5 surprising things weather satellites can show beyond clouds

A weather-satellite image can contain much more than a cloud forecast. Dust crosses water, smoke stretches away from a fire, and snow changes the shape of a landscape. Different sensors and processing methods bring different features into view.

The key is to ask what the image actually measures. NOAA's Advanced Baseline Imager, or ABI, observes multiple visible and infrared bands. A colored product can combine those measurements to emphasize a feature. Its colors do not necessarily reproduce what a person looking out of a spacecraft window would see. Source: NOAA's ABI overview.

1. Airborne dust can leave a colored fingerprint

Dust can be difficult to distinguish from its background in a single band. NOAA's Dust RGB combines infrared information to help separate airborne dust from clouds and the surface. In the product's legend, some daytime dust appears pink or magenta. Those are assigned display colors, not pink particles drifting through the sky. Source: NOAA's Dust RGB quick guide.

Why it matters: the product helps a reader follow the extent and movement of a plume. Keep in mind: colors depend on conditions, and thin dust can be subtle. Consult the exact product legend; a color rule from one composite may be wrong for another.

2. Volcanic ash can be separated from an ordinary cloudy scene

NOAA's volcanic-ash product uses several ABI infrared channels to identify pixels that may contain ash and estimate properties such as cloud height and mass loading. Those derived properties go beyond simply noticing that something spread away from a volcano. Source: NOAA's GOES-R data-products guide.

Why it matters: ash information supports specialist assessment of a hazard to aviation and surrounding communities. Keep in mind: an algorithmic estimate is not a sample taken inside the plume. Some non-volcanic dust can also be flagged. NOAA's technical explanation notes the challenges of validating ash clouds and the role of background conditions. This article is an image-reading introduction, not aviation or emergency guidance. Source: NOAA's ash algorithm overview.

3. A fire hotspot can stand out before you can pick out its smoke

Infrared observations can reveal unusually hot areas. ABI's shortwave infrared band is useful for viewing fire hotspots, while a Fire Temperature RGB combines bands to make hot features easier to distinguish. NOAA has published examples that overlay this product on a broader scene. Source: ABI band 7 quick guide; NOAA's 2017 Detwiler Fire example.

Why it matters: heat and smoke answer different questions about an event. Keep in mind: a displayed hotspot is not a photograph of individual flames or a map of the entire burned area. The pixel, sensor and processing determine what the product can represent.

4. Smoke shows where the plume goes, not just where the fire burns

Daytime visible imagery can show smoke through the way its particles scatter sunlight. NOAA's fire examples distinguish the smoke plume from the hot source, and combine products to display both together. In a sequence, that separation makes the plume's movement easier to follow. Source: NOAA's explanation of smoke and fire observations.

Why it matters: a fire's visible effect can extend well beyond its source. Keep in mind: a daytime image of smoke aloft is not a direct measurement of what a person is breathing at ground level. Cloud cover, lighting and the choice of product also affect visibility. Use appropriate air-quality observations for exposure questions.

5. Snow and ice can change the map beneath the weather

Visible and near-infrared observations help distinguish snow and ice from other surfaces. ABI includes a near-infrared band commonly called the Snow/Ice band. NOAA's broader snow-and-ice analysis combines available information rather than assuming one clear image is always enough. Source: ABI spectral attributes; NOAA's snow-and-ice analysis overview.

Why it matters: the boundary between covered and uncovered ground is useful environmental context. Keep in mind: clouds can hide that boundary. A snow-covered area on a map does not by itself tell you the snow's depth, the strength of lake ice or whether a surface is safe to cross.

Read the label before reading the colors

• Find the satellite and instrument.
• Check the observation time and time zone, rather than the time you downloaded the image.
• Identify the band, RGB composite or derived product.
• Read its legend and note missing or obscured areas.
• Separate what the product shows from the conclusion you want to draw.

For more on viewing regions and ABI observations, continue with LaunchDetect Academy's ABI lesson. To explore launch observations, use the LaunchDetect archive and inspect the evidence supplied with a record. The NOAA capabilities described here do not establish that LaunchDetect detects or classifies all five phenomena.