Dr. Randall Cerveny is a professor in the School of Geographical Sciences and Urban Planning at Arizona State University. He is the author of the book Weather's Greatest Mysteries Solved!

Photograph by Kimberly Dumke
  • 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 NationsWorld 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.”

    Investigative Tools

    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!

    Meteorological Sleuth
    Randy Cerveny, weather detective.

    Meteorological Sleuth
    Some of weathers greatest mysteries investigated by Randy Cerveny include:

    • The Mystery of the Dead T. Rex explores the possibility that a huge meteor crashed into the Earth, causing the death of the dinosaurs.
    • The Mystery of the Saharan Hippos investigates how fossils of river-dwelling hippopotamuses could be found in the middle of the Sahara Desert.
    • The Mystery of the Mayan Megadrought investigates the possibility that a drought led to the downfall of the powerful Mayan civilization.
  • Term Part of Speech Definition Encyclopedic Entry
    A. E. Douglass Noun

    (18671962) American astronomer and dendrochronologist.

    algae Plural Noun

    (singular: alga) diverse group of aquatic organisms, the largest of which are seaweeds.

    analyze Verb

    to study in detail.

    asteroid Noun

    irregularly shaped planetary body, ranging from 6 meters (20 feet) to 933 kilometers (580 miles) in diameter, orbiting the sun between Mars and Jupiter.

    atmosphere Noun

    layers of gases surrounding a planet or other celestial body.

    Encyclopedic Entry: atmosphere
    bedrock Noun

    solid rock beneath the Earth's soil and sand.

    Encyclopedic Entry: bedrock
    chemistry Noun

    study of the atoms and molecules that make up different substances.

    civilization Noun

    complex way of life that developed as humans began to develop urban settlements.

    Encyclopedic Entry: Key Components of Civilization
    climate Noun

    all weather conditions for a given location over a period of time.

    Encyclopedic Entry: climate
    climate change Noun

    gradual changes in all the interconnected weather elements on our planet.

    Encyclopedic Entry: Earth's Changing Climate
    climatologist Noun

    person who studies long-term patterns in weather.

    cloud cover Noun

    amount of sky covered with clouds.

    cylinder Noun

    tube or long, circular object.

    dendrochronology Noun

    study of tree rings and how they can identify and date weather events and changes in the atmosphere.

    desert Noun

    area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.

    Encyclopedic Entry: desert
    dinosaur Noun

    very large, extinct reptile chiefly from the Mesozoic Era, 251 million to 65 million years ago.

    drought Noun

    period of greatly reduced precipitation.

    Encyclopedic Entry: drought
    dust storm Noun

    weather pattern of wind blowing dust over large regions of land.

    dwelling Noun

    a place to live.

    essential Adjective


    expensive Adjective

    very costly.

    extinct Adjective

    no longer existing.

    extract Verb

    to pull out.

    fog Noun

    clouds at ground level.

    Encyclopedic Entry: fog
    forecast Verb

    to predict, especially the weather.

    glacial cycle Noun

    long period of cold climate where glaciers may cover large parts of the Earth. Also called an Ice Age.

    glacial ice Noun

    precipitation that has hardened on top of glaciers, forming another layer on the glacier.

    glacier Noun

    mass of ice that moves slowly over land.

    Encyclopedic Entry: glacier
    hail Noun

    precipitation that falls as ice.

    Encyclopedic Entry: hail
    hill Noun

    land that rises above its surroundings and has a rounded summit, usually less than 300 meters (1,000 feet).

    Encyclopedic Entry: hill
    hippopotamus Noun

    large mammal native to Africa that lives near rivers.

    historical record Noun

    document written at the time an event happened, and later studied.

    humid Adjective

    containing a large amount of water vapor.

    ice core Noun

    sample of ice taken to demonstrate changes in climate over many years.

    incident Noun

    event or happening.

    interpretation Noun

    way of understanding an event or set of facts.

    intricacies Plural Noun


    labor-intensive Adjective

    requiring a lot of work and effort.

    literally Adverb

    exactly what is said, without exaggeration.

    Maya Noun

    people and culture native to southeastern Mexico and Central America.

    meteor Noun

    rocky debris from space that enters Earth's atmosphere. Also called a shooting star or falling star.

    Encyclopedic Entry: meteor
    meteorite Noun

    type of rock that has crashed into Earth from outside the atmosphere.

    Encyclopedic Entry: meteorite
    meteorologist Noun

    person who studies patterns and changes in Earth's atmosphere.

    meteorology Noun

    study of weather and atmosphere.

    Encyclopedic Entry: meteorology
    observation Noun

    something that is learned from watching and measuring an object or pattern.

    palynologist Noun

    person who studies pollen and its impact on the environment and organisms.

    palynology Noun

    study of pollen.

    phenomenon Noun

    an unusual act or occurrence.

    physical geography Noun

    study of the natural features and processes of the Earth.

    physics Noun

    study of the physical processes of the universe, especially the interaction of matter and energy.

    plant Noun

    organism that produces its own food through photosynthesis and whose cells have walls.

    pollen Noun

    powdery material produced by plants, each grain of which contains a male gamete capable of fertilizing a female ovule.

    pollutant Noun

    chemical or other substance that harms a natural resource.

    precipitation Noun

    all forms in which water falls to Earth from the atmosphere.

    Encyclopedic Entry: precipitation
    raindrop Noun

    drop of liquid from the atmosphere.

    sediment core Noun

    cylinder of accumulated sediment of a region, visible as layers.

    sleuth Noun

    detective or investigator.

    specific Adjective

    exact or precise.

    statistics Noun

    the collection and analysis of sets of numbers.

    storm Noun

    severe weather indicating a disturbed state of the atmosphere resulting from uplifted air.

    sunspot Noun

    dark, cooler area on the surface of the sun that can move, change, and disappear over time.

    supervolcano Noun

    volcano capable of ejecting more than 1,000 cubic kilometers (240 cubic miles) of material.

    temperature Noun

    degree of hotness or coldness measured by a thermometer with a numerical scale.

    Encyclopedic Entry: temperature
    tornado Noun

    a violently rotating column of air that forms at the bottom of a cloud and touches the ground.

    tree ring Noun

    layered formation in the trunk of a tree that marks its growth at least once a year.

    T. rex Noun

    (Tyrannosaurus rex) large carnivorous or scavenger dinosaur.

    unique Adjective

    one of a kind.

    United Nations Noun

    international organization that works for peace, security and cooperation.

    vegetation Noun

    all the plant life of a specific place.

    verify Verb

    to prove as true.

    volcanic ash Noun

    fragments of lava less than 2 millimeters across.

    Encyclopedic Entry: Human and Environmental Impacts of Volcanic Ash
    volcano Noun

    an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.

    Encyclopedic Entry: Plate Tectonics and Volcanic Activity
    weather Noun

    state of the atmosphere, including temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness.

    Encyclopedic Entry: weather
    wind Noun

    movement of air (from a high pressure zone to a low pressure zone) caused by the uneven heating of the Earth by the sun.

    World Meteorological Organization Noun

    United Nations agency that studies the Earth's atmosphere, its interaction with the oceans, the climate, and the distribution of water resources.