clouds

The following statements are false but are perceived to be true by many people. Scientific hypotheses and theories are subject to revision on the basis of observations, improvements in technology, and continued scrutiny. Inevitably certain "truths" are reconsidered. This is how honest science works. Brief explanations follow each of the FALSE statements and web site links are provided for reinforcement and/or substantiation. For the few items in which there is controversy or clear disagreement, the scientific view is presented.

T. Ansel Toney
Professor of Earth Sciences (retired)
©1990; last revision May, 2007

There are no hurricanes in the Pacific.
Tropical cyclonic systems with sustained winds of 74 m.p.h. or greater in the Northern Hemisphere's Eastern Pacific (off Mexico for example) are officially called eastern Pacific hurricanes. "Hurricane" and "typhoon" are two different names for the same type of storm.
We would be better off if the air were perfectly clean.
If it were perfectly clean, clouds could not form and we would have no rain. Condensation in perfectly clean air would not occur unless the relative humidity was about 800%. In nature, relative humidity does not get nearly that high.
If the wind blows toward the northeast it is called a northeast wind.
Wind direction is described according to the direction from which it comes. Thus, a wind blowing toward the northeast is a southwest wind because it is coming from the southwest and heading toward the northeast. A west wind blows from the west and toward the east.
Waterspouts are merely tornadoes over water.
Though they look similar, true waterspouts are much less energetic and form in a different type of cloud, cumulus congestus. Tornadoes form in cumulonimbus. This distinction is rarely made in media news releases. Tornadoes can occur over water in which case they are sometimes called "tornadic waterspouts."
If rainwater were not acid our environment would be improved.
It is a good thing that unpolluted rain is acid because nutrients that plants use must be dissolved and the acidity of the water helps to facilitate that dissolving. However, if rainwater is polluted it might be too acidic (called "acid rain").
We would be better off with no atmospheric greenhouse effect.
The average temperature of the earth's surface is about +59 degrees Fahrenheit. With no greenhouse effect it would be about negative 1 degree Fahrenheit (33 degrees below freezing). The earth would not be a suitable place to live at that cold temperature. What would we eat? How could we tolerate the temperatures?
All monsoons are characterized by voluminous rainfall.
"Monsoon" comes from the Arabic, "Mausim" which means "season." Some Winter monsoons are very dry with air flow mainly from continent to ocean. By the way, the phrase monsoon season is redundant. It's like saying "season season."
Most deaths and injuries in hurricanes are due to objects flying in the air or structures collapsing.
Actually, most are due to flooding from the storm surge and heavy rains. There are exceptions of course, like 1992's Andrew. It was a relatively dry hurricane. Mudslides, a form of "mass wasting" in hilly and mountainous regions, are also a great hazard.
All cyclones are storms.
Hurricanes and tornadoes are cyclonic storms. But, ANY rotational weather system with a low pressure center is a cyclone whether or not there are stormy conditions and regardless of size. Anticyclones are rotational systems with relatively high central pressures. If a cyclone is rotating opposite to the typical for its hemisphere (say clockwise instead of counterclockwise in the northern hemisphere) it is still a cyclone because of the low central pressure.
The relative humidity where rain is falling must be 100%.
Cloud droplets usually form when the relative humidity is 100% but that is happening far above the surface. On the surface the relative humidity is usually less than 100%. It takes about a million average-sized cloud droplets to make one average-sized raindrop. Raindrops can fall through relatively dry air yet not entirely evaporate before reaching the surface but they will be smaller than they were when they began their descent. At other times rain can evaporate entirely before reaching the surface forming an interesting pattern called "virga."
Television weather reporters must have degrees in meteorology.
To get the Seal of Approval from the American Meteorological Society the reporter must have at least 12 semester hours of study in the atmospheric, oceanic, or related hydrologic sciences from an accredited institution of higher learning. But no degree is needed. Please note that most television weather reporters have very little or no formal education and do not possess the AMS Seal of Approval. However, some do a very good job. There are about 200 active holders of the AMS Seal.