Articles | Volume 18, issue 19
https://doi.org/10.5194/amt-18-5265-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-18-5265-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
10 Oct 2025
Research article |
| 10 Oct 2025
| 10 Oct 2025
Comparisons of polarimetric radio occultation measurements with WRF model simulation for tropical cyclones
Global Atmospheric Observation and Data Application Research Center, National Central University, Taoyuan City, Taiwan
Ying-Hwa Kuo
UCAR Community Programs, University Corporation for Atmospheric Research, Boulder, CO, USA
Hsiu-Wen Li
Global Atmospheric Observation and Data Application Research Center, National Central University, Taoyuan City, Taiwan
Ramon Padullés
Institute of Space Sciences (ICE-CSIC), Institute of Space Studies of Catalonia (IEEC), Barcelona, Spain
Estel Cardellach
Institute of Space Sciences (ICE-CSIC), Institute of Space Studies of Catalonia (IEEC), Barcelona, Spain
Francis Joseph Turk
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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This research examines the characteristics of low-level GNSS radio occultation (RO) refractivity bias over ocean and land and its dependency on the RO retrieval uncertainty, atmospheric temperature, and moisture. We propose methods for estimating the region-dependent refractivity bias. Our methods can be applied to calibrate the refractivity bias under different atmospheric conditions and thus improve the applications of the GNSS RO data in the deep troposphere.
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The results of comparing the polarimetric radio occultation observables and the ice water content retrieved from the CloudSat radar in a global and statistical way show a strong correlation between the geographical patterns of both quantities for a wide range of heights. This implies that horizontally oriented hydrometeors are systematically present through the whole globe and through all vertical levels, which could provide insights on the physical processes leading to precipitation.
Cited articles
Anthes, R. A.: Exploring Earth's atmosphere with radio occultation: contributions to weather, climate and space weather, Atmos. Meas. Tech., 4, 1077–1103, https://doi.org/10.5194/amt-4-1077-2011, 2011.
Barker, D., Huang, X.-Y., Liu, Z., Auligné, T., Zhang, X., Rugg, S., Ajjaji, R., Bourgeois, A., Bray, J., Chen, Y., Demirtas, M., Guo, Y.-R., Henderson, T., Huang, W., Lin, H.-C., Michalakes, J., Rizvi, S., and Zhang, X.: The weather research and forecasting model's community variational/ensemble data assimilation system: WRFDA, Bull. Amer. Meteor. Soc., 93, 831–843, https://doi.org/10.1175/BAMS-D-11-00167.1, 2012.
Bringi, V. N. and Chandrasekar, V.: Polarimetric Doppler weather radar: principles and applications, Cambridge University Press, https://doi.org/10.1017/CBO9780511541094, 2001.
Cardellach, E., Tomás, S., Oliveras, S., Padullés, R., Rius, A. de la Torre-Juárez, M., Turk, F. J., Ao, C. O., Kursinski, E. R., Schreiner, B., Ector, D., and Cucurull, L.: Sensitivity of PAZ LEO polarimetric GNSS radio-occultation experiment to precipitation events, IEEE Trans. Geosci. Remote. Sens., 53, 190–206, https://doi.org/10.1109/TGRS.2014.2320309, 2015.
Cardellach, E., Padullés, R., Tomás, S., Turk, F. J., Ao, C. O., and de la Torre-Juárez, M.: Probability of intense precipitation from polarimetric GNSS radio occultation observations, Quart. J. Roy. Meteor. Soc., 144, 206–220, https://doi.org/10.1002/qj.3161, 2018.
Cardellach, E., Oliveras, S., Rius, A., Tomás, S., Ao, C. O., Franklin, G. W., Iijima, B. A., Kuang, D., Meehan, T. K., Padullés, R., de la Torre-Juárez, M., Turk, F. J., Hunt, D. C., Schreiner, W. S., Sokolovskiy, S. V., Van Hove, T., Weiss, J. P., Yoon, Y., Zeng, Z., Clapp, J., Xia-Serafino, W., and Cerezo, F.: Sensing heavy precipitation with GNSS polarimetric radio occultations, Geophys. Res. Lett., 46, 1024–1031, https://doi.org/10.1029/2018GL080412, 2019.
Cardellach, E., Padullés, R., Turk, F. J., de la Torre-Juárez, M., Ao, C. O., Wang, K.-N., Kubar, T., Cucurull, L., Kuo, Y.-H., Braun, J., Murphy, M., Nguyen, V., Talpe, M., Kursinski, E. R., Brandmeyer, J., Aparicio, J. M., Chen, S.-Y., and Xie, F.: Roadmap towards full exploitation of the GNSS Polarimetric Radio Occultations. Outcome of the working group on Polarimetric Radio Occultations during the 2nd PAZ Workshop and IROWG-10, International Radio Occultation Working Group, https://doi.org/10.20350/digitalCSIC/16636, 2024.
Chang, C.-C. and Yang, S.-C.: Impact of assimilating Formosat-7/COSMIC-II GNSS radio occultation data on heavy rainfall prediction in Taiwan, Terr. Atmos. Ocean. Sci., 33, 7, https://doi.org/10.1007/s44195-022-00004-4, 2022.
Chang, W.-Y., Wang Chen, T.-C., and Lin, P.-L.: Characteristics of the Raindrop Size Distribution and Drop Shape Relation in Typhoon Systems in the Western Pacific from the 2D Video Disdrometer and NCU C-Band Polarimetric Radar, J. Atmos. Oceanic Tech., 26, 1973–1993, https://doi.org/10.1175/2009JTECHA1236.1, 2009.
Chen, S.-H. and Sun, W.-Y.: A one-dimensional time dependent cloud model, J. Meteorol. Soc. Japan. Ser. II, 80, 99–118, https://doi.org/10.2151/jmsj.80.99, 2002.
Chen, S.-Y., Kuo, Y.-H., and Huang, C.-Y.: The impact of GPS RO data on the prediction of tropical cyclogenesis using a nonlocal observation operator: An initial assessment, Mon. Wea. Rev., 148, 2701–2717, https://doi.org/10.1175/MWR-D-19-0286.1, 2020.
Chen, S.-Y., Shih, C.-P., Huang, C.-Y., and Teng, W.-H.: An impact study of GNSS RO data on the prediction of Typhoon Nepartak (2016) using a multiresolution global model with 3D-hybrid data assimilation, Wea. Forecasting, 36, 957–977, https://doi.org/10.1175/WAF-D-20-0175.1, 2021.
Cintineo, R., Otkin, J. A., Xue, M., and Kong, F.: Evaluating the performance of planetary boundary layer and cloud microphysical parameterization schemes in convection-permitting ensemble forecasts using synthetic GOES-13 satellite observations, Mon. Wea. Rev., 142, 163–182, https://doi.org/10.1175/MWR-D-13-00143.1, 2014.
Cucurull, L.: Recent impact of COSMIC-2 with improved radio occultation data assimilation algorithms, Wea. Forecasting, 38, 1829–1847, https://doi.org/10.1175/WAF-D-22-0186.1, 2023.
National Centers for Environmental Prediction, National Weather Service, NOAA, U.S. Department of Commerce (DOC/NOAA/NWS/NCEP): NCEP GDAS/FNL 0.25 Degree Global Tropospheric Analyses and Forecast Grids, updated daily, NSF National Center for Atmospheric Research [data set], https://doi.org/10.5065/D65Q4T4Z, 2015.
Ehrendorfer, M.: Predicting the uncertainty of numerical weather forecasts: A review, Meteor. Z., 6, 147–183, https://doi.org/10.1127/metz/6/1997/147, 1997.
Gleisner, H., Lauritsen, K. B., Nielsen, J. K., and Syndergaard, S.: Evaluation of the 15 year ROM SAF monthly mean GPS radio occultation climate data record, Atmos. Meas. Tech., 13, 3081–3098, https://doi.org/10.5194/amt-13-3081-2020, 2020.
Gleisner, H., Ringer, M. A., and Healy, S. B.: Monitoring global climate change using GNSS radio occultation, npj Clim. Atmos. Sci., 5, 6, https://doi.org/10.1038/s41612-022-00229-7, 2022.
Hernández, K. S., Gómez-Ríos, S., Henao, J. J., Robledo, V., Cardona, Á. R., and Rendón, A. M.: Rainfall Sensitivity to Microphysics and Planetary Boundary Layer Parameterizations in Convection-Permitting Simulations over Northwestern South America, J. Meteorol. Res., 38, 805–825, https://doi.org/10.1007/s13351-024-3156-4, 2024.
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J-N.: ERA5 hourly data on single levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.adbb2d47, 2023.
Ho, S.-P., Anthes, R. A., Ao, C. O., Healy, S., Horanyi, A., Hunt, D., Mannucci, A. J., Pedatella, N., Randel, W. J., Simmons, A., Steiner, A., Xie, F., Yue, X., and Zeng, Z.: The COSMIC/FORMOSAT-3 radio occultation mission after 12 years: Accomplishments, remaining challenges, and potential impacts of COSMIC-2, Bull. Amer. Meteor. Soc., 101, E1107–E1136, https://doi.org/10.1175/BAMS-D-18-0290.1, 2020.
Hong, S.-Y. and Lim, J.-O. J.: The WRF single-moment 6-class microphysics scheme (WSM6), Asia-Pacific J. Atmos. Sci., 42, 129–151, 2006.
Hong, S.-Y., Noh, Y., and Dudhia, J.: A new vertical diffusion package with an explicit treatment of entrainment processes, Mon. Wea. Rev., 134, 2318–2341, https://doi.org/10.1175/MWR3199.1, 2006.
Hong, T.-X., Huang, C.-Y., Lin, C.-Y., Lien, G.-Y., Huang, Z.-M., and Chen, S.-Y.: Impacts of GNSS RO Data on Typhoon Forecasts Using Global FV3GFS with GSI 4DEnVar, Atmosphere, 14, 735, https://doi.org/10.3390/atmos14040735, 2023.
Hristova-Veleva, S., Haddad, Z., Chau, A., Stiles, B. W., Turk, F. J., Li, P. P., Knosp, B., Vu, Q., Shen, T.-P., Lambrigtsen, B., Seo, E.-K., and Su, H.: Impact of microphysical parameterizations on simulated hurricanes – using multi-parameter satellite data to determine the particle size distributions that produce most realistic storms, Atmosphere, 12, 154, https://doi.org/10.3390/atmos12020154, 2021.
Iacono, M. J., Delamere, J. S., Mlawer, E. J., Shephard, M. W., Clough, S. A., and Collins, W. D.: Radiative forcing by long-lived greenhouse gases: Calculations with the AER radiative transfer models, J. Geophys. Res. Atmos., 113, https://doi.org/10.1029/2008JD009944, 2008.
Kain, J. S.: The Kain–Fritsch convective parameterization: an update, J. Appl. Meteorol., 43, 170–181, https://doi.org/10.1175/1520-0450(2004)043<0170:TKCPAU>2.0.CO;2, 2004.
Lien, G.-Y., Lin, C.-H., Huang, Z.-M., Teng, W.-H., Chen, J.-H., Lin, C.-C., Ho, H.-H., Huang, J.-Y., Hong, J.-S., Cheng, C.-P., and Huang, C.-Y.: Assimilation impact of early FORMOSAT-7/COSMIC-2 GNSS radio occultation data with Taiwan's CWB Global Forecast System, Mon. Wea. Rev., 149, 2171–2191, https://doi.org/10.1175/MWR-D-20-0267.1, 2021.
Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Chen, Y., Goldfarb, L., Gomis, M. I., Matthews, J. B. R., Berger, S., Huang, M., Yelekçi, O., Yu, R., Zhou, B., Lonnoy, E., Maycock, T. K., Waterfield, T., Leitzell, K., and Caud, N.: Climate change 2021: The physical science basis. Contribution of working group I to the sixth assessment report of the intergovernmental panel on climate change, https://doi.org/10.1017/9781009157896, 2021.
Morrison, H., Thompson, G., and Tatarskii, V.: Impact of cloud microphysics on the development of trailing stratiform precipitation in a simulated squall line: Comparison of one-and two-moment schemes, Mon. Wea. Rev., 137, 991–1007, https://doi.org/10.1175/2008MWR2556.1, 2009.
Murphy Jr., M. J., Haase, J. S., Padullés, R., Chen, S.-H., and Morris, M. A.: The potential for discriminating microphysical processes in numerical weather forecasts using airborne polarimetric radio occultations, Remote Sens., 11, 2268, https://doi.org/10.3390/rs11192268, 2019.
Padullés, R., Ao, C. O., Turk, F. J., de la Torre Juárez, M., Iijima, B., Wang, K. N., and Cardellach, E.: Calibration and validation of the Polarimetric Radio Occultation and Heavy Precipitation experiment aboard the PAZ satellite, Atmos. Meas. Tech., 13, 1299–1313, https://doi.org/10.5194/amt-13-1299-2020, 2020.
Padullés, R., Cardellach, E., Turk, F. J., Ao, C. O., de la Torre Juárez, M., Gong, J., and Wu, D. L.: Sensing horizontally oriented frozen particles with polarimetric radio occultations aboard PAZ: Validation using GMI coincident observations and Cloudsat a priori information, IEEE Trans. Geosci. Remote. Sens., 60, 1–13, https://doi.org/10.1109/TGRS.2021.3065119, 2022.
Padullés, R., Cardellach, E., Paz, A., Oliveras, S., Hunt, D. C., Sokolovskiy, S., Weiss, J.-P., Wang, K.-N., Turk, F. J., Ao, C. O., and de la Torre Juárez, M.: The PAZ polarimetric radio occultation research dataset for scientific applications, Earth Syst. Sci. Data, 16, 5643–5663, https://doi.org/10.5194/essd-16-5643-2024, 2024.
Ruston, B. and Healy, S.: Forecast impact of FORMOSAT-7/COSMIC-2 GNSS radio occultation measurements, Atmos. Sci. Lett., 22, e1019, https://doi.org/10.1002/asl.1019, 2021.
Skamarock, W. C., Klemp, J. B., Dudhia, J., Gill, D. O., Liu, Z., Berner, J., Wang, W., Powers, J. G., Duda, M. G., Barker, D. M., and Huang, X.-Y.: A Description of the Advanced Research WRF Model Version 4.3 (No. NCAR/TN-556+STR) [code], https://doi.org/10.5065/1dfh-6p97, 2021.
Tabari, H.: Climate change impact on flood and extreme precipitation increases with water availability, Sci. Rep., 10, 13768, https://doi.org/10.1038/s41598-020-70816-2, 2020.
Talpe, M. J., Nguyen, V. A., and Tomás-Martínez, S.: Initial Polarimetric Radio Occultation Results from Spire's Nanosatellite Constellation: Satellite Payload, Collection and Calibration, Bull. Amer. Meteor. Soc., 106, E714–734, https://doi.org/10.1175/BAMS-D-23-0314.1, 2025.
Tao, W.-K., Simpson, J., and McCumber, M.: An ice-water saturation adjustment, Mon. Wea. Rev., 117, 231–235, https://doi.org/10.1175/1520-0493(1989)117<0231:AIWSA>2.0.CO;2, 1989.
Tao, W.-K., Wu, D., Lang, S., Chern, J.-D., Peters-Lidard, C., Fridlind, A., and Matsui, T.: High-resolution NU-WRF simulations of a deep convective-precipitation system during MC3E: Further improvements and comparisons between Goddard microphysics schemes and observations, J. Geophys. Res. Atmos., 121, 1278–1305, https://doi.org/10.1002/2015JD023986, 2016.
Thompson, G., Field, P. R., Rasmussen, R. M., and Hall, W. D.: Explicit forecasts of winter precipitation using an improved bulk microphysics scheme. Part II: Implementation of a new snow parameterization, Mon. Wea. Rev., 136, 5095–5115, https://doi.org/10.1175/2008MWR2387.1, 2008.
Turk, F. J., Cardellach, E., de la Torre-Juárez, M., Padullés, R., Wang, K.-N., Ao, C. O., Kubar, T., Murphy, M. J., Neelin, J. D., Emmenegger, T., Wu, D., Nguyen, V., Kursinski, E. R., Masters, D., Kirstetter, P., Cucurull, L., and Lonitz, K.: Advances in the Use of Global Navigation Satellite System Polarimetric Radio Occultation Measurements for NWP and Weather Applications, Bull. Amer. Meteor. Soc., 105, E905–E914, https://doi.org/10.1175/BAMS-D-24-0050.1, 2024.
Short summary
This study used Polarimetric radio occultation (PRO) observations to evaluate simulations of cloud hydrometeors with five microphysics schemes for three typhoons from 2019 and 2021. The simulated cloud hydrometeors distributions varied significantly depending on model initial conditions, typhoon structures, and microphysics schemes. Results in this study demonstrate the potential for using PRO observation to evaluate the performance of different microphysics schemes in numerical models.
This study used Polarimetric radio occultation (PRO) observations to evaluate simulations of...
