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The characteristics of Asian-dust storms during 2000–2002: From the source to the sea
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Atmospheric Environment 41 (2007) 9136–9145 www.elsevier.com/locate/atmosenv
The characteristics of Asian-dust storms during 2000–2002: From the source to the sea Zhang Kaia,b,, Gao Huiwanga a
Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Qingdao 266003, China b Institute of Atmospheric Physics (IAP), Chinese Academy of Science (CAS), Beijing 100029, China Received 21 June 2006; received in revised form 30 July 2007; accepted 1 August 2007
Abstract About 42 Asian-dust storms influenced the mainland and China during 2000–2002. Based on the Micaps meteorology data provided by China Meteorological Administration, the basic characteristics, including the source, movement route and influenced areas were studied for each case. It was shown that about 70% Asian-dust storms that influence China came from Mongolia, and were strengthened during the way from west to east. In 2000–2002, there was about 63.9% Asian-dust weather that might have affected China seas through three different routes. The probability is affecting the Bohai Sea was 27.4%, the Yellow Sea 30.9%, the East China Sea 12.3%, the Korea Channel 20.2% and the Japan Sea 9.2%. Annual dry deposition flux to the Yellow Sea was about 0.13 g m2 d1, and in spring was 0.20 g m2 d1. The total amount of dry deposition to the Yellow Sea was 17.9 Tg yr1. r 2007 Elsevier Ltd. All rights reserved. Keyword: Asian-dust aerosols; Movement route; Dry deposition flux; China seas
1. Introduction The Asian-dust weather (ADW) is a kind of disaster phenomena. The severe Asian dust has not only great effect on the quality of atmosphere environment in cities and on people’s health, but also can transport by northwest wind dust to the China seas, and it can exert beneficial or baneful effects on marine ecosystem (Duce et al., 1980; Uematsu et al., 1983; Merrill et al., 1989; Wang Corresponding author. Laboratory of Marine Environmental
Science and Ecology, Ocean University of China, Qingdao 266003, China. E-mail address: [email protected] (Z. Kai). 1352-2310/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2007.08.007
et al., 2000; Shao et al., 2003a,b). Central Asia is one of the world’s largest dust sources. There is a huge belt of arid and semi-arid areas in the world map from Central Eurasia to the Far East, i.e. Kazakhstan, Mongolia and Northern China. Many Asia Dust storms occur frequently in these areas (Qiu et al., 2001; Qian et al., 2002). The atmosphere has been known to be a significant pathway for the transport of Asian-dust aerosols (ADA) from the west of China to the coastal areas and oceans. Some previous studies show that the meteorological conditions, strong wind behind the cyclone and free troposphere by westerly jet, are favorable for transportation of the Asian dust to the China seas (Merrill et al., 1989;
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Kim and Park, 2001). There have been many researches regarding the long-range transport of Asian dust to Hong Kong, Taiwan (Fang et al., 1999; Lin, 2001) and the China sea, such as the Bohai Sea and the Yellow Sea (Gao et al., 1992a; Liu et al., 1998; Zhang et al., 2001), the Korea Channel (Kim and Park, 2001; Ogunjobi et al., 2004), the Japan Sea (Ma et al., 2001, 2004), and even the West Pacific Ocean (Gao et al., 1992b; Zhang, 1994). Duce et al. (1980) and Uematsu et al. (1983) found that the mineral aerosols of the West Pacific Ocean originated mainly from the arid region of central and eastern Asia. Zhang et al. (1992) found that the atmosphere aerosols and the deposition in the North Pacific Ocean had relations with the Loess Plateau of China. The ADW plays an active role in the biogeochemical cycles of trace elements in the mid-latitude Northern Hemisphere (Okada et al., 1990; Zhang et al., 1997). Therefore, the interest of atmospheric chemists and aerosols scientists has turned to the matter exchange between atmosphere and ocean. The study of dust deposition, the seas and its effect on marine ecosystem has become the main points in several international core projects of International Geosphere-Biosphere Programme (IGBP), such as Surface Ocean-Lower Atmosphere Study (SOLAS) and Joint Global Ocean Flux Study (JGOFS). The long-range transport of Asian dust may even contribute to the formation of haze layers in the China sea, and the Asian dust from the Asian continent may exert significant radiative forcing over a large area of the North Pacific region (Uematsu et al., 1983; Gao et al., 1992a, b). A large number of studies on the ADA to the China seas have been reported. However, most of these studied either single case of Asian dust storms or several ones (Fang et al., 1999; Kim and Park, 2001; Lin, 2001; Ma et al., 2001). Where the whole series of these storms each year ADA come from? What is the probability of ADA deposition into China seas? What is the flux of ADA observed deposition into the Yellow Sea? During 2000–2002, about 42 severe dust storms occurred in north China and most cases were found to transport dust aerosols long distances, even to China seas. Based on the Micaps meteorology data provided by China Meteorological Administration and observations of dry aerosol deposition flux in Beijing and Qingdao, 42 cases influencing the mainland and China areas and the dry deposition flux to the Yellow Sea were analyzed.
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2. The source of Asian-dust aerosols Loess lands, deserts and ‘‘Gobi deserts’’ are widely distributed along with deserts in the northwest Asia, where the Climate is very dry and the natural environment is very poor. The desert/Gobi region in northwest of China is located at high elevation and covers an area of 1.3 106 km2 (Zhang et al., 2001). The magnitude of Asian-dust emissions from this source remains highly uncertain but is expected to be of the order of 800 Tg yr1 (Zhang et al., 1997). Shao et al. (2003b) studied that the net dust emission of the Gobi desert reaches 16 t km2 d1 and the Loess Plateau receives about 1.6–4.3 t km2 d1. There were about 42 ADW episodes in 2000–2002, 12 cases in 2000, 18 cases in 2001, and 12 cases in 2002, respectively. Shao and Wang (2003a) analyzed the synoptic features of ADW episodes of 2000–2002, respectively. They found that ADW episodes in different regions were generated by different synoptic systems. Almost all ADW episodes were generated by the strong northwesterly air flows in the cold regimes of lowpressure systems. In Taklimakan desert, ADW was mostly associated with light winds. In this paper, we define the original region of ADW episodes as the first station that finds the dust storm. The ADW episodes were classified into two types according to their original region: episodes with source inside China and those with their sources outside China. In statistical studies on the Asian-dust cases during 2000–2002, about 70% of the ADW episodes affecting China originated from Mongolia. The desert of Inner-Mongolia, the Gobi Desert and the Loess Plateau of China strengthened the ADW episodes greatly when they transported from west to east in China (Liu et al., 2004). The original region of ADW episodes was different from the sources of ADA episodes. It is shown in Fig. 1 that the source area of ADA episodes moved to the east gradually year by year from 2000 to 2002. In 2000–2002, the main source areas of ADA episodes were located in the deserts in Inner-Mongolia, Taklimakan desert and Loess Plateau or even intrusions from Mongolia. Within the 12 dust weathers in 2000 (Fig. 1a), 75.0% of ADW originated from Mongolia. About 11.1% of ADA came from Mongolia, 56.9% came from Inner-Mongolia, and 23.6% came from the Loess Plateau. In 2001 (Fig. 1b), 66.7% of ADW originated from Mongolia. We observes that
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Fig. 1. Source is of Asian-dust aerosols in 2000–2002. The numbers under the name of a place in these figures are the percent of Asian-dust weathers from this area contributing to the total number of dust weathers in this year. (a) 2000; (b) 2001 and (c) 2002.
70.4% of ADA came from Inner-Mongolia, 14.8% from Mongolia and 18.5% from Taklimakan desert. In 2002 (Fig. 1c), 66.7% of ADW originated from
Mongolia. From Inner-Mongolia 54.2% of ADA came and 29.2% from Mongolia. Loess Plateau mainly added to or enhanced the degrees of severely
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of the dust weather. In 2000, 23.6% ADA episodes were strengthened in this plateau. Dust aerosols enhanced in Loess Plateau mainly affected the North China Plain, and the middle and lower reaches of the Yangtze River. 3. The movement route of Asian-dust aerosols to the sea The long-range transport of ADA from East Asia over the East China Sea and the North Pacific Ocean has well been recognized and documented in the literature over the past several years (Duce et al., 1980; Gao et al., 1992a, b; Liu et al., 1998; Wang et al., 2000; Kim and Park, 2001; Lin, 2001; Zhang et al., 2001). A study showed that the ADA were transported in the free troposphere at about 700 mbar from the west to the east (Duce et al., 1980). Lin (2001) found that the long-range transport of ADA to Taiwan was usually, in height between 500 and 1500 m. Fang et al. (1999) found that the ADA reached Hong Kong by way of the East China Sea. Kim and Park (2001) observed a sand transportation case during 25–27 January 1999, another originated from the arid region of central and eastern Asia. ADA were transported from the Gobi desert, Loess Plateau, the Shandong Peninsula another reached the Bohai Sea, the Yellow Sea and even Korea Peninsula. It was examined whether frequent strong winds were the primary reason for frequent occurrences of dust outbreak during 2000–2002 through the annual variation and spatial distribution between dust outbreak and surface wind (Kurosaki and Mikami,
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2003). Some meteorological conditions necessary for a severe dust storm are: strong surface wind to lift dust particles, strong turbulence or convection to disperse dust particles several hundreds of meters, and strong wind to transport dust particles over long distances (Shao et al., 2003a). Lim and Chun (2006) found that the distributions of threshold wind velocity of ADW, 6.5 m s1 were very similar during the entire period 1993–2004. By the north–west air current, more than half of the ADW from the northwest China was found to be distributed widely in the northern part of China and the remaining half was transported long distances to the sea, in 2000–2002. Of these ADWs nine instances affected the China sea in 2000, eight instances in 2001, and eight instances in 2002. After analyzing all these cases, we found that the ADA moved into China sea through different routes. The movement routs of ADA was defined as the appearance frequency of ADA in each weather station in 2000–2002. In general, we observed three movement routes of ADA to the sea (Fig. 2). They are: (1) the Asian dust storm that occurred in Mongolia entering China from the east of innerMongolia, by the way of Hunshandake desert and Horqin desert. There deposited dust into the Bohai Sea, the Korea Strait, the Japan Sea and the Yellow Sea (Route 1). The character of these was short movement distance and high frequency. (2) Asian dust coming from Mongolia entering China from the west of inner-Mongolia. The transported from west to east, and branched into three paths as shown in Fig. 2, and then the sunk into the Bohai Sea, the Yellow Sea, the Korea Strait, the Japan Sea
Fig. 2. Movement routes of Asian-dust aerosols to the sea in 2000–2002.
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and the East China Sea (Route 2). The character of these was long movement distance. The source of ADA was more than one, and the affected range was wide. (3) Asian dust that occurred in Mongolia and the northwest of China that transported by the high northwest current and sunk into the Yellow Sea, the East China Sea and even the West Pacific Ocean (Route 3). The character of these was low frequency, and this route was the effective way for ADA to the East China Sea and the West Pacific Ocean. The three routes were not independent, combination patterns are possible, especially when the dust storm is strong, as with the storm that occurred happened during 19–22 March 2002. Taklimakan desert has frequently high ADW (Fig. 1), but few ADA could affect the other region which was associated with the synoptic system and the topography (Shao et al., 2003). 4. Probability of Asian-dust deposition in China seas In 2000–2002, there were about 63.9% ADW that affected China seas. In 2000, the Korea Strait is probability the most affect sea in ADA, and the effect probability was 31.1%. Then, comes Bohai Sea with 22% and thus the Yellow Sea with 20.2%. In 2001 and 2002, the Yellow Sea was affects with high probability, and the probabilities were 39.5% and 33.0%, respectively. Then comes the Bohai Sea, 31.2% in 2001 and 29% in 2002. In a word, the
14.8%
22.0%
probability of ADA deposition to the Bohai Sea and the Yellow Sea was more than probability of deposition in this East China Sea, and probability of deposition into the South China Sea was the least (Fig. 3). The region origination of ADA to the Bohai Sea mostly is the east of Inner-Mongolia, some parts of Mongolia, the west of Inner-Mongolia and Loess Plateau. Some ADA episodes had origin in Mongolia and the east of Inner-Mongolia, and some from the west of Inner-Mongolia, Taklimakan desert and Loess Plateau deposition in the Yellow Sea. The region of origination of ADA the Korea Strait and the Japan Sea is mostly Mongolia, west of Inner-Mongolia, that culminated in east of InnerMongolia and Loess Plateau. The region of origination of ADA that ended in the East China Sea is Mongolia, the desert of Inner-Mongolia, Taklimakan desert, Chaidamu Basin and Loess Plateau. The storm that occurred during 19–22 March 2002 was the strongest since 1995, the year from which China began to monitor dust storms systematically. This strong dust storms affect more than 120 countries in eight northern provinces and about 130 million people get affected. Air Pollution Index (API) (is released from State Environmental Protection Administration. If API is 4300, it means the air is severely polluted). On 20 March for Hohhot (Inner-Mongolia), Lanzhou (Gansu) and Xining Bohai Sea
7.8% 12.8%
Yellow Sea
31.2%
East China Sea Korea Strait Japan Sea
8.7% 31.1%
20.2%
2000 year
11.9%
2000 year
5.0% 16.5%
39.5%
9.2% 27.4%
29.0% 20.2%
16.5% 12.3% 2002 year
33.0%
the average of three year
30.9%
Fig. 3. Probability of Asian-dust aerosols deposition into different seas.
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(Qinghai) all topped, with a maximum of 500. Severe dusty weather also affected Korea and Japan. This severe storm originated in Mongolia, and the city of Hami, Xinjiang Province, was the first station in China to record the dust storm at 02:00, 19 March 2002 (Fig. 4). The source of this ADA was in Mongolia, the west of Inner-Mongolia to Loess Plateau and the east of Inner-Mongolia. This
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deposited dust the Bohai Sea, the Yellow Sea on 20 March 2002, and into the Korea Strait and the Japan Sea on 21 March 2002. The main route of ADA to the sea was Mongolia-the west of InnerMongolia-Loess Plateau and the east of InnerMongolia-the Bohai Sea, the Yellow Sea, the Korea Strait and the Japan Sea (Routes 1 and 2). Other route of the ADA was from Mongolia, InnerMongolia and Loess Plateau, and it deposited into
Fig. 4. Dust phenomenon during the period from 19 to 22 March 2002.
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the East China Sea and the West Pacific Ocean through the high transport (Route 3). According to the satellite data, part of ADA was transported and deposited in the East China Sea and even in the West Pacific Ocean. 5. The dry deposition flux to the Yellow Sea Zhang (1994) found that on comparison with riverine input nutrition element, the atmospheric deposition has significant impact on marine bioproductions in this region, which may be of equal or even more importance compared to river impact. Therefore, studying deposition flux from atmosphere to the sea is important. The Yellow Sea is a semi-enclosed, western Pacific marginal sea occupying the broad continental shelf between China and Korea. The area is about 3.8 105 km2. Zhang et al. (2001) indicated that the ADA samples from the Yellow Sea showed a strong relationship with the Asian desert area. In order to analyze the dry deposition flux to the Yellow Sea, we measured aerosol sample at Qingdao, which was a coastal city bordering the Yellow Sea in the east (Fig. 5). At the same time, we also measured aerosol sample at Beijing to compare the difference dry deposition between the coastal city (Qingdao) and the inland city (Beijing). Aerosol samples were collected by Nuclepore filter for inorganic species. The filters were dried and weighed to estimate the concentration of aerosols in the laboratory which was kept at a constant temperature (25 1C) and constant humidity (37%) before and after collecting the sample. The sample
change was undertaken in a clean room, with all protection and precautions taken to avoid contamination. The dry deposition collector was a box made of stainless steel. The of the bottom was a rectangle 25 cm 20 cm, and the effective area was 22.5 cm 17.5 cm, and the height of the box was 25 cm (Odabasi et al., 2002). The formula used for calculating the dry deposition flux is F¼
W after W before , ST
where F is the dry deposition flux. Wafter and Wbefore stand for the filter weight before and after the experiment, respectively. S represents the area of the filter (0.225 m 0.175 m) and T represents the duration of the experiment. The sampling instrument in Beijing (391580 N, 1161220 E) was installed on the roof of the State Key Laboratory of atmospheric Boundary Layer Physics and Atmospheric Chemistry building (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Science (CAS). The building is about 8 m high above the ground and is located near a residential area, in the northwest part of Beijing between the third and fourth ring roads of the city. The sampling instrument in Qingdao (361030 N, 1201250 E) was installed on the top of Baguanshan mountain, inside of Ocean University of China. The altitude of Baguanshan mountain is 65 m above the mean sea level (msl), and the station is near seashore. The experimental ran continuously from the 27 March 2002 to the 28 February 2003 in Beijing, and from 1 May 2001 to 17 December 2002 in Qingdao.
Fig. 5. Location of Qingdao and Beijing.
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ADW occurred most frequently in spring, between March and May, and showed a clear seasonal cycle. Fig. 6 showed obviously that the dry deposition flux was higher in spring than in other seasons ADW. The dry deposition flux during Asian-dust season was 10 times more than that in non-Asian-dust season. The dry deposition flux of ADA reached 8.1 g m2 d1 on 8 April 2002 in Beijing which was 30 times higher than the usual levels. The concentration of atmosphere aerosols was higher in May in Qingdao than the annual average, and the dry deposition flux increased because ADW occurred most frequently in spring (March–May). The second higher dry deposition flux appeared in November in winter during which the ADW easily occurs at desert and loess areas in northwest of China continent. The average dry deposition flux was 0.20–0.30 g m2 d1 in Beijing and 0.13 g m2 d1 in Qingdao in (Fig. 6). The dry deposition fluxes in Beijing and that is Qingdao during 1–31 October 2002 and 1 November to 1 December 2002 were as follows: the fluxed in Beijing were 0.33 and 0.42 g m2 d1, respectively, and the fluxes in Qingdao were 0.13 and 0.16 g m2 d1, respectively. The dry deposition flux in Beijing were 3.2 and 2.7 times those in Qingdao. One reason is the distance between the sources of ADA and the cities; and the other reason is the background meteorology condition. Beijing lies in the northwest of the north China plain. Atmosphere is dry and the dust aerosols are emitted from the ground in wind. Qingdao is a coastal city, lies in the southern tip of the Shandong Peninsula in Northern China. Atmosphere was wet and the dust aerosols are less. Uematsu et al. (1985) estimated the total deposition of atmospheric mineral to the central North
Pacific to be 20 Tg yr1. Gao et al. (1997) estimated the total atmospheric deposition of dust to the China Sea to be 67 Tg yr1, and the accounts for 14% of the total atmospheric deposition of dust in the entire North Pacific Ocean. In our experiment, all dry deposition of the ADA to the Yellow Sea was estimated at 17.9 Tg yr1. Gao et al. (1992a) estimated that atmospheric fluxes over the Yellow Sea ranged from 10 to 89 g m2 yr1. Zhang et al. (1993) studied the annual Asian-dust flux to the Yellow Sea during 1989–1990, and found the average as 50–60 g m2 yr1. In our experiment, the annual dry deposition flux of ADA to the Yellow Sea was about 51.3 g m2 yr1 and in spring (March–May) it was 73 g m2 yr1. The difference in the dust flux estimates was due to the different methodologies used for the dust measurement. In addition, this estimate of the dust flux to the Yellow Sea was based on data from several sites, and this may not be representative and applicable to the entire Yellow Sea. In Fig. 6, we can see that most of the effective samples in Qingdao were collected in spring and autumn, and because the ADA emission in the spring season accounts for a half of that of a whole year (Xuan et al., 2000), the average flux to the Yellow Sea was higher than the real one. 6. Conclusion There were about 42 cases influencing the mainland China areas in 2000–2002, 12 cases in 2000, 18 cases in 2001, and 12 cases in 2002, respectively. The origins of ADW episodes were different from the sources of ADA episodes, and about 70% ADW episodes that influenced China originated in Mongolia. Northwest air current, supports about 63.9% ADW episodes that were capable of affecting China
1.6
0.25 dry deposition flux (g m-2 d-1)
dry deposition flux (g m-2 d-1)
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1.4
Beijing
1.2 1 0.8 0.6 0.4 0.2 0
0.2
Qingdao
0.15 0.1 0.05 0
Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb 2002
2003 Month
May
Jun
Sep
Nov
Dec
2001
Feb 2002
Month
Fig. 6. Seasonal variation of dry deposition flux in Qingdao and Beijing.
Oct
Nov
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seas. The ADA came to the sea through three different routes. First one was Mongolia-the east of Inner-Mongolia-the Bohai Sea, the Yellow Sea, the Korea Strait and the Japan Sea. Second one was Mongolia, Taklimakan desert-the west of InnerMongolia, the Loess Plateau-the Bohai Sea, the Yellow Sea, the East China Sea, the Korea Strait and the Japan Sea. Third one was Taklimakan desert, Chaidamu Basin-the Loess Plateau-the Yellow Sea, the East China Sea and the West Pacific Ocean. The probability of the Bohai Sea getting affected was 27.4%, the Yellow Sea 30.9%, the East China Sea 12.3%, the Korea Channel 20.2% and the Japan Sea 9.2%, respectively. The all dry deposition of the Yellow Sea was 17.9 Tg yr1. The dry deposition flux of ADA was higher in spring (73 g m2 yr1) than the in annual average (51.3 g m2 yr1). Since the impact of ADA on the oceanic biosphere largely depends on the quantity of material deposited, such a high dry deposition flux of ADA over East Asia must play an important role in biogeochemical cycles in the Yellow Sea.
Acknowledgments This project was supported by NSFC Key Project under grant no. 4049062. The authors gratefully acknowledge Zhu Yanjun who provided us the Micaps meteorology data in 2000–2002, Zhang Renjian and Sheng Lifang who provided us the dry deposition of Asian-dust aerosol data in Beijing and Qingdao.
References Duce, R.A., Unni, C.K., Ray, B.J., Prospero, J.M., Merrill, J.T., 1980. Long-range atmospheric transport of soil dust from Asia to the tropical North Pacific: temporal variability. Science 209, 1522–1524. Fang, M., Zheng, M., Wang, F., Chim, K.S., Kot, S.C., 1999. The long-range transport of aerosols from northern China to Hong Kong—a multi-technique study. Atmospheric Environment 33, 1803–1817. Gao, Y., Arimoto, R., Duce, R.A., Lee, D.S., Zhou, M.Y., 1992a. Input of atmospheric trace elements and the mineral matter to the Yellow Sea during the spring of a low-dust year. Journal of Geophysical Research 97, 3767–3777. Gao, Y., Arimoto, R., Merril, J.T., Duce, R.A., 1992b. Relationship between the dust concentration over eastern Asia and the remote North Pacific. Journal of Geophysical Research 97, 9867–9872.
Gao, Y., Arimoto, R., Duce, R.A., et al., 1997. Temporal and spatial distributions of dust and its deposition to the China Sea. Tellus 49B (2), 172–189. Kim, B.G., Park, S.U., 2001. Transport and evolution of a winter-time Yellow Asian observed in Korea. Atmospheric Environment 35, 3191–3201. Kurosaki, Y., Mikami, M., 2003. Recent frequent dust events and their relation to surface wind in East Asia. Geophysical Research Letters 30, 1,736. Lim, J.Y., Chun, Y., 2006. The characteristics of Asian dust events in Northeast Asia during the springtime from 1993 to 2004. Global and Planetary Change 52, 231–247. Lin, T.H., 2001. Long-range transport of yellow Asian to Taiwan in Spring 2000: observed evidence and simulation. Atmospheric Environment 35, 5873–5882. Liu, C.L., Zhang J., Yu, Z.G., et al., 1998. Atmospheric transport of heavy metals to the Yellow Sea. In: G.H. Hong, J. Zhang, B.K. Park (Eds.), Health of the Yellow Sea. South Korea. Liu, W., Feng, Q., Wang, T., Zhang, Y., Shi, J., 2004. Physicochemistry and mineralogy of storm dust and dust sediment in Northern China. Advances in Atmospheric Sciences 21 (5), 775–783. Ma, C.J., Kasahara, M., Ho¨ller, R., Kamiya, T., 2001. Characteristics of single particles sampled in Japan during the Asian dust-storm period. Atmospheric Environment 35, 2707–2714. Ma, C.J., Tohno, S., Kasahara, M., Hayakawa, S., 2004. Properties of the size-resolved and individual cloud droplets collected in western Japan during the Asian dust storm event. Atmospheric Environment 38, 4519–4529. Merrill, J.T., Uematsu, M., Bleck, R., 1989. Meteorological analyses of long-range transport of mineral aerosol over the North Pacific. Journal of Geophysical Research 94, 8584–8598. Odabasi, M., Muezzinoglu, A., Bozlaker, A., 2002. Ambient concentrations and dry deposition fluxes of trace elements in Izmir, Turkey. Atmospheric Environment 36, 5841–5851. Ogunjobi, K.O., He, Z., Kim, K.W., Kim, Y.J., 2004. Aerosol optical depth during episodes of Asian dust storms and biomass burning at Kwangju, South Korea. Atmospheric Environment 38, 1313–1323. Okada, K., Narus, H., Tanaka, T., Nemoto, O., 1990. X-ray spectrometry of individual Asian dust-storm particles over the Japanese islands and the North Pacific Ocean. Atmospheric Environment 24A (6), 1369–13780. Qian, Z.A., Song, M.H., Li, W.Y., 2002. Analyses on distributive variation and forecast of sand-dust storms in recent 50 years in North China. Journal of Desert Research 22 (2), 106–111 (in Chinese). Qiu, X.F., Zen, Y., Miao, Q.L., 2001. Temporal-spatial distribution as well as tracks and source areas of Asian-dust storms in China. Acta Geographica Sinica 56 (3), 316–322 (in Chinese). Shao, Y., Wang, J., 2003a. A climatology of Northeast Asian dust events. Meteorologische Zeitschrift 12 (4), 187–196. Shao, Y., Yang, Y., Wang, J., et al., 2003b. Northeast Asian dust storms: real-time numerical prediction and validation. Journal of Geophysical Research 108 (D22), 4691. Uematsu, M., Duce, R.A., Prospero, J.M., et al., 1983. Transport of mineral aerosol from Asia over the North Pacific Ocean. Journal of Geophysics Research 88, 5343–5352.
ARTICLE IN PRESS Z. Kai, G. Huiwang / Atmospheric Environment 41 (2007) 9136–9145 Uematsu, M., Duce, R.A., Prospero, J.M., 1985. Deposition of atmospheric mineral particles in the North Pacific Ocean. Journal of Atmospheric Chemistry 3 (1), 123–138. Wang, Z.F., Ueda, H.M., Huang, M.Y., 2000. A deflation module for use in modeling long-range transport of yellow Asian over East Asia. Journal of Geophysics Research 105, 26947–26959. Xuan, J., Liu, G., Du, K., 2000. Dust emission inventory in Northern China. Atmospheric Environment 34, 4565–4570. Zhang, J., 1994. Atmospheric wet deposition of nutrient elements: correlation with harmful biological blooms in northwest Pacific Coastal Zones. AMBIO 23 (8), 173–189. Zhang, J., Huang, W.W., Liu, S.M., et al., 1992. Transport of particulate heavy metals towards the China Sea: a
9145
preliminary study and comparison. Marine Chemistry 40 (3), 161–178. Zhang, J., Liu, S.M., Lu, X., et al., 1993. Characterizing Asian winddust transport to the Northwest Pacific Ocean. Direct measurement of the dust flux for two years. Tellus 45B (4), 335–345. Zhang, X.Y., Arimoto, R., An, Z.S., 1997. Dust emissions from Chinese desert sources linked to variations in atmospheric circulation. Journal of Geophysical Research 102, 28041–28047. Zhang, J., Wu, Y., Liu, C.L., Shen, Z.B., Yu, Z.G., Zhang, Y., 2001. Aerosol characters from the desert region of Northwest China and the Yellow Sea in spring and summer: observations at Minqin, Qingdao, and Qianliyan in 1995–1996. Atmospheric Environment 35, 5007–5018.
Atmospheric Environment 41 (2007) 9136–9145 www.elsevier.com/locate/atmosenv
The characteristics of Asian-dust storms during 2000–2002: From the source to the sea Zhang Kaia,b,, Gao Huiwanga a
Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Qingdao 266003, China b Institute of Atmospheric Physics (IAP), Chinese Academy of Science (CAS), Beijing 100029, China Received 21 June 2006; received in revised form 30 July 2007; accepted 1 August 2007
Abstract About 42 Asian-dust storms influenced the mainland and China during 2000–2002. Based on the Micaps meteorology data provided by China Meteorological Administration, the basic characteristics, including the source, movement route and influenced areas were studied for each case. It was shown that about 70% Asian-dust storms that influence China came from Mongolia, and were strengthened during the way from west to east. In 2000–2002, there was about 63.9% Asian-dust weather that might have affected China seas through three different routes. The probability is affecting the Bohai Sea was 27.4%, the Yellow Sea 30.9%, the East China Sea 12.3%, the Korea Channel 20.2% and the Japan Sea 9.2%. Annual dry deposition flux to the Yellow Sea was about 0.13 g m2 d1, and in spring was 0.20 g m2 d1. The total amount of dry deposition to the Yellow Sea was 17.9 Tg yr1. r 2007 Elsevier Ltd. All rights reserved. Keyword: Asian-dust aerosols; Movement route; Dry deposition flux; China seas
1. Introduction The Asian-dust weather (ADW) is a kind of disaster phenomena. The severe Asian dust has not only great effect on the quality of atmosphere environment in cities and on people’s health, but also can transport by northwest wind dust to the China seas, and it can exert beneficial or baneful effects on marine ecosystem (Duce et al., 1980; Uematsu et al., 1983; Merrill et al., 1989; Wang Corresponding author. Laboratory of Marine Environmental
Science and Ecology, Ocean University of China, Qingdao 266003, China. E-mail address: [email protected] (Z. Kai). 1352-2310/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2007.08.007
et al., 2000; Shao et al., 2003a,b). Central Asia is one of the world’s largest dust sources. There is a huge belt of arid and semi-arid areas in the world map from Central Eurasia to the Far East, i.e. Kazakhstan, Mongolia and Northern China. Many Asia Dust storms occur frequently in these areas (Qiu et al., 2001; Qian et al., 2002). The atmosphere has been known to be a significant pathway for the transport of Asian-dust aerosols (ADA) from the west of China to the coastal areas and oceans. Some previous studies show that the meteorological conditions, strong wind behind the cyclone and free troposphere by westerly jet, are favorable for transportation of the Asian dust to the China seas (Merrill et al., 1989;
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Kim and Park, 2001). There have been many researches regarding the long-range transport of Asian dust to Hong Kong, Taiwan (Fang et al., 1999; Lin, 2001) and the China sea, such as the Bohai Sea and the Yellow Sea (Gao et al., 1992a; Liu et al., 1998; Zhang et al., 2001), the Korea Channel (Kim and Park, 2001; Ogunjobi et al., 2004), the Japan Sea (Ma et al., 2001, 2004), and even the West Pacific Ocean (Gao et al., 1992b; Zhang, 1994). Duce et al. (1980) and Uematsu et al. (1983) found that the mineral aerosols of the West Pacific Ocean originated mainly from the arid region of central and eastern Asia. Zhang et al. (1992) found that the atmosphere aerosols and the deposition in the North Pacific Ocean had relations with the Loess Plateau of China. The ADW plays an active role in the biogeochemical cycles of trace elements in the mid-latitude Northern Hemisphere (Okada et al., 1990; Zhang et al., 1997). Therefore, the interest of atmospheric chemists and aerosols scientists has turned to the matter exchange between atmosphere and ocean. The study of dust deposition, the seas and its effect on marine ecosystem has become the main points in several international core projects of International Geosphere-Biosphere Programme (IGBP), such as Surface Ocean-Lower Atmosphere Study (SOLAS) and Joint Global Ocean Flux Study (JGOFS). The long-range transport of Asian dust may even contribute to the formation of haze layers in the China sea, and the Asian dust from the Asian continent may exert significant radiative forcing over a large area of the North Pacific region (Uematsu et al., 1983; Gao et al., 1992a, b). A large number of studies on the ADA to the China seas have been reported. However, most of these studied either single case of Asian dust storms or several ones (Fang et al., 1999; Kim and Park, 2001; Lin, 2001; Ma et al., 2001). Where the whole series of these storms each year ADA come from? What is the probability of ADA deposition into China seas? What is the flux of ADA observed deposition into the Yellow Sea? During 2000–2002, about 42 severe dust storms occurred in north China and most cases were found to transport dust aerosols long distances, even to China seas. Based on the Micaps meteorology data provided by China Meteorological Administration and observations of dry aerosol deposition flux in Beijing and Qingdao, 42 cases influencing the mainland and China areas and the dry deposition flux to the Yellow Sea were analyzed.
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2. The source of Asian-dust aerosols Loess lands, deserts and ‘‘Gobi deserts’’ are widely distributed along with deserts in the northwest Asia, where the Climate is very dry and the natural environment is very poor. The desert/Gobi region in northwest of China is located at high elevation and covers an area of 1.3 106 km2 (Zhang et al., 2001). The magnitude of Asian-dust emissions from this source remains highly uncertain but is expected to be of the order of 800 Tg yr1 (Zhang et al., 1997). Shao et al. (2003b) studied that the net dust emission of the Gobi desert reaches 16 t km2 d1 and the Loess Plateau receives about 1.6–4.3 t km2 d1. There were about 42 ADW episodes in 2000–2002, 12 cases in 2000, 18 cases in 2001, and 12 cases in 2002, respectively. Shao and Wang (2003a) analyzed the synoptic features of ADW episodes of 2000–2002, respectively. They found that ADW episodes in different regions were generated by different synoptic systems. Almost all ADW episodes were generated by the strong northwesterly air flows in the cold regimes of lowpressure systems. In Taklimakan desert, ADW was mostly associated with light winds. In this paper, we define the original region of ADW episodes as the first station that finds the dust storm. The ADW episodes were classified into two types according to their original region: episodes with source inside China and those with their sources outside China. In statistical studies on the Asian-dust cases during 2000–2002, about 70% of the ADW episodes affecting China originated from Mongolia. The desert of Inner-Mongolia, the Gobi Desert and the Loess Plateau of China strengthened the ADW episodes greatly when they transported from west to east in China (Liu et al., 2004). The original region of ADW episodes was different from the sources of ADA episodes. It is shown in Fig. 1 that the source area of ADA episodes moved to the east gradually year by year from 2000 to 2002. In 2000–2002, the main source areas of ADA episodes were located in the deserts in Inner-Mongolia, Taklimakan desert and Loess Plateau or even intrusions from Mongolia. Within the 12 dust weathers in 2000 (Fig. 1a), 75.0% of ADW originated from Mongolia. About 11.1% of ADA came from Mongolia, 56.9% came from Inner-Mongolia, and 23.6% came from the Loess Plateau. In 2001 (Fig. 1b), 66.7% of ADW originated from Mongolia. We observes that
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Fig. 1. Source is of Asian-dust aerosols in 2000–2002. The numbers under the name of a place in these figures are the percent of Asian-dust weathers from this area contributing to the total number of dust weathers in this year. (a) 2000; (b) 2001 and (c) 2002.
70.4% of ADA came from Inner-Mongolia, 14.8% from Mongolia and 18.5% from Taklimakan desert. In 2002 (Fig. 1c), 66.7% of ADW originated from
Mongolia. From Inner-Mongolia 54.2% of ADA came and 29.2% from Mongolia. Loess Plateau mainly added to or enhanced the degrees of severely
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of the dust weather. In 2000, 23.6% ADA episodes were strengthened in this plateau. Dust aerosols enhanced in Loess Plateau mainly affected the North China Plain, and the middle and lower reaches of the Yangtze River. 3. The movement route of Asian-dust aerosols to the sea The long-range transport of ADA from East Asia over the East China Sea and the North Pacific Ocean has well been recognized and documented in the literature over the past several years (Duce et al., 1980; Gao et al., 1992a, b; Liu et al., 1998; Wang et al., 2000; Kim and Park, 2001; Lin, 2001; Zhang et al., 2001). A study showed that the ADA were transported in the free troposphere at about 700 mbar from the west to the east (Duce et al., 1980). Lin (2001) found that the long-range transport of ADA to Taiwan was usually, in height between 500 and 1500 m. Fang et al. (1999) found that the ADA reached Hong Kong by way of the East China Sea. Kim and Park (2001) observed a sand transportation case during 25–27 January 1999, another originated from the arid region of central and eastern Asia. ADA were transported from the Gobi desert, Loess Plateau, the Shandong Peninsula another reached the Bohai Sea, the Yellow Sea and even Korea Peninsula. It was examined whether frequent strong winds were the primary reason for frequent occurrences of dust outbreak during 2000–2002 through the annual variation and spatial distribution between dust outbreak and surface wind (Kurosaki and Mikami,
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2003). Some meteorological conditions necessary for a severe dust storm are: strong surface wind to lift dust particles, strong turbulence or convection to disperse dust particles several hundreds of meters, and strong wind to transport dust particles over long distances (Shao et al., 2003a). Lim and Chun (2006) found that the distributions of threshold wind velocity of ADW, 6.5 m s1 were very similar during the entire period 1993–2004. By the north–west air current, more than half of the ADW from the northwest China was found to be distributed widely in the northern part of China and the remaining half was transported long distances to the sea, in 2000–2002. Of these ADWs nine instances affected the China sea in 2000, eight instances in 2001, and eight instances in 2002. After analyzing all these cases, we found that the ADA moved into China sea through different routes. The movement routs of ADA was defined as the appearance frequency of ADA in each weather station in 2000–2002. In general, we observed three movement routes of ADA to the sea (Fig. 2). They are: (1) the Asian dust storm that occurred in Mongolia entering China from the east of innerMongolia, by the way of Hunshandake desert and Horqin desert. There deposited dust into the Bohai Sea, the Korea Strait, the Japan Sea and the Yellow Sea (Route 1). The character of these was short movement distance and high frequency. (2) Asian dust coming from Mongolia entering China from the west of inner-Mongolia. The transported from west to east, and branched into three paths as shown in Fig. 2, and then the sunk into the Bohai Sea, the Yellow Sea, the Korea Strait, the Japan Sea
Fig. 2. Movement routes of Asian-dust aerosols to the sea in 2000–2002.
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and the East China Sea (Route 2). The character of these was long movement distance. The source of ADA was more than one, and the affected range was wide. (3) Asian dust that occurred in Mongolia and the northwest of China that transported by the high northwest current and sunk into the Yellow Sea, the East China Sea and even the West Pacific Ocean (Route 3). The character of these was low frequency, and this route was the effective way for ADA to the East China Sea and the West Pacific Ocean. The three routes were not independent, combination patterns are possible, especially when the dust storm is strong, as with the storm that occurred happened during 19–22 March 2002. Taklimakan desert has frequently high ADW (Fig. 1), but few ADA could affect the other region which was associated with the synoptic system and the topography (Shao et al., 2003). 4. Probability of Asian-dust deposition in China seas In 2000–2002, there were about 63.9% ADW that affected China seas. In 2000, the Korea Strait is probability the most affect sea in ADA, and the effect probability was 31.1%. Then, comes Bohai Sea with 22% and thus the Yellow Sea with 20.2%. In 2001 and 2002, the Yellow Sea was affects with high probability, and the probabilities were 39.5% and 33.0%, respectively. Then comes the Bohai Sea, 31.2% in 2001 and 29% in 2002. In a word, the
14.8%
22.0%
probability of ADA deposition to the Bohai Sea and the Yellow Sea was more than probability of deposition in this East China Sea, and probability of deposition into the South China Sea was the least (Fig. 3). The region origination of ADA to the Bohai Sea mostly is the east of Inner-Mongolia, some parts of Mongolia, the west of Inner-Mongolia and Loess Plateau. Some ADA episodes had origin in Mongolia and the east of Inner-Mongolia, and some from the west of Inner-Mongolia, Taklimakan desert and Loess Plateau deposition in the Yellow Sea. The region of origination of ADA the Korea Strait and the Japan Sea is mostly Mongolia, west of Inner-Mongolia, that culminated in east of InnerMongolia and Loess Plateau. The region of origination of ADA that ended in the East China Sea is Mongolia, the desert of Inner-Mongolia, Taklimakan desert, Chaidamu Basin and Loess Plateau. The storm that occurred during 19–22 March 2002 was the strongest since 1995, the year from which China began to monitor dust storms systematically. This strong dust storms affect more than 120 countries in eight northern provinces and about 130 million people get affected. Air Pollution Index (API) (is released from State Environmental Protection Administration. If API is 4300, it means the air is severely polluted). On 20 March for Hohhot (Inner-Mongolia), Lanzhou (Gansu) and Xining Bohai Sea
7.8% 12.8%
Yellow Sea
31.2%
East China Sea Korea Strait Japan Sea
8.7% 31.1%
20.2%
2000 year
11.9%
2000 year
5.0% 16.5%
39.5%
9.2% 27.4%
29.0% 20.2%
16.5% 12.3% 2002 year
33.0%
the average of three year
30.9%
Fig. 3. Probability of Asian-dust aerosols deposition into different seas.
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(Qinghai) all topped, with a maximum of 500. Severe dusty weather also affected Korea and Japan. This severe storm originated in Mongolia, and the city of Hami, Xinjiang Province, was the first station in China to record the dust storm at 02:00, 19 March 2002 (Fig. 4). The source of this ADA was in Mongolia, the west of Inner-Mongolia to Loess Plateau and the east of Inner-Mongolia. This
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deposited dust the Bohai Sea, the Yellow Sea on 20 March 2002, and into the Korea Strait and the Japan Sea on 21 March 2002. The main route of ADA to the sea was Mongolia-the west of InnerMongolia-Loess Plateau and the east of InnerMongolia-the Bohai Sea, the Yellow Sea, the Korea Strait and the Japan Sea (Routes 1 and 2). Other route of the ADA was from Mongolia, InnerMongolia and Loess Plateau, and it deposited into
Fig. 4. Dust phenomenon during the period from 19 to 22 March 2002.
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the East China Sea and the West Pacific Ocean through the high transport (Route 3). According to the satellite data, part of ADA was transported and deposited in the East China Sea and even in the West Pacific Ocean. 5. The dry deposition flux to the Yellow Sea Zhang (1994) found that on comparison with riverine input nutrition element, the atmospheric deposition has significant impact on marine bioproductions in this region, which may be of equal or even more importance compared to river impact. Therefore, studying deposition flux from atmosphere to the sea is important. The Yellow Sea is a semi-enclosed, western Pacific marginal sea occupying the broad continental shelf between China and Korea. The area is about 3.8 105 km2. Zhang et al. (2001) indicated that the ADA samples from the Yellow Sea showed a strong relationship with the Asian desert area. In order to analyze the dry deposition flux to the Yellow Sea, we measured aerosol sample at Qingdao, which was a coastal city bordering the Yellow Sea in the east (Fig. 5). At the same time, we also measured aerosol sample at Beijing to compare the difference dry deposition between the coastal city (Qingdao) and the inland city (Beijing). Aerosol samples were collected by Nuclepore filter for inorganic species. The filters were dried and weighed to estimate the concentration of aerosols in the laboratory which was kept at a constant temperature (25 1C) and constant humidity (37%) before and after collecting the sample. The sample
change was undertaken in a clean room, with all protection and precautions taken to avoid contamination. The dry deposition collector was a box made of stainless steel. The of the bottom was a rectangle 25 cm 20 cm, and the effective area was 22.5 cm 17.5 cm, and the height of the box was 25 cm (Odabasi et al., 2002). The formula used for calculating the dry deposition flux is F¼
W after W before , ST
where F is the dry deposition flux. Wafter and Wbefore stand for the filter weight before and after the experiment, respectively. S represents the area of the filter (0.225 m 0.175 m) and T represents the duration of the experiment. The sampling instrument in Beijing (391580 N, 1161220 E) was installed on the roof of the State Key Laboratory of atmospheric Boundary Layer Physics and Atmospheric Chemistry building (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Science (CAS). The building is about 8 m high above the ground and is located near a residential area, in the northwest part of Beijing between the third and fourth ring roads of the city. The sampling instrument in Qingdao (361030 N, 1201250 E) was installed on the top of Baguanshan mountain, inside of Ocean University of China. The altitude of Baguanshan mountain is 65 m above the mean sea level (msl), and the station is near seashore. The experimental ran continuously from the 27 March 2002 to the 28 February 2003 in Beijing, and from 1 May 2001 to 17 December 2002 in Qingdao.
Fig. 5. Location of Qingdao and Beijing.
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ADW occurred most frequently in spring, between March and May, and showed a clear seasonal cycle. Fig. 6 showed obviously that the dry deposition flux was higher in spring than in other seasons ADW. The dry deposition flux during Asian-dust season was 10 times more than that in non-Asian-dust season. The dry deposition flux of ADA reached 8.1 g m2 d1 on 8 April 2002 in Beijing which was 30 times higher than the usual levels. The concentration of atmosphere aerosols was higher in May in Qingdao than the annual average, and the dry deposition flux increased because ADW occurred most frequently in spring (March–May). The second higher dry deposition flux appeared in November in winter during which the ADW easily occurs at desert and loess areas in northwest of China continent. The average dry deposition flux was 0.20–0.30 g m2 d1 in Beijing and 0.13 g m2 d1 in Qingdao in (Fig. 6). The dry deposition fluxes in Beijing and that is Qingdao during 1–31 October 2002 and 1 November to 1 December 2002 were as follows: the fluxed in Beijing were 0.33 and 0.42 g m2 d1, respectively, and the fluxes in Qingdao were 0.13 and 0.16 g m2 d1, respectively. The dry deposition flux in Beijing were 3.2 and 2.7 times those in Qingdao. One reason is the distance between the sources of ADA and the cities; and the other reason is the background meteorology condition. Beijing lies in the northwest of the north China plain. Atmosphere is dry and the dust aerosols are emitted from the ground in wind. Qingdao is a coastal city, lies in the southern tip of the Shandong Peninsula in Northern China. Atmosphere was wet and the dust aerosols are less. Uematsu et al. (1985) estimated the total deposition of atmospheric mineral to the central North
Pacific to be 20 Tg yr1. Gao et al. (1997) estimated the total atmospheric deposition of dust to the China Sea to be 67 Tg yr1, and the accounts for 14% of the total atmospheric deposition of dust in the entire North Pacific Ocean. In our experiment, all dry deposition of the ADA to the Yellow Sea was estimated at 17.9 Tg yr1. Gao et al. (1992a) estimated that atmospheric fluxes over the Yellow Sea ranged from 10 to 89 g m2 yr1. Zhang et al. (1993) studied the annual Asian-dust flux to the Yellow Sea during 1989–1990, and found the average as 50–60 g m2 yr1. In our experiment, the annual dry deposition flux of ADA to the Yellow Sea was about 51.3 g m2 yr1 and in spring (March–May) it was 73 g m2 yr1. The difference in the dust flux estimates was due to the different methodologies used for the dust measurement. In addition, this estimate of the dust flux to the Yellow Sea was based on data from several sites, and this may not be representative and applicable to the entire Yellow Sea. In Fig. 6, we can see that most of the effective samples in Qingdao were collected in spring and autumn, and because the ADA emission in the spring season accounts for a half of that of a whole year (Xuan et al., 2000), the average flux to the Yellow Sea was higher than the real one. 6. Conclusion There were about 42 cases influencing the mainland China areas in 2000–2002, 12 cases in 2000, 18 cases in 2001, and 12 cases in 2002, respectively. The origins of ADW episodes were different from the sources of ADA episodes, and about 70% ADW episodes that influenced China originated in Mongolia. Northwest air current, supports about 63.9% ADW episodes that were capable of affecting China
1.6
0.25 dry deposition flux (g m-2 d-1)
dry deposition flux (g m-2 d-1)
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1.4
Beijing
1.2 1 0.8 0.6 0.4 0.2 0
0.2
Qingdao
0.15 0.1 0.05 0
Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb 2002
2003 Month
May
Jun
Sep
Nov
Dec
2001
Feb 2002
Month
Fig. 6. Seasonal variation of dry deposition flux in Qingdao and Beijing.
Oct
Nov
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seas. The ADA came to the sea through three different routes. First one was Mongolia-the east of Inner-Mongolia-the Bohai Sea, the Yellow Sea, the Korea Strait and the Japan Sea. Second one was Mongolia, Taklimakan desert-the west of InnerMongolia, the Loess Plateau-the Bohai Sea, the Yellow Sea, the East China Sea, the Korea Strait and the Japan Sea. Third one was Taklimakan desert, Chaidamu Basin-the Loess Plateau-the Yellow Sea, the East China Sea and the West Pacific Ocean. The probability of the Bohai Sea getting affected was 27.4%, the Yellow Sea 30.9%, the East China Sea 12.3%, the Korea Channel 20.2% and the Japan Sea 9.2%, respectively. The all dry deposition of the Yellow Sea was 17.9 Tg yr1. The dry deposition flux of ADA was higher in spring (73 g m2 yr1) than the in annual average (51.3 g m2 yr1). Since the impact of ADA on the oceanic biosphere largely depends on the quantity of material deposited, such a high dry deposition flux of ADA over East Asia must play an important role in biogeochemical cycles in the Yellow Sea.
Acknowledgments This project was supported by NSFC Key Project under grant no. 4049062. The authors gratefully acknowledge Zhu Yanjun who provided us the Micaps meteorology data in 2000–2002, Zhang Renjian and Sheng Lifang who provided us the dry deposition of Asian-dust aerosol data in Beijing and Qingdao.
References Duce, R.A., Unni, C.K., Ray, B.J., Prospero, J.M., Merrill, J.T., 1980. Long-range atmospheric transport of soil dust from Asia to the tropical North Pacific: temporal variability. Science 209, 1522–1524. Fang, M., Zheng, M., Wang, F., Chim, K.S., Kot, S.C., 1999. The long-range transport of aerosols from northern China to Hong Kong—a multi-technique study. Atmospheric Environment 33, 1803–1817. Gao, Y., Arimoto, R., Duce, R.A., Lee, D.S., Zhou, M.Y., 1992a. Input of atmospheric trace elements and the mineral matter to the Yellow Sea during the spring of a low-dust year. Journal of Geophysical Research 97, 3767–3777. Gao, Y., Arimoto, R., Merril, J.T., Duce, R.A., 1992b. Relationship between the dust concentration over eastern Asia and the remote North Pacific. Journal of Geophysical Research 97, 9867–9872.
Gao, Y., Arimoto, R., Duce, R.A., et al., 1997. Temporal and spatial distributions of dust and its deposition to the China Sea. Tellus 49B (2), 172–189. Kim, B.G., Park, S.U., 2001. Transport and evolution of a winter-time Yellow Asian observed in Korea. Atmospheric Environment 35, 3191–3201. Kurosaki, Y., Mikami, M., 2003. Recent frequent dust events and their relation to surface wind in East Asia. Geophysical Research Letters 30, 1,736. Lim, J.Y., Chun, Y., 2006. The characteristics of Asian dust events in Northeast Asia during the springtime from 1993 to 2004. Global and Planetary Change 52, 231–247. Lin, T.H., 2001. Long-range transport of yellow Asian to Taiwan in Spring 2000: observed evidence and simulation. Atmospheric Environment 35, 5873–5882. Liu, C.L., Zhang J., Yu, Z.G., et al., 1998. Atmospheric transport of heavy metals to the Yellow Sea. In: G.H. Hong, J. Zhang, B.K. Park (Eds.), Health of the Yellow Sea. South Korea. Liu, W., Feng, Q., Wang, T., Zhang, Y., Shi, J., 2004. Physicochemistry and mineralogy of storm dust and dust sediment in Northern China. Advances in Atmospheric Sciences 21 (5), 775–783. Ma, C.J., Kasahara, M., Ho¨ller, R., Kamiya, T., 2001. Characteristics of single particles sampled in Japan during the Asian dust-storm period. Atmospheric Environment 35, 2707–2714. Ma, C.J., Tohno, S., Kasahara, M., Hayakawa, S., 2004. Properties of the size-resolved and individual cloud droplets collected in western Japan during the Asian dust storm event. Atmospheric Environment 38, 4519–4529. Merrill, J.T., Uematsu, M., Bleck, R., 1989. Meteorological analyses of long-range transport of mineral aerosol over the North Pacific. Journal of Geophysical Research 94, 8584–8598. Odabasi, M., Muezzinoglu, A., Bozlaker, A., 2002. Ambient concentrations and dry deposition fluxes of trace elements in Izmir, Turkey. Atmospheric Environment 36, 5841–5851. Ogunjobi, K.O., He, Z., Kim, K.W., Kim, Y.J., 2004. Aerosol optical depth during episodes of Asian dust storms and biomass burning at Kwangju, South Korea. Atmospheric Environment 38, 1313–1323. Okada, K., Narus, H., Tanaka, T., Nemoto, O., 1990. X-ray spectrometry of individual Asian dust-storm particles over the Japanese islands and the North Pacific Ocean. Atmospheric Environment 24A (6), 1369–13780. Qian, Z.A., Song, M.H., Li, W.Y., 2002. Analyses on distributive variation and forecast of sand-dust storms in recent 50 years in North China. Journal of Desert Research 22 (2), 106–111 (in Chinese). Qiu, X.F., Zen, Y., Miao, Q.L., 2001. Temporal-spatial distribution as well as tracks and source areas of Asian-dust storms in China. Acta Geographica Sinica 56 (3), 316–322 (in Chinese). Shao, Y., Wang, J., 2003a. A climatology of Northeast Asian dust events. Meteorologische Zeitschrift 12 (4), 187–196. Shao, Y., Yang, Y., Wang, J., et al., 2003b. Northeast Asian dust storms: real-time numerical prediction and validation. Journal of Geophysical Research 108 (D22), 4691. Uematsu, M., Duce, R.A., Prospero, J.M., et al., 1983. Transport of mineral aerosol from Asia over the North Pacific Ocean. Journal of Geophysics Research 88, 5343–5352.
ARTICLE IN PRESS Z. Kai, G. Huiwang / Atmospheric Environment 41 (2007) 9136–9145 Uematsu, M., Duce, R.A., Prospero, J.M., 1985. Deposition of atmospheric mineral particles in the North Pacific Ocean. Journal of Atmospheric Chemistry 3 (1), 123–138. Wang, Z.F., Ueda, H.M., Huang, M.Y., 2000. A deflation module for use in modeling long-range transport of yellow Asian over East Asia. Journal of Geophysics Research 105, 26947–26959. Xuan, J., Liu, G., Du, K., 2000. Dust emission inventory in Northern China. Atmospheric Environment 34, 4565–4570. Zhang, J., 1994. Atmospheric wet deposition of nutrient elements: correlation with harmful biological blooms in northwest Pacific Coastal Zones. AMBIO 23 (8), 173–189. Zhang, J., Huang, W.W., Liu, S.M., et al., 1992. Transport of particulate heavy metals towards the China Sea: a
9145
preliminary study and comparison. Marine Chemistry 40 (3), 161–178. Zhang, J., Liu, S.M., Lu, X., et al., 1993. Characterizing Asian winddust transport to the Northwest Pacific Ocean. Direct measurement of the dust flux for two years. Tellus 45B (4), 335–345. Zhang, X.Y., Arimoto, R., An, Z.S., 1997. Dust emissions from Chinese desert sources linked to variations in atmospheric circulation. Journal of Geophysical Research 102, 28041–28047. Zhang, J., Wu, Y., Liu, C.L., Shen, Z.B., Yu, Z.G., Zhang, Y., 2001. Aerosol characters from the desert region of Northwest China and the Yellow Sea in spring and summer: observations at Minqin, Qingdao, and Qianliyan in 1995–1996. Atmospheric Environment 35, 5007–5018.