Articles | Volume 26, issue 17
https://doi.org/10.5194/acp-26-12435-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-26-12435-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Orographic impacts of Réunion Island and Madagascar on heavy rainfall during Tropical Cyclone Batsirai (2022)
Keun-Ok Lee
CORRESPONDING AUTHOR
Laboratoire de l'Atmosphère et des Cyclones, UMR 8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, La Réunion, France
Soline Bielli
Centre National de Recherches Météorologiques, Université de Toulouse, Météo-France, CNRS, Toulouse, France
Clément Soufflet
Laboratoire de l'Atmosphère et des Cyclones, UMR 8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, La Réunion, France
Rémi Laxenaire
Laboratoire de l'Atmosphère et des Cyclones, UMR 8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, La Réunion, France
Kevin Hoarau
Laboratoire de l'Atmosphère et des Cyclones, UMR 8105, CNRS, Université de La Réunion, Météo-France, Saint-Denis, La Réunion, France
Related authors
No articles found.
Rémi Laxenaire, Eric P. Chassignet, Xiaobiao Xu, Alan J. Wallcraft, Luna Hiron, Brian K. Arbic, Maarten C. Buijsman, Miguel Solano, and Shane Elipot
Geosci. Model Dev., 19, 5571–5599, https://doi.org/10.5194/gmd-19-5571-2026, https://doi.org/10.5194/gmd-19-5571-2026, 2026
Short summary
Short summary
Surface kinetic energy reflects the distribution of ocean circulation across temporal and spatial scales, shaping energy transfer and mixing in the upper ocean. In a series of North and Equatorial Atlantic numerical simulations, we show that the surface kinetic energy is sensitive to the model's choices in grid and seafloor resolution and to the tides and wind variability, offering guidance for the configuration of future ocean simulations.
Yan Barabinot, Sabrina Speich, Xavier Carton, Pierre L'Hégaret, Corentin Subirade, Rémi Laxenaire, and Johannes Karstensen
Ocean Sci., 21, 1849–1872, https://doi.org/10.5194/os-21-1849-2025, https://doi.org/10.5194/os-21-1849-2025, 2025
Short summary
Short summary
Mesoscale eddies are rotating oceanic currents key to ocean variability. Off Brazil’s northeast coast, the North Brazil Current generates on average 4.5 eddies per year, which drift towards the West Indies, transporting waters from the Southern Hemisphere. Using data collected at sea by the EUREC4A-OA cruise, this study reveals that deep eddies transport 5 times more water than surface ones, reshaping our understanding of the regional water transport.
Yawouvi Dodji Soviadan, Miriam Beck, Joelle Habib, Alberto Baudena, Laetitia Drago, Alexandre Accardo, Remi Laxenaire, Sabrina Speich, Peter Brandt, Rainer Kiko, and Stemmann Lars
Biogeosciences, 22, 3485–3501, https://doi.org/10.5194/bg-22-3485-2025, https://doi.org/10.5194/bg-22-3485-2025, 2025
Short summary
Short summary
Key parameters representing the gravity flux in global models are sinking speed and vertical attenuation of exported material. We calculate, for the first time, these parameters in situ in the ocean for six intermittent blooms followed by export events using high-resolution (3 d) time series of 0–1000 m depth profiles from imaging sensors mounted on an Argo float. We show that sinking speed depends not only on size but also on the morphology of the particles, with density being an important property.
Alexandre Accardo, Rémi Laxenaire, Alberto Baudena, Sabrina Speich, Rainer Kiko, and Lars Stemmann
Biogeosciences, 22, 1183–1201, https://doi.org/10.5194/bg-22-1183-2025, https://doi.org/10.5194/bg-22-1183-2025, 2025
Short summary
Short summary
The open ocean helps mitigate climate change by storing CO2 via the biological carbon pump (BCP), which involves processes like organic carbon production at the surface and transferring it to the deep ocean via various pathways. By deploying an autonomous platform, we found significant marine snow accumulation from the surface to the mesopelagic zone in frontal regions between eddies. We suggest that the coupling of hydrodynamics at eddy edges and biological activity may enhance this process.
Pierre L'Hégaret, Florian Schütte, Sabrina Speich, Gilles Reverdin, Dariusz B. Baranowski, Rena Czeschel, Tim Fischer, Gregory R. Foltz, Karen J. Heywood, Gerd Krahmann, Rémi Laxenaire, Caroline Le Bihan, Philippe Le Bot, Stéphane Leizour, Callum Rollo, Michael Schlundt, Elizabeth Siddle, Corentin Subirade, Dongxiao Zhang, and Johannes Karstensen
Earth Syst. Sci. Data, 15, 1801–1830, https://doi.org/10.5194/essd-15-1801-2023, https://doi.org/10.5194/essd-15-1801-2023, 2023
Short summary
Short summary
In early 2020, the EUREC4A-OA/ATOMIC experiment took place in the northwestern Tropical Atlantic Ocean, a dynamical region where different water masses interact. Four oceanographic vessels and a fleet of autonomous devices were deployed to study the processes at play and sample the upper ocean, each with its own observing capability. The article first describes the data calibration and validation and second their cross-validation, using a hierarchy of instruments and estimating the uncertainty.
Cited articles
Arivelo, T. and Lin, Y.-L.: Climatology of heavy orographic rainfall induced by tropical cyclones over Madagascar: From synoptic to mesoscale perspectives, Earth Sci. Res., 5, https://doi.org/10.5539/esr.v5n2p132, 2016.
Barbary, D., Leroux, M.-D., and Bousquet, O.: The orographic effect of Réunion Island on tropical cyclone track and intensity, Atmos. Sci. Lett., 20, e882, https://doi.org/10.1002/asl.882, 2018.
Bender, M. A., Tuleya R. E., and Kurihara, Y.: A numerical study of the effect of a mountain-range on a landfalling tropical cyclone, Mon. Weather Rev., 113, 567–582, 1985.
Bender, M. A., Tuleya R. E., and Kurihara, Y.: A numerical study of the effect of island terrain on tropical cyclones, Mon. Weather Rev., 115, 130–155, 1987.
Cattiaux, J., Chauvin, F., Bousquet, O., Malardel, S., and Tsai, C. L.: Projected changes in the southern Indian ocean cyclone activity assessed from high-resolution experiments and CMIPS models, J. Climate, 33, 4975–4991, 2020.
Chan, K. T. F., Zhang, K., Wu, Y., and Chan, J. C. L: Landfalling hurricane track modes and decay, Nature, 606, E7–E11, https://doi.org/10.1038/s41586-022-04791-1, 2022.
Chang, C. P., Yeh, T. C., and Chen, J. M.: Effects of terrain on the surface-structure of typhoons over Taiwan, Mon. Weather Rev., 121, 734–752, 1993.
Chen, T. C., Wang, S. Y., Huang, W. R., and Yen, M. C.: Variation of the East Asian Summer Monsoon rainfall, J. Climate, 17, 744–762, https://doi.org/10.1175/1520-0442(2004)017<0744:VOTEAS>2.0.CO;2, 2004.
Cheng, L.-W., Yu, C.-K., and Chen, S.-P.: Identifying mechanisms of tropical cyclone generated orographic precipitation with Doppler radar and rain gauge observations, Clim. Atmos. Sci., 8, 35, https://doi.org/10.1038/s41612-025-00921-4 2025.
Chien, F. C. and Chiu, Y. C.: A composite study of southwesterly flows and rainfall in Taiwan, J. Meteorol. Soc. Jpn., 97, 1023–1040, https://doi.org/10.2151/jmsj.2019-057, 2019.
Colella, P. and Woodward, P. R.: The piecewise parabolic method (PPM) for gas dynamical simulations, J. Comput. Phys., 54, 174–201, https://doi.org/10.1016/0021-9991(84)90143-8, 1984.
Combot, C., Mouche, A., Knaff, J., Zhao, Y., Zhao, Y., Vinour, L., Quilfen, Y., and Chapron, B.: Extensive high-resolution Synthetic Aperture Radar (SAR) data analysis of Tropical Cyclones: comparisons with SFMR flights and Best-Track, Mon. Weather Rev., 148, 4545–4563, https://doi.org/10.1175/MWR-D-20-0005.1, 2020.
Cuxart, J., Bougeault, P., and Redelsperger, J. L.: A turbulence scheme allowing for mesoscale and large-eddy simulations, Q. J. Roy. Meteor. Soc., 126, 1–30, https://doi.org/10.1002/qj.49712656202, 2000.
Davies, H.: A lateral boundary formulation for multi-level prediction models, Q. J. Roy. Meteor. Soc., 102, 405–418, 1976.
Duchiron, B.: Variabilité interannuelle de la pluviométrie dans l'espace riverain de l'Océan Indien, Thèse de doctorat de l'université de Paris 7, 272 pp., https://theses.fr/2002PA070022 (last access: 28 August 2026), 2002.
Duffourg, F., Lee, K.-O., Ducrocq, V., Flamant, C., Chazette, P., and Girolamo, P.: Role of moisture patterns in the backbuilding formation of HyMeX IOP13 Heavy precipitation systems, Q. J. Roy. Meteor. Soc., 144, 291–303, https://doi.org/10.1002/qj.3201, 2018.
Dyson, L.: Heavy daily-rainfall characteristics over the Gauteng Province, Water SA, 35, https://doi.org/10.4314/wsa.v35i5.49188, 2009.
Emanuel, K. A.: Increasing destructiveness of tropical cyclones over the past 30 years, Nature, 436, 686–688, https://doi.org/10.1038/nature03906, 2005.
Fitchett, J. M. and Grab, S. W.: A 66-year tropical cyclone record for South-East Africa: temporal trends in a global context, Int. J. Climatol., 34, 3604–3615, https://doi.org/10.1002/joc.3932, 2014.
Gahtan, J., Knapp, K. R., Schreck, C. J., Diamond, H. J., Kossin, J. P., and Kruk, M. C.: International best track archive for climate stewardship (IBTrACS) project, Version 4r01, NOAA National Centers for Environmental Information, https://doi.org/10.25921/82ty-9e16, 2024.
Gal-Chen, T. and Somerville, R. C. J.: On the use of a coordinate transformation for the solution of the Navier-Stokes equations, J. Comput. Phys., 17, 209–228, https://doi.org/10.1016/0021-9991(75)90037-6, 1975.
Grodsky, S. A. and Carton, J. A.: The intertropical convergence zone in the south Atlantic and the Equatorial cold tongue, J. Climate, 16, 723–733, https://doi.org/10.1175/1520-0442(2003)016<0723:TICZIT>2.0.CO;2, 2003.
Hamuro, M., Kawata, Y, Matsuda, S., Matsuno, T., Nakamura, N., Tak, T., Takeda, T., and Yanai, M.: Precipitation bands of Typhoon Vera in 1959 (Part 1), J. Meteor. Soc. Jpn., 47, 298–308, https://doi.org/10.2151/jmsj1965.47.4_298, 1969.
Hastenrath, S. and Lamb, P.: On the dynamics and climatology of surface flow over the Equatorial ocean, Tellus, 30, 436–448, https://doi.org/10.1111/j.2153-3490.1978.tb00859.x, 1978.
Jiang, Q.: Moist dynamics and orographic precipitation, Tellus, 55A, 301–316, 2003.
Jolivet, S., Chane-Ming, F., Barbary, D., and Roux, F.: A numerical study of orographic forcing on TC Dina (2002) in South West Indian Ocean, Ann. Geophys., 31, 107–125, https://doi.org/10.5194/angeo-31-107-2013, 2013.
Kanada, S., Minda, H., Geng, B., and Takeda, T.: Rainfall enhancement of band-shaped convective cloud system in the downwind side of an isolated island, J. Meteor. Soc. Jpn., 78, 47–67, 2000.
Kantha, L.: Time to replace the Saffir-Simpson hurricane scale?, Eos, 87, 3–6, https://doi.org/10.1029/2006EO010003, 2006.
Khan, M. J. U., Durand, F., Afroosa, M., Coulet, P., Bertin, X., Mueller, V., Krien, Y., and Wainwright, C.: Tropical cyclone induced compound flooding in Madagascar: a coupled modeling approach, Nat. Hazards, 121, 11013–11050, https://doi.org/10.1007/s11069-025-07209-z, 2025.
Knapp, K. R., Kruk, M. C., Levinson, D. H., Diamond, H. J., and Neumann, C. J.: The international best track archive for climate stewardship (IBTrACS): Unifying tropical cyclone best track data, B. Am. Meteorol. Soc., 91, 363–376, https://doi.org/10.1175/2009BAMS2755.1, 2010.
Knutson, T. R., Sirutis, J. J., Vecchi, G. A., Farner, S., Zhao, M., Kim, H. S., Bender, M. Tuleya, R. E., Held, I. M., and Villarini, G.: Dynamical downscaling projections of twenty-first-century Atlantic hurricane activity: CMIP3 and CMIP5 model-based scenarios, J. Climate, 26, 6591–6617, https://doi.org/10.1175/JCLI-D-12-00539.1., 2013.
Kruk, M. C., Knapp, K. R., and Levinson, D. H.: A technique for merging global tropical cyclone best track data, J. Atmos. Ocean. Tech., 27, 680–692, https://doi.org/10.1175/2009JTECHA1267.1, 2010.
Lac, C., Chaboureau, J.-P., Masson, V., Pinty, J.-P., Tulet, P., Escobar, J., Leriche, M., Barthe, C., Aouizerats, B., Augros, C., Aumond, P., Auguste, F., Bechtold, P., Berthet, S., Bielli, S., Bosseur, F., Caumont, O., Cohard, J.-M., Colin, J., Couvreux, F., Cuxart, J., Delautier, G., Dauhut, T., Ducrocq, V., Filippi, J.-B., Gazen, D., Geoffroy, O., Gheusi, F., Honnert, R., Lafore, J.-P., Lebeaupin Brossier, C., Libois, Q., Lunet, T., Mari, C., Maric, T., Mascart, P., Mogé, M., Molinié, G., Nuissier, O., Pantillon, F., Peyrillé, P., Pergaud, J., Perraud, E., Pianezze, J., Redelsperger, J.-L., Ricard, D., Richard, E., Riette, S., Rodier, Q., Schoetter, R., Seyfried, L., Stein, J., Suhre, K., Taufour, M., Thouron, O., Turner, S., Verrelle, A., Vié, B., Visentin, F., Vionnet, V., and Wautelet, P.: Overview of the Meso-NH model version 5.4 and its applications, Geosci. Model Dev., 11, 1929–1969, https://doi.org/10.5194/gmd-11-1929-2018, 2018.
Lee, K. O., Uyeda, H., Shingo, S., and Lee, D. I.: Dual-Doppler radar analysis of the enhancement of a precipitation system on the northern side of Mt. Halla, Jeju Island, Korea on 6 July 2007, Atmos. Res., 118, 133–152, https://doi.org/10.1016/j.atmosres.2012.06.017, 2012.
Lee, K. O., Uyeda, H., and Lee, D. I.: Effect of an isolated elliptical terrain (Jeju Island) on rainfall enhancement in a moist environment, Tellus A, 66, 20484, https://doi.org/10.3402/tellusa.v66.20484, 2014.
Lee, K. O., Flamant, C., Ducrocq, V., Duffourg, F., Fourrié, N, Delanoë, J., and Bech, J.: Initiation and development of a mesoscale convective system in the Ebro River Balley and related heavy precipitation over northeastern Spain during HyMeX IOP15a, Q. J. Roy. Meteor. Soc., https://doi.org/10.1002/qj.2978, 2017.
Lee, K.-O., Flamant, C., Duffourg, F., Ducrocq, V., and Chaboureau, J.-P.: Impact of upstream moisture structure on a back-building convective precipitation system in south-eastern France during HyMeX IOP13, Atmos. Chem. Phys., 18, 16845–16862, https://doi.org/10.5194/acp-18-16845-2018, 2018.
Le Quotidien: Batsirai, 47 millions de pertes agricoles, https://www.lequotidien.re/article/actualites/2022/02/11/batsirai-47-millions-de-pertes-agricoles (last access: 31 March 2026), 2022.
Lin, Y.-L. and Crosby Savage III, L: Effects of landfall location and the approach angle of a cyclone vortex encountering a mesoscale mountain range, J. Atmos. Sci., 68, 2095–2106, https://doi.org/10.1175/2011JAS3720.1, 2011.
Lin, Y.-L., Ensley, D. B., Chiao, S., and Huang, C.-Y.: Orographic influences on rainfall and track deflection associated with the passage of a tropical cyclone, Mon. Weather Rev., 130, 2929–2950, 2002.
Lin, Y.-L., Chen, S. Y., Hill, C. M., and Huang, C.-Y.: Control parameters for the influence of a mesoscale mountain range on cyclone track continuity and deflection, J. Atmos. Sci., 62, 1849–1866, 2005.
Masson, V., Le Moigne, P., Martin, E., Faroux, S., Alias, A., Alkama, R., Belamari, S., Barbu, A., Boone, A., Bouyssel, F., Brousseau, P., Brun, E., Calvet, J.-C., Carrer, D., Decharme, B., Delire, C., Donier, S., Essaouini, K., Gibelin, A.-L., Giordani, H., Habets, F., Jidane, M., Kerdraon, G., Kourzeneva, E., Lafaysse, M., Lafont, S., Lebeaupin Brossier, C., Lemonsu, A., Mahfouf, J.-F., Marguinaud, P., Mokhtari, M., Morin, S., Pigeon, G., Salgado, R., Seity, Y., Taillefer, F., Tanguy, G., Tulet, P., Vincendon, B., Vionnet, V., and Voldoire, A.: The SURFEXv7.2 land and ocean surface platform for coupled or offline simulation of earth surface variables and fluxes, Geosci. Model Dev., 6, 929–960, https://doi.org/10.5194/gmd-6-929-2013, 2013.
Mlawer, E. J., Taubman, S. J., Brown, P. D., Iacono, M. J., and Clough, S. A.: Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave, J. Geophys. Res., 102, 16663–16682, 1997.
Mouche, A., Chapron, B., Knaff, J., Zhao, Y., Zhang, B., and Combot, C.: Copolarized and Cross‐Polarized SAR Measurements for High‐Resolution Description of Major Hurricane Wind Structures: Application to Irma Category 5 Hurricane, J. Geophys. Res.-Oceans, 124, 3905–3922, https://doi.org/10.1029/2019JC015056, 2019.
Neeham, H. F., Keim, B. D., and Sathiaraj, D.: A review of tropical cyclone-generated storm surges: global data sources, observations, and impacts, Rev. Geophys., 53, 545–591, https://doi.org/10.1002/2014rg000477, 2015.
OCHA: Southern Africa: cyclone season flash update no. 6 (Tropical Cyclone Batsirai) (7 February 2022), https://web.archive.org/web/20220214103935/https://floodlist.com/africa/madagascar-death-cyclone-batsirai-update-february-2022 (last access: 31 March 2026), 2022.
Parrish, J. R., Burpee, R. W., and Marks Jr., F. D.: Rainfall patterns observed by digitized radar during the landfall of Hurricane Frederic (1979), Mon. Weather Rev., 110, 1933–1944, https://doi.org/10.1175/1520-0493(1982)110<1933:RPOBDR>2.0.CO;2, 1982.
Pinty, J. P. and Jabouille, P.: A mixed-phased cloud parametrization for use in a mesoscale non-hydrostatic model: Simulations of a squall line and of orographic precipitation, in: Proc. Of the Conference on Cloud Physics, Amer. Meteorol. Soc, Boston, Everett, WA, USA, 17–21 August 1998, 217–220, http://mesonh.aero.obs-mip.fr/mesonh/dir_publication/pinty_jabouille_ams_ccp1998.pdf (last access: 28 August 2026), 1998.
Rakotoarimanana, Z. M. H., Rakotoarimanana, Z. H., Pandin, M. G. R., and Waloejo, C. S.: Analysis of tropical cyclones 2000–2020 in Madagascar, Disaster Adv., 15, 20 pp., https://doi.org/10.25303/1503da1320, 2022.
Romatschke, U., Medina, S., and Houze, R. A.: Regional, seasonal, and diurnal variations of extreme convection in the south Asian region, J. Climate, 23, 419–439, https://doi.org/10.1175/2009JCLI3140.1, 2010.
Roux, F., Chang-Min, F., Lasserre-Bigorry, A., and Nuissier, O.: Structure and evolution of intense tropical cyclone Dina near La Réunion on 22 January 2022: GB-EVTD analysis of single Doppler radar observations, J. Atmos. Ocean. Tech., 21, 1501–1518, https://doi.org/10.1175/1520-0426(2004)021<1501:SAEOIT>2.0.CO;2, 2004.
Tuleya, R. E. and Kurihara, Y.: A numerical simulation of the landfall of tropical cyclones, J. Atmos. Sci., 35, 242–257, 1978.
Wu, C.-C.: Numerical simulation of Typhoon Gladys (1994) and its interaction with Taiwan terrain using the GFDL hurricane model, Mon. Weather Rev., 129, 1533–1549, 2001.
Wu, C. C. and Kuo Y. H.: Typhoons affecting Taiwan: Current understanding and future challenges, B. Am. Meteorol. Soc., 80, 67–80, 1999.
Wu, C.-C., Yen, T.-H., Huang, Y.-H., Yu, C.-K., and Chen, S.-G.: Statistical characteristic of heavy rainfall associated with typhoons near Taiwan based on high-density automatic rain gauge data, B. Am. Meteorol. Soc., 97, 1363–1375, 2016.
Wu, Y.-C., Yang, M.-J., and Rogers, R. F.: Examining terrain effects on the evolution of precipitation and vorticity of typhoon Fanapi (2010) after departing the central mountain range of Taiwan, Mon. Weather Rev., https://doi.org/10.1175/MWR-D-21-0205.1, 2022.
Yeh, T. C. and Elsberry, R. L.: Interaction of typhoons with the Taiwan orography. Part I: Upstream track deflections, Mon. Weather Rev., 121, 3193–3212, 1993a.
Yeh, T. C. and Elsberry, R. L.: Interaction of typhoons with the Taiwan orography. Part II: Continuous and discontinuous tracks across the island, Mon. Weather Rev., 121, 3213–3233, 1993b.
Yu, C.-K. and Cheng, L.-W.: Distribution and mechanism of orographic precipitation associated with typhoon Morakot (2009), J. Atmos. Sci., 70, 2894–2915, 2014.
Short summary
Tropical cyclones forming in the southwest Indian Ocean frequently affect mountainous island nations. However, their role in modulating rainfall has not yet been thoroughly investigated. Using both observational data and a high-resolution numerical model, we aim to improve our understanding of the orographic effects of Madagascar and Réunion Island on approaching tropical cyclone (TC) track, intensity, and, ultimately, heavy rainfall using a representative case: TC Batsirai (2022).
Tropical cyclones forming in the southwest Indian Ocean frequently affect mountainous island...
Altmetrics
Final-revised paper
Preprint