Kang et al. (2025) Modification of Similarity Relationships and Parameterization of Submesoscale Motions Under Spectral Regimes Over Uniform Flat Terrain

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2025
• Date: 2025-12-12
• Authors: P. Kang, Yan Ren, Hongsheng Zhang, Jiening Liang, Pengfei Tian, Xianjie Cao, Jiayun Li, Lei Zhang
• DOI: 10.1029/2025jd044580

Research Groups

The abstract does not explicitly list specific research groups, labs, or departments, but mentions "Horqin station" as the location for data collection.

Short Summary

This study investigates the impact of submesoscale motions and turbulence intermittency on flux estimation in the atmospheric boundary layer, identifying four distinct turbulence regimes. It establishes revised surface-layer similarity relationships by removing submesoscale motions and proposes an empirical parameterization for submesoscale wind speed standard deviations, significantly improving turbulence representation.

Objective

• To identify and characterize distinct turbulence regimes in the atmospheric boundary layer based on the impacts of submesoscale motions and turbulence intermittency.
• To establish revised surface-layer similarity relationships that account for submesoscale motions, particularly in regimes where they cause significant deviations from classical theory.
• To propose and validate an empirical parameterization linking dimensionless submesoscale wind speed standard deviations to the bulk Richardson number.

Study Configuration

• Spatial Scale: Local, point-based high-resolution atmospheric turbulence observations over relatively uniform flat terrain (Horqin station).
• Temporal Scale: Continuous high-resolution turbulence time series, analyzed spectrally to characterize different regimes and their impacts.

Methodology and Data

• Models used:
  • Spectral analysis for identifying turbulence regimes.
  • Hilbert-Huang transform-based separation for removing submesoscale motions.
  • Empirical parameterization relationship development.
• Data sources:
  • High-resolution atmospheric turbulence observations from Horqin station.
  • Five independent datasets used for validating the proposed empirical parameterization.

Main Results

• Four distinct turbulence regimes were identified through spectral analysis, each representing different impacts of submesoscale motions and turbulence intermittency.
• Regime 2, dominated by submesoscale motions leading to large-scale intermittency, was the most frequent, occurring in over 70% of observations.
• Marked differences were observed in turbulence time series characteristics and the performance of similarity relationships across the four regimes.
• Revised surface-layer similarity relationships were established for Regimes 2 and 4 by applying a Hilbert-Huang transform-based separation to remove submesoscale motions.
• In this filtered framework, countergradient transport was substantially reduced, and the new formulations demonstrated significant improvements with positive skill scores.
• An empirical parameterization relationship was proposed, linking the dimensionless submesoscale wind speed standard deviations to the bulk Richardson number, and validated for robustness and applicability using five independent datasets.

Contributions

• Provides a systematic identification and characterization of four distinct turbulence regimes in the atmospheric boundary layer, highlighting the pervasive influence of submesoscale motions and intermittency.
• Introduces a novel methodological approach using Hilbert-Huang transform for separating submesoscale motions, enabling the development of more accurate similarity relationships.
• Establishes revised surface-layer similarity relationships that significantly improve flux estimation by accounting for submesoscale effects, particularly reducing countergradient transport.
• Proposes and validates a robust empirical parameterization for submesoscale wind speed standard deviations, offering a practical tool for atmospheric modeling.
• Offers both methodological and theoretical foundations for enhancing the representation of boundary layer turbulence in high-resolution atmospheric models.

Funding

The abstract does not contain information regarding specific projects, programs, or reference codes that funded this research.

Citation

@article{Kang2025Modification,
  author = {Kang, P. and Ren, Yan and Zhang, Hongsheng and Liang, Jiening and Tian, Pengfei and Cao, Xianjie and Li, Jiayun and Zhang, Lei},
  title = {Modification of Similarity Relationships and Parameterization of Submesoscale Motions Under Spectral Regimes Over Uniform Flat Terrain},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2025},
  doi = {10.1029/2025jd044580},
  url = {https://doi.org/10.1029/2025jd044580}
}