The Sun is the main source of energy for our planet, and it is a star that has a higher impact on our lives. The Sun is a dynamic body, a source of strong gravity force, continuously emits radiation and energetic particles. The continuous stream of particles generated by the Sun is called the solar wind. The solar wind determines the condition of the space between the Sun and Earth and even beyond, so-called space weather. The huge impact on the space weather has rapid and highly energetic processes in the solar atmosphere, such as flares or coronal mass ejection. The flare is a high increase of intensity in the solar atmosphere connected with the emission of the particles. The coronal mass ejection (CME) is a huge release of energy and mass from the solar atmosphere into space. The strong flares or CMEs can be a source of the beautiful aurora and can be a danger for astronauts, satellites, and generate geomagnetic storms that can damage our electric systems, pipelines, and radiocommunication.
To understand the processes responsible for solar wind creation and predict them, we must first link how the activity in the outer part of the Sun, called the solar atmosphere, influences the solar wind and space weather. To this aim, we focus on the solar atmosphere. The solar atmosphere is divided into three layers based on the temperature and density changes. They are the photosphere, chromosphere, and solar corona. The photosphere has a temperature of around 6000°C. The photosphere is the deepest layer we can observe; hence it is defined as the solar surface. Then, the temperature slightly increases in the layer called the chromosphere. Finally, the temperature riches more than a million degrees Celsius in the solar corona. The solar corona is the outer part of the solar atmosphere. According to the dynamics, we can distinguish three main groups of regions in the solar corona. (1) The coronal hole is the relatively cold and is build from less dense plasma then other regions in the solar corona. (2) Hotter and higher dynamic region with numerous small-scale structures (usually up to 10 000km) is called the quiet Sun. (3) The active region is the most dynamic, full-filled with large structures (e.g., hot coronal loops). The active regions are the source of the flares and the CMEs.
Satellite observations allow us to investigate the evolution of the solar atmosphere. We use simultaneous multi-satellite observation of active regions. The continuous monitoring of the solar atmosphere from photosphere to the solar corona provides the Solar Dynamics Observatory. The more detail information about the photosphere and chromosphere is obtained by Interface Region Imaging Spectrograph (IRIS). Satellite Hinode observe the solar corona. However, the most details data are provided by the Solar Orbiter. Launched in the 2020 mission, the Solar Orbiter provides the images of the solar atmosphere with unprecedented spatial (~100km/pixel) and temporal (~1.5 sec) resolution as well as in-situ measurements of the solar wind properties. First, we study the topology and temporal evolution of the solar active regions, flares and CMEs. We analyse the plasma velocity, density, temperature and magnetic field. This data allows us to understand the processes and physics of the solar atmosphere. Then, the solar disk observations are linked with changes of the solar wind properties. The solar wind properties are measured in-situ. Finally, we show how the evolution of the solar disk structure influences solar wind and space weather.