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Tracking of known problems and subsequent fixes is an important issue for MODIS data users. This page will act as a repository of all known MODIS Atmosphere Data Product problems, as well as how to determine the problematic version (and the fixed version) of the HDF data -- therefore data users should check this page for updates regularly. Data Users unfamiliar with how to properly track problems and fixes by determining the version of their downloaded HDF files should refer to the documentation in the Introduction sublink (the top link along the LHS of this page).
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Note that a checkmark (✔) in the tables below means Data Issue or Quality Statement applies. A blank means it's been fixed or does not apply.
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<strong>Cloud Data Issues: Table of Contents & Anchor Links </strong>
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(Note: Anchor Links point to a specific place within this page.)
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<strong>Collection/Platform where Issues Apply</strong>
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<strong>Issue</strong>
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<strong>Impact</strong>
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<strong>C7.0/Terra</strong>
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<strong>C7.0/Aqua</strong>
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<a href="#Issue01">#1. High Cloud Fraction Infrared Error </a>
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✔
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✔
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<strong>Issue #1: High_Cloud_Fraction_Infrared Parameter Computation Error </strong>
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<img src="https://atmosphere-imager.gsfc.nasa.gov/sites/default/files/ModAtmo/Imp…" data-align="right" alt="Impact meter showing low levels" width="122" height="80"> <strong>Description:</strong> Due to a code bug in the L3 Pre-Yori code, the Parameter High_Cloud_Fraction_Infrared was computed incorrectly. This was inadvertantly set equal to the Cirrus_Fraction_Infrared parameter. This item was fixed in the Collection 7.0 L3 production code starting with L3 files produced after 17 Sept 2026 (Day 260).
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There is a workaround for users interested in this parameter to compute it "on the fly" from other parts of the L3 file. The recipe is
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Denominator = (Cirrus_Fraction_Infrared: Pixel_Counts) / (Cirrus_Fraction_Infrared: Mean)
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Numerator = Sum the first 4 bins of Cloud_Top_Pressure: Histogram_Counts
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High_Cloud_Fraction_Infrared = Numerator / Denominator
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<strong>Production Dates Affected:</strong> All C7.0 L3 files processed prior to 17 Sept 2026 (Day 260)
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<strong>Affected Platform: </strong>Aqua and Terra
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<strong>Collections Affected: </strong>Collection 7.0
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