Acceleration of tropical cyclogenesis by self-aggregation feedbacks.

Caroline J Muller, David M Romps
Author Information
  1. Caroline J Muller: Laboratoire de Météorologie Dynamique (LMD)/Institut Pierre Simon Laplace (IPSL), École Normale Supérieure, Paris Sciences & Lettres (PSL) Research University, Sorbonne Université, École Polytechnique, CNRS, F-75005 Paris, France; carolinemuller123@gmail.com. ORCID
  2. David M Romps: Department of Earth and Planetary Science, University of California, Berkeley, CA 94720.

Abstract

Idealized simulations of tropical moist convection have revealed that clouds can spontaneously clump together in a process called self-aggregation. This results in a state where a moist cloudy region with intense deep convection is surrounded by extremely dry subsiding air devoid of deep convection. Because of the idealized settings of the simulations where it was discovered, the relevance of self-aggregation to the real world is still debated. Here, we show that self-aggregation feedbacks play a leading-order role in the spontaneous genesis of tropical cyclones in cloud-resolving simulations. Those feedbacks accelerate the cyclogenesis process by a factor of 2, and the feedbacks contributing to the cyclone formation show qualitative and quantitative agreement with the self-aggregation process. Once the cyclone is formed, wind-induced surface heat exchange (WISHE) effects dominate, although we find that self-aggregation feedbacks have a small but nonnegligible contribution to the maintenance of the mature cyclone. Our results suggest that self-aggregation, and the framework developed for its study, can help shed more light into the physical processes leading to cyclogenesis and cyclone intensification. In particular, our results point out the importance of the longwave radiative cooling outside the cyclone.

Keywords

References

  1. Surv Geophys. 2017;38(6):1199-1236 [PMID: 31997841]

Word Cloud

Created with Highcharts 10.0.0self-aggregationtropicalcyclonefeedbacksconvectioncyclogenesissimulationsprocessresultsdeepmoistcanshowcyclonesintensificationIdealizedrevealedcloudsspontaneouslyclumptogethercalledstatecloudyregionintensesurroundedextremelydrysubsidingairdevoididealizedsettingsdiscoveredrelevancerealworldstilldebatedplayleading-orderrolespontaneousgenesiscloud-resolvingacceleratefactor2contributingformationqualitativequantitativeagreementformedwind-inducedsurfaceheatexchangeWISHEeffectsdominatealthoughfindsmallnonnegligiblecontributionmaintenancematuresuggestframeworkdevelopedstudyhelpshedlightphysicalprocessesleadingparticularpointimportancelongwaveradiativecoolingoutsideAccelerationconvectiveaggregation

Similar Articles

Cited By