NCL temp diff 18lev

Summary

NCL temp diff 18lev is a diverging colormap from ncar. Two arms meet at a pivot of lightness 1.00, hue sweeps 186° from blue to orange, and order holds under all three colorblind simulations.

NCAR standard temperature anomaly.

Perceptual profile (OKLCh)

• Lightness: 0.245 → 0.305 (range 0.754, min 0.245, max 0.998); non-monotonic; midpoint 0.998
• Chroma: min 0.001, max 0.218, mean 0.113
• Hue: 260.5° → 29.2° (span 186.2°), path folded; quadrants: blue, azure, red, orange
• Pivot: t 0.498, lightness 0.998, hue jump 154.9°, smoothness 0.575
• Endpoint temperature: cool → warm
• Perceptual ΔE: total 174.2, mean/step 0.683, max step 1.150, smoothness 0.747, speed 0.683

Colorblind safety (ΔE under simulated CVD)

• Protanopia: ΔE total 154.1; preserves order: yes
• Deuteranopia: ΔE total 155.8; preserves order: yes
• Tritanopia: ΔE total 175.2; preserves order: yes

Related

• Family: ncar
• Source: NCL/NCAR — UCAR (via hhuangwx/cmaps MIT wrapper)
• Similar diverging maps: NCL precip diff 12lev
• All colormaps