Balance and Change

For Earth’s surface temperatures to remain steady, heat gain from sunlight must equal heat loss to the atmosphere. Energy equilibrium occurs when incoming energy equals outgoing energy.

Incoming Sunlight

Outgoing Heat

Borrowing the concept of an accountant's ledger with accounts payable and account receivable, the balance of incoming and outgoing energy is the atmosphere's energy budget.

Because of Earth's orientation to the sun, solar radiation is directed at the equator more so than to the poles. Evaporation, convection, rainfall, winds, and circulation are all processes working non-stop in the atmosphere and in the oceans to redistribute energy from incoming solar radiation.

Any phenomena that disturb the balance of incoming or outgoing energy (i.e., atmospheric energy budget) changes Earth’s net energy. Surface temperatures rise or fall accordingly.

In a state of energy equilibrium, mean temperatures would not change.

“It ever was, and is, and shall be, ever-living fire, in measures being kindled and in measures going out.”
― Heraclitus, (535-475 BC)

REFERENCES

• Climate and Earth's Energy Budget, Rebecca Lindsey, Earth Observatory, 2009.
• Diagram of the Earth's Energy Budget, Wikipedia.
• Earth’s Energy Budget, Earth Observatory.

Water Tale

Spinning a globe on its axis, or viewing satellite images of the earth, the immense surface area of water is deceiving. Most of the earth is covered by water. But two-dimensions belies the three-dimensional truth.

Consider two spheres:

Earth Sphere
The earth is a sphere slightly flattened at the poles. If it was possible to drill a core through the earth, it would be 7,918 miles long. The earth's diameter is about 7,918 miles across. 

Water Sphere
If every water molecule on earth was contained by a sphere, the sphere would be much smaller than the earth sphere. Visualized as a sphere, earth's water would be 860 miles across.

Volume of all earth's water as compared to the earth's volume.
US Geological Survey

Water as a sphere	Earth as a sphere
860 mile diameter	7,918 mile diameter

The tiny blue sphere located east of the much larger total water sphere represents all of the fresh water found in the ground, lakes, swamps, and rivers. The fresh water sphere is 169.5 miles in diameter.

You could not step twice into the same rivers; for other waters are ever flowing on to you.
― Heraclitus of Ephesus

REFERENCES

• The USGS Water Science School

Tuning Our Senses

Responding to the urge to immerse myself, I deliberately alert my mind to the prospect of incoming data. I have experienced the automaton-like phenomena of pinging my senses in a sort of mental roll-call:

What can I see? What can I smell? What can I hear?

Yet in what I imagine to be heightened awareness, I am often surprised ― not by what I see, hear, or smell, rather by the flicker of something I have just missed.

A School of Minnows

Sensual acuity is like a muscle needing the discipline of exercise and practice.

Annie Dillard devotes a chapter to Seeing in Pilgrim at Tinker Creek. She writes that the most obvious objects in nature are often the most difficult to see.

Nature is one of those line drawings of a tree that are puzzles for children.
― Annie Dillard

We are creatures deceived by expectation. Often we only see what we expect.

My eyes account for less than one percent of the weight of my head. I'm bony and dense; I see what I expect.― Annie Dillard

How do we tune our senses to the unexpected?

If you do not expect the unexpected you will not find it, for it is not to be reached by search or trail. ― Heraclitus