Improving Global Weather Prediction in GFDL SHiELD Through an Upgraded GFDL Cloud Microphysics Scheme

Geophysical Research Letters

Bretherton

et al. 2022

Self Cite

Intense convection, featuring large vertical motions and water phase changes, has profound consequences for many aspects of atmospheric and climate science. Intense convection is a major source of weather hazards due to its association with heavy rain, damaging winds, and large hail. Worldwide, the daily economic loss related to intense convection is about 108 million US dollars over the period 1970(WMO, 2021. In the context of climate, intense convection plays a critical role in Earth's energy balance, as intense convection modulates radiative balance through its effect on both the incoming solar radiation and the outgoing longwave radiation. Furthermore, intense convection modulates energy transfer dynamically and thermodynamically within the atmosphere.Previous global model studies (e.g., Diffenbaugh et al., 2013) argued that a warming climate is likely to enhance the frequency and intensity of intense convection. The argument, however, is based on the analysis of convective environmental proxies (e.g., low-level wind shear and convective available potential energy [CAPE]), rather than the simulation of the convection itself. This limitation arises because traditional climate models have too coarse a grid to simulate intense convection explicitly. Alternatively, high-resolution regional dynamical downscaling can simulate intense convection explicitly (e.g., Hoogewind et al., 2017). However, those regional studies cannot reveal the full global distribution of intense convection.

Section: Global Storm‐resolving Model X‐shield and Experiments Designmentioning

confidence: 99%

Impact of Warmer Sea Surface Temperature on the Global Pattern of Intense Convection: Insights From a Global Storm Resolving Model

Cheng

Geophysical Research Letters

Bretherton

et al. 2022

Self Cite

“…The model SHiELD and the GFDL MP are the same as Zhou, Harris, Chen, Gao, et al. (2022). The 13‐km horizontal resolution and 91 vertical levels follow Harris et al.…”

Section: Frameworkmentioning

confidence: 99%

“…In the relocation of cloud and precipitation processes, the time step is changed from physics time step to time step of vertical remapping, the thermodynamic relationships are revised to be consistent with the FV3 dynamical core, which conserves moist total energy, and the sedimentation of precipitating species is separated from other microphysical processes and conducted by a time‐implicit upwind advection scheme or alternatively FV3's Lagrangian vertical remapping. The cloud and precipitation processes are parameterized by the GFDL single‐moment five‐category cloud microphysics scheme (GFDL MP, Zhou et al., 2019; Harris et al., 2020; Zhou, Harris, and Chen, 2022; Zhou, Harris, Chen, Gao, et al., 2022) in SHiELD. We call it the in‐line GFDL MP (IMP) as it is in‐lined within the FV3 dynamical core.…”

Section: Frameworkmentioning

confidence: 99%

“…The source code of SHiELD is the same as that in Zhou, Harris, Chen, Gao, et al. (2022) and is available at https://doi.org/10.5281/zenodo.5800223. The ERA5 data on pressure levels can be obtained from https://doi.org/10.24381/cds.bd0915c6, while that on the single level can be obtained from https://doi.org/10.24381/cds.adbb2d47.…”

Section: Data Availability Statementmentioning

confidence: 99%

“…(2020), Zhou, Harris, Chen, Gao, et al. (2022), and references therein. Section 2 describes the proposed dynamics‐physics framework in detail.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Integrated Dynamics‐Physics Coupling for Weather to Climate Models: GFDL SHiELD With In‐Line Microphysics

Zhou

Geophysical Research Letters

2022

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Atmospheric models consist of two main parts: dynamical core and physical parameterizations. Traditionally, dynamical cores and physical parameterizations have been engineered in isolation for the sake of tractability (Donahue and Caldwell (2018); Gross et al. (2018), and references therein). These two independent components are coupled and advanced using the same time step, either parallel or sequentially split (Ubbiali et al., 2021). Ubbiali et al. (2021) analyzed six strategies of dynamics-physics coupling in atmospheric models. They emphasized that the coupling remained an open problem in atmospheric modeling and were conscious that significantly more effort is required to fully understand the implications for a full-fledged model. Gross et al. ( 2018) described many challenging aspects of dynamics-physics, including the time-stepping of different components, an incomplete understanding of the role of coupling, thermodynamic incompatibility between components, the extension to ocean and land coupling to the atmosphere, and more.Dynamics-physics coupling is complicated, mainly by the three following aspects.Standpoint 1: Dynamical and physical processes have different physical time scales, and the design of the dynamical core and dynamics-physics coupling should reflect this. Fast processes should be computed on a shorter time step and called more frequently, while slow processes should be computed on a longer time step and

A Global Survey of Rotating Convective Updrafts in the GFDL X-SHiELD 2021 Global Storm Resolving Model

Zhou

Kaltenbaugh³

et al. 2022

Preprint

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Thunderstorm updrafts are sometimes observed to rotate. This is well-understood in the context of severe weather in continental convection, especially over the contiguous United States (CONUS), for example, Kain et al. (2008). More recently the role of vortical hot towers (VHTs;Guimond et al., 2010;Hendricks et al., 2004) in tropical cyclone intensity changes has become better understood. But updraft rotation is typically studied in isolated events, and it has not been considered as a broadly distributed phenomenon. This is in part due to the lack of observations of rotating convection. Indeed, the frequency of strongly rotating updrafts-especially mesocyclones-even in the CONUS was poorly understood before the installation of a dense nationwide Doppler radar network, as seen through the increases in radar-detected tornadoes after 1990 (Verbout et al., 2006) and improved understanding that most mesocyclones are not associated with tornadoes (Trapp et al., 2005). The spatial distribution of rotating updrafts has been scarcely studied except as for its role in creating severe weather, specifically supercell thunderstorms, mesoscale convective systems (MCSs), and tornadoes. Rotation of sub-severe storms-those not meeting National Weather Service severe weather criteria-has apparently not been studied