气候变化领域集成服务门户(CCPortal): One Step at a Time: How Model Time Step Significantly Affects Convection-Permitting Simulations

CCPortal

DOI	10.1029/2018MS001418
	One Step at a Time: How Model Time Step Significantly Affects Convection-Permitting Simulations
	Barrett A.I.; Wellmann C.; Seifert A.; Hoose C.; Vogel B.; Kunz M.
发表日期	2019
ISSN	19422466
起始页码	641
结束页码	658
卷号	11 期号:3
英文摘要	We show that there is a strong sensitivity of cloud microphysics to model time step in idealized convection-permitting simulations using the COnsortium for Small-scale MOdeling model. Specifically, we found a 53% reduction in precipitation when the time step is increased from 1 to 15 s, changes to the location of precipitation and hail reaching the surface, and changes to the vertical distribution of hydrometeors. The effect of cloud condensation nuclei perturbations on precipitation also changes both magnitude and sign with the changing model time step. The sensitivity arises because of the numerical implementation of processes in the model, specifically the so-called “splitting” of the dynamics (e.g., advection and diffusion) and the parameterized physics (e.g., microphysics scheme). Calculating one step at a time (sequential-update splitting) gives a significant time step dependence because large supersaturation with respect to liquid is generated in updraft regions, which strongly affect parameterized microphysical process rates—in particular, ice nucleation. In comparison, calculating both dynamics and microphysics using the same inputs of temperature and water vapor (hybrid parallel splitting) or adding an additional saturation adjustment within the dynamics reduces the time step sensitivity of surface precipitation by limiting the supersaturation seen by the microphysics, although sensitivity to time step remains for some processes. ©2019. The Authors.
英文关键词	convection permitting; microphysics; parallel splitting; physics-dynamics coupling; saturation adjustment; time step
语种	英语
scopus关键词	Dynamics; Supersaturation; Advection and diffusions; Cloud condensation nuclei; Dynamics coupling; Microphysics; Numerical implementation; Parallel splitting; Time step; Vertical distributions; Precipitation (meteorology); cloud microphysics; convective cloud; hail; hydrometry; permittivity; precipitation (climatology); supersaturation; time series analysis; vertical distribution; water vapor
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156946
作者单位	Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany; Deutscher Wetterdienst, Offenbach, Germany
推荐引用方式 GB/T 7714	Barrett A.I.,Wellmann C.,Seifert A.,et al. One Step at a Time: How Model Time Step Significantly Affects Convection-Permitting Simulations[J],2019,11(3).
APA	Barrett A.I.,Wellmann C.,Seifert A.,Hoose C.,Vogel B.,&Kunz M..(2019).One Step at a Time: How Model Time Step Significantly Affects Convection-Permitting Simulations.Journal of Advances in Modeling Earth Systems,11(3).
MLA	Barrett A.I.,et al."One Step at a Time: How Model Time Step Significantly Affects Convection-Permitting Simulations".Journal of Advances in Modeling Earth Systems 11.3(2019).