2. Lower-Level Structure: Peak Intensity

ERA5 shows a compact and intense lower-level wind maximum near the storm center.

The strong wind signal is clearly visible at both 850 hPa and 925 hPa.

JRA-55 captures the broader cyclonic circulation, but the inner-core wind structure is smoother and less concentrated.

This suggests that ERA5 represents Hinnamnor’s peak-intensity structure more sharply than JRA-55.

The 850 hPa sequence shows how the lower-level circulation develops before and after peak intensity.

ERA5 shows a compact wind maximum around thestorm center throughout the peak period.

In JRA-55, the circulation appears broader and smoother, with weaker inner-core wind concentration.

The red boxes indicate the selected peak intensity time for detailed comparison.

At 925 hPa, ERA5 also shows a concentrated wind maximum near the storm center.

The strong lower-level signal remains visible before and after the peak time.

JRA-55 represents a weaker and more diffuse near-surface circulation.

This supports the interpretation that ERA5 captures the lower-level inner-core structure more clearly.

Overall Interpretation

At peak intensity, ERA5 captures a compact and intense lower-level inner-core structure around Typhoon Hinnamnor.

In contrast, JRA-55 represents the storm as a broader and smoother circulation with a weaker inner-core wind signal.

This suggests that ERA5 provides a sharper representation of the storm’s lower-level structure during its strongest phase.