Here they come! What special features do these two Fengyun satellites have?

On June 1, Fengyun-3E, Fengyun-4B and their ground application systems entered operational trial operation and began to provide observation data and application services to global users.

As members of the global observation service sequence, what exactly do they do? What services can they provide? What "special skills" do they have? Let's take a look!

FY-3E

The Fengyun-3E, known as the "Dawn Star", was successfully launched on July 5, 2021. It is the world's first civilian dawn-dusk orbit operational satellite.

The satellite carries 11 payloads, including three newly developed instruments, filling the gap in satellite data observations in the dawn and dusk periods for global numerical weather forecast models. my country has thus become the first country in the world to simultaneously conduct all-day, all-weather, high-spectral, three-dimensional quantitative remote sensing in the dawn and dusk orbits, morning orbits, and afternoon orbits.

Model diagram of Fengyun-3E satellite

Image source: National Satellite Meteorological Center

Fengyun-3E can provide observation data of the Earth's atmosphere at dawn. Combined with observations from orbiting satellites in the morning and afternoon, it increases the frequency of monitoring of changing characteristics of solar radiation and geophysical parameters, and can more accurately reveal the changing characteristics of the Earth's atmosphere.

On September 2, 2021, the first batch of high-precision, multi-band solar images from Fengyun-3E were officially released to the outside world. These images show the physical state of the solar atmosphere at different levels and locations, which can help people better monitor and predict the activity level of the sun. This function is also one of the features of Fengyun-3E.

FY-3E monitors solar activity

Image source: National Satellite Meteorological Center

Solar X-ray image of Fengyun-3E

Image source: National Satellite Meteorological Center

On September 29, 2021, Fengyun-3E released observation images to the public for the second time. This was also the first time that global ocean wind field information was released. As shown in the figure below, we can clearly see typical climate features commonly used by forecasters in weather analysis, such as the equatorial convergence zone, subtropical high pressure, trade winds, monsoons, cross-equatorial airflows, and circumpolar westerlies.

Monthly average product of Fengyun-3E ocean surface wind field (September 2021)

Image source: National Satellite Meteorological Center

In addition, Fengyun-3E can also observe the global atmospheric temperature field. For example, Figure 1 shows the global temperature distribution at four altitudes of 950 hPa, 850 hPa, 700 hPa and 500 hPa at dawn on September 27, 2021.

Vertical layer distribution of the global atmospheric temperature field of Fengyun-3E satellite (at dawn on September 27, 2021).

Image 1 Source: National Satellite Meteorological Center

Figure 2 is the vertical temperature distribution map of Typhoon Chandu on September 10, 2021. It can be seen from the figure that the temperature in the vertical direction of Chandu shows an obvious "cold-warm-cold" structure, and the typhoon's deep warm core structure characteristics are clear.

Three-dimensional detection of typhoon structure by Fengyun-3E (the wind field and warm structure of Typhoon Chandu on the ocean surface at dawn on September 10, 2021)

Image 2 Source: National Satellite Meteorological Center

Global surface temperature product for October 2021. The global surface temperatures at four times of day and night and at dawn and dusk obtained by the Fengyun-3D and E satellites can form an observation time chain. Warm colors in the figure indicate high temperatures and cold colors indicate low temperatures.

Image 3 Source: National Satellite Meteorological Center

In addition to the ocean surface wind field and the global atmospheric temperature field, Fengyun-3E can also observe changes in the global atmospheric humidity field. The four small pictures shown in Figure 4 are water vapor distribution maps at 950 hPa, 850 hPa, 700 hPa and 500 hPa respectively.

Vertical layer distribution of the global atmospheric humidity field of Fengyun-3E satellite (at dawn on September 27, 2021).

Image 4 Source: National Satellite Meteorological Center

As can be seen from Picture 4, the lower the level, the more abundant the water vapor content. We can also see that the Indian monsoon and the East Asian monsoon continuously bring a large amount of water vapor from the Indian Ocean and the Western Pacific to my country.

In addition, if a certain area encounters a typhoon, then there will be obvious high humidity areas in the observation map of Fengyun-3E. For example, in Figure 4, there are two high humidity areas on the eastern and southern oceans of my country, corresponding to the 2021 13th and 14th typhoons "Conson" and "Cantu" respectively.

Temporal evolution of the global atmospheric humidity field of FY-3E (September 11-26, 2021, dawn, 850 hPa)

Image 5 Source: National Satellite Meteorological Center

On November 4, 2021, the Fengyun-3E "Dawn" satellite released observation images to the public for the third time. The images and animations released this time are from the low-light medium-resolution spectroscopic imager on board the Fengyun-3E satellite. This is also the first time that the Fengyun meteorological satellite has monitored the distribution of clouds and city lights on Earth during dawn and dusk.

A satellite image taken by Dawnstar at dusk on October 17, 2021 at 20:18 (UTC), as the satellite flew over South America.

Image source: National Satellite Meteorological Center

Visible light image of the Arctic on August 1, 2021. The Arctic in the weak light of the summer polar day. The "Dawn Star" near the Arctic Circle can observe the polar image in a dim state.

Image source: National Satellite Meteorological Center

Image source: National Satellite Meteorological Center

After commercial operation, FY-3E will form a three-way network with FY-3C and D satellites, providing complete global observation data in numerical forecast mode every 6 hours, effectively improving the accuracy and timeliness of global numerical weather forecasts, which is of great significance to improving the global Earth observation system.

FY-4B

Fengyun-4B was successfully launched on June 3, 2021. It is the first operational satellite of my country's new generation of geostationary meteorological satellite. This marks that my country's new generation of geostationary satellite observation system has officially entered the operational development stage, which is of great significance to ensure the upgrading and replacement of my country's geostationary meteorological satellites and continuous, reliable and stable operational operation.

Fengyun-4B image source: National Satellite Meteorological Center

On July 1, 2021, my country's new generation of geostationary meteorological satellite Fengyun-4B successfully acquired the first batch of high-precision and high-efficiency visible light observation images.

The first color composite image obtained by the geostationary orbit radiation imager of Fengyun-4B

Image source: National Satellite Meteorological Center

At 8:00 on June 28, 2021, the 1-minute, 250-meter resolution panchromatic band image products and 500-meter resolution true color composite image and animation products "amazed" the morning weather consultation; on July 1, Fengyun-4B conducted minute-level animation tracking of clouds over Beijing, and the smooth picture accurately displayed the refined evolution characteristics! Fengyun-4B played an important supporting role.

FY-4B geostationary meteorological satellite observes the eruption of Hongahaapai Island volcano

Image source: National Satellite Meteorological Center

It is reported that the FY-4B satellite has been optimized in design based on the mature technology of the FY-4A test satellite, fully tapping the satellite platform and payload capabilities, improving the overall reliability, stability and detection accuracy of the satellite, and adding a fast imager with regional imaging capability of 250-meter resolution in minutes.

After FY-4B is put into commercial operation, it will form a dual-satellite network with FY-4A to further meet the service needs of meteorological monitoring and forecasting, emergency disaster prevention and mitigation, etc. in my country and countries and regions along the “Belt and Road”.

Up to now, my country has successfully launched 19 Fengyun meteorological satellites of two generations and four types, of which seven are in orbit. As an important part of the World Meteorological Organization's global operational application meteorological satellite sequence and the duty satellite of the International Charter Mechanism for Major Disasters, it is continuously providing data products and services to 123 countries and regions around the world.

These meteorological satellites will effectively support "global monitoring, global forecasting, and global services", play an important role in serving the construction of the "Belt and Road", and further enhance the comprehensive observation capabilities and application service capabilities of my country's meteorological satellites.

Editor: Wang Tingting

Produced by: Science Popularization China

Produced by: Jiang Hong (China Meteorological News Agency)

Producer: China Science Expo