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Firefly Grid Lines

Published by NOAA National Centers for Environmental Information | National Oceanic and Atmospheric Administration, Department of Commerce | Metadata Last Checked: December 19, 2025 | Last Modified: 2018-02-07T00:00:00.000+00:00
Layers of 1, 5, 10, and 20 degree latitude and longitude intervals are provided to establish an optional cartographic hierarchy for enhanced figure/ground presentation. Finer grid lines (1 degree interval) are given a thinner line weight. The courser grid lines (through 20 degree interval) are shown with thicker line weight. The stacking of these grid lines create an additive opacity effect so that the courser lines appear more boldly. This sort of nested mesh provides visual interest, a consistent referential framework as the map reader zooms in and out, and the ability to visually track and compare the relative location of features across ordinate lines. Grid lines have been clipped by their coincident location over land or ocean. This provides the cartographer an added level of stylistic freedom when choosing to show or hide and symbolize various graticule scales depending on the underlying feature.

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