Evaluation of ERA5 Significant Wave Height versus New Multi-Mission Satellite Altimeter Measurements in an Enclosed Basin

Year 2025, Volume: 27 Issue: 81, 382 - 392, 29.09.2025

Fulya Islek

https://doi.org/10.21205/deufmd.2025278106

Abstract

The present study aims to examine the accuracy of significant wave height (Hs) based on the ECMWF (European Center for Medium-Range Weather Forecasts) ERA5. The ERA5 reanalysis datasets are retrieved for the period 2002−2021, having spatial and temporal resolutions of 0.50  0.50 and 1 hour, respectively. The ERA5 Hs datasets are validated versus in-situ measurements. The ERA5 reanalysis datasets are reasonably well matched at four measurement stations, as indicated by a relatively high correlation coefficient (r, Q-Q plot) and low statistical error measures (bias, NBI, SI, and RMSE). The results indicate that the ERA5 datasets perform well in estimating Hs in the Black Sea. The ERA5 Hs is used for the spatial validation of the data from the European Space Agency for Sea State Climate Change Initiative (ESA CCI-SS). The ESA CCI-SS, a new multi-mission satellite altimeter measurement of the Hs datasets, provides the data with a 1.0  1.0 spatial resolution and monthly temporal resolution, spanning from 2002 to 2021. It has been determined that ESA CCI-SS (v3, latest version) datasets from the multi-mission altimeter measurements are in good agreement with the ERA5 reanalysis data over the entire Black Sea. The results of the long-term (20-year average) and monthly averages exhibit that the ESA CCI-SS datasets are a good alternative data source in terms of Hs and can be reliably used for the Hs in the Black Sea wave climate studies.

Keywords

Significant wave height , ERA5 reanalysis data , Satellite altimeter measurement , Wave climate , Black Sea.

Kapalı Bir Havzada Yeni Çok Amaçlı Uydu Altimetre Ölçümlerine Karşı ERA5 Belirgin Dalga Yüksekliğinin Değerlendirmesi

Abstract

Bu çalışma, ECMWF (Avrupa Orta Menzilli Hava Tahminleri Merkezi) ERA5 verilerini temel alan belirgin dalga yüksekliğinin (Hs) doğruluğunu değerlendirmeyi amaçlamaktadır. ERA5 yeniden analiz verileri, 2002−2021 dönemi için 0.50  0.50 standart uzamsal çözünürlük ve 1 saat zaman adımı ile indirilmiştir. ERA5 Hs verileri yerinde ölçümlere karşı doğrulanmıştır. ERA5 yeniden analiz verileri nispeten yüksek bir korelasyon katsayısına (r, Q-Q grafiği) ve düşük istatistiksel hata ölçütlerine (bias, NBI, SI ve RMSE) sahip olması nedeniyle tüm ölçüm istasyonlarında makul derecede iyi eşleşmiştir. ERA5 verileri, Karadeniz bölgesi için Hs’in tahmininde iyi bir performans sergilemiştir. ERA5 Hs verileri, Avrupa Uzay Ajansı İklim Değişikliği Girişimi Deniz Durumu (ESA CCI-SS) verilerinin uzamsal doğrulamasında kullanılmıştır. Hs verilerinin yeni çok amaçlı uydu altimetre ölçümü olan ESA CCI-SS, 2002'den 2021'ye kadar uzanan 1.0  1.0 uzamsal çözünürlük ve aylık zamansal çözünürlükte veri sağlamaktadır. Çok amaçlı altimetre ölçümlerinden elde edilen ESA CCI-SS (v3, son sürüm) veri setlerinin tüm Karadeniz çalışma alanı için ERA5 Hs verileri ile oldukça iyi bir uyum içinde olduğu belirlenmiştir. Uzun dönemli (20-yıllık ortalama) ve aylık ortalamaların sonuçları, ESA CCI-SS verilerinin Hs açısından iyi bir alternatif veri kaynağı olduğu ve Karadeniz dalga iklimi çalışmalarında Hs için güvenilir bir şekilde kullanılabileceğini göstermektedir.

Keywords

Belirgin dalga yüksekliği , ERA5 yeniden analiz verileri , Uydu altimetre verileri , Dalga iklimi , Karadeniz.

References

• Gulev, S.K., Grigorieva, V., Sterl, A., Wolf, D. 2003. Assessment of the reliability of wave observations from voluntary observing ships: insights from the validation of a global wind wave climatology based on voluntary observing ship data. Journal of Geophysical Research: Oceans, Vol.108(C7), p.3236. DOI: 10.1029/2002JC001437.
• Saprykina, Y., Kuznetsov, S. 2018. Analysis of the variability of wave energy due to climate changes on the example of the Black Sea. Energies, Vol.11, p.2020. DOI: 10.3390/en11082020
• Menéndez, M., Méndez, F.J., Losada, I.J., et al. 2008. Variability of extreme wave heights in the northeast Pacific Ocean based on buoy measurements. Geophysical Research Letters, Vol.35(22), p.L22607. DOI: 10.1029/2008GL035394
• Islek, F., Yuksel, Y., Sahin, C., Ari Guner, H.A. 2021. Long-term analysis of extreme wave characteristics based on the SWAN hindcasts over the Black Sea using two different wind fields. Dynam. Atmos. Oceans, Vol.94, p.101165. DOI: 10.1016/j.dynatmoce.2020.101165
• Young, I.R., Ribal, A. 2022. Can Multi-Mission Altimeter Datasets Accurately Measure Long-Term Trends in Wave Height? Remote Sensing, Vol.14(4), p.974. DOI: 10.3390/rs14040974
• Zhai, R., Huang, C., Yang, W., Tang, L., Zhang, W. 2023. Applicability evaluation of ERA5 wind and wave reanalysis data in the South China Sea. Journal of Oceanology and Limnology. DOI: 10.1007/s00343-022-2047-8
• Alves, J.H.G.M., Young, I.R. 2003. On estimating wave heights using combined Geosat, Topex/Poseidon and ERS-1 altimeter data. Applied Ocean Research, Vol.25(4), pp.167–186. DOI: 10.1016/j.apor.2004.01.002
• Koedel, U., Schuetze, C., Fischer, P., Bussmann, I., Sauer, P.K., et al. 2022. Challenges in the Evaluation of Observational Data Trustworthiness From a Data Producers Viewpoint (FAIR+). Frontiers in Environmental Science, Vol.9, p.772666. DOI: 10.3389/fenvs.2021.772666
• Kumar, P., Debele, S.E., Sahani, J., Rawat, N., Marti-Cordona, B., et al. 2021. An overview of monitoring methods for assessing the performance of nature-based solutions against natural hazards. Earth-Science Reviews, Vol.217, p.103603. DOI: 10.1016/j.earscirev.2021.103603
• Skalvik, A.M., Saetre, C., Froysa, K.E., Bjork, R.N., Tengberg, A. 2023. Challenges, limitations, and measurement strategies to ensure data quality in deep-sea sensors. Frontiers in Marine Science, Vol.10, p.1152236. DOI: 10.3389/fmars.2023.1152236
• Caloiero, T., Aristodemo, F., Ferraro, D.A. 2022. Annual and seasonal trend detection of significant wave height, energy period and wave power in the Mediterranean Sea. Ocean Engineering, Vol.243, p.110322. DOI: 10.1016/j.oceaneng.2021.110322
• Çalışır, E., Soran, M.B., Akpınar, A. 2021. Quality of the ERA5 and CFSR winds and their contribution to wave modelling performance in a semi-closed sea. Journal of Operational Oceanography, Vol.16(2), pp.106–130. DOI: 10.1080/1755876X.2021.1911126
• Ozbahceci, B.O. 2020. Extreme value statistics of wind speed and wave height of the Marmara Sea based on combined radar altimeter data. Advances in Space Research, Vol.66, pp.2302–2318. DOI: 10.1016/j.asr.2019.08.025
• Feng, X., Chen, X. 2021. Feasibility of ERA5 reanalysis wind dataset on wave simulation for the western inner-shelf of Yellow Sea. Ocean Engineering, Vol.236, p.109413. DOI: 10.1016/j.oceaneng.2021.109413
• Wang, J., Liu, J., Wang, Y., Liao, Z., Sun, P. 2021. Spatiotemporal variations and extreme value analysis of significant wave height in the South China Sea based on 71-year long ERA5 wave reanalysis. Applied Ocean Research, Vol.113, p.102750. DOI: 10.1016/j.apor.2021.102750
• Giudici, A., Jankowski, M.Z., Mannikus, R., Najafzadeh, F., Suursaar, Ü., Soomere, T. 2023. A comparison of Baltic Sea wave properties simulated using two modelled wind data sets. Estuarine, Coastal and Shelf Science, Vol.290, p.108401. DOI: 10.1016/j.ecss.2023.108401
• Anusree, A., Kumar, V.S. 2024. Mean wave direction and wave height in the ERA5 reanalysis dataset: Comparison with measured data in the coastal waters of India. Dynamics of Atmospheres and Oceans, Vol.107, p.101478. DOI: 10.1016/j.dynatmoce.2024.101478
• Mahmoodi, K., Ghassemi, H., Razminia, A. 2019. Temporal and spatial characteristics of wave energy in the Persian Gulf based on the ERA5 reanalysis dataset. Energy, Vol.187, p.115991. DOI: 10.1016/j.energy.2019.115991
• Patra, A., Min, S.K., Seong, M.G. 2020. Climate variability impacts on global extreme wave heights: Seasonal assessment using satellite data and ERA5 reanalysis. Journal of Geophysical Research: Oceans, Vol.125, p.e2020JC016754. DOI: 10.1029/2020JC016754
• Naseef, T.M., Sanil Kumar, V. 2020. Climatology and trends of the Indian Ocean surface waves based on 39-year long ERA5 reanalysis data. International Journal of Climatology, Vol.40, pp.979–1006. DOI: 10.1002/joc.6251
• Rusu, L., Rusu, E. 2021. Evaluation of the Worldwide Wave Energy Distribution Based on ERA5 Data and Altimeter Measurements. Energies, Vol.14, p.394. DOI: 10.3390/en14020394
• Shi, H., Cao, X., Li, Q., Li, D., Sun, J., et al. 2021. Evaluating the accuracy of ERA5 wave reanalysis in the water around China. Journal of Ocean University of China, Vol.20(1), pp.1–9. DOI: 10.1007/s11802-021-4496-7
• Zecchetto, S., De Bisasio, F. 2007. Sea Surface Winds over the Mediterranean Basin from Satellite Data (2000–04): Meso- and Local-Scale Features on Annual and Seasonal Time Scales. Journal of Applied Meteorology and Climatology, Vol.46, pp.814–827. DOI: 10.1175/JAM2498.1
• Garmashov, A.V., Kubryakov, A.A., Shokurov, M.V., Stanichny, S.V., Toloknov, A.I., Korovushkin, Y.N. 2016. Comparing satellite and meteorological data on wind velocity over the Black Sea. Izvestiya Atmospheric and Oceanic Physics, Vol.52(3), pp.309–316.
• Kubryakov, A., Stanichny, S., Shokurov, M., Garmashov, A. 2019. Wind velocity and wind curl variability over the Black Sea from QuikScat and ASCAT satellite measurements. Remote Sensing of Environment, Vol.224, pp.236–258. DOI: 10.1016/j.rse.2019.01.034
• Efimov, V.V., Anisimov, A.E. 2011. Climatic parameters of wind-field variability in the Black Sea region: numerical reanalysis of regional atmospheric circulation. Izvestiya Atmospheric and Oceanic Physics, Vol.47(3), pp.350–361. DOI: 10.1134/S0001433811030030
• Islek, F., Yuksel, Y. 2022. Evaluation of future wind power potential and their projected changes in the Black Sea and possible stable locations for wind farms. Ocean Engineering, Vol.266, p.112832. DOI: 10.1016/j.oceaneng.2022.112832
• Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., et al. 2020. The ERA5 global reanalysis. Quarterly Journal of the Royal Meteorological Society, Vol.146, pp.1999–2049. DOI: 10.1002/qj.3803
• Piollé, J.F., Dodet, G., Quilfen, Y. 2022. ESA Sea State Climate Change Initiative (Sea_State_cci): Global remote sensing merged multi-mission monthly gridded significant wave height from altimetry, L4 product, version 3. NERC EDS Centre for Environmental Data Analysis. DOI: 10.5285/9c350d4ff7ee438f9f1fc7252cbb2282
• Ozhan, E., Abdalla, S. 2002. Wind and Deep Water Wave Atlas of Turkish Coasts. Turkish National Coastal Zone Management Committee/MEDCOAST, Middle East Technical University, Ankara, pp.445.
• Ari Guner, H.A., Yuksel, Y., Ozkan Cevik, E. 2013. Estimation of wave parameters based on nearshore wind–wave correlations. Ocean Engineering, Vol.63, pp.52–62.
• Islek, F., Yuksel, Y., Sahin, C. 2020. Assessments of long-term wind and wave trends in the Black Sea. Proceedings of the Virtual Conference on Coastal Engineering. DOI: 10.9753/icce.v36v.waves.5
• Islek, F., Yuksel, Y., Sahin, C. 2022. Evaluation of regional climate models and future wave characteristics in an enclosed sea: A case study of the Black Sea. Ocean Engineering, Vol.262, p.112220. DOI: 10.1016/j.oceaneng.2022.112220
• Islek, F., Yuksel, Y. 2021. Inter-comparison of long-term wave power potential in the Black Sea based on the SWAN wave model forced with two different wind fields. Dynamics of Atmospheres and Oceans, Vol.93, p.101192. DOI: 10.1016/j.dynatmoce.2020.101192
• Islek, F., Yuksel, Y., Sahin, C. 2020. Spatiotemporal long-term trends of extreme wind characteristics over the Black Sea. Dynamics of Atmospheres and Oceans, Vol.90, p.101132. DOI: 10.1016/j.dynatmoce.2020.101132
• Islek, F., Yuksel, Y., Sahin, C. 2022. Evaluation of regional climate models and future wind characteristics in the Black Sea. International Journal of Climatology, Vol.42, pp.1877–1901. DOI: 10.1002/joc.7341
• Islek, F., Yuksel, Y., Sahin, C. 2020b. Long-term variability of the mean sea level pressure field over the Black Sea. Aquatic Ecosystem Health & Management, Vol.23(4), pp.453–464. DOI: 10.1080/14634988.2020.1807233