Dr. Randall Cerveny has always had an interest in weather. Growing up in Nebraska, he enjoyed watching for storms and tornadoes from his family’s home, which was on a hill and offered wide views of the surrounding area.
Today, Cerveny is a world-renowned climatologist. He teaches physical geography, climate change, meteorology, and other subjects at Arizona State University in Tempe, Arizona. He researches and verifies global weather records for the United Nations’ World Meteorological Organization Commission for Climatology.
Cerveny also writes books about weather and climate. In 2006, he presented a collection of strange weather incidents in Freaks of the Storm (From Flying Cows to Stealing Thunder, The World's Strangest True Weather Stories). In his 2009 book, Weather’s Greatest Mysteries Solved!, he acts as a weather detective, trying to answer questions such as “Why did T. rex become extinct?” and “Why did the Mayan civilization disappear?”
Weather vs. Climate
Before investigating a weather mystery, one must understand the differences between weather and climate. Weather is the short-term state of the atmosphere. Aspects include temperature, humidity, cloud cover, precipitation, and wind. Climate, on the other hand, is the long-term systems of weather and other atmospheric conditions.
“At its core, climate may be defined as the ‘collections’ or ‘groups’ of different types of weather. . . . In short, ‘climate’ is the general and ‘weather’ is the specific,” according to Cerveny.
A meteorologist, a scientist who studies weather, might make a 10-day weather forecast. Meteorologists and meteorological reports often appear on television, radio, or in a newspaper.
A climatologist, on the other hand, might study statistics of weather conditions over many years to look for patterns. A climatologist might also investigate a phenomenon—such as hail or a dust storm—and its causes.
There is a lot of overlap in the study of meteorology and climatology. “In order to study the ‘general’ of climate, we first need to study the ‘specific’ of weather,” says Cerveny.
Compared with fields such as physics and chemistry, which have been studied for hundreds of years, meteorology and climatology are quite young.
“Many of the major advances in our knowledge of weather have only been made since the turn of the 20th century,” says Cerveny. As a result, “we don’t yet have a complete understanding of all the intricacies of weather and climate.”
Ideas about climatology and weather events often result in debate and even modification. “One of the best features of climate science is that it is constantly being updated,” says Cerveny. “What we believed yesterday may not be our viewpoint tomorrow. As new evidence becomes available, different interpretations of the event become possible.”
Climate and weather investigators use a variety of research methods. These include reviewing historical records, ice core analysis, palynology (pollen analysis), and dendrochronology (tree ring analysis).
Historical records include personal observations, official governmental reports, or even newspaper articles. Some historical records date back to early human culture. “We have records of sunspot observations, particularly those made in China, that extend back for 2,000 years or more,” says Cerveny.
Still, 2,000 years is not very long in the history of our 4.5 billion-year-old planet, so scientists must look elsewhere to investigate older events.
Ice core analysis provides the opportunity to determine past temperatures, precipitation, and even things like the eruption of volcanoes or the impact of meteorites.
In ice core analysis, scientists study layers of glacial ice. The layers at the bottom are the oldest. Over hundreds of thousands of years, volcanic ash, pollutants, pollen, and other chemicals in the atmosphere gathered into raindrops or fog. This precipitation fell onto snow that later became glaciers. This glacial ice is what is extracted and analyzed by scientists studying ice cores. The process is very labor-intensive and expensive, but it is essential to climatology because it provides information from an amazingly long time ago.
According to Cerveny, “Ice core scientists in both Greenland and Antarctica have actually drilled to the bedrock under those two landmasses—literally miles deep in the ice! That means, specifically for Antarctica, drilling over a mile into the ice (over 3,200 meters). The extracted ice core dated back 740,000 years and reveals as many as eight distinct glacial cycles!”
Palynology is another method to research climate events. “Pollen deposited into a lake can be one of the key indicators used to measure climate change,” Cerveny writes.
Just as ice core scientists drill to extract tubes of ice, palynologists drill into lake beds to extract sediment cores. These cores record vegetation changes over time. Sediment cores reveal what plants, algae, and other organisms were present during what period. This may indicate the temperature of the lake, or the amount of sunlight it received. Sediment cores allow scientists to determine environmental changes and the climate variations that may have caused them.
But digging into the ground isn’t the only way to dig into the past. In dendrochronology, cores are taken from trees, providing an above-ground approach for studying climate. The field was created by A. E. Douglass. “One of the first things that he noted was the timescale of tree rings is ‘absolute’; that is, individual years can be identified and, in fact, in some cases, individual seasons within a year can be precisely seen in the tree rings,” Cerveny says.
Tree-ring records can reveal if a period of time was very cold, wet, or exposed to certain chemicals, such as volcanic ash or air pollution. Rings closest to the center are the oldest. Today, living trees are not harmed by the coring procedure. The cylinders of wood that are extracted are only the width of a pencil, and trees quickly recover.
In Weather’s Greatest Mysteries Solved!, Cerveny uses dendrochronology, palynology, ice cores, and historical records to examine climate mysteries of the past and present.
“Suspects” that caused the mysteries to occur vary widely and include an asteroid striking Earth and the eruption of a “supervolcano” in Indonesia. How can things like that influence our weather and climate? And what effect does it have on us? To find that out, you will need to read the book!