Tropical cyclogenesis in warm climates simulated by a cloud-system resolving model
- 239 Downloads
Here we investigate tropical cyclogenesis in warm climates, focusing on the effect of reduced equator-to-pole temperature gradient relevant to past equable climates and, potentially, to future climate change. Using a cloud-system resolving model that explicitly represents moist convection, we conduct idealized experiments on a zonally periodic equatorial β-plane stretching from nearly pole-to-pole and covering roughly one-fifth of Earth’s circumference. To improve the representation of tropical cyclogenesis and mean climate at a horizontal resolution that would otherwise be too coarse for a cloud-system resolving model (15 km), we use the hypohydrostatic rescaling of the equations of motion, also called reduced acceleration in the vertical. The simulations simultaneously represent the Hadley circulation and the intertropical convergence zone, baroclinic waves in mid-latitudes, and a realistic distribution of tropical cyclones (TCs), all without use of a convective parameterization. Using this model, we study the dependence of TCs on the meridional sea surface temperature gradient. When this gradient is significantly reduced, we find a substantial increase in the number of TCs, including a several-fold increase in the strongest storms of Saffir–Simpson categories 4 and 5. This increase occurs as the mid-latitudes become a new active region of TC formation and growth. When the climate warms we also see convergence between the physical properties and genesis locations of tropical and warm-core extra-tropical cyclones. While end-members of these types of storms remain very distinct, a large distribution of cyclones forming in the subtropics and mid-latitudes share properties of the two.
KeywordsTropical cyclones Climate change Atmospheric modeling Paleoclimate
We thank two anonymous reviewers for their constructive comments on the paper. Financial support was provided by grants to AVF from the David and Lucile Packard Foundation, NSF (AGS-0163807), and NOAA (NA14OAR4310277). WRB was supported by Office of Naval Research award N000141512531. JS was supported by the Russian Foundation for Basic Research (grant #17-05-00509) and the Russian Science Foundation (grant #14-50-00095). Support from the Yale University Faculty of Arts and Sciences High Performance Computing facility is acknowledged.
- Blake ES, Kimberlain TB, Berg RJ, Cangialosi GP, Beven JL II (2013) Tropical cyclone report: Hurricane Sandy. National Hurricane Center Tech. Rep. AL182012, 22–29 October 2012. https://data.globalchange.gov/reference/13960922-e064-4be9-97cc-83572b69b666
- Browning GL, Kreiss H-O (1986) Scaling and computation of smooth atmospheric motions. Tellus A 38A:295–313. https://doi.org/10.1111/j.1600-0870.1986.tb00417.x CrossRefGoogle Scholar
- Carmichael MJ, Lunt DJ, Huber M, Heinemann M, Kiehl J, LeGrande A, Loptson CA, Roberts CD, Sagoo N, Shields C, Valdes PJ, Winguth A, Winguth C, Pancost RD (2016) A model-model and data-model comparison for the early Eocene hydrological cycle. Clim Past 12:455–481. https://doi.org/10.5194/cp-12-455-2016 CrossRefGoogle Scholar
- Chiang JCH, Friedman AR (2012) Extratropical cooling, interhemispheric thermal gradients, and tropical climate change. Annu Rev Earth Planet Sci 40:383–412. https://doi.org/10.1146/annurev-earth-042711-105545 CrossRefGoogle Scholar
- Emanuel KA (2013b) Response of downscaled tropical cyclones to climate forcing: results and interpretation. In: U.S. CLIVAR hurricane workshop. 2013, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, June 5–7Google Scholar
- Emanuel KA, Nolan D (2004) Tropical cyclone activity and the global climate system. In: 26th Conf. on hurricanes and tropical meteorology. American Meteor Society, 10A.2, Miami, FLGoogle Scholar
- Huang A, Li H, Sriver RL, Fedorov AV, Brierley CM (2017) Regional variations in the ocean response to tropical cyclones: ocean mixing versus low cloud suppression. Geophys Res Lett 44(4):1947–1955Google Scholar
- Kiehl JT, Shields CA, Khairoutdinov M (2012) Hurricanes during the Paleocene-Eocene thermal maximum. In: AGU fall meeting abstractsGoogle Scholar
- Knutson TR, Tuleya RE (2004) Impact of CO2-induced warming on simulated hurricane intensity and precipitation: sensitivity to the choice of climate model and convective parameterization. J Clim 17:3477–3495. https://doi.org/10.1175/1520-0442(2004)017<3477:IOCWOS>2.0.CO;2.
- MacDonald AE, Lee JL, Sun S (2000) QNH: design and test of a quasi-nonhydrostatic model for mesoscale weather prediction. Mon Weather Rev 128:1016–1036. https://doi.org/10.1175/1520-0493(2000)128<1016:QDATOA>2.0.CO;2 CrossRefGoogle Scholar
- Maue RN, Hart RE (2005) Warm-seclusion extratropical cyclone development: sensitivity to the nature of the incipient vortex. In: 21st conference on weather analysis and forecasting/17th conference on numerical weather prediction. Abstract P1.16Google Scholar
- Pauluis O (2004) Boundary layer dynamics and cross-equatorial Hadley circulation. J Atmos Sci 61:1161–1173. https://doi.org/10.1175/1520-0469(2004)061<1161:BLDACH>2.0.CO;2Google Scholar
- Xie S-P, Philander SGH (1994) A coupled ocean-atmosphere model of relevance to the ITCZ in the eastern Pacific. Tellus A 46:340–350. https://doi.org/10.1034/j.1600-0870.1994.t01-1-00001.x CrossRefGoogle Scholar