[en] This article presents an evaluation and sensitivity analysis of km‐scale simulations of an unprecedented extreme rainfall event over Europe, with a specific focus on sub‐hourly extremes, size distributions, and kinetic energy (KE) of rain. These variables are critical for hydrological applications, such as flood forecasting or soil‐loss monitoring, but are rarely directly obtained from numerical weather prediction (NWP) models. The simulations presented here reproduce the overall characteristics of the event, but overestimate the extreme rain rates. The rain rate–KE relation was well‐captured, despite too large volume‐mean drop diameters. Amongst the sensitivities investigated, the representation of the raindrop self‐collection–breakup equilibrium and the raindrop size‐distribution shape were found to have the most profound impact on the rainfall characteristics. While extreme rain rates varied within 30%, the rain KE varied by a factor of four between the realistic perturbations to the microphysical assumptions. Changes to the aerosol concentration and rain terminal velocity relations were found to have a relatively smaller impact. Given the large uncertainties, a continued effort to improve the model physics will be indispensable to estimate rain intensities and KE reliably for direct hydrological applications.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Van Weverberg, K. ; Meteorological and Climatological Research Unit Royal Meteorological Institute of Belgium Brussels Belgium ; Atmospheric Processes and Parametrizations Met Office Exeter UK ; Department of Geography Ghent University Ghent Belgium
Ghilain, Nicolas ; Université de Liège - ULiège > Sphères ; Meteorological and Climatological Research Unit Royal Meteorological Institute of Belgium Brussels Belgium
Goudenhoofdt, E.; Meteorological and Climatological Research Unit Royal Meteorological Institute of Belgium Brussels Belgium
Barbier, M.; Department of Geography Ghent University Ghent Belgium
Koistinen, E.; Department of Geography Ghent University Ghent Belgium
Doutreloup, Sébastien ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie
Van Schaeybroeck, B.; Meteorological and Climatological Research Unit Royal Meteorological Institute of Belgium Brussels Belgium ; Department of Geography Ghent University Ghent Belgium
Frankl, A.; Department of Geography Ghent University Ghent Belgium
Field, P. ; Atmospheric Processes and Parametrizations Met Office Exeter UK ; Institute for Climate and Atmospheric Science University of Leeds Leeds UK
Language :
English
Title :
Sensitivity of simulated rain intensity and kinetic energy to aerosols and warm‐rain microphysics during the extreme event of July 2021 in Belgium
Publication date :
27 May 2024
Journal title :
Quarterly Journal of the Royal Meteorological Society
Abdul-Razzak, H. & Ghan, S.J. (2000) A parameterization of aerosol activation: 2. Multiple aerosol types. Journal of Geophysical Research: Atmospheres, 105, 6837–6844.
Abel, S.J. & Shipway, B.J. (2007) A comparison of cloud-resolving model simulations of trade wind cumulus with aircraft observations taken during rico. Quarterly Journal of the Royal Meteorological Society, 133, 781–794.
Angulo-Martínez, M., Beguería, S., Latorre, B. & Fernández-Raga, M. (2018) Comparison of precipitation measurements by ott parsivel2 and thies lpm optical disdrometers. Hydrology and Earth System Sciences, 22, 2811–2837.
Atlas, D. & Ulbrich, C.W. (1977) Path-and area-integrated rainfall measurement by microwave attenuation in the 1–3 cm band. Journal of Applied Meteorology and Climatology, 16, 1322–1331.
Bao, J. & Windmiller, J.M. (2021) Impact of microphysics on tropical precipitation extremes in a global storm-resolving model. Geophysical Research Letters, 48, e2021GL094206.
Barros, A.P., Prat, O.P., Shrestha, P., Testik, F.Y. & Bliven, L.F. (2008) Revisiting low and list (1982): evaluation of raindrop collision parameterizations using laboratory observations and modeling. Journal of the Atmospheric Sciences, 65, 2983–2993.
Beheng, K. (1994) A parameterization of warm cloud microphysical conversion processes. Atmospheric Research, 33, 193–206.
Bellouin, N., Rae, J., Jones, A., Johnson, C., Haywood, J. & Boucher, O. (2011) Aerosol forcing in the climate model intercomparison project (cmip5) simulations by hadgem2-es and the role of ammonium nitrate. Journal of Geophysical Research: Atmospheres, 116, D20206. https://doi.org/10.1029/2011JD016074
Bollinne, A., Florins, P., Hecq, P., Homerin, D., Renard, V. & Wolfs, J. (1984) Etude de l'energie des pluies en climat tempere oceanique d'europe atlantique. Zeitschrift für Geomorphologie, 49, 27–35.
Boutle, I., Eyre, J. & Lock, A. (2014) Seamless stratocumulus simulations across the turbulent gray zone. Monthly Weather Review, 142, 1655–1668.
Boutle, I., Finnenkoetter, A., Lock, A. & Wells, H. (2016) The london model: forecasting fog at 333 m resolution. Quarterly Journal of the Royal Meteorological Society, 142, 360–371.
Brandt, C.J. (1990) Simulation of the size distribution and erosivity of raindrops and throughfall drops. Earth Surface Processes and Landforms, 15, 687–698.
Brown, A., Milton, S., Cullen, M., Golding, B., Mitchell, J. & Shelly, A. (2012) Unified modeling and prediction of weather and climate: a 25-year journey. Bulletin of the American Meteorological Society, 93, 1865–1877.
Bush, M., Boutle, I., Edwards, J., Finnenkoetter, A., Franklin, C., Hanley, K. et al. (2023) The second met office unified model–jules regional atmosphere and land configuration, ral2. Geoscientific Model Development, 16, 1713–1734.
Bush, M., Flack, D., Arnold, A., Best, M., Bohnenstengel, S., Boutle, I. et al. (2023) Unifying mid-latitude and tropical regional model configurations: the third met office unified model-jules regional atmosphere and land configuration, RAL3. Quarterly Journal of the Royal Meteorological Society in preparation.
Cerro, C., Bech, J., Codina, B. & Lorente, J. (1998) Modeling rain erosivity using disdrometric techniques. Soil Science Society of America Journal, 62, 731–735.
Chen, B., Wang, J. & Gong, D. (2016) Raindrop size distribution in a midlatitude continental squall line measured by thies optical disdrometers over east china. Journal of Applied Meteorology and Climatology, 55, 621–634.
Chen, J.-P., Hsieh, T.-W., Lin, Y.-C. & Yu, C.-K. (2022) Accurate parameterization of precipitation particles' fall speeds for bulk cloud microphysics schemes. Atmospheric Research, 273, 106171.
Edwards, J. & Slingo, A. (1996) Studies with a flexible new radiation code. I: choosing a configuration for a large-scale model. Quarterly Journal of the Royal Meteorological Society, 122, 689–719.
Fan, J., Rosenfeld, D., Zhang, Y., Giangrande, S.E., Li, Z., Machado, L.A.T. et al. (2018) Substantial convection and precipitation enhancements by ultrafine aerosol particles. Science, 359, 411–418.
Fehlmann, M., Rohrer, M., von Lerber, A. & Stoffel, M. (2020) Automated precipitation monitoring with the thies disdrometer: biases and ways for improvement. Atmospheric Measurement Techniques, 13, 4683–4698.
Field, P.R., Hill, A., Shipway, B., Furtado, K., Wilkinson, J., Miltenberger, A. et al. (2023) Implementation of a double moment cloud microphysics scheme in the uk met office regional numerical weather prediction model. Quarterly Journal of the Royal Meteorological Society, 149, 703–739.
Fowler, H., Lenderink, G., Prein, A. & Westra, S. (2021) Anthropogenic intensification of short-duration rainfall extremes. Nature Reviews Earth and Environment, 2, 107–122.
Freeman, S.W., Igel, A.L. & van den Heever, S.C. (2019) Relative sensitivities of simulated rainfall to fixed shape parameters and collection efficiencies. Quarterly Journal of the Royal Meteorological Society, 145, 2181–2201.
Friedrich, K., Higgins, S., Masters, F.J. & Lopez, C.R. (2013) Articulating and stationary parsivel disdrometer measurements in conditions with strong winds and heavy rainfall. Journal of Atmospheric and Oceanic Technology, 30, 2063–2080.
Gatidis, C., Schleiss, M., Unal, C. & Russchenberg, H. (2020) A critical evaluation of the adequacy of the gamma model for representing raindrop size distributions. Journal of Atmospheric and Oceanic Technology, 37, 1765–1779.
Gordon, H., Field, P.R., Abel, S.J., Barrett, P., Bower, K., Crawford, I. et al. (2020) Development of aerosol activation in the double-moment unified model and evaluation with clarify measurements. Atmospheric Chemistry and Physics, 20, 10997–11024.
Gunn, R. & Kinzer, G.D. (1949) The terminal velocity of fall for water droplets in stagnant air. Journal of Atmospheric Sciences, 6, 243–248.
Gutiérrez, J.M., Maraun, D., Widmann, M., Huth, R., Hertig, E., Benestad, R. et al. (2019) An intercomparison of a large ensemble of statistical downscaling methods over europe: results from the value perfect predictor cross-validation experiment. International Journal of Climatology, 39, 3750–3785.
Hagelin, S., Son, J., Swinbank, R., McCabe, A., Roberts, N. & Tennant, W. (2017) The met office convective-scale ensemble, mogreps-uk. Quarterly Journal of the Royal Meteorological Society, 143, 2846–2861.
Hamilton, D.S., Lee, L.A., Pringle, K.J., Reddington, C.L., Spracklen, D.V. & Carslaw, K.S. (2014) Occurrence of pristine aerosol environments on a polluted planet. Proceedings of the National Academy of Sciences, 111, 18466–18471.
Journee, M., Goudenhoofdt, E., Vannitsem, S. & Delobbe, L. (2023) Quantitative rainfall analysis of the 2021 mid-July flood event in Belgium. Hydrology and Earth System Sciences, 27, 3169–3189.
Junger, L., Hohensinner, S., Schroll, K., Wagner, K. & Seher, W. (2022) Land use in flood-prone areas and its significance for flood risk management: a case study of alpine regions in Austria. Land, 11(3), 392. https://doi.org/10.3390/land11030392
Kain, J.S., Willington, S., Clark, A.J., Weiss, S.J., Weeks, M., Jirak, I.L. et al. (2017) Collaborative efforts between the united states and united kingdom to advance prediction of high-impact weather. Bulletin of the American Meteorological Society, 98, 937–948.
Keat, W.J., Stein, T.H.M., Phaduli, E., Landman, S., Becker, E., Bopape, M.-J.M. et al. (2019) Convective initiation and storm life cycles in convection-permitting simulations of the met office unified model over south africa. Quarterly Journal of the Royal Meteorological Society, 145, 1323–1336.
Khain, A.P., Beheng, K.D., Heymsfield, A., Korolev, A., Krichak, S.O., Levin, Z. et al. (2015) Representation of microphysical processes in cloud-resolving models: spectral (bin) microphysics versus bulk parameterization. Reviews of Geophysics, 53, 247–322.
Kumar, M., Sahu, A.P., Sahoo, N., Dash, S.S., Raul, S.K. & Panigrahi, B. (2022) Global-scale application of the rusle model: a comprehensive review. Hydrological Sciences Journal, 67, 806–830.
Lebo, Z.J., Morrison, H. & Seinfeld, J.H. (2012) Are simulated aerosol-induced effects on deep convective clouds strongly dependent on saturation adjustment? Atmospheric Chemistry and Physics, 12, 9941–9964.
Leone, A. & Pica, M. (1993) Caratteristiche dinamiche e simulazione delle piogge. Parte prima: Fondamenti teorici. Rivista di Ingegneria Agraria, 3, 167–175.
Liu, J. & Orville, H. (1969) Numerical modeling of precipitation and cloud shadow effects on mountain-induced cumuli. Journal of the Atmospheric Sciences, 26, 1283–1298.
Low, T.B. & List, R. (1982) Collision, coalescence and breakup of raindrops. Part i: experimentally established coalescence efficiencies and fragment size distributions in breakup. Journal of Atmospheric Sciences, 39, 1591–1606.
Luo, M., Liu, T., Meng, F., Duan, Y., Frankl, A., Bao, A. et al. (2018) Comparing bias correction methods used in downscaling precipitation and temperature from regional climate models: a case study from the kaidu river basin in western china. Water, 10(8), 1046. https://www.mdpi.com/2073-4441/10/8/1046
Manners, J., Edwards, J., Hill, P. & Thelen, J. (2018) Socrates (suite of community radiative transfer codes based on edwards and slingo), Tech. rep. UK: Met Office. https://code.metoffice.gov.uk/trac/socrates
Matthews, F., Panagos, P. & Verstraeten, G. (2022) Simulating event-scale rainfall erosivity across European climatic regions. Catena, 213, 106157.
Milbrandt, J.A. & McTaggart-Cowan, R. (2010) Sedimentation-induced errors in bulk microphysics schemes. Journal of the Atmospheric Sciences, 67, 3931–3948.
Milbrandt, J.A. & Yau, M.K. (2005) A multimoment bulk microphysics parameterization. Part i: analysis of the role of the spectral shape parameter. Journal of the Atmospheric Sciences, 62, 3051–3064.
Mohr, S., Ehret, U., Kunz, M., Ludwig, P., Caldas-Alvarez, A., Daniell, J.E. et al. (2023) A multi-disciplinary analysis of the exceptional flood event of july 2021 in central europe – part 1: event description and analysis. Natural Hazards and Earth System Sciences, 23, 525–551.
Morrison, H., van Lier-Walqui, M., Fridlind, A.M., Grabowski, W.W., Harrington, J.Y., Hoose, C. et al. (2020) Confronting the challenge of modeling cloud and precipitation microphysics. Journal of Advances in Modeling Earth Systems, 12, e2019MS001689.
Naumann, A.K. & Seifert, A. (2016) Evolution of the shape of the raindrop size distribution in simulated shallow cumulus. Journal of the Atmospheric Sciences, 73, 2279–2297.
Nissan, H. & Toumi, R. (2013) Dynamic simulation of rainfall kinetic energy flux in a cloud resolving model. Geophysical Research Letters, 40, 3331–3336.
Oektem, R., Romps, D.M. & Varble, A.C. (2023) No warm-phase invigoration of convection detected during goamazon. Journal of the Atmospheric Sciences, 80(10), 2345–2364.
Orr, A., Phillips, T., Webster, S., Elvidge, A., Weeks, M., Hosking, S. et al. (2014) Met office unified model high-resolution simulations of a strong wind event in antarctica. Quarterly Journal of the Royal Meteorological Society, 140, 2287–2297.
Prein, A., Rasmussen, R., Ikeda, K. & Liu, C. (2017) The future intensification of hourly precipitation extremes. Nature Climate Change, 7, 48–52.
Renard, K., Foster, G., Weesies, G., McCool, D. & Yoder, D. (1997) Predicting soil erosion by water: a guide to conservation planning with the revised universal soil loss equation RUSLE. US: Department of Agriculture.
Riechelmann, T., Noh, Y. & Raasch, S. (2012) A new method for large-eddy simulations of clouds with lagrangian droplets including the effects of turbulent collision. New Journal of Physics, 14, 065008.
Roberts, N.M. & Lean, H.W. (2008) Scale-selective verification of rainfall accumulations from high-resolution forecasts of convective events. Monthly Weather Review, 136, 78–97.
Rosenfeld, D. (1999) Trmm observed first direct evidence of smoke from forest fires inhibiting rainfall. Geophysical Research Letters, 26, 3105–3108.
Saleeby, S.M., Dolan, B., Bukowski, J., Valkenburg, K.V., van den Heever, S.C. & Rutledge, S.A. (2022) Assessing raindrop breakup parameterizations using disdrometer observations. Journal of the Atmospheric Sciences, 79, 2949–2963.
Salles, C., Poesen, J. & Sempere-Torres, D. (2002) Kinetic energy of rain and its functional relationship with intensity. Journal of Hydrology, 257, 256–270.
Seifert, A. (2005) On the shape-slope relation of drop size distributions in convective rain. Journal of Applied Meteorology, 44, 1146–1151.
Seifert, A. (2008) On the parameterization of evaporation of raindrops as simulated by a one-dimensional rainshaft model. Journal of the Atmospheric Sciences, 65, 3608–3619.
Seifert, A. & Beheng, K. (2006) A two-moment cloud microphysics parameterization for mixed-phase clouds. Part 1: model description. Meteorology and Atmospheric Physics, 92, 45–66.
Sougnez, A. (2010) Caractérisation des précipitations atmosphériques sur le campus universitaire du Sart Tilan, Liège. Utilisation'un disdromèt a lase. PhD thesis. Belgium: Université de Liège.
Tao, W.-K., Chen, J.-P., Li, Z., Wang, C. & Zhang, C. (2012) Impact of aerosols on convective clouds and precipitation. Reviews of Geophysics, 50, RG2001. https://doi.org.1029/2011RG000369
Thies. (2004) Laster precipitation monitor: instructions for use. Göttingn, Germany: Adolf Thies GmbH & Co.
Tilg, A.-M., Vejen, F., Hasager, C.B. & Nielsen, M. (2020) Rainfall kinetic energy in Denmark: relationship with drop size, wind speed, and rain rate. Journal of Hydrometeorology, 21, 1621–1637.
Tradowsky, J., Philip, S. & Kreienkamp, F. (2023) Attribution of the heavy rainfall events leading to severe flooding in western Europe during July 2021. Climatic Change, 176, 90.
Uijlenhoet, R. & Stricker, J. (1999) Dependence of rainfall interception on drop size-a comment. Journal of Hydrology, 217, 157–163.
Ullrich, S.L., Hegnauer, M., Nguyen, D.V., Merz, B., Kwadijk, J. & Vorogushyn, S. (2021) Comparative evaluation of two types of stochastic weather generators for synthetic precipitation in the rhine basin. Journal of Hydrology, 601, 126544.
Uplinger, W. (1981) A new formula for raindrop terminal velocity. Conference on radar meteorology, 20th, Boston, MA, 389-391.
Usón, A. & Ramos, M. (2001) An improved rainfall erosivity index obtained from experimental interrill soil losses in soils with a Mediterranean climate. Catena, 43, 293–305.
Vaittinada Ayar, P., Vrac, M., Bastin, S. & Carreau, J. (2016) Intercomparison of statistical and dynamical downscaling models under the euro- and med-cordex initiative framework: present climate evaluations. Climate Dynamics, 46, 1301–1329.
Van Weverberg, K. (2013) Impact of environmental instability on convective precipitation uncertainty associated with the nature of the rimed ice species in a bulk microphysics scheme. Monthly Weather Review, 141, 2841–2849.
Van Weverberg, K., Goudenhoofdt, E., Blahak, U., Brisson, E., Demuzere, M., Marbaix, P. et al. (2014) Comparison of one-moment and two-moment bulk microphysics for high-resolution climate simulations of intense precipitation. Atmospheric Research, 147-148, 145–161.
Van Weverberg, K. & Morcrette, C. (2022) Sensitivity of cloud-radiative effects to cloud fractin parametrizations in tropical, midlatitude, and arctic kilometre-scale simulations. Quarterly Journal of the Royal Meteorological Society, 148, 2563–2586.
Van Weverberg, K., Morcrette, C.J., Boutle, I., Furtado, K. & Field, P.R. (2021) A bimodal diagnostic cloud fraction parameterization. Part i: motivating analysis and scheme description. Monthly Weather Review, 149, 841–857.
Van Weverberg, K., Vogelmann, A.M., Morrison, H. & Milbrandt, J.A. (2012) Sensitivity of idealized squall-line simulations to the level of complexity used in two-moment bulk microphysics schemes. Monthly Weather Review, 140, 1883–1907.
Varble, A.C., Igel, A.L., Morrison, H., Grabowski, W.W. & Lebo, Z.J. (2023) Opinion: a critical evaluation of the evidence for aerosol invigoration of deep convection. EGUsphere, 2023, 1–31.
Verlinde, J. & Cotton, W.R. (1993) Fitting microphysical observations of nonsteady convective clouds to a numerical model: an application of the adjoint technique of data assimilation to a kinematic model. Monthly Weather Review, 121, 2776–2793.
Walters, D., Baran, A.J., Boutle, I., Brooks, M., Earnshaw, P., Edwards, J. et al. (2019) The met office unified model global atmosphere 7.0/7.1 and jules global land 7.0 configurations. Geoscientific Model Development, 12, 1909–1963.
Webster, S., Uddstrom, M., Oliver, H. & Vosper, S. (2008) A high-resolution modelling case study of a severe weather event over new zealand. Atmospheric Science Letters, 9, 119–128.
Williams, K.D., Copsey, D., Blockley, E.W., Bodas-Salcedo, A., Calvert, D., Comer, R. et al. (2018) The met office global coupled model 3.0 and 3.1 (gc3.0 and gc3.1) configurations. Journal of Advances in Modeling Earth Systems, 10, 357–380.
Yin, S., Nearing, M.A., Borrelli, P. & Xue, X. (2017) Rainfall erosivity: an overview of methodologies and applications. Vadose Zone Journal, 16, 1–16.
