Projects per year
Abstract
A cloud-resolving model (CRM) is used to investigate how a prototype tropical circulation driven by a sea surface temperature (SST) contrast changes in a warmer climate. The CRM is used to simulate a region of the atmosphere with a positive SST anomaly, and the large-scale circulation in this region is represented using the weak temperature gradient (WTG) and damped gravity wave (DGW) parameterizations, where the large-scale vertical velocity within the domain is related to the deviation of the simulated density profile from a reference profile representative of the tropical mean state. The behavior of the circulation in response to an increase in SST of both the domain and reference state (i.e., uniform warming) is examined. While the vertical velocity shows an increase in its maximum strength with warming, its value in the lower to midtroposphere decreases. Since the water vapor concentration is largest in the lower troposphere, this leads to a dynamic weakening of precipitation under warming. To understand these results, a simple model for the thermodynamic structure of a convecting atmosphere based on a bulk entraining plume is employed. The model uses a fixed entrainment rate and the relative humidity profiles from the CRM to predict the temperature profiles of the domain and reference state. The vertical velocity profiles calculated from these predicted temperature profiles reproduce important aspects of those simulated with the CRM. This simple modeling framework reveals that the effect of entrainment is crucial to understanding the dynamic response of precipitation to warming, providing a stepping stone to understanding the factors driving changes to the tropical precipitation distribution in a future warmer climate.
Original language | English |
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Pages (from-to) | 5855-5868 |
Number of pages | 14 |
Journal | Journal of Climate |
Volume | 35 |
Issue number | 18 |
DOIs | |
Publication status | Published - 15 Sept 2022 |
Keywords
- Atmospheric circulation
- Cloud resolving models
- Entrainment
- Large-scale motions
- Parameterization
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ARC Centre of Excellence for Climate Extremes
Pitman, A. J., Jakob, C., Alexander, L., Reeder, M., Roderick, M., England, M. H., Abramowitz, G., Abram, N., Arblaster, J., Bindoff, N. L., Dommenget, D., Evans, J. P., Hogg, A. M., Holbrook, N. J., Karoly, D. J., Lane, T. P., Sherwood, S. C., Strutton, P., Ebert, E., Hendon, H., Hirst, A. C., Marsland, S., Matear, R., Protat, A., Wang, Y., Wheeler, M. C., Best, M. J., Brody, S., Grabowski, W., Griffies, S., Gruber, N., Gupta, H., Hallberg, R., Hohenegger, C., Knutti, R., Meehl, G. A., Milton, S., de Noblet-Ducoudre, N., Or, D., Petch, J., Peters-Lidard, C., Overpeck, J., Russell, J., Santanello, J., Seneviratne, S. I., Stephens, G., Stevens, B., Stott, P. A. & Saunders, K.
Monash University – Internal University Contribution, Monash University – Internal School Contribution, Monash University – Internal Faculty Contribution, University of New South Wales (UNSW), Australian National University (ANU), University of Melbourne, University of Tasmania, Bureau of Meteorology (BOM) (Australia), Department of Planning and Environment (DPE) (New South Wales)
1/01/17 → 31/12/24
Project: Research
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The weather-climate connection in Australian climate change
Jakob, C., Singh, M. & Reeder, M.
1/10/20 → 30/06/24
Project: Research
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Intense thunderstorms in the tropics and subtropics under global warming
Australian Research Council (ARC)
1/06/19 → 31/12/22
Project: Research