Using satellites to predict the start of the pollen season


How satellite measurement can predict the start of the pollen season.

Satellites are normally used for used for three things: communication, taking images and using laser to measure the conditions on earth. But is it possible to use satellites to predict and monitor the development of pollen levels in the atmosphere?

By measuring how light is spread in the atmosphere, satellites can measure the number of particles in the air. However, pollen is hard to detect in this manner. This is partly because pollen reflect light poorly, and partly because pollen is easily confused with other particles. So this approach is not well suited for measuring the number of pollen grains in the atmosphere.

But where satellite measurements come into play is to predict the start of the pollen season. The onset of the pollen season is related to the growth of leaves, e.g. when the leaves have reached a certain development, the plants start to emit pollen.

Vegetation index – chlorophyll levels as seen from space

Satellites can be used to measure the number of leaves that have sprouted by measuring the light reflected by chlorophyll in the leaves. This is illustrated in the video below, which shows the amount of light reflected by chlorophyll over Northern Europe. The images in the video are not generated from photographies taken by satellites, but generated from measurements taken by a spectrometer in satellites. The green color in the video shows the level of the so-called NDVI-index, or vegetation index. Deeper green means a higher value of the NDVI-index.

Vegetation/NDVI index showing the chlorophyll in plants in Northern Europe, derived from satellite measurements.

What does this tell us about pollen levels?

But how can this be used to predict pollen levels? Several studies have shown that there is a correlation between the level of the NDVI-index and the onset of the pollen season. It is not sufficient that the NDVI is above zero, e.g. the start of greening; it has to reach certain levels before the pollen season starts.

Hence, the most obvious use of satellites services with regard to pollen is not the measurements of pollen grains in atmosphere or images of foliage, but rather the measurement of how much light that is absorbed by chlorophyll.

In our previous post about pollen in Europe, we estimate the pollen spread by using on-ground monitoring as basis. We at Airmine are combining the NDVI-index with the on-ground monitoring of pollen and weather data in our pollen forecasting models. We aim to give you detailed forecasts for the onset of the pollen season for birch in Europe, stay with us to be informed!

Stay updated!

We keep your data private.

Airmine app

Track your symptoms to air pollution and pollen & get local air quality forecasts

Get it on Google Play


Better air in Beijing than San Francisco

Last week, you'd rather breathe Delhi air than take a stroll in San Francisco. Smoke and ashes from the huge forest make air quality on the US West Coast the worst in the world.

Air pollution shortens more lives than smoking, drugs and malaria

Although we are in the midst of a global pandemic, air pollution remains the single major contributor to loss in life expectancy across the globe.

Has air quality improved during lockdowns?

Delhi has had much cleaner air during the Covid-19 lockdowns, whereas we do not find the same improvement in PM2.5 levels in Oslo, Norway.

Birch pollen – how did it develop?

The birch season is over for this year - we have dived into our data and created a visualisation of how it developed in Europe.

Grass pollen levels still high in Central Europe

High levels in Denmark, Germany and Poland, France may have seen the peak. Grass pollen in UK and Scandinavia is on the rise as northern Europe really warms up.

Monitoring Air Pollution With Airmine’s Air Quality Index API

Learn how to use our Air Quality API in this short tutorial. The API is designed for web, IoT, and mobile app developers. It is a free API that gives you access to the PM2.5 concentration at any given location, both current concentration and a 8-days forecast.

Grass blooming in Central Europe

The grass season is long - and Central Europe is in the midst of the blooming. Northern Europe is starting to feel the season.

Birch pollen – the north gets the rest

The birch pollen season is almost finished in most of Central and South Europe. The inhabitants of the northern regions can still expect moderate to high levels, as the weather (finally) warms up.

A first look at the grass pollen season

Grass pollen is the most common pollen allergy in Europe and the season is well under way. Central Europe can expect high levels, while the cold weather further north let us wait for the spread.

The birch pollen front continues north – temporary slowdown due to colder weather

Central Europe past the peak, Nordic countries still on the rise The...

PM2.5 levels drop in Wuhan, China

PM2.5 levels drop by almost 40% after the quarantine in Wuhan, China. We expect reductions in air pollution for the rest of the world as the pandemic develops.

Air pollution kills – and costs

About 7 million people die from air pollution annually, and costs to society are huge. But lots can be - and is - done to reduce it.