Does anyone know typhoon 1997+0 1 have a name?

Because there was no name for the typhoon at that time, it was called typhoon 97 1 1 ~ ~

The following is the relevant information ~ ~

Typhoon 97 1 1 and the rainstorm in Qingdao

Preliminary analysis

Wu Hanchun Shen Gao Liuxi

Typhoon 97 1 1 suddenly turned north on 14 19 17. At 08:00- 14:00 on the 20th, the typhoon moved by leaps and bounds from north to east. This is because the low-level jet strengthened the cyclone circulation in the typhoon inverted trough area, resulting in a new center. The rainstorm in Qingdao is the result of abundant water vapor, strong convergence and upward movement and cold air.

Jump and move; Low-level jet; Typhoon; torrential rain

Preliminary analysis of the track of typhoon 97 1 1

Heavy rain in Qingdao

Wu Jiejing Liu Fangzhen Han Chunshen

(Qingdao Meteorological Bureau, Qingdao 266003)

Gaoliuxi

(Shandong Meteorological Observatory, Jinan 25003 1, China)

Abstract: Due to the change of circulation situation, Typhoon 97/KOOC-0//KOOC-0/suddenly turned to the north on August/KOOC-0/9/KOOC-0/4: 00. At 08:00- 14:00 on August 20, a new cyclone center appeared because the low-level jet strengthened the cyclone circulation in the typhoon trough area, and the typhoon jumped to the northeast. The rainstorm in Qingdao is the result of a large amount of water vapor, strong convergent updraft and cold air.

Keywords jumping low-level jet typhoon storm

Typhoon 97 1 1 was generated in the northwest Pacific 15.4 N, 153.8 E at 08: 00 on August, 1997, and gradually strengthened into a strong typhoon, moving steadily to the west-northwest direction at the speed of18km/h. On June 8th, it landed in Wenling City, Zhejiang Province at 2 1 32 19 and 14. The typhoon suddenly accelerated northward near Tongling, Anhui Province, moved out of Shandong via northern Jiangsu, Luzhong and Laizhou Bay, entered Bohai Bay, landed in Liaoning, and finally weakened and disappeared near Shenyang at 2 1 (Figure/)

Figure 1 97 1 1 typhoon track map

Figure 1 Typhoon 97 1 1

Qingdao is affected by typhoon 97 1 1 and cold air from north to south. 1 from 20: 00 to 06: 00 on June 8, 1997, there was a general rainstorm-heavy rainstorm, and there was heavy rainstorm in some areas (table1). The maximum total rainfall occurred in Niaoyi Lane, reaching 639mm ... The reservoir inflow in the city was about 300m3, which fundamentally alleviated the once-in-a-century drought since the summer of 1997. From June 9 14 to June 20 14, the northeast wind in Qingdao turned to southeast wind, with an average wind force of 7-8, the maximum wind speed of 25.6 m/s and the sea surface wind force of 9- 10. Due to the astronomical tide when typhoon 97 1 1 affected Qingdao, the highest tidal level in Qingdao Port was 55 1cm, which caused a severe storm surge disaster. Typhoon storm surge washed away seawalls, 44 sections of the coast, 5 river dams and 8 docks, washed away ships 120, scallops 1. 1.000 mu, and more than 250 tons of seafood, causing great losses to Qingdao's coastal areas. This is another typhoon that has a great influence on Qingdao after No.8509 and No.9216 typhoons. In the whole process of typhoon 97 1 1, there are three problems worthy of attention: (1) Typhoon suddenly accelerated northward on June 9 14; (2) Jump to the northeast at 08: 00 on the 20th; (3) The causes of heavy rain in Qingdao. They are the key to predict the moving path of this typhoon and the accompanying precipitation process. Let's analyze three problems.

Table11August 997 18 0 6: 00 precipitation in Qingdao (mm)

Table 1 Rainfall in Qingdao from 20: 00 on August 20th to 06: 00 on August 20th (mm)

In Qingdao, Laoshan, Jiaonan, Jiaozhou and Laixi, flatness is ink fragrance.

Rainfall185.4170.7158.4150.8 308.5 246.9 482.5

Cause analysis of typhoon 1 suddenly accelerating northward

At 08: 00 on August 1997, the westerly circulation on the isobaric surface at 500hPa is zonal circulation, with two long troughs near 50 E and120 e respectively, and a wide high-pressure ridge near 85 e. The low trough line near120 e is located in Hailar-Beijing-Taiyuan. All the above indicators indicate that the trough will move eastward in the future.

At this time, the subtropical high is divided into two centers, located in the northern part of Jiangsu and the southern coast of Japan, and connected with the continental high centered on Chongqing into an east-west high ridge (figure omitted). At the same time, the typhoon is located about 130km south of Okinawa Island, that is, 24.5 degrees north latitude and 128.4 degrees east longitude. As the typhoon is located on the south side of the subtropical high in southern Japan, it is guided by a wide range of east-southeast basic airflow from June 10 to August 18, and its path is always oriented. 19, 14, the typhoon suddenly moved northward, and the speed increased from 25km/h to 33 km/h. According to the analysis, there are five reasons for the sudden acceleration of the typhoon to the north.

1. 1 The subtropical high on the east side of typhoon strengthened and guided northward.

At 08: 00 on August 18, the circulation situation of 500 hPa isobaric surface changed significantly. The Chongqing continental high weakened and disappeared due to the cold air attack in the eastern Qinghai-Tibet Plateau, and the subtropical high center along the coast of northern Jiangsu moved eastward to join the strengthened subtropical high center in southern Japan, which strengthened the subtropical high on the east side of the typhoon. Line 588 extends northward from the Sea of Japan to the Korean Peninsula, the ridge of subtropical high rises northward to 35 N, and the southerly wind on the west side becomes a typhoon diversion flow, and the wind speed increases from 8m/s to 14 ~ 20m/s, forming a southeast jet. In this way, the typhoon will turn to the north under the traction of the turning airflow. At 08: 00 on August 19, the subtropical high on the east side of the typhoon was further strengthened, and the 588 line rose two latitudes to the north and extended to the Shandong Peninsula to the west, so the distance between the typhoon and the subtropical high was closer (Figure 2). With the increase of the pressure gradient between the two, the speed of typhoon northward also increases.

Fig. 21500 HPA height field (potential meter) at 08: 09 on August, 997.

Figure 2 Isogram of 500 hPa at 08: 00

August 19, 1997 (10 gravimeter)

Southwest airflow direction in front of westerly trough1.2

On August 18, Hailar-Beijing-Taiyuan original trough was blocked by the subtropical high near Japan, and it did not move much, but obviously deepened to the south, and the bottom of the trough extended to 30 N. At this time, the southwest airflow in front of the trough was obviously strengthened, forming a southwest jet, with the speed of the jet axis ≥ 14m/s and the maximum wind speed above 20 m/s. Once the typhoon entered the trough, the southwest

The east-west fracture of 1.3 equatorial convergence line caused the typhoon to move northward.

At 08: 00 on August 18, the equatorial convergence line was east-west between 20 and 25 N. Because the westerly trough developed strongly and deepened to the latitude where the equatorial convergence line was located, the equatorial convergence line broke at the bottom of the trough. This is the result of the interaction between mid-latitude and low-latitude circulation. This adjustment has obvious influence on the typhoon on the east side of the fault zone, which will make the typhoon move to the north under the guidance of the southerly airflow.

To sum up, the long-wave adjustment of the circulation in the subtropical zone, the westerly trough and the equatorial convergence zone changed the basic flow field around the typhoon, making typhoon 97 1 1 move to the west-northwest direction and suddenly accelerate northward.

1.4 Typhoon moves to variable high energy center or variable high energy tongue.

We use the total temperature of 17 isobar at 08: 500hPa to subtract the total temperature of 16 at 08: 00, and draw the situation map of the variable energy field (Figure 3). As can be seen from the figure, there is a long and narrow high-value zone of positive variable energy from Nanjing, Wenzhou, Zhejiang to Dunhua, Jilin. The center of positive variable energy is near Nanjing, Hangzhou, with a central value of +20℃. At 08: 00 on 17, the typhoon was about 130km southeast of Okinawa. According to the relevant indexes of the method for predicting the energy field of the northbound typhoon path [1], it can be clearly seen that the typhoon will move northward to Anhui, Jiangsu, Shandong and Northeast China along the high value area of positive variable energy.

Fig. 3124-hour variable energy distribution (℃) at 500 hPa at 08: 07 on August, 997 and typhoon track forecast.

Fig. 3 24-hour 500 hPa energy distribution and typhoon track forecast at 08: 00 on August 17.

At 08: 00 on June 5438+08, the typhoon center was at 26.7 N,123.9 E, while the typhoon W-NW direction was a low-value area of atmospheric variability, and the vicinity of Hangzhou and Nanjing was still a high-value area of atmospheric variability (as shown in the figure). Therefore, the typhoon continued to approach Hangzhou and Nanjing, and then moved north. The center of the typhoon is 30.0 degrees north latitude and 1 19.0 degrees east longitude, which is120km west of Hangzhou. At this time, the energy transformation center is in the west of Lianyungang, and the high-energy tongue extends to the central part of Shandong (not shown), which indicates that the typhoon will continue to move northward through the Bohai Sea in central Shandong.

Typhoon 1.5 moves along its main cloud system.

The cloud characteristics of satellite cloud images are closely related to the future moving direction of typhoons. Before 08: 00 on 18, typhoon 97 1 1 moved to the west-northwest direction in an approximately circular vortex cloud system. At 18 and 14, a cloud system began to spread and develop in the north-south direction around the typhoon, and the typhoon cloud pattern changed from the original circle to the ellipse with the north-south direction as the long axis. On the night of 18, after the typhoon landed, a wide cloud belt was formed on the north side of the typhoon with the eastward movement of the westerly trough. Under the action of its own inertia, the typhoon moves northwest near Tongling, then moves northward along the main cloud system on its north side (Figure 4 and Figure 5), and finally merges into the westerly trough. From here, we can see that the typhoon cloud system has changed from the original round cloud system to the oval cloud system, which indicates that the typhoon will turn and move in the direction of its main cloud system.

Figure 41Infrared cloud image at 20: 32 on August, 1997.

Figure 4 18,1infrared cloud image at 20: 32 on August, 997.

Fig. 51infrared cloud image at 06: 32 on August, 1997.

Fig. 5 19,1infrared cloud image at 6: 32 on August, 997.

Cause Analysis of Typhoon No.2 Jumping from North to East

1 08:00- 14:00 on 20th, 997, the typhoon moved from Xuzhou to the northeast of Yangjiaogou with a moving speed of 62km/h, while at other times, the moving speed of the typhoon was generally 30km/h, which means that the moving speed increased by about1times. In order to find out the reason, we compared the distribution of water vapor flux on the isobaric surface of 18 from 08: 00 to 20: 00 on August 8, and found that the maximum water vapor flux was 35g/(hPa.s.cm) near Okinawa Island, and the maximum area extended all the way to the northwest of Zhejiang coast (figure omitted). At 08: 00 on June 5438+09, the maximum water vapor flux of 3 1g/(hPa.s.cm) moved to Nanjing and Hangzhou (not shown), and all the water vapor came from typhoon 97 1 1. That is to say, the maximum water vapor flux from 18 to 19 is always near the typhoon center. At 08: 00 on the 20th, the water vapor flux center further northward to Qingdao-Yellow River Estuary, with the maximum value of 38g/(hPa.s.cm). At this time, the water vapor comes from two branches, one is the water vapor transported by SE jet between typhoon and subtropical high, and the other is the water vapor transported by SW jet from South China Sea and Bay of Bengal. These two streams of water vapor meet in the south of the Yellow Sea and fall to the north of typhoon 97 1 1.

Fig. 61water vapor flux diagram at 08: 700hPa on August 20th, 997.

Gram/(Pascal seconds cm)

Figure 61Water Vapor Flux of 700 hPa at 08:00 on August 20th, 997

With these two water vapor channels, abundant water vapor and energy were obtained in the typhoon inverted trough. Due to the cyclone shear and the convergence of the wind speed on the left side of the jet, the cyclone circulation in the inverted trough was strengthened, so a new center was generated at 14 on the 20th.

At this time, the water vapor flux at the center of the original typhoon (34.4 N,117.5 E) is the minimum in the surrounding area, that is, 5g/(HPA s cm), and the typhoon will soon disappear without water vapor and energy supply. Therefore, the typhoon appeared discontinuous jumping movement during this period.

Cause analysis of typhoon rainstorm

3. 1 Cold air is a necessary condition for typhoon and rainstorm.

In August 1997, cold air from East Siberia arrived in North China via Mongolia. Then, with the deepening and slow eastward movement of the cold trough in North China, the cold air arrived in Shandong. At the same time, with the northward approach of Typhoon 97 1 1, a large amount of warm and humid air carried by it entered Shandong Peninsula, and the intersection of cold and warm air provided the necessary conditions for the rainstorm in Qingdao.

3.2 Typhoons carry rich water vapor.

1At 08: 00 on August 8, 8, Typhoon 97 1 1 was located at 26.3 degrees north latitude and 123.9 degrees east longitude, and the maximum water vapor flux center was 35g/(hPa.s.cm) near Okinawa Island. At 08: 00 on 19, the typhoon was in the southeast of Huangshan, and the maximum water vapor flux of 3 1g/(hPa.s.cm) moved to Nanjing. At 08: 00 on the 20th, the typhoon was near Xuzhou, and the center of water vapor flux moved to Qingdao-Yellow River Estuary, with the maximum value of 38g/(hPa.s.cm). As the typhoon landed northward, the center of water vapor flux moved from Okinawa to Qingdao via Nanjing. A large amount of warm and humid water vapor brought by typhoons, water vapor transported from the South China Sea and the Bay of Bengal, and water vapor continuously transported from the western Pacific to the north by the southeast jet provide abundant water vapor conditions for typhoon rainstorm in Qingdao.

3.3 Vertical upward movement is intense.

Calculate the atmospheric vertical velocity ω(× 10-4hPa/s) on the isobaric surface of 700hPa in eastern China from August 17 to August/2/2008, and it can be found that the negative center is in the south of Okinawa at 08: 00, and the value is-144; 18 moved to 200km east of Hangzhou, and the value was-142; /kloc-at 08: 00 on 0/9, there was a center near Qingdao with a value of -72, and the other center was in Hangzhou with a value of-75; At 08: 00 on the 20th, the largest negative center appeared in the west of Qingdao, with the value of-156 (pictured). It can be seen that the negative center of ω matched with typhoon moves to Qingdao. On June 5438+09 ~ 20, there was a strong upward movement near Qingdao, which was beneficial to the occurrence of heavy rain. The reality is that from June 5438 to September 20, there were heavy rains in our city for two consecutive days, which is consistent with the analysis.

3.4 Mesoscale convergence line is the key system to produce rainstorm.

According to the three-hour intensive observation data of seven observation points in Qingdao, at 20: 00 on 19, there is a mesoscale shear line of northeast wind and southeast wind in Qingdao-Laoshan area excited by the ground cold front located east of the Hetao. At the top of this mesoscale shear line, the wind shear of ne and SE is the strongest convergence area, and the strength of cold and warm air is equal, which is easy to cause heavy precipitation. At the top of the shear line, Jimo has produced 70.9 millimeters of rainfall in the past three hours. /kloc-at 23: 00 on October 9, this shear line still exists, and it rained 69.3mm in Jimo in the past three hours. At 02: 00 on the 20th, this shear line moved slightly to the west. At the top of the shear line, the rainfall in Jimo is 66.4mm and that in Laixi is 4 1.6mm in the last three hours (Figure 7). At 05: 00 on the 20th, the shear line moved westward to the first line from Jiaozhou to Laixi, and the rainfall at the top of Laixi in the past three hours was 74.0mm.. ..

Fig. 7 Wind shear map of Qingdao at 02: 00 on August 20th, 0997+65438.

Figure 71Wind field in Qingdao at 02:00 on August 20th, 997.

The above results reveal that the formation, development and movement of small and medium-scale systems are directly related to the rainstorm area under the favorable large-scale circulation background, which opens up a new way for the forecast of rainstorm area in the future.

4 conclusion

(1) The distribution of the variable high-energy center or variable high-energy tongue on the isobaric surface of 500 HPA and the main cloud system of typhoon have a good indication significance for typhoon track prediction.

(2) When the typhoon landing on the southeast coast of China weakens, the warm and humid air carried by SE low-level jet or SW low-level jet will continue to flow in, which will develop again, possibly creating a new center in the typhoon trough area, leading to typhoon jumping.

(3) The favorable large-scale circulation background is a necessary prerequisite for the rainstorm, and the generation, development and movement of the meso-and small-scale systems excited by it have reference value for the rainstorm area forecast.

Author: Wu Jing (Qingdao Meteorological Bureau, Qingdao 266003)

Liu (Qingdao Meteorological Bureau, Qingdao 266003)

Han Chunshen (Qingdao Meteorological Bureau, Qingdao 266003)

Gao Liuxi (Shandong Meteorological Observatory, Jinan 25003 1)

References:

1 Wang et al: Typhoon and gale weather forecast in the Yellow Sea and Bohai Sea, meteorology, 1990, (7): 35 ~ 38.