The Earth Story

Aerosol Earth

Many people already know a bit about aerosols in the sense that they come from aerosol cans such as deodorants and bugs sprays. However, the true meaning of "aerosol" is any liquid or solid substance in the form of extremely fine particles so small that they may be mistaken as a gas. Few realize that these aerosols are ever present all across the globe. Each breath we take is contains millions solids and liquids ranging in size from nanometers to micrometers.

The image shown above is a result of model that uses mathematical equations to model physical processes or quantities. Inputs for the model come from various satellites and sensors placed on the globe itself. NASA’s Goddard Earth Observing System Forward Processing (GEOS FP) model output for aerosols for August 23rd, 2018 is highlighted in the above image.

Upon observation, trails of smoke from forest fires and other sources can be seen along with a number of tropical cyclones and sandstorms. As one would expect, these events kick up quite a bit of particles and droplets.

-♞Ren T

Image Credit:

https://go.nasa.gov/2MWZ4go

Sources/References:

https://go.nasa.gov/2MWZ4go https://go.nasa.gov/2CcS3Ss

A touch of pink in the sky

Auroras are often seen with an impressive green color, but sometimes they can show off other colors, such as red, blue or purple. However, pink auroras, as seen in the picture below, are a rare treat.

Our sun is an active star, with solar flares erupting from the surface quite regularly. The eruptions send solar particles streaking through space and when these particles interact with gases in the Earth's atmosphere, they produce a dazzling display of colored lights. The color of the light produced -- which spans the visible spectrum (i.e.red-orange-yellow-green-blue-indigo-purple) -- depends on what type of gas the particles interact with and also in what part of the atmosphere the reaction is taking place.

Incoming particles are prone to collide with specific gases at different heights. For example, above 300km in the atmosphere, where oxygen is the most common gas, collisions generate a red light. Between 100-300km, collisions with oxygen produce yellow/green auroras, and around 100km, these collisions cause red light. Nitrogen molecules can glow red or blue, while hydrogen and helium produce colors such as blue or purple.

As you can see, several colors can be radiated by distinct particles, but pink isn't on the list, since it's not a spectral color. In order to get pink, a source of collisions is required to create red and blue light and together these colors combine to appear pink or magenta. This means that when we see a pink aurora, what we actually see is the combination of red and blue light emitted by molecules from the upper atmosphere; our eyes just perceive this balance of the two colors as pink.

There is no doubt that the auroras are one of nature's most stunning shows, but if you ever get the chance to observe a pink aurora, you are quite the lucky person, since this is a rare phenomenon.

-- Su

Sources: http://bit.ly/2rkxjo8 http://bit.ly/2rUpOD3

Photo credit: http://bit.ly/2rc1ZUh - photo by Jan Curtis/Geophysical Institute at the University of Alaska, ACRC

Nature's Fireworks

Lightning strikes through this volcano’s ash plume as the magma erupts through the mountain peak. Although this phenomenon is still widely misunderstood, many scientists believe that as tiny rock particles explode, separate, and collide with one another, they become electrically charged. The difference in the rocks’ aerodynamics causes a separation of charge between the particles. As the charge strengthens and the right conditions are met, a strike of lightning occurs, oftentimes miles long.

For a related post, visit: http://on.fb.me/1a3MCT9

--Pete D

Photo Credit: James C. Jervis http://bit.ly/12g9zZc

References: 1. http://news.discovery.com/earth/rocks-fossils/volcanic-lightning-how-does-it-work-130329.htm 2. http://geology.com/articles/volcanic-lightning/

Specific Heat, Oceans, and Fog This fog along the coast of Maine results from the temperature difference between the air and water, which causes droplets of water to condense on particulates when the dew point is reached. Temperature gradients exist between the ocean or land and the air, as each passes heat to one another. Water has a huge ability to hold a lot of heat, affecting the surrounding air and land. This ability of water to hold heat is related to the concept of specific heat, the amount of heat required to raise the temperature of 1 gram of substance by 1 degree Celsius. Water has a very high specific heat, due to the hydrogen bonds forming between the polar water molecules. The heat capacity of a substance is its specific heat multiplied by its mass, and water has a much higher mass than air. Combine this high mass with a very large specific heat, and water has the ability to hold a lot of heat! This is why coastal climates are more regulated than inland locations, as the large bodies of water release great stores of heat slowly in the winter, and slowly absorb the heat in the spring to summer. Land and air, however, have lower specific heats, and lose and gain their heat much faster than water. These properties are a cause for concern when considering the recent increase of surface ocean temperature that followed over a decade of stalled readings. It takes a lot of heat to raise the ocean’s temperature, and it seems the ocean is indicating the magnitude of this heat by the record high temperature this year, compared to the span of time since systematic observation began. -MH Read More:  http://bit.ly/13w5lFP http://bit.ly/1wIG5Wi Photo Credit: MH