How scientists study prehistoric weather - paleoclimatology

Here I’ve shared how scientists develop forecasts and predictions of our planet’s weather: from ground and airborne observations and data from stationary and orbiting satellites. Those data that are gathered are put through algorithms on computers that help create weather forecasts and predictions. It’s not a perfect science and likely never will be.

So, how are scientists gathering data on what weather occurred in the past — way back before people predicted our weather — even before people? Paleoclimatology is the field of study that digs deep, literally, to find answers on what the weather was like hundreds of thousands of years ago.

Paleoclimatologists are kind of like paleontologists. The exception is they aren’t looking for fossilized animal bones. They scour the Earth looking for clues hidden in our planet’s natural environmental records. Those clues are buried at the bottoms of oceans and seas in deep sediments. Clues are also found in large coral reefs and are in glaciers and large ice caps. Rings of trees can give clues to our past weather, as well.

Each of these nature’s recording devices can give scientists data on many elements of past weather patterns from the lack of abundance of precipitation to high and low atmospheric temperatures. The segmentation is in the form of a layer, a band, or ring, each covering a fixed amount of time. That fixed amount of time is generally one year or a growth period.

One very successful method of researching the planet’s prehistoric weather has been the ice core records. In regions of thick ice sheets, like Greenland and Antarctica, ice cores have been drilled down into the ice. One incredible ice core took some four years to drill. The final ice core was nearly two miles long. The project was the Greenland Ice Sheet Project 2 (GISP2). The researchers referred to it as The Two-Mile Time Machine.

The climatological record pulled from that ice core covered about the past 110,000 years of weather data. There are older records covering about 750,000 years that came from ice cores in Antarctica. Ice cores have been taken from thick mountain glaciers in Peru’s Andes Mountains, Tanzania (Mount Kilimanjaro) and the Himalayas in Asia.

The cores provide annual records of temperature, precipitation, composition of the atmosphere, major volcanic activity and wind patterns. The reliability of ice cores is built into the resilience of the thick ice sheets. Dr. Richard Alley puts it, “The ice sheet can be compared to a frozen roast that is put directly into the oven. The outside heats up quickly, but the center remains cold, close to the temperature of the freezer, for a long time.”

No existing ice sheets around here, just some remaining glacial erratics.

Let’s visit the weather data for the month of March 2021. All data is gathered from my home weather station. Final results from around our region do vary.

Precipitation was on the scarce side at 0.12 inches. This was all rain, no snow. We have had snow in March. In 1951, 9.8 inches fell, and the mean snowfall is 0.7 inches. The record high precipitation for March was 4.13 inches in 2012, while the all-time low was 0.04 inches in 1969. Temperatures for the month were a high of 62.4˚F on the 18th; the low was 23.3° on the 30th. The mean was 42.6˚. The all-time high was 74˚ back in 1942. The all-time low was -1˚ in 2019. The all-time mean is 41.1˚.

The night sky is clearing. Here’s what to watch for, thanks to our friends at EarthSky.com. “April 2021 showcases 3 bright planets. Mars is the only easy-to-see bright planet in the evening sky. Jupiter and Saturn adorn the early morning hours. Mercury and Venus hover too close to the sun’s glare for easy viewing. There will be a full Moon on April 26, called the Pink Moon. It will be a Super Moon — a tad closer to the Earth than normal.”