How do the meteorologists of Mount Everest's elevation survey gain insight into the "day and time" and how can Chinese technology stabilize the "geographic location"? Expert interpretation →

Meteorological support knows "days"

  The height of Mount Everest in 2020 was measured three times, and the first two times had to be retreated to the camp due to the weather, which is enough to illustrate the importance of the weather. So how did the meteorologist understand the weather this time to ensure that the team members finally reached the summit?

The weather conditions on Mount Everest become more complicated as the altitude increases

  Mount Everest Base Camp is located at an altitude of 5200 meters, and there is a straight line distance of about 19 kilometers from the top of the peak, but as the altitude continues to rise, the weather conditions are becoming more and more complicated.

  Hu Xiao, Chief Analyst of Meteorological Services, China Weather Network, China Meteorological Administration: There are very unique weather characteristics near Mount Everest, there are three: rapid change of weather phenomenon, high wind and low temperature. Because the terrain is relatively complex and the temperature is low, the natural conditions for building a meteorological monitoring station are not above 5200 meters. Therefore, in the process of mountain climbing, we will use means such as air balloon, emergency command vehicle and satellite to monitor.

Bei'ao Great Ice Wall: Jing

Collapses and avalanches often occur

  In this mission, the first difficulty encountered by the surveying mountaineering team, and the biggest difficulty of this mission, is the Bei'ao Great Ice Wall located at an altitude of 6990 meters.

  An ice and snow wall with a height difference of nearly 400 meters and a thickness of more than 100 meters is a dangerous section of the north slope of Mount Everest where collapse and avalanches often occur. Among them, on May 8th, during the first summit climb to 6700 meters above sea level, the players retreated to the forward camp based on the snow depth to judge the danger of snow drift. On May 11th, the team members encountered the danger of drifting snow at the Great Ice Wall of Bei'ao.

  Hu Xiao, Chief Analyst, Meteorological Service, China Weather Network, China Meteorological Administration: When he came to Bei'ao Camp, which was 7000 meters above and below. The influence of wind will be highlighted. In general, the wind speed for climbing Mount Everest safely is 15 meters per second, and when it exceeds 20 meters per second, there will be danger, that is, when the wind is greater than level 8.

"Big tuyere": wind speed up to level 12

  The "big wind" at an altitude of 7500 meters is the second challenge to challenge Mount Everest.

  According to public information, due to the narrow terrain, the wind speed can reach a maximum of 12 levels, and it is sometimes taken by the strong wind to take away the mountaineering bag and extensive frostbite. Because the annual temperature here is below 0 ° C, every time the wind increases by 2 levels, the cold sense of the human body will drop by 6-8 ° C. When snow falls again, it is even more difficult.

  Hu Xiao, Chief Analyst of Meteorological Services, China Weather Network, China Meteorological Administration: This summit has been suspended twice on the 12th and 22nd, both of which were affected by heavy snowfall. Especially on the 21st, due to the impact of "Anpan", the snow depth of Camp No. 2 at 7790 meters even reached 1 meter.

Attack the "second step" and seize the "good weather" window

  The third difficulty of this summit is the rocky cliff at an altitude of 8700 meters above the climbing route on the northern slope of Mount Everest. This is also known as the "second step". There is a nearly vertical wall of 4 meters with a slope of more than 80 degrees. , Is the last difficulty to reach the summit.

  Hu Xiao, Chief Analyst of Meteorological Services, China Weather Network, China Meteorological Administration: Near the peak of Mount Everest, a strong wind of more than 50 meters per second was detected, which is equivalent to a super typhoon level, so the wind will be very strong, on the 27th The last few hours of summiting, so this meteorological support team continuously releases sounding balloons to ensure the success of the summit.

  The forecast service team releases a special report on the Everest elevation measurement weather to the mountaineering team and the national survey team at 10 o'clock and 18 o'clock every day, and develops downscale forecasts of the temperature and wind field at various levels in the Everest region to determine the peak weather window for the mountaineering team. 1. Provide scientific support for the summit plan.

China's science and technology to stabilize the "geographical advantage"

  Measuring one ’s height for one person is enough, and measuring “height” for Mount Everest requires a combination of multiple scientific and technological measures. This time, the height measurement of Mount Everest has led to the emergence of self-developed technology products in China.

Beidou satellite navigation system is used for the height measurement of Mount Everest for the first time

  To accurately determine the height of Mount Everest, satellite measurement of the global navigation satellite system is an important part.

  At the peak, the GNSS receiver can obtain information such as the plane position and the height of the snow surface at the peak through satellites, so as to convert the altitude. Earlier measurements of Mount Everest relied mainly on the GPS system of the United States. This year, the Beidou satellite navigation system was mainly used. The GNSS receivers used with the Beidou system were also made in China.

Equipment localization accuracy and reliability have been greatly improved

  Since the height measurement of Mount Everest is carried out in extreme environments, many measurement equipments need to be specially modified and developed. For this reason, many domestic manufacturers and a large group of national measurement have jointly developed many types of special measurement equipment.

  The zenith meter, gravimeter, peak target target, and ultra-long-distance rangefinder used for triangulation measurement are all domestic instruments. Among them, the target that was erected on the top of Mount Everest today has greatly increased its technological content.

  Chen Xianjun, deputy chief engineer of the National Basic Geographic Information Center of the Ministry of Natural Resources: It is equipped with satellite measurement antennas and meteorological equipment.

China's first aviation gravity survey on Mount Everest

  The accuracy of Mount Everest's elevation measurement depends on two key factors: one is the position of the summit of Mount Everest, and the other is the position of the starting surface of the altitude.

  Therefore, for the first time, China has carried out aerial gravity measurement in the Everest region, which can improve the accuracy of the geoid in the Everest region from the meter level to the centimeter level. Previously, gravity measurement was generally carried out on the ground by surveying and mapping team members operating equipment.

  Xiong Shengqing, Chief Scientist of China Aeronautical Geophysical and Remote Sensing Center: We are using the international leading "Aerogeology No. 1" measurement platform. On this platform, we have integrated the most advanced aerogravimeter and aerial camera in the world for the first time. And aviation laser radar altimeter.

For the first time to achieve 5G full coverage of the north slope of Mount Everest

  Whether it is the data transmission of the surveying and mapping team or the process of letting everyone see the climbing team climb to the top, the smooth network is indispensable.

  By setting up multiple base stations at 5,300 meters, 5,800 meters, and 6,500 meters above sea level, the coverage of signals on the northern slope of Mount Everest is basically covered. In particular, mobile 5G signals have covered the top of Mount Everest. In the course of this mission, this set of 5G equipment not only took the lead in technology, but also withstood the test of severe low temperature environment, and achieved the first mobile live broadcast to reach the summit of Mount Everest.

  On May 27, the Chinese mountaineering team once again stood on top of the world, staying for 150 minutes, creating a new record of the length of time the Chinese stayed on the summit of Mount Everest, and will obtain precious data for the benefit of mankind. Those pictures that overcome difficulties and conquer the top of the world step by step will become eternal.