Researchers studied insect abundance using weather radar data. At each of nearly 140 sites, scientists used a radar scan taken at noon every day of the year. They removed the rain, snow and hail from these weather scans. That allowed them to see the density of insects above each site each day. Then they added up all the scans from one site for a whole year. That let them see the annual insect density at every site. They averaged these values across all the sites and plotted that average every year from 2012 to 2021 (Figure A).

They also studied the average density of insects at each site over the 10-year period (size of dots in Figure B) and the change in density during that time (color of dot).

average: (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.

biology: The study of living things. The scientists who study them are known as biologists.

climate change: Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.

data: Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

density: The measure of how condensed some object is, found by dividing its mass by its volume.

dimension: Descriptive features of something that can be measured, such as length, width or time.

factor: Something that plays a role in a particular condition or event; a contributor.

federal: Of or related to a country’s national government (not to any state or local government within that nation). For instance, the National Science Foundation and National Institutes of Health are both agencies of the U.S. federal government.

filter: (v.) The process of screening some things out on the basis of traits such as size, density, electric charge.

forest: An area of land covered mostly with trees and other woody plants.

information: (as opposed to data) Facts provided or trends learned about something or someone, often as a result of studying data.

insect: A type of arthropod that as an adult will have six segmented legs and three body parts: a head, thorax and abdomen. There are hundreds of thousands of insects, which include bees, beetles, flies and moths.

meteorologist: Someone who studies weather and climate events.

organism: Any living thing, from elephants and plants to bacteria and other types of single-celled life.

particle: A minute amount of something.

population: (in biology) A group of individuals (belonging to the same species) that lives in a given area.

radar: A system for calculating the position, distance or other important characteristic of a distant object. It works by sending out periodic radio waves that bounce off of the object and then measuring how long it takes that bounced signal to return. Radar can detect moving objects, like airplanes. It also can be used to map the shape of land — even land covered by ice.

radio: Referring to radio waves, or the device that receives these transmissions. Radio waves are a part of the electromagnetic spectrum that people often use for long-distance communication. Longer than the waves of visible light, radio waves are used to transmit radio and television signals. They also are used in radar. Many astronomical objects also radiate some of their energy as radio waves.

radio waves: Waves in a part of the electromagnetic spectrum. They are a type that people now use for long-distance communication. Longer than the waves of visible light, radio waves are used to transmit radio and television signals. They also are used in radar.

spherical: Adjective for something that is round (as a sphere).

trillion: A number representing a million million — or 1,000,000,000,000 — of something.

wave: A disturbance or variation that travels through space and matter in a regular, oscillating fashion.

weather: Conditions in the atmosphere at a localized place and a particular time. It is usually described in terms of particular features, such as air pressure, humidity, moisture, any precipitation (rain, snow or ice), temperature and wind speed. Weather constitutes the actual conditions that occur at any time and place. It’s different from climate, which is a description of the conditions that tend to occur in some general region during a particular month or season.