The weather after the Sichuan earthquake

After the Sichuan earthquake, Chengdu Institute of Plateau Meteorology studied the characteristics of meteorological elements before and after the earthquake. According to the instructions of the provincial bureau, in order to do a good job in popular science propaganda and scientific and technological consultation for earthquake relief, the research materials are hereby printed and distributed to all units for reference. The provincial bureau requires all units to pay close attention to the characteristics and changes of climatic conditions and do a good job in publicizing relevant popular science knowledge and meteorological services.

Variation characteristics of meteorological elements before and after Wenchuan earthquake in Sichuan Province

This paper mainly selects 10 stations with automatic meteorological observation stations near major earthquake areas such as Chengdu, Dujiangyan, Pengzhou, Chongqing, Mianzhu, Pingwu, Beichuan, Jiangyou, Shifang and Qingchuan, and analyzes the precipitation, temperature, wind speed and wind speed near the major earthquake areas two days before and after the "5. 12" Wenchuan earthquake.

1. Variation characteristics of precipitation

From 00: 00 to 08: 00 on May 12, 2008 (hereinafter referred to as Beijing time), the evolution characteristics of hourly precipitation at the observation stations near the main earthquake area are as follows: There was basically no obvious precipitation process at the observation stations during the day on May 12, and the main precipitation period appeared from the night after the June 12 earthquake to the early morning of June 14. Among them, from 08: 00 on June 5438+02 to 08: 00 on June 5438+03, there was a heavy rain of 26.3 mm in Dujiangyan, with light rain in Chengdu, Pengzhou, Shifang, Chongqing and Jiangyou. From 08: 00 to 13, there was a heavy rain of 30.5 mm in Shifang, 37.3 mm in Chongqing, 32.9 mm in Pengzhou and 2 1.3 mm in Dujiangyan.

In addition, there is no precipitation process in Chongqing 12. The first precipitation occurred at 04: 00 on 13, and the precipitation intensity gradually increased, reaching a peak of 5.3 mm/ 1h at 06: 00 on 13, and then the rainfall intensity weakened. However, 13 increased at night, and the precipitation at this station continued until 07: 00 on 14. There was no precipitation in Wenjiang 12 in Chengdu, and precipitation occurred at 05: 00 on13, and then gradually increased. The peak value of precipitation appeared at 2 1 on 13, reaching 3.8 mm/ 1h, and the precipitation process ended at 07: 00 on 14. Dujiangyan 12 began to rain at 22: 00, which appeared earlier than other places in Chengdu, such as Chongqing, Wenjiang and Pengzhou, and the precipitation intensity was also strong. At 05: 00 on1mm/1h, the precipitation process continued until 05: 00 on 14. 12 There is basically no precipitation process in Pengzhou, and the precipitation starts at 04: 00 on13, with weak intensity. It increases in the evening of 13 and reaches the peak at 22: 00 at night, that is, the precipitation process of 14 ends at 07: 00. There is light rain on Jiangyou 12 15, 0.4 mm/ 1h, and there is no precipitation at other times. On 13, precipitation occurred again at 08: 00-07: 00, and reached the strongest at 13 15. There is no data for the earthquake on June 2nd1May 22nd in Shifang. There was precipitation at 00: 00 on June 38+03, which lasted until 05: 00 on June 38+04, and the precipitation increased at night on June 38+03, with the peak values at 19 and 20: 00 and 4.9.

2. Characteristics of temperature change

At 00:00- 18:00 on may/2, 2008, the hourly temperature evolution characteristics of the observation stations near the main earthquake area are as follows: on may 12, the daily temperature variation characteristics of each station are obvious, with the lowest temperature appearing at around 06: 00 in the morning and the highest temperature appearing at 12. After the 14: 28 earthquake, the daily variation characteristics of temperature at each station on 13 were not obvious, and there was an obvious cooling process at each station. The maximum cooling intensity in 2 4 hours exceeds 10℃, and the temperature at each station keeps low from 13 to 14 08, with a small change range of 65438+.

3. Variation characteristics of wind speed

From 00: 00 on May 12, 2008 to 08: 00 on May 4, 2008, the hourly wind speed evolution characteristics of the observation stations near the main earthquake area are as follows: Before the earthquake, the wind speed characteristics of other stations except Pingwu were similar to the temperature, the wind speed decreased at night, increased around noon, and the maximum value generally appeared in the afternoon. After the earthquake, the wind speed at each station changed from 13 to 14, and the maximum wind speed at many stations appeared at night. The maximum wind speed at Dujiangyan Station appeared at 04: 00 on 13, reaching 1 0.7m/s, which was1h earlier than the maximum hourly precipitation.

4. Characteristics of air pressure change

From 00: 00 on May 12, 2008 to 08: 00 on May 4, 2008, the evolution characteristics of hourly air pressure at various observation stations near the main earthquake area are as follows: before and after the earthquake, the air pressure at each station changed little and was relatively gentle; Pingwu and Qingchuan are above 800m above sea level, and the air pressure is relatively low, about 920hPa, Dujiangyan is 707.00m, about 930hPa, and Beichuan is above sea level. However, it should be noted that from 12 to 14 before and after the earthquake, the air pressure at each station showed a trend of continuous and gradual increase.

5. Some preliminary conclusions

From the above analysis, it can be seen that before and after the Wenchuan earthquake in Sichuan on May 12, 2008, the changes of meteorological elements near the main earthquake area showed certain differences. Especially on the day of the earthquake, there was basically no obvious precipitation process. The main precipitation process began on the night after the earthquake 13, and precipitation occurred at several stations for more than hours after the earthquake 10, and basically ended on the morning of 14. On the day of the earthquake, the daily change of temperature was obvious. The temperature at each station reached the highest value three hours before the earthquake, and most places were around 28℃. However, the daily variation characteristics of the temperature on 13 ~ 14 days after the earthquake were not obvious. Corresponding to the precipitation process, the temperature dropped obviously at each station, and the maximum cooling intensity exceeded 10℃ for 24 hours, and the temperature remained low. Before and after the earthquake, the wind speed showed different changes. Before the earthquake, the wind speed weakened at night and increased around noon, and the maximum usually appeared in the afternoon. However, after the earthquake, the time of maximum wind speed changed, and many stations appeared at night. The pressure changes slightly and gently before and after the earthquake, but it should be noted that from 12 to 14, the pressure at each station shows a continuous and gradual upward trend.

In a word, the analysis of the changes of meteorological factors such as precipitation, temperature, wind speed and air pressure near the main earthquake area two days before and after the "5. 12" Wenchuan earthquake reveals some basic changing facts, but it is worthy of our great attention and necessary research.

China Meteorological Bureau Chengdu Plateau Meteorological Institute

On May 28, 2008 12 14: 28, an earthquake measuring 8.0 on the Richter scale occurred in Wenchuan County, Aba Prefecture, Sichuan Province. Its intensity and intensity exceed that of Tangshan earthquake, which is the most destructive and widespread earthquake since the founding of New China. As we know, an earthquake is a phenomenon in which the local medium inside the earth breaks sharply, producing seismic waves, thus causing ground vibration in a certain range. Earthquakes, especially strong earthquakes, always cause various physical and chemical changes, biological changes and meteorological changes underground and above ground during their gestation and occurrence. Then, before and after the "5. 12" Wenchuan earthquake, what are the changes of meteorological elements around the main earthquake areas?