Articles | Volume 2, issue 2
https://doi.org/10.5194/wcd-2-475-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wcd-2-475-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Jun 2021
Research article |
| 09 Jun 2021
| 09 Jun 2021
Atmospheric convergence zones stemming from large-scale mixing
Gabriel M. P. Perez
CORRESPONDING AUTHOR
Department of Meteorology, University of Reading, Reading, United Kingdom
Pier Luigi Vidale
Department of Meteorology, University of Reading, Reading, United Kingdom
National Centre for Atmospheric Science, Reading, United Kingdom
Nicholas P. Klingaman
Department of Meteorology, University of Reading, Reading, United Kingdom
National Centre for Atmospheric Science, Reading, United Kingdom
Thomas C. M. Martin
Department of Atmospheric Sciences, University of São Paulo, São Paulo, Brazil
Related authors
No articles found.
Malcolm J. Roberts, Kevin A. Reed, Qing Bao, Joseph J. Barsugli, Suzana J. Camargo, Louis-Philippe Caron, Ping Chang, Cheng-Ta Chen, Hannah M. Christensen, Gokhan Danabasoglu, Ivy Frenger, Neven S. Fučkar, Shabeh ul Hasson, Helene T. Hewitt, Huanping Huang, Daehyun Kim, Chihiro Kodama, Michael Lai, Lai-Yung Ruby Leung, Ryo Mizuta, Paulo Nobre, Pablo Ortega, Dominique Paquin, Christopher D. Roberts, Enrico Scoccimarro, Jon Seddon, Anne Marie Treguier, Chia-Ying Tu, Paul A. Ullrich, Pier Luigi Vidale, Michael F. Wehner, Colin M. Zarzycki, Bosong Zhang, Wei Zhang, and Ming Zhao
Geosci. Model Dev., 18, 1307–1332, https://doi.org/10.5194/gmd-18-1307-2025, https://doi.org/10.5194/gmd-18-1307-2025, 2025
Short summary
Short summary
HighResMIP2 is a model intercomparison project focusing on high-resolution global climate models, that is, those with grid spacings of 25 km or less in the atmosphere and ocean, using simulations of decades to a century in length. We are proposing an update of our simulation protocol to make the models more applicable to key questions for climate variability and hazard in present-day and future projections and to build links with other communities to provide more robust climate information.
Hans Segura, Xabier Pedruzo-Bagazgoitia, Philipp Weiss, Sebastian K. Müller, Thomas Rackow, Junhong Lee, Edgar Dolores-Tesillos, Imme Benedict, Matthias Aengenheyster, Razvan Aguridan, Gabriele Arduini, Alexander J. Baker, Jiawei Bao, Swantje Bastin, Eulàlia Baulenas, Tobias Becker, Sebastian Beyer, Hendryk Bockelmann, Nils Brüggemann, Lukas Brunner, Suvarchal K. Cheedela, Sushant Das, Jasper Denissen, Ian Dragaud, Piotr Dziekan, Madeleine Ekblom, Jan Frederik Engels, Monika Esch, Richard Forbes, Claudia Frauen, Lilli Freischem, Diego García-Maroto, Philipp Geier, Paul Gierz, Álvaro González-Cervera, Katherine Grayson, Matthew Griffith, Oliver Gutjahr, Helmuth Haak, Ioan Hadade, Kerstin Haslehner, Shabeh ul Hasson, Jan Hegewald, Lukas Kluft, Aleksei Koldunov, Nikolay Koldunov, Tobias Kölling, Shunya Koseki, Sergey Kosukhin, Josh Kousal, Peter Kuma, Arjun U. Kumar, Rumeng Li, Nicolas Maury, Maximilian Meindl, Sebastian Milinski, Kristian Mogensen, Bimochan Niraula, Jakub Nowak, Divya Sri Praturi, Ulrike Proske, Dian Putrasahan, René Redler, David Santuy, Domokos Sármány, Reiner Schnur, Patrick Scholz, Dmitry Sidorenko, Dorian Spät, Birgit Sützl, Daisuke Takasuka, Adrian Tompkins, Alejandro Uribe, Mirco Valentini, Menno Veerman, Aiko Voigt, Sarah Warnau, Fabian Wachsmann, Marta Wacławczyk, Nils Wedi, Karl-Hermann Wieners, Jonathan Wille, Marius Winkler, Yuting Wu, Florian Ziemen, Janos Zimmermann, Frida A.-M. Bender, Dragana Bojovic, Sandrine Bony, Simona Bordoni, Patrice Brehmer, Marcus Dengler, Emanuel Dutra, Saliou Faye, Erich Fischer, Chiel van Heerwaarden, Cathy Hohenegger, Heikki Järvinen, Markus Jochum, Thomas Jung, Johann H. Jungclaus, Noel S. Keenlyside, Daniel Klocke, Heike Konow, Martina Klose, Szymon Malinowski, Olivia Martius, Thorsten Mauritsen, Juan Pedro Mellado, Theresa Mieslinger, Elsa Mohino, Hanna Pawłowska, Karsten Peters-von Gehlen, Abdoulaye Sarré, Pajam Sobhani, Philip Stier, Lauri Tuppi, Pier Luigi Vidale, Irina Sandu, and Bjorn Stevens
EGUsphere, https://doi.org/10.5194/egusphere-2025-509, https://doi.org/10.5194/egusphere-2025-509, 2025
Short summary
Short summary
The nextGEMS project developed two Earth system models that resolve processes of the order of 10 km, giving more fidelity to the representation of local phenomena, globally. In its fourth cycle, nextGEMS performed simulations with coupled ocean, land, and atmosphere over the 2020–2049 period under the SSP3-7.0 scenario. Here, we provide an overview of nextGEMS, insights into the model development, and the realism of multi-decadal, kilometer-scale simulations.
Colin G. Jones, Fanny Adloff, Ben B. B. Booth, Peter M. Cox, Veronika Eyring, Pierre Friedlingstein, Katja Frieler, Helene T. Hewitt, Hazel A. Jeffery, Sylvie Joussaume, Torben Koenigk, Bryan N. Lawrence, Eleanor O'Rourke, Malcolm J. Roberts, Benjamin M. Sanderson, Roland Séférian, Samuel Somot, Pier Luigi Vidale, Detlef van Vuuren, Mario Acosta, Mats Bentsen, Raffaele Bernardello, Richard Betts, Ed Blockley, Julien Boé, Tom Bracegirdle, Pascale Braconnot, Victor Brovkin, Carlo Buontempo, Francisco Doblas-Reyes, Markus Donat, Italo Epicoco, Pete Falloon, Sandro Fiore, Thomas Frölicher, Neven S. Fučkar, Matthew J. Gidden, Helge F. Goessling, Rune Grand Graversen, Silvio Gualdi, José M. Gutiérrez, Tatiana Ilyina, Daniela Jacob, Chris D. Jones, Martin Juckes, Elizabeth Kendon, Erik Kjellström, Reto Knutti, Jason Lowe, Matthew Mizielinski, Paola Nassisi, Michael Obersteiner, Pierre Regnier, Romain Roehrig, David Salas y Mélia, Carl-Friedrich Schleussner, Michael Schulz, Enrico Scoccimarro, Laurent Terray, Hannes Thiemann, Richard A. Wood, Shuting Yang, and Sönke Zaehle
Earth Syst. Dynam., 15, 1319–1351, https://doi.org/10.5194/esd-15-1319-2024, https://doi.org/10.5194/esd-15-1319-2024, 2024
Short summary
Short summary
We propose a number of priority areas for the international climate research community to address over the coming decade. Advances in these areas will both increase our understanding of past and future Earth system change, including the societal and environmental impacts of this change, and deliver significantly improved scientific support to international climate policy, such as future IPCC assessments and the UNFCCC Global Stocktake.
Omar V. Müller, Patrick C. McGuire, Pier Luigi Vidale, and Ed Hawkins
Hydrol. Earth Syst. Sci., 28, 2179–2201, https://doi.org/10.5194/hess-28-2179-2024, https://doi.org/10.5194/hess-28-2179-2024, 2024
Short summary
Short summary
This work evaluates how rivers are projected to change in the near future compared to the recent past in the context of a warming world. We show that important rivers of the world will notably change their flows, mainly during peaks, exceeding the variations that rivers used to exhibit. Such large changes may produce more frequent floods, alter hydropower generation, and potentially affect the ocean's circulation.
Bjorn Stevens, Stefan Adami, Tariq Ali, Hartwig Anzt, Zafer Aslan, Sabine Attinger, Jaana Bäck, Johanna Baehr, Peter Bauer, Natacha Bernier, Bob Bishop, Hendryk Bockelmann, Sandrine Bony, Guy Brasseur, David N. Bresch, Sean Breyer, Gilbert Brunet, Pier Luigi Buttigieg, Junji Cao, Christelle Castet, Yafang Cheng, Ayantika Dey Choudhury, Deborah Coen, Susanne Crewell, Atish Dabholkar, Qing Dai, Francisco Doblas-Reyes, Dale Durran, Ayoub El Gaidi, Charlie Ewen, Eleftheria Exarchou, Veronika Eyring, Florencia Falkinhoff, David Farrell, Piers M. Forster, Ariane Frassoni, Claudia Frauen, Oliver Fuhrer, Shahzad Gani, Edwin Gerber, Debra Goldfarb, Jens Grieger, Nicolas Gruber, Wilco Hazeleger, Rolf Herken, Chris Hewitt, Torsten Hoefler, Huang-Hsiung Hsu, Daniela Jacob, Alexandra Jahn, Christian Jakob, Thomas Jung, Christopher Kadow, In-Sik Kang, Sarah Kang, Karthik Kashinath, Katharina Kleinen-von Königslöw, Daniel Klocke, Uta Kloenne, Milan Klöwer, Chihiro Kodama, Stefan Kollet, Tobias Kölling, Jenni Kontkanen, Steve Kopp, Michal Koran, Markku Kulmala, Hanna Lappalainen, Fakhria Latifi, Bryan Lawrence, June Yi Lee, Quentin Lejeun, Christian Lessig, Chao Li, Thomas Lippert, Jürg Luterbacher, Pekka Manninen, Jochem Marotzke, Satoshi Matsouoka, Charlotte Merchant, Peter Messmer, Gero Michel, Kristel Michielsen, Tomoki Miyakawa, Jens Müller, Ramsha Munir, Sandeep Narayanasetti, Ousmane Ndiaye, Carlos Nobre, Achim Oberg, Riko Oki, Tuba Özkan-Haller, Tim Palmer, Stan Posey, Andreas Prein, Odessa Primus, Mike Pritchard, Julie Pullen, Dian Putrasahan, Johannes Quaas, Krishnan Raghavan, Venkatachalam Ramaswamy, Markus Rapp, Florian Rauser, Markus Reichstein, Aromar Revi, Sonakshi Saluja, Masaki Satoh, Vera Schemann, Sebastian Schemm, Christina Schnadt Poberaj, Thomas Schulthess, Cath Senior, Jagadish Shukla, Manmeet Singh, Julia Slingo, Adam Sobel, Silvina Solman, Jenna Spitzer, Philip Stier, Thomas Stocker, Sarah Strock, Hang Su, Petteri Taalas, John Taylor, Susann Tegtmeier, Georg Teutsch, Adrian Tompkins, Uwe Ulbrich, Pier-Luigi Vidale, Chien-Ming Wu, Hao Xu, Najibullah Zaki, Laure Zanna, Tianjun Zhou, and Florian Ziemen
Earth Syst. Sci. Data, 16, 2113–2122, https://doi.org/10.5194/essd-16-2113-2024, https://doi.org/10.5194/essd-16-2113-2024, 2024
Short summary
Short summary
To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines is proposed as an international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.
Jon Seddon, Ag Stephens, Matthew S. Mizielinski, Pier Luigi Vidale, and Malcolm J. Roberts
Geosci. Model Dev., 16, 6689–6700, https://doi.org/10.5194/gmd-16-6689-2023, https://doi.org/10.5194/gmd-16-6689-2023, 2023
Short summary
Short summary
The PRIMAVERA project aimed to develop a new generation of advanced global climate models. The large volume of data generated was uploaded to a central analysis facility (CAF) and was analysed by 100 PRIMAVERA scientists there. We describe how the PRIMAVERA project used the CAF's facilities to enable users to analyse this large dataset. We believe that similar, multi-institute, big-data projects could also use a CAF to efficiently share, organise and analyse large volumes of data.
Rafaela Jane Delfino, Gerry Bagtasa, Kevin Hodges, and Pier Luigi Vidale
Nat. Hazards Earth Syst. Sci., 22, 3285–3307, https://doi.org/10.5194/nhess-22-3285-2022, https://doi.org/10.5194/nhess-22-3285-2022, 2022
Short summary
Short summary
We showed the effects of altering the choice of cumulus schemes, surface flux options, and spectral nudging with a high level of sensitivity to cumulus schemes in simulating an intense typhoon. We highlight the advantage of using an ensemble of cumulus parameterizations to take into account the uncertainty in simulating typhoons such as Haiyan in 2013. This study is useful in addressing the growing need to plan and prepare for as well as reduce the impacts of intense typhoons in the Philippines.
Rebecca J. Oliver, Lina M. Mercado, Doug B. Clark, Chris Huntingford, Christopher M. Taylor, Pier Luigi Vidale, Patrick C. McGuire, Markus Todt, Sonja Folwell, Valiyaveetil Shamsudheen Semeena, and Belinda E. Medlyn
Geosci. Model Dev., 15, 5567–5592, https://doi.org/10.5194/gmd-15-5567-2022, https://doi.org/10.5194/gmd-15-5567-2022, 2022
Short summary
Short summary
We introduce new representations of plant physiological processes into a land surface model. Including new biological understanding improves modelled carbon and water fluxes for the present in tropical and northern-latitude forests. Future climate simulations demonstrate the sensitivity of photosynthesis to temperature is important for modelling carbon cycle dynamics in a warming world. Accurate representation of these processes in models is necessary for robust predictions of climate change.
Ambrogio Volonté, Andrew G. Turner, Reinhard Schiemann, Pier Luigi Vidale, and Nicholas P. Klingaman
Weather Clim. Dynam., 3, 575–599, https://doi.org/10.5194/wcd-3-575-2022, https://doi.org/10.5194/wcd-3-575-2022, 2022
Short summary
Short summary
In this study we analyse the complex seasonal evolution of the East Asian summer monsoon. Using reanalysis data, we show the importance of the interaction between tropical and extratropical air masses converging at the monsoon front, particularly during its northward progression. The upper-level flow pattern (e.g. the westerly jet) controls the balance between the airstreams and thus the associated rainfall. This framework provides a basis for studies of extreme events and climate variability.
Eduardo Moreno-Chamarro, Louis-Philippe Caron, Saskia Loosveldt Tomas, Javier Vegas-Regidor, Oliver Gutjahr, Marie-Pierre Moine, Dian Putrasahan, Christopher D. Roberts, Malcolm J. Roberts, Retish Senan, Laurent Terray, Etienne Tourigny, and Pier Luigi Vidale
Geosci. Model Dev., 15, 269–289, https://doi.org/10.5194/gmd-15-269-2022, https://doi.org/10.5194/gmd-15-269-2022, 2022
Short summary
Short summary
Climate models do not fully reproduce observations: they show differences (biases) in regional temperature, precipitation, or cloud cover. Reducing model biases is important to increase our confidence in their ability to reproduce present and future climate changes. Model realism is set by its resolution: the finer it is, the more physical processes and interactions it can resolve. We here show that increasing resolution of up to ~ 25 km can help reduce model biases but not remove them entirely.
Mark R. Muetzelfeldt, Reinhard Schiemann, Andrew G. Turner, Nicholas P. Klingaman, Pier Luigi Vidale, and Malcolm J. Roberts
Hydrol. Earth Syst. Sci., 25, 6381–6405, https://doi.org/10.5194/hess-25-6381-2021, https://doi.org/10.5194/hess-25-6381-2021, 2021
Short summary
Short summary
Simulating East Asian Summer Monsoon (EASM) rainfall poses many challenges because of its multi-scale nature. We evaluate three setups of a 14 km global climate model against observations to see if they improve simulated rainfall. We do this over catchment basins of different sizes to estimate how model performance depends on spatial scale. Using explicit convection improves rainfall diurnal cycle, yet more model tuning is needed to improve mean and intensity biases in simulated summer rainfall.
Anna B. Harper, Karina E. Williams, Patrick C. McGuire, Maria Carolina Duran Rojas, Debbie Hemming, Anne Verhoef, Chris Huntingford, Lucy Rowland, Toby Marthews, Cleiton Breder Eller, Camilla Mathison, Rodolfo L. B. Nobrega, Nicola Gedney, Pier Luigi Vidale, Fred Otu-Larbi, Divya Pandey, Sebastien Garrigues, Azin Wright, Darren Slevin, Martin G. De Kauwe, Eleanor Blyth, Jonas Ardö, Andrew Black, Damien Bonal, Nina Buchmann, Benoit Burban, Kathrin Fuchs, Agnès de Grandcourt, Ivan Mammarella, Lutz Merbold, Leonardo Montagnani, Yann Nouvellon, Natalia Restrepo-Coupe, and Georg Wohlfahrt
Geosci. Model Dev., 14, 3269–3294, https://doi.org/10.5194/gmd-14-3269-2021, https://doi.org/10.5194/gmd-14-3269-2021, 2021
Short summary
Short summary
We evaluated 10 representations of soil moisture stress in the JULES land surface model against site observations of GPP and latent heat flux. Increasing the soil depth and plant access to deep soil moisture improved many aspects of the simulations, and we recommend these settings in future work using JULES. In addition, using soil matric potential presents the opportunity to include parameters specific to plant functional type to further improve modeled fluxes.
Liang Guo, Ruud J. van der Ent, Nicholas P. Klingaman, Marie-Estelle Demory, Pier Luigi Vidale, Andrew G. Turner, Claudia C. Stephan, and Amulya Chevuturi
Geosci. Model Dev., 13, 6011–6028, https://doi.org/10.5194/gmd-13-6011-2020, https://doi.org/10.5194/gmd-13-6011-2020, 2020
Short summary
Short summary
Precipitation over East Asia simulated in the Met Office Unified Model is compared with observations. Moisture sources of EA precipitation are traced using a moisture tracking model. Biases in moisture sources are linked to biases in precipitation. Using the tracking model, changes in moisture sources can be attributed to changes in SST, circulation and associated evaporation. This proves that the method used in this study is useful to identify the causes of biases in regional precipitation.
Yingxia Gao, Nicholas P. Klingaman, Charlotte A. DeMott, and Pang-Chi Hsu
Geosci. Model Dev., 13, 5191–5209, https://doi.org/10.5194/gmd-13-5191-2020, https://doi.org/10.5194/gmd-13-5191-2020, 2020
Short summary
Short summary
Both the air–sea coupling and ocean mean state affect the fidelity of simulated boreal summer intraseasonal oscillation (BSISO). To elucidate their relative effects on the simulated BSISO, a set of experiments was conducted using a superparameterized AGCM and its coupled version. Both air–sea coupling and cold ocean mean state improve the BSISO amplitude due to the suppression of the overestimated variance, while the former (latter) could further upgrade (degrade) the BSISO propagation.
Jack Giddings, Adrian J. Matthews, Nicholas P. Klingaman, Karen J. Heywood, Manoj Joshi, and Benjamin G. M. Webber
Weather Clim. Dynam., 1, 635–655, https://doi.org/10.5194/wcd-1-635-2020, https://doi.org/10.5194/wcd-1-635-2020, 2020
Short summary
Short summary
The impact of chlorophyll on the southwest monsoon is unknown. Here, seasonally varying chlorophyll in the Bay of Bengal was imposed in a general circulation model coupled to an ocean mixed layer model. The SST increases by 0.5 °C in response to chlorophyll forcing and shallow mixed layer depths in coastal regions during the inter-monsoon. Precipitation increases significantly to 3 mm d-1 across Myanmar during June and over northeast India and Bangladesh during October, decreasing model bias.
Cited articles
Allshouse, M. R. and Peacock, T.: Refining finite-time Lyapunov exponent ridges and the challenges of classifying them, Chaos, 25, 087410,
https://doi.org/10.1063/1.4928210, 2015. a
Alpert, L.: The intertropical convergence zone of the eastern Pacific region (I), B. Am. Meteorol. Soc., 26, 426–432, 1945. a
Ambrizzi, T. and Ferraz, S. E.: An objective criterion for determining the
South Atlantic Convergence Zone, Front. Environ. Sci., 3, 23, https://doi.org/10.3389/fenvs.2015.00023, 2015. a, b, c, d
Ambrizzi, T., Hoskins, B. J., and Hsu, H.-H.: Rossby wave propagation and
teleconnection patterns in the austral winter, J. Atmos. Sci., 52, 3661–3672, 1995. a
Aref, H.: Stirring by chaotic advection, J. Fluid Mech., 143, 1–21, 1984. a
Arraut, J. M., Nobre, C., Barbosa, H. M., Obregon, G., and Marengo, J.: Aerial rivers and lakes: looking at large-scale moisture transport and its relation to Amazonia and to subtropical rainfall in South America, J. Climate, 25, 543–556, 2012. a
Beron-Vera, F. J., Olascoaga, M. J., Brown, M. G., and Koçak, H.: Zonal
jets as meridional transport barriers in the subtropical and polar lower
stratosphere, J. Atmos. Sci., 69, 753–767, 2012. a
Berry, G. and Reeder, M. J.: Objective identification of the intertropical
convergence zone: Climatology and trends from the ERA-Interim, J. Climate, 27, 1894–1909, 2014. a
Bowman, K.: Manifold geometry and mixing in observed atmospheric flows, unpublished manuscript, Texas A & M University, Texas, 2000. a
CPTEC: Synoptic synthesis January 2020, available at:
https://s1.cptec.inpe.br/admingpt/tempo/pdf/sintese_mensal_012020 [Modo de Compatibilidade].pdf, last access: 2 October 2020. a
Cunningham, C., Alexander, C., and Cavalcanti, I. F. D. A.: Intraseasonal modes of variability affecting the South Atlantic Convergence Zone, Int. J. Climatol., 26, 1165–1180, 2006. a
Dacre, H. F., Clark, P. A., Martinez-Alvarado, O., Stringer, M. A., and Lavers, D. A.: How do atmospheric rivers form?, B. Am. Meteorol. Soc., 96, 1243–1255, 2015. a
Demory, M.-E., Vidale, P. L., Roberts, M. J., Berrisford, P., Strachan, J.,
Schiemann, R., and Mizielinski, M. S.: The role of horizontal resolution in
simulating drivers of the global hydrological cycle, Clim. Dynam., 42,
2201–2225, 2014. a
de Souza Custodio, M., Da Rocha, R. P., Ambrizzi, T., Vidale, P. L., and
Demory, M.-E.: Impact of increased horizontal resolution in coupled and
atmosphere-only models of the HadGEM1 family upon the climate patterns of
South America, Clim. Dynam., 48, 3341–3364, 2017. a
Dierckx, P.: Curve and surface fitting with splines, Oxford University Press,
Oxford, 1995. a
Dommenget, D. and Latif, M.: A cautionary note on the interpretation of EOFs,
J. Climate, 15, 216–225, 2002. a
d'Ovidio, F., Isern-Fontanet, J., López, C., Hernández-García,
E., and García-Ladona, E.: Comparison between Eulerian diagnostics and
finite-size Lyapunov exponents computed from altimetry in the Algerian basin,
Deep-Sea Res. Pt. I, 56, 15–31, 2009. a
ECMWF: Welcome to the Climate Data Store, available at: https://cds.climate.copernicus.eu/, last access: 4 June 2021. a
Farazmand, M., Blazevski, D., and Haller, G.: Shearless transport barriers in
unsteady two-dimensional flows and maps, Physica D, 278, 44–57, 2014. a
Fletcher, R. D.: The general circulation of the tropical and equatorial atmosphere, J. Meteorol., 2, 167–174, 1945. a
Fulton, J. and Hegerl, G.: Reliable Pattern Extraction For Climate Data, in: 9th International Workshop on Climate Informatics, Amphi Jean Jaurès, École Normale Supérieure, Paris, France, 2019. a
Garaboa-Paz, D., Eiras-Barca, J., Huhn, F., and Pérez-Muñuzuri, V.:
Lagrangian coherent structures along atmospheric rivers, Chaos, 25, 063105, https://doi.org/10.1063/1.4919768, 2015. a, b, c
Garaboa-Paz, D., Eiras-Barca, J., and Pérez-Muñuzuri, V.: Climatology of Lyapunov exponents: the link between atmospheric rivers and large-scale mixing variability, Earth Syst. Dynam., 8, 865–873, https://doi.org/10.5194/esd-8-865-2017, 2017. a, b, c
Grimm, A. M.: Madden–Julian Oscillation impacts on South American summer
monsoon season: precipitation anomalies, extreme events, teleconnections, and
role in the MJO cycle, Clim. Dynam., 53, 907–932, 2019. a
Guo, H., He, W., Peterka, T., Shen, H.-W., Collis, S. M., and Helmus, J. J.:
Finite-time lyapunov exponents and lagrangian coherent structures in uncertain unsteady flows, IEEE T. Visual. Comput. Graph., 22, 1672–1682, 2016. a
Haller, G.: A variational theory of hyperbolic Lagrangian coherent structures, Physica D, 240, 574–598, 2011. a
Haller, G.: Lagrangian coherent structures, Annu. Rev. Fluid Mech., 47, 137–162, 2015. a
Haller, G. and Beron-Vera, F. J.: Geodesic theory of transport barriers in
two-dimensional flows, Physica D, 241, 1680–1702, 2012. a
Haller, G. and Yuan, G.: Lagrangian coherent structures and mixing in
two-dimensional turbulence, Physica D, 147, 352–370, 2000. a
Hortal, M.: The development and testing of a new two-time-level semi-Lagrangian scheme (SETTLS) in the ECMWF forecast model, Q. J. Roy. Meteorol. Soc., 128, 1671–1687, 2002. a
Insel, N., Poulsen, C. J., and Ehlers, T. A.: Influence of the Andes Mountains on South American moisture transport, convection, and precipitation, Clim. Dynam., 35, 1477–1492, 2010. a
Jorgetti, T., da Silva Dias, P. L., and de Freitas, E. D.: The relationship
between South Atlantic SST and SACZ intensity and positioning, Clim. Dynam., 42, 3077–3086, 2014. a
Lanfredi, I. S. and De Camargo, R.: Classification of Extreme Cold Incursions
over South America, Weather Forecast., 33, 1183–1203, 2018. a
Lekien, F. and Ross, S. D.: The computation of finite-time Lyapunov exponents
on unstructured meshes and for non-Euclidean manifolds, Chaos, 20, 017505, https://doi.org/10.1063/1.3278516, 2010. a
Lenters, J. and Cook, K. H.: Summertime precipitation variability over South
America: Role of the large-scale circulation, Mon. Weather Rev., 127, 409–431, 1999. a
Liebmann, B., Kiladis, G. N., Vera, C. S., Saulo, A. C., and Carvalho, L. M.:
Subseasonal variations of rainfall in South America in the vicinity of the
low-level jet east of the Andes and comparison to those in the South Atlantic
convergence zone, J. Climate, 17, 3829–3842, 2004. a
Marengo, J., Liebmann, B., Grimm, A., Misra, V., d. Silva Dias, P. L.,
Cavalcanti, I. F. A., Carvalho, L. M. V., Berbery, E., Ambrizzi, T., Vera, C. S., Saulo, A. C., Nogues-Paegle, J., Zipser, E., Seth, A., and Alves, L. M.: Recent developments on the South American monsoon system, Int. J. Climatol., 32, 1–21, 2012. a, b
Mo, K. C. and Paegle, J. N.: The Pacific–South American modes and their
downstream effects, Int. J. Climatol., 21, 1211–1229, 2001. a
Monahan, A. H., Fyfe, J. C., Ambaum, M. H., Stephenson, D. B., and North, G. R.: Empirical orthogonal functions: The medium is the message, J. Climate, 22, 6501–6514, 2009. a
Montini, T. L., Jones, C., and Carvalho, L. M.: The South American low-level
jet: a new climatology, variability, and changes, J. Geophys. Res.-Atmos., 124, 1200–1218, 2019. a
Nieto, R. F. and Chao, W. C.: Aqua-planet simulations of the formation of the
South Atlantic convergence zone, Int. J. Climatol., 33, 615–628, 2013. a
Olascoaga, M. J., Rypina, I., Brown, M. G., Beron-Vera, F. J., Koçak, H.,
Brand, L. E., Halliwell, G., and Shay, L. K.: Persistent transport barrier on
the West Florida Shelf, Geophys. Res. Lett., 33, L22603, https://doi.org/10.1029/2006GL027800, 2006. a
Peikert, R. and Sadlo, F.: Height ridge computation and filtering for
visualization, in: 2008 IEEE Pacific Visualization Symposium, 5–7 March 2008, Kyoto, Japan, 119–126, 2008. a
Peikert, R., Günther, D., and Weinkauf, T.: Comment on “Second derivative
ridges are straight lines and the implications for computing Lagrangian
Coherent Structures, Physica D, 242, 65–66, 2013. a
Perez, G. and Martin, T.: LagrangianCoherence (Version v1.01), Zenodo, https://doi.org/10.5281/zenodo.4747229, 2021. a
Perez, G. M. and Silva Dias, M. A.: Long-term study of the occurrence and time of passage of sea breeze in São Paulo, 1960–2009, Int. J. Climatol., 37, 1210–1220, 2017. a
Pierrehumbert, R. T. and Yang, H.: Global chaotic mixing on isentropic
surfaces, J. Atmos. Sci., 50, 2462–2480, 1993. a
Poveda, G., Jaramillo, L., and Vallejo, L. F.: Seasonal precipitation patterns along pathways of South American low-level jets and aerial rivers, Water Resour. Res., 50, 98–118, 2014. a
Raupp, C. F. and Silva Dias, P. L.: Interaction of equatorial waves through
resonance with the diurnal cycle of tropical heating, Tellus A, 62, 706–718, 2010. a
Ruiz-Vasquez, M., Arias, P. A., Martínez, J. A., and Espinoza, J. C.:
Effects of Amazon basin deforestation on regional atmospheric circulation and
water vapor transport towards tropical South America, Clim. Dynam., 54, 4169–4189, https://doi.org/10.1007/s00382-020-05223-4, 2020. a
Rutherford, B., Dangelmayr, G., and Montgomery, M. T.: Lagrangian coherent
structures in tropical cyclone intensification, Tech. rep., NAVAL Postgraduate School, Dept. of Meteorology, Monterey, CA, 2011. a
Silva Dias, M. A., Vidale, P. L., and Blanco, C. M.: Case study and numerical
simulation of the summer regional circulation in São Paulo, Brazil,
Bound.-Lay. Meteorol., 74, 371–388, 1995. a
Sprenger, M. and Wernli, H.: The LAGRANTO Lagrangian analysis tool – version 2.0, Geosci. Model Dev., 8, 2569–2586, https://doi.org/10.5194/gmd-8-2569-2015, 2015. a
Trenberth, K. E.: Atmospheric moisture recycling: Role of advection and local
evaporation, J. Climate, 12, 1368–1381, 1999. a
Uvo, C. B., Repelli, C. A., Zebiak, S. E., and Kushnir, Y.: The relationships
between tropical Pacific and Atlantic SST and northeast Brazil monthly
precipitation, J. Climate, 11, 551–562, 1998. a
Vera, C., Baez, J., Douglas, M., Emmanuel, C., Marengo, J., Meitin, J.,
Nicolini, M., Nogues-Paegle, J., Paegle, J., Penalba, O., Salio, P., Saulo, C., Silva Dias, M. A., Silva Dias, P., and Zipser, E.: The South American low-level jet experiment, B. Am. Meteorol. Soc., 87, 63–78, 2006. a
Vera, C. S., Vigliarolo, P. K., and Berbery, E. H.: Cold season synoptic-scale waves over subtropical South America, Mon. Weather Rev., 130, 684–699, 2002. a
Vindel, J. M., Valenzuela, R. X., Navarro, A. A., and Polo, J.: Temporal and
spatial variability analysis of the solar radiation in a region affected by
the intertropical convergence zone, Meteorol. Appl., 27, e1824, https://doi.org/10.1002/met.1824, 2020. a
Welander, P.: Studies on the general development of motion in a
two-dimensional, ideal fluid, Tellus, 7, 141–156, 1955. a
Zemp, D. C., Schleussner, C.-F., Barbosa, H. M. J., van der Ent, R. J., Donges, J. F., Heinke, J., Sampaio, G., and Rammig, A.: On the importance of cascading moisture recycling in South America, Atmos. Chem. Phys., 14, 13337–13359, https://doi.org/10.5194/acp-14-13337-2014, 2014. a, b
Short summary
Much of the rainfall in tropical regions comes from organised cloud bands called convergence zones (CZs). These bands have hundreds of kilometers. In South America (SA), they cause intense rain for long periods of time. To study these systems, we need to define and identify them with computer code. We propose a definition of CZs based on the the pathways of air, selecting regions where air masses originated in separated regions meet. This method identifies important mechanisms of rain in SA.
Much of the rainfall in tropical regions comes from organised cloud bands called convergence...
