General knowledge of mountaineering

Mountain climbing is an excellent way for people to get close to nature, understand nature, and learn about themselves. Mountain climbing is one of the forms of outdoor leisure activities for people, and it is also an excellent way for people to exercise. In addition to mountain sports knowledge and medical knowledge, mountaineering enthusiasts must also understand the meteorological knowledge related to mountaineering, understand the natural laws related to weather, and follow these rules to arrange mountaineering activities.

Generally speaking, mountaineering enthusiasts must understand the climatic conditions and weather conditions of the mountaineering area when formulating their own mountaineering plans, as well as the natural laws related to the above climate conditions and weather conditions. This chapter mainly discusses climbing in high mountains (above 5000m above sea level).

There are many climate knowledge in mountainous areas, which mainly include the start and end time of the rainy season, the change of upper-air winds above 5000m, and the daily variation of surface wind speed at different altitudes. Understanding the beginning and end of the rainy season is mainly to arrange the mountaineering plan. During the mountaineering period, we should try our best to avoid the rainy season and choose the dry season. Understand that the change of high altitude winds above 5000m is extremely important for climbing over 5000m mountains. According to the experience of our country's mountaineers, for amateur mountaineers, mountaineers should choose the season with low wind speed (less than 7 winds). Avoid the windy (more than 7 winds) season. The aforementioned climate conditions are an important meteorological basis for mountaineering enthusiasts to choose the climbing season. Understanding the daily changes in the speed of the mountain surface is mainly for the daily climbing time.

In the mountaineering season, the main high mountain areas in China are concentrated in the Qinghai-Tibet Plateau and the Tianshan Mountains.

On the Qinghai-Tibet Plateau, because the average altitude is between 4000m and -4500m, gale winds often occur above 6000m due to the surface topography. Therefore, in the Qinghai-Tibet Plateau, climbing more than 6000m high mountains, in addition to considering the beginning and end of the rainy season should also consider the seasonal changes in the altitude of wind speed, in order to more accurately select the mountaineering season.

The rainy season in most parts of the Tibetan Plateau (such as the northwest and the northern side of the Himalayas) is from June to September, and the precipitation from July to August is the largest; however, in the southern edge of the Tibetan Plateau, the rainy season appears at 4 Month and June and October. Therefore, mountaineering in these areas should try to avoid their rainy season. Generally speaking, the seasonal variation of the wind speed above 6000 m above sea level on the Tibetan Plateau is mainly determined by the change of the subtropical westerly jet stream (also known as the "southwest westerly jet belt"). The position of the subtropical westerly jet stream is where the strong winds appear. position. According to statistics, the wind speed over the Qinghai-Tibet Plateau (6000m--9000m) is the largest from January to March and from November to December. It is generally not suitable for climbing mountains above 6000m. Taking the above two conditions together, it is best to climb the mountain season above 6000m on the Qinghai-Tibet Plateau from late April to early June, mid-September to early October.

The peaks of the Tianshan Mountains are relatively low compared to the Qinghai-Tibet Plateau, with altitudes generally ranging from 5000m to 7500m, and the highest peak of the Tianshan Mountains, the Aksutu Mul, is only 7435.3m. High-altitude wind speeds in the Tianshan Mountains are affected by the westerlies at mid-high latitudes. The rapids zone (also known as the "Northern Branch Westerly Stream") affects. Due to the low height of the westerly jet belt at the mid- and high-latitudes, the wind speeds of 5000--8000m over the Tianshan Mountains area are very large. Therefore, we must consider the seasonal changes of the upper-level wind speed when climbing over 5000m peaks. This is different from climbing on the Qinghai-Tibet Plateau. The rainy season of the Tianshan Mountains occurs from June to August, and the wind speed at high altitudes (from 5000m to 8000m) is relatively small from April to July. The wind speed at the upper level from May to June is the minimum. Obviously, April to May is suitable for mountaineering.

The statistical analysis of mountaineering time selection shows that in mountain areas, the daily variation of surface wind speed is larger than that of plain areas, and the higher the altitude, the greater the change in wind speed. For example, in the spring and early summer, on the Qinghai-Tibet Plateau, the daily variation in surface wind speed at an altitude of 4500 m above sea level is 4.5 times the altitude of 1000 m. At a height of 4500 m, the wind speed at 2 to 6 o'clock local time is larger than the average wind speed at night and in the morning. 5.5 meters/second. It is speculated that the diurnal variation of surface wind speed at an altitude of 6000m to 8000m is about 6 to 8 times the altitude of 1000m, that is, the wind speed in the afternoon is about 7.3 to 9.8m/s higher than the wind speed at night and in the morning.

Accordingly, the Mountaineering Meteorological Group recommends to the Chinese mountaineering team that they should “start early and camp early” at high altitudes. The Chinese mountaineering team has since 1975 started early departure and early camping as one of the mountaineering regulations. In the Everest region, the Chinese team set a local time to start at 2 o'clock in the morning and camp at 2 o'clock in the afternoon. Recently, when mountaineers from all countries climbed the summit of Mount Everest, they started earlier in the assault camp on the North and South Slopes. At 00: 00 local time, it is guaranteed to complete the summit before 12 o'clock local time.

Mountaineers can refer to use, according to different seasons and different altitudes, to determine their own "early departure" and "birth camp" time. In principle, the higher the altitude, the earlier the time of departure and camping, and the daily change of surface wind speed in spring and autumn will be larger. It should be as early as possible, and the daily change of the surface wind in summer should be small, so that it can be reduced earlier.