Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

A New Method to Construct a Horizontal Resolution-Dependent Wind Speed Adjustment Factor for Tropical Cyclones in Global Climate Model Simulations

TitleA New Method to Construct a Horizontal Resolution-Dependent Wind Speed Adjustment Factor for Tropical Cyclones in Global Climate Model Simulations
Publication TypeJournal Article
Year of Publication2020
JournalGeophysical Research Letters
Volume47
Number11
Pagese2020GL087528
Abstract / Summary

A new method to construct a horizontal resolution‐dependent wind speed adjustment factor for evaluating tropical cyclones (TCs) in global climate models (GCMs) is presented. In contrast to the previous studies that used idealized axisymmetric wind fields, this study analyzes 48 hr of 10‐s surface wind fields from 1‐km TC simulations. The adjustment factor is derived from filtering the simulated TC wind fields onto various horizontal grid spacings typical of those used in GCMs. The new adjustment factor leads to TCs with greater intensity than the existing adjustment factors for horizontal grid spacings smaller than 30 km. This difference is attributed to more realistic wind fields in the TC simulations that contain highly asymmetric, localized patches of higher wind speeds instead of axisymmetric wind fields. Applying the new adjustment factor to select GCM simulations suggests the common interpretation of low‐intensity bias in GCM‐simulated TCs might be slightly exaggerated. 

URLhttps://doi.org/10.1029/2020GL087528
DOI10.1029/2020GL087528
Journal: Geophysical Research Letters
Year of Publication: 2020
Volume: 47
Number: 11
Pages: e2020GL087528
Publication Date: 06/2020

A new method to construct a horizontal resolution‐dependent wind speed adjustment factor for evaluating tropical cyclones (TCs) in global climate models (GCMs) is presented. In contrast to the previous studies that used idealized axisymmetric wind fields, this study analyzes 48 hr of 10‐s surface wind fields from 1‐km TC simulations. The adjustment factor is derived from filtering the simulated TC wind fields onto various horizontal grid spacings typical of those used in GCMs. The new adjustment factor leads to TCs with greater intensity than the existing adjustment factors for horizontal grid spacings smaller than 30 km. This difference is attributed to more realistic wind fields in the TC simulations that contain highly asymmetric, localized patches of higher wind speeds instead of axisymmetric wind fields. Applying the new adjustment factor to select GCM simulations suggests the common interpretation of low‐intensity bias in GCM‐simulated TCs might be slightly exaggerated. 

DOI: 10.1029/2020GL087528
Citation:
Moon, Y, D Kim, S Camargo, A Wing, KA Reed, MF Wehner, and M Zhao.  2020.  "A New Method to Construct a Horizontal Resolution-Dependent Wind Speed Adjustment Factor for Tropical Cyclones in Global Climate Model Simulations."  Geophysical Research Letters 47(11): e2020GL087528.  https://doi.org/10.1029/2020GL087528.