SEVIRI RGBs:

Natural color RGB : used to interpret surface and atmospheric such as vegetated areas , cloud & ocean.

0.6 µm Vis; 0.8 µm NIR; 1.6 µm

Color scheme:

Low clouds are white

Vegetation is green

Deserts are reddish brown

Snow cover and high ice clouds are cyan

Air mass RGB: can monitor the evolution of cyclones, in particular rapid cyclogenesis, jet streak and PV anomalies; provides information mainly about the main and upper levels of the atmosphere.

Red: 6.2 µm WV – 7.3 µm WV BT difference

Green: 9.7 µm IR – 10.8 µm IR BT difference

Blue: 6.2 µm WV BT

Color scheme:

Ozone-poor tropical air masses are green

Ozone-rich polar air masses are blue

Dry air masses in the upper troposphere (such as those related to sub-tropical high pressure systems, PV anomalies, jet streaks, and deformation zones) are red to orange

High-level clouds are white

Mid-level clouds are brown

Magenta often appears at the edge of the full disk (due to limb darkening/cooling effect) and should be disregarded

Convection RGB: used to identify important microphysical trends in convection, such as small ice particles that mark intense updraft and are potential indicator of imminent severe weather.

Red:6.2 minus 7.3 µm WV BT difference

Green: 3.9 minus 10.8 µm IR BT difference

Blue: 1.6 minus 0.64 µm reflectance difference

Color scheme:

The background is dark blue and magenta

High-level, thick, ice clouds, including convective cumulonimbus clouds, appear red

Yellow is usually indicative of small ice particles within convective cloud tops, but may also be associated with elevated updrafts such as in high altitude orographic wave clouds

Dust RGB: used to monitor the evolution of dust clouds both day and night

Red: 12.0 minus 10.8 µm IR BT difference

Green: 10.8 minus 8.7 µm IR BT difference

Blue: 10.8 µm IR

Color scheme:

The color of dust varies, from red for very high-level dust (quite rare), to bright magenta for low-level dust during daytime, to dark magenta for low-level dust at night

Thick, high-level clouds are red

Thin, high-level clouds are dark blue or black, except in sandy areas where they may appear in shades of are green and yellow

Thick, middle-level clouds appear brown

Thin, middle-level clouds appear green

Low clouds appear pink when the atmosphere is warm and olive green when the atmosphere is cold

Moist low levels, particularly a moist boundary layer, appear in bluish shades

Land and water backgrounds appear in shades of green and blue

Volcanic Ash RGB: detect ash, sulfur dioxide, and ice crystal from volcanic eruptions, can be used to detect plumes for long distances downstream of an eruption.

Red: 12.0 minus 10.8 µm IR BT difference

Green: 10.8 minus 8.7 µm IR BT difference

Blue: 10.8 µm IR

Color scheme:

Sulphur dioxide cloud is aqua-green (lower and middle latitudes) and yellow (at higher latitudes and for larger viewing angles near the edge of the full Earth disk)

Depending on the height, temperature and particle size, ash goes from being bright red and pink (when it is very cold) to magenta (when it is warm) to yellow (when it is composed of very small ash particles)

Thin cirrus appears black or dark blue

High thick clouds and thunderstorms appear brown, with shades of orange and red for clouds composed of smaller ice particles

Middle and lower clouds may appear in lighter shades of brown, blue, and green (at higher latitudes and for larger viewing angles near the edge of the full Earth disk)

Blowing dust may appear as magenta

Moist low levels, particularly the boundary layer, appear in bluish shades

Surface features appear in lighter shades of blue, green, and dull magenta

Day Microphysics RGB: useful for cloud analysis, convection, low cloud, fog, snow and fires

Red: 0.8 µm NIR reflectance

Green: 3.9 µm SWIR (reflected solar component only) Blue: 10.8 µm IR

Color scheme:

The surface appears in shades of blue

Low clouds appear yellow to greenish (small droplets) to magenta (large droplets)

High ice clouds appear deep red (large ice particles) to bright orange (small ice particles)

Fog and low cloud RGB: Enables the detection of fog and low cloud at night when visible imagery is not available, can help classify clouds.

Color scheme:

Low clouds are yellow to light green

Thick, high clouds are red

Thin, high clouds are dark blue to black

Land and sea surfaces appear in various colors