Measurements from the Tropomi instrument and the lidar of the climate satellite EarthCARE correspond very well, both over land and sea. This is evident from new research that successfully utilized data from two satellite instruments for the first time, for which the KNMI has scientific leadership. Tropomi provides daily information about every location on Earth, while EarthCARE provides detailed information directly below the satellite.
The climate satellite EarthCARE, launched in May 2024, is equipped with a lidar - a laser-based technology - that performs rapid measurements to spatially map the environment. This instrument, called ATLID, measures the properties and height of thin clouds and particulate matter. Tropomi, which has been onboard the Sentinel-5P satellite since 2017, measures the composition of the atmosphere more accurately than ever and provides information about the ozone layer, air quality, and climate. This instrument measures how many greenhouse gases and other gases are present in the air, such as methane, ozone, nitrogen dioxide, and carbon monoxide. Every day it shows how these gases are distributed around the world. Additionally, it can indicate where clouds and particulate matter are located in the air, including the determination of height.
Interaction between Clouds and Particulate Matter
Clouds significantly influence the temperature on Earth. They can reflect sunlight and cool the Earth. Therefore, it is important to understand how clouds and particulate matter (such as smoke, pollen, or sea salt) interact, but much remains unknown. Clouds may be the most studied phenomena in the atmosphere, yet we still do not know exactly what happens when a particulate matter particle comes into contact with a cloud droplet. Sometimes a droplet can form around the particle, but it can also be that the particle absorbs heat from the sun and thus causes the droplet to evaporate. What happens depends on the type of particle and the conditions in the air. There are many possibilities, but we do not yet understand everything.
To better understand the connection between clouds and particulate matter, EarthCARE was launched in May 2024. This mission is a collaboration between the European Space Agency (ESA) and the Japanese organization JAXA. EarthCARE is specifically designed to measure precisely what the air layers below the satellite look like. With various measuring instruments, such as a radar and a lidar, a kind of cross-section of the atmosphere is created from space. This allows us to better see where clouds and particulate matter are located and how they change together. This data helps us better understand the role of clouds in the climate.
