Up in the Sky Quiz

Question: The Fujita scale, or F-scale, is used for classifying the intensity of what kind of weather disturbance?

Answer: The Fujita scale, or F-scale, is a system of classifying tornado intensity based on damage to structures and vegetation.

Question: What does an anemometer measure?

Answer: An anemometer is a device that measures the speed of airflow in the atmosphere, in wind tunnels, and in other gas-flow applications. Most widely used for wind-speed measurements is the revolving-cup electric anemometer, in which the revolving cups drive an electric generator.

Question: Tornado Alley in the United States extends through which states?

Answer: Tornado Alley is the region in the United States of maximum tornado frequency. It is traditionally defined as extending from western Texas northeast through the western and central portions of Oklahoma and Kansas and across most of Nebraska.

Question: Acid rain is formed by the reaction of which two gases with water?

Answer: Scientific studies have shown that the process that results in the formation of acid rain generally begins with the discharge of sulfur dioxide and nitrogen oxides into the atmosphere. The gases combine with atmospheric water vapour to form sulfuric and nitric acids. When rain or some other form of precipitation falls to the Earth’s surface, it is highly acidic, frequently with a pH less than 4.

Question: Which country reports the largest number of tornadoes per land area each year?

Answer: The United Kingdom has the most tornadoes per land size, most of them weak. Almost all reported tornadoes in the United Kingdom are associated with vigorous convection occurring in advance of and along a cold frontal boundary.

Question: What phenomenon was once frequently seen atop ships’ masts and church steeples and can now occasionally be spotted at the tips of an airplane’s wings?

Answer: Saint Elmo’s fire is a brushlike discharge of atmospheric electricity that sometimes appears as a faint light on the extremities of pointed objects, such as church towers or the masts of ships during stormy weather, or along electric power lines. Also called corona discharge, it is commonly observed on the periphery of propellers and along the wing tips, windshield, and nose of aircraft flying in dry snow, in ice crystals, or near thunderstorms.

Question: What is created by the action of sunlight on gaseous nitrogen oxides and hydrocarbons in the atmosphere?

Answer: Photochemical smog has its origin in the nitrogen oxides and hydrocarbon vapours emitted by automobiles and other sources, which then undergo photochemical reactions in the lower atmosphere. The highly toxic gas ozone arises from the reaction of nitrogen oxides with hydrocarbon vapours in the presence of sunlight.

Question: Most clouds and weather systems are contained within which region of the atmosphere?

Answer: Most clouds and weather systems occur in the troposphere, the lowest region of the atmosphere, which extends from the Earth's surface to about 10–18 km (6–11 miles) above the Earth’s surface.

Question: Ionized channels open up between regions of negative and positive charge and, in just thousandths of a second, millions of volts are transmitted and the immediate area is heated to 30,000 °C (50,000 °F). What has happened?

Answer: Cloud-to-ground lightning is initiated by a preliminary breakdown process within the cloud, typically between the centre region of negative charge and the small positive charge below it. This process creates a channel of partially ionized air—that is, air in which neutral atoms and molecules have been converted to electrically charged ones. Next, a stepped leader (initial lightning stroke) forms and propagates downward, and a very bright return stroke propagates back to the cloud. The potential difference between cloud and ground is of the order of 10 to 100 million volts, and the peak temperatures in the return-stroke channel are on the order of 30,000 °C (50,000 °F). The entire process is very rapid; the leader stroke reaches the ground in about 30 milliseconds, and the return stroke reaches the centre of the cloud in about 100 microseconds.