To determine the periods of the year, we rely on the seasons, which are climatic cycles of approximately three months each characterized by stable weather conditions in a given region. The seasons are spring, summer, autumn and winter. Their sequence is caused by the inclination of the Earth's axis in relation to the plane of its orbit, causing different regions to receive different amounts of sunlight during the year.
This phenomenon affects not only temperatures and day length, but also the intensity and inclination of sunlight falling on the surface. These variations have a direct impact on flora, especially in areas farther from the equator, where the seasons are more marked. Temperate and boreal zones, such as Europe and North America, show very pronounced seasonal changes, which are reflected in vegetation cycles.
Breath of the Earth
Not only do the seasons influence the climate, but they also directly affect the cycles of vegetation. This phenomenon is known as the Earth's breathing. As the seasons change, plants respond in diverse ways. deciduous plants, such as oaks or chestnuts, lose their leaves in autumn to avoid water loss in winter and sprout again in spring, preparing for flowering and reproduction.
Vegetation cycles include fundamental processes, such as seed germination, growth, flowering and leaf fall. The regularity of these cycles is closely connected to the seasonal climate. However, phenomena such as the climate change and deforestation have seriously affected these natural rhythms, modifying growth times and affecting biodiversity.
This cyclical process has allowed scientists to observe a kind of “breathing” of the planet, visible through satellite images. In these animations, we can see how vegetation grows, absorbing carbon dioxide (CO2) in spring and summer, and how it releases carbon when it goes dormant during autumn and winter.
The “breath of the Earth” is not only visually stunning, but is essential to the life cycle of every species on the planet. We depend on this cycle for our daily needs. foods, oxygen and other crucial resources.
Seasonal changes in vegetation and satellite data
Nobody Bremer has developed striking visualizations about the “breathing” of the Earth, based on data from the NOAA STAR (Satellite Research and Applications Center). They use the sensor VIIRS (Visible Infrared Imager Radiometer Suite), which is on board the satellite SNPP (Suomi National Polar-Orbiting Partnership). This device measures weekly changes in global vegetation, providing detailed information on how greenness changes throughout the year.
Through these images, it is possible to observe how the changes are more pronounced in regions of the northern hemisphere, where large seasonal variations are recorded. Areas such as New Zealand, Brazil and southern Africa show an inverse cycle due to their location in the southern hemisphere, where the seasons occur in opposite ways.
Greenness: a key variable in the study of seasonal cycles
A key indicator to measure these seasonal changes is the Greenness, or the Normalized Difference Vegetation Index (NDVI)This index measures the amount of vegetation present in a region and is used to detect the beginning of the growing season, as well as senescence or the end of the life cycle of plants at the end of autumn.
The NDVI is also a crucial tool for climate change studies, as the reduction or increase in greenness could indicate drastic changes in plant growth patterns due to rising global temperatures. In areas without vegetation, such as deserts or mountains, the index can also provide relevant information on ground conditions.
The scientific challenges behind animating Earth's breathing
The development of the animation that reflects the Earth's breathing, based on vegetation cycles, represented a major challenge. animation spans 50.000 cycles, corresponding to the 52 weeks of a year. Using advanced algorithms, an accurate representation of how vegetation absorbs and releases CO2 during each weekly cycle was created.
The technical complexity of this process included trying out various animation methods until achieving the best possible representation. The sequence shows how forests and other vegetated areas “breathe,” absorbing large amounts of carbon dioxide in spring and summer to release it during the winter months.
As the creators of the animation mention, it is possible to observe even more detailed and slower versions to appreciate how the processes develop with a more precise temporal resolution.
The Earth and its carbon “breathing”
The concept of the carbon respiration The Earth's climate is crucial to understanding how vegetation cycles influence the global carbon cycle. During the cycle, plants absorb carbon through photosynthesis and release it during decomposition or when they are burned. This system of constant carbon exchange between the atmosphere, soils and oceans is vital to the global climate balance.
El ocean The ocean also plays a key role in this process, absorbing huge amounts of carbon, much more than is stored in the atmosphere and the terrestrial biosphere. In fact, the ocean captures more carbon than terrestrial ecosystems. However, plants continue to be one of the most important elements, especially in tropical and temperate latitudes, where they absorb more CO2 during spring and summer, while releasing it in winter.
This exchange is highly sensitive to changes in climate, making studies on carbon respiration a key element in global efforts to mitigate climate change.
The impact of climate change on seasonal cycles
El climate change has begun to disrupt these cyclical patterns. Higher global temperatures are causing vegetation cycles to move earlier, shifting the timing of germination and senescence. Growing seasons have also lengthened in several regions, which, while initially likely to appear beneficial to agriculture, can have disastrous long-term effects as it destroys the natural balance of ecosystems.
Tropical ecosystems, for example, are undergoing significant changes. Amazonian rainforests, which act as major carbon sinks, are losing their ability to capture CO2 due to increased deforestation and increasingly frequent droughts. If this capacity continues to be lost, the carbon cycle will be deeply affected, increasing the amount of CO2 in the atmosphere and accelerating global warming.
The importance of investigating the seasonal cycles of vegetation lies not only in understanding how nature responds to climate change, but in how we can mitigate its effects through the conservation of key ecosystems such as rainforests, boreal regions and, crucially, oceans.
Each of these processes, from photosynthesis to Earth's respiration, reveals the complex interconnectedness that keeps our climate and life on the planet in balance. As we face the challenges of climate change, understanding and protecting these cycles becomes more crucial than ever.