd63-4370-9fbd-bab1305a9eb1. [Google Scholar]
Bruevich, E, Bruevich V, Yakunina G. 2014. Changed relation between solar 10.7-cm Radio flux and some activity indices which describe the radiation at different altitudes of atmosphere during cycles 21–23. J Astrophys Astron 35: 1–15. https://doi.org/10.1007/s12036-014-9258-0. [Google Scholar]
Camps, A, Vall-llossera M, Duffo N, Zapata M, Corbella I, Torres F, Barrena V. 2004. Sun effects in 2-D aperture synthesis radiometry imaging and their cancelation. IEEE Trans Geosci Rem Sens 42 1161–1167. https://doi.org/10.1109/TGRS.2004.826561. [Google Scholar]
Corbella, I, Torres F, Duffo N, Duran I, Gonzalez-Gambau V, Martin-Neira M. 2019. Wide field of view microwave interferometric radiometer imaging. Rem Sens 11 (6): 682. https://doi.org/10.3390/rs11060682. [Google Scholar]
Corbella, I, Ubeda N, Vall-llossera M, Camps A, Torres F. 2004. The visibility function in interferometric aperture synthesis radiometry. IEEE Trans Geosci Rem Sens 42: 1677–1682. https://doi.org/10.1109/TGRS.2004.830641. [Google Scholar]
Covington, AE. 1969. Solar radio emission at 10.7 cm, 1947–1968. J Roy Astron Soc Can 63: 125. [Google Scholar]
Crapolicchio R, Capolongo E, Bigazzi A. 2016. Sun L-band brightness temperature estimate from Soil Moisture and Ocean Salinity (SMOS) Mission: A Potential New Space Weather Application for SMOS Data. In: Living Planet Symposium, Proceedings of the conference held 9–13 May 2016 in Prague, Czec Republic, Ouwehand L (Ed.), Vol. 740, ESA-SP, pp. 81. ISBN: 978-92-9221-305-3. [Google Scholar]
Crapolicchio R., Casella D, Marqué C. 2018. Solar Radio Observations from Soil Moisture and Ocean Salinity (SMOS) Mission. In: IGARSS 2018 – 2018 IEEE International Geoscience and Remote Sensing Symposium, Valencia, Spain, pp. 4111–4114. https://doi.org/10.1109/IGARSS.2018.8518756. [Google Scholar]
Dudok de Wit, T, Bruinsma S. 2017. The 30 cm radio flux as a solar proxy for thermosphere density modelling. J Space Weather Space Clim, 7: A9. https://doi.org/10.1051/swsc/2017008. [CrossRef] [EDP Sciences] [Google Scholar]
Dudok de Wit, T, Bruinsma S, Shibasaki K. 2014. Synoptic radio observations as proxies for upper atmosphere modelling. J Space Weather Space Clim 4: A06. https://doi.org/10.1051/swsc/2014003. [CrossRef] [EDP Sciences] [Google Scholar]
Dudok de Wit, T, Lefèvre L, Clette F. 2016. Uncertainties in the sunspot numbers: estimation and implications. Sol Phys 9–10: 2709–2731. https://doi.org/10.1007/s11207-016-0970-6. [Google Scholar]
Dudok de Wit, T, Moussaoui S, Guennou C, Auchère F, Cessateur G, Kretzschmar M, Vieira L, Goryaev F. 2012. Coronal temperature maps from solar EUV images: a blind source separation approach. Sol Phys 283: 31–47. https://doi.org/10.1007/s11207-012-0142-2. [Google Scholar]
Flores-Soriano, M. 2024. Solar radio bursts impact on the International GNSS Service Network during Solar Cycle 24. J Space Weather Space Clim 14: 32. https://doi.org/10.1051/swsc/2024034. [Google Scholar]
Flores-Soriano, M, Cid C, Crapolicchio R. 2021. Validation of the SMOS mission for space weather operations: the potential of near real-time solar observation at 1.4 GHz. Space Weather 19: e2020SW002649. 10.1029/2020SW002649. [CrossRef] [Google Scholar]
Garcìa, RD, Oliva R, Crapolicchio R, Neira MM. 2022. SMOS v724 third mission reprocessing: brightness temperature quality and stability. IEEE Trans Geosci Rem Sens 60: 5305010. https://doi.org/10.1109/TGRS.2022.3206118. [Google Scholar]
Giersch, O, Kennewell J. 2022. Analysis of the radio solar telescope network’s noon flux observations over three solar cycles (1988–2020). Radio Sci 57: e2022RS007456. https://doi.org/10.1029/2022RS007456. [Google Scholar]
Gutierrez A, Barbosa J, Almeida N, Catarino N, Freitas J, Ventura M, Reis J, Zundo M. 2007. SMOS L1 processor prototype: From digital counts to brightness temperatures. In: IEEE International Geoscience and Remote Sensing Symposium, pp. 3626–3630. https://doi.org/10.1109/IGARSS.2007.4423631. [Google Scholar]
Hathaway, DH. 2015. The solar cycle. Liv Rev Sol Phys 12: 4. https://doi.org/10.1007/lrsp-2015-4. [Google Scholar]
Holland, RL, Vaughan WW. 1984. Lagrangian least-squares prediction of solar flux. J Geophys Res Space Phys 89 (A1): 11–16. https://doi.org/10.1029/JA089iA01p00011. [Google Scholar]
Kaplan, K. 2024. The characteristic properties of solar activity in Solar Cycle 24, Kinemat Phys Celest Bodies 40: 105–115. https://doi.org/10.3103/S0884591324020041. [Google Scholar]
Kerr, Y, Font J, Philippe W, Camps A, Temes J, Corbella I, Torres F, Ubeda N, Vallilossera M, Caudal G. 2000. New radiometers: SMOS-a dual pol L-band 2D aperture synthesis radiometer. IEEE Aerospace Conf Proc 5: 119–128. https://doi.org/10.1109/AERO.2000.878481. [Google Scholar]
Kerr, YH, Waldteufel P, Wigneron J-P, Delwart S, Cabot F, et al. 2009. The SMOS mission: new tool for monitoring key elements of the global water cycle. Proc IEEE 98: 1354–1366. https://doi.org/10.1109/JPROC.2010.2043032. [Google Scholar]
Khazaal, A, Cabot F, Anterrieu E, Kerr YH. 2020. A new direct Sun Correction Algorithm for the soil moisture and ocean salinity space mission. IEEE J Sel Top Appl Earth Obs Remote Sens 13: 1164–1173. https://doi.org/10.1109/JSTARS.2020.2971063. [CrossRef] [Google Scholar]
Kintner, PMJ, O’Hanlon B, Gary DE, Kintner PMS. 2009. Global Positioning System and solar radio burst forensics. Radio Sci 44: RS0A08. https://doi.org/10.1029/2008RS004039. [Google Scholar]
Lomb, NR. 1976. Least-squares frequency analysis of unequally spaced data. Astrophys Space Sci, 39: 447–462. https://doi.org/10. [CrossRef] [Google Scholar]
Martin-Neira M, Oliva R, Onrubia R, Corbello I, Duffo N, et al. . 2021. SMOS instrument performance after more than 11 years in Orbit. In: 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, Brussels, Belgium, pp. 7744–7747. doi: 10.1109/IGARSS47720.2021.9554206 [Google Scholar]
Mecklenburg, S, Drusch M, Kaleschke L, Rodriguez-Fernandez N, Reul N, et al. 2016. ESA’s Soil Moisture and Ocean Salinity mission: From science to operational applications. Rem Sens Environ 180: 3–18. https://doi.org/10.1016/j.rse.2015.12.025. [Google Scholar]
Mecklenburg, S, Drusch M, Kerr Y, Martin Neira M, Steven D, Buenadicha G, Reul N, Daganzo E, Oliva R, Crapolicchio R. 2012. ESA’s Soil Moisture and Ocean Salinity Mission: Mission Performance and Operations. IEEE Trans Geosci Rem Sens 50: 1354–1366. https://doi.org/10.1109/TGRS.2012.2187666. [Google Scholar]
Morosan, DE, Rasanen JE, Kumari A, Kilpua EKJ, Bisi MM, et al. 2022. Exploring the circular polarisation of low-frequency solar radio bursts with LOFAR. Sol Phys 297: 47. https://doi.org/10.1007/s11207-022-01976-9. [Google Scholar]
Nita, GM, Gary DE, Lanzerotti LJ. 2004. Statistics of solar microwave radio burst spectra with implications for operations of microwave radio systems. Space Weather 2 (11): S11005. https://doi.org/10.1029/2004SW000090. [Google Scholar]
Oberoi, D, Sharma R, Rogers A. 2017.Estimating solar flux density at low radio frequencies using a sky brightness model. Sol Phys 292: 1–16. https://doi.org/10.1007/s11207-017-1096-1. [CrossRef] [Google Scholar]
Pulupa, M, Bale SD, Jebaraj IC, Romeo O, Krucker S. 2025. Highly polarized type III storm observed with Parker Solar Probe. Astrophys J Lett 987: 34. https://doi.org/10.3847/2041-8213/ade5a8. [Google Scholar]
Reul, N, Tenerelli J, Chapron B, Waldteufel P. 2007. Modeling sun glitter at L-band for sea surface salinity remote sensing with SMOS, IEEE Trans Geosci Rem Sens 45 (7): 2073–2087. https://doi.org/10.1109/TGRS.2006.890421. [Google Scholar]
Sato, H, Jakowski N, Berdermann J, Jiricka K, Heßelbarth A, Banys D, Wilken V. 2019. Solar Radio Burst Events on 6 September 2017 and its impact on GNSS signal frequencies. Space Weather 17 (6): 816–826. https://doi.org/10.1029/2019SW002198. [CrossRef] [Google Scholar]
Selhorst, C, Silva A, Costa J. 2004. Radius variations over a solar cycle. Astron Astrophys 420 (3): 1117–1121. https://doi.org/10.1051/0004-6361:20034382. [Google Scholar]
Shimojo, M, Iwai K, Asai A, Nozawa S, Minamidani T, Saito M. 2017. Variation of solar microwave spectrum in the last half century. Astrophys J 848: 62. https://doi.org/10.3847/1538-4357/aa8c75. [Google Scholar]
Tanaka, H, Castelli J, Covington A, Krüger A, Landecker T, Tlamicha A. 1973. Absolute calibration of solar radio flux density in the microwave region. Sol Phys 29: 243–262. https://doi.org/10.1007/BF00153452. [Google Scholar]
Tapping, K. 1987. Recent solar radio astronomy at centimeter wavelengths: The temporal variability of the 10.7-cm flux. J Geophys Res Atmos 92 (D1): 829–838. [Google Scholar]
Tapping, K, Charrois D. 1994. Limits to the accuracy of the 10.7 cm flux. Sol Phys 150: 305–315. https://doi.org/10.1007/BF00712892. [Google Scholar]
Viereck, R, Puga L, Mcmullin D, Judge D, Weber M, Tobiska WK. 2001. The Mg II index: a proxy for solar EUV. Geophys Res Lett 28: 1343–1346. https://doi.org/10.1029/2000GL012551. [Google Scholar]
Viereck, RA, Floyd LE, Crane PC, Woods TN, Knapp BG, Rottman G, Weber M, Puga LC, DeLand MT. 2004. A composite Mg II index spanning from 1978 to 2003. Space Weather 2 (10): S10005. https://doi.org/10.1029/2004SW000084. [NASA ADS] [CrossRef] [Google Scholar]

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