The Weather Guys

Portrait of Increase Lapham (Photo credit: Wisconsin Historical Society archives)

Many consider Increase Lapham to be one of Wisconsin’s greatest scientists.  Though never formally educated, Lapham demonstrated an early talent for topographical sketching and became an engineer and surveyor of canals in the 1830s.

He was born in Palmyra, New York, on March 7, 1811, the fifth of 13 children in a poor Quaker family.  Early in 1836, he was invited to Milwaukee as chief engineer in charge of building the Rock River Canal (which was never built).

Lapham made contributions in many scientific endeavors including cartography, geology, ecosystems science, and Native American history of Wisconsin.  One of his foremost interests was weather and climate.

He sent frequent reports of maritime casualties to Milwaukee’s congressional representative, Gen. Halbert Paine, which eventually prompted Paine to introduce a joint resolution on Feb. 2, 1980, requiring the Secretary of War to “provide for taking meteorological observations at the military stations in the interior of the continent … and for giving notice on the northern lakes (the Great Lakes) … of the approach and force of storms.”

The resolution passed and one week later, President Ulysses S. Grant, who personal experiences during the Civil War had long ago convinced him of the utility of meteorological information for military activities, signed it into law.

On Nov. 1, 1870, the United States Army Signal Service — what would grow to become the National Weather Service — began operations.

On Nov. 8, 1870, Dr. Increase Lapham, who had been the catalyst for the formation of the Signal Service, issued its first official storm warning for the waters of Lake Michigan.

Compared to a roadway, a bridge has more surface area to exchange energy with the atmosphere, and thus will cool down to the air temperature — and freeze — quicker. (Photo credit: Beaver Dam Daily Citizen archives)

Living in a cold climate, we are used to seeing signs that say “bridge freezes before road.”

The fundamental reason is that a bridge hangs above the ground, while the roadway rests on the ground. Water on a road or bridge will freeze once the surface becomes cold enough. So, the bridge must cool faster than the roadway.

Whether something warms or cools is related to its energy gains and losses. So, as you stand facing an evening bonfire, your front warms because it gains more energy than it loses, while your back cools as it loses more energy to the cooler night air than it gains.

The energy losses from a bridge occur along the top surface and also along its side and bottom. Compared to a roadway, a bridge has more surface area to exchange energy with the atmosphere, and thus will cool down to the air temperature quicker.

Many bridges are made of metal and concrete, both of which are good heat conductors. Thus, when cold air comes in contact with the bridge surfaces, heat is quickly transferred from the bridge to the colder air, cooling the bridge and its surfaces.

A roadway also loses heat from its surface to the cold air above. However, the road surface also gains energy from the ground. So, while the roadway will cool down, it does not cool as fast because of the energy gains it gets from the warmer ground below. Because of those extra energy gains, the roadway cools more slowly and doesn’t form ice as quickly as the bridge.