World’s Oceans Have Blue Skies Only 10% Of The Time

Blue skies smiling at me, nothing but blue skies do I see…. or so the famous song says.

It couldn’t be more wrong. Even worse we are all in danger if it become true, and there is a danger that could become so.

NASA’s Aqua Satellite

As series of new papers reveals data from NASA’s Aqua satellite, launched in Dec. 2011, showing that the Earth is a mostly cloudy place, there are almost never blue skies over the oceans. The oceans which cover 72% of the planet have clear skies just 10% of the time. Over land it’s a bit sunnier where clear skies prevail 33% of the time. Over some scant desert regions in mountain rain shadows like the high Atacama desert of Northern Chile, the Tibetan Plateau, and California’s Death Valley where clouds are dramatically missing and there are blue skies smiling at you most of the time.

Our blue planet’s cloudy nature is now unmistakably seen in the global cloud map, based on data collected by the Moderate Resolution Imaging Spectrometer (MODIS) on NASA’s Aqua satellite as well as a fleet of other satellites and data sources. MODIS has for a few years now collected data to generate a new global map of cloudiness every single day. The summary map in this new work shows an average of all of several satellite’s cloud observations between July 2002 and April 2015. Colors range from dark blue (no clouds) to light blue (some clouds) to white (frequent clouds).

Geoengineering More Clouds Shown To Be A Fallacious Idea

A consequence of these new observations is to reveal the folly in notions pitched by some institutions and researchers seeking a good feed at the climate change research trough. They have proposed costly research on their ‘geoengineering” schemes that would produce more clouds over already cloudy oceans (rising albedo) to reflect sunlight away and thus cool the planet. This hair-brained global warming mitigation notion is one that should have been relegated to the dust bin long ago as the naturally cloudy condition of this blue planet is already saturated.

The best means of helping to mitigate the impact of fossil fuel age CO2 on the planet is well in hand and is in fact ‘dust.” Here’s how dust in the wind may be the salvation of the planet.

Vast Swaths Of Sky Are Almost Always Cloudy

There are three broad bands where Earth’s skies are likely to be most cloudy: one band is a narrow strip near the equator and two wider strips are found to the north and south in mid-latitudes. The band near the equator is a function of the large-scale circulation patterns—or Hadley cells—present in the tropics. Hadley cells are defined by cool air sinking near the 30 degree latitude line north and south of the equator and warm air rising near the equator where winds from separate Hadley cells converge.

Global cloud cover 2011-2015

As warm, moist air converges at lower altitudes near the equator, it rises and cools and therefore can hold less moisture. This causes water vapor to condense into cloud particles and produces a dependable band of thunderstorms in an area known as the Inter Tropical Convergence Zone (ITCZ).

Clouds also tend to form in abundance in the middle latitudes 60 degrees north and south of the equator. This is where the edges of polar and mid-latitude (or Ferrel) circulation cells collide and push air upward, fueling the formation of the large-scale frontal systems that dominate weather patterns in the mid-latitudes.

In some of the less cloudy parts of the world, the influence of other physical processes are visible. For instance, the shape of the landscape can influence where clouds form. Mountain ranges force air currents upward, so rains tend to form on the windward (wind-facing) slopes of the mountain ranges. By the time the air has moved over the top of a range, there is little moisture left. This produces deserts on the lee side of mountains.

Examples of deserts caused by rain shadows that are visible in the map above are the Tibetan Plateau (north of the Himalayan Mountains) and Death Valley (east of the Sierra Nevada Range in California). A rain shadow caused by the Andes Mountains contributes to the dryness of the coastal Atacama Desert in South America as well, but several other factors relating to ocean currents and circulation patterns are important. While clouds tend to form where air rises as part of atmospheric circulation patterns, descending air inhibits cloud formation. Since air descends between about 15 and 30 degrees north and south of the equator, clouds are rare and deserts are common at this latitude.

Tragically our ocean skies are losing their vital cloudiness as ocean plankton that make those clouds are in cataclysmic decline.

NASA Earth Observations Cloud Fraction. Accessed May 7, 2015.
NCAR/UCAR Climate Data Guide Cloud Observations from MODIS. Accessed May 7, 2015.