Environmental Influences on Deep Convective Upscale Growth Rate in Central Argentina From a Convection‐Permitting Simulation

Journal Article · Wed Dec 31 00:00:00 EST 2025 · Journal of Geophysical Research. Atmospheres

DOI:https://doi.org/10.1029/2025JD044251· OSTI ID:3011666

Sasaki, Clayton R. S. ^[1]; Rowe, Angela K. ^[2]; McMurdie, Lynn A. ^[1]; Varble, Adam C. ^[3]; Zhang, Zhixiao ^[4]

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1. Univ. of Washington, Seattle, WA (United States)
2. Univ. of Wisconsin, Madison, WI (United States)
3. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
4. Univ. of Oxford (United Kingdom)

This study uses a convection‐permitting model simulation to describe the environmental conditions under which convective upscale growth occurs in central Argentina, particularly examining environmental parameters when deep convection initially forms that could differentiate the rate of initial upscale growth. Simulated mesoscale convective systems (MCSs) are separated into slow and rapid growth by the rate of spatial growth from convection initiation until reaching the MCS scale. A low‐level jet (LLJ) is found more frequently near the deep convection that experiences rapid growth to an MCS, but its presence alone is not predictive of rapid growth. Using spatially‐averaged parameters, we find that rapid growth to MCSs also occurs in environments that are significantly more thermodynamically favorable with greater low‐level moisture and instability. Fewer significant differences are found in the kinematic environment with only the 0–2 km vertical wind shear magnitude being significantly larger for rapid growth MCSs compared to slow growth MCSs, potentially related to LLJs often peaking near this height. When focusing only on MCSs with the slowest and fastest growth rates, elevated‐layer shear is significantly smaller for very rapid growth MCSs, suggesting elevated‐layer shear may help discriminate between the upper and lower bounds of growth rate. Finally, when upscale growth occurs near the Sierras de Córdoba (SDC) with a LLJ present, rapid growth is also supported by favorable wind shear orientation. However, this does not hold for upscale growth occurring away from the SDC, highlighting the importance of interpreting shear direction relative to the orientation of features initiating deep convection.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Atmospheric Radiation Measurement (ARM) Data Center
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF); USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Contributing Organization: Argonne National Laboratory (ANL), Argonne, IL (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Grant/Contract Number: AC02-05CH11231; AC05-00OR22725; AC05-76RL01830
• OSTI ID: 3011666
• Journal Information: Journal of Geophysical Research. Atmospheres, Journal Name: Journal of Geophysical Research. Atmospheres Journal Issue: 1 Vol. 131; ISSN 2169-8996; ISSN 2169-897X
• Publisher: American Geophysical Union; Wiley
• Country of Publication: United States
• Language: English