Moisture sources of the Alashan Sand Seas in western Inner Mongolia, China during the Last Glacial Maximum and mid-Holocene: Interpretation from modern analogues, paleoclimatic simulations and geological records

doi:10.1007/s11442-019-1707-x

Abstract

Abstract:

Knowledge of moisture sources is of great significance for understanding climatic change and landscape evolution in desert environments. In this paper, we aim to clarify moisture origins for the Alashan (Alxa) Sand Seas (ALSS) in western Inner Mongolia and their transport pathways during the Last Glacial Maximum (LGM) and the mid-Holocene using modern analogues and paleoclimatic simulations. Precipitation data for the period 1959-2015 from meteorological stations in the study area and wind and specific humidity data from the European Center for Medium-Range Weather Forecasts (ECMWF) daily reanalysis were adopted to determine the moisture sources of summer precipitation in the ALSS. In addition paleoclimate simulations under PMIP3/CMIP5 protocols were used to detect the atmospheric circulation and precipitation at 21 ka BP and 6 ka BP over the ALSS. We also reviewed paleoclimate records from the ALSS to acquire a semi-quantitative reconstruction of the moisture history during the late Pleistocene and Holocene. Our results suggest that the summer monsoon transported water vapor from the Indian Ocean and the South China Sea to the ALSS during July and August, causing increased precipitation. The dominant moisture source was from the southwest monsoon, while the East Asian summer monsoon also partly contributed to precipitation in the ALSS. The increased humidity during the period 8.2-4.2 ka BP in the ALSS, as derived from both climate simulation outputs and sedimentary records, was caused by monsoons according to the outputs of simulations. At 21 ka BP, the moisture sources of the ALSS were greatly associated with the prevailing westerlies.

Key words: Badain Jaran Desert, Tengger Desert, Ulan Buh Desert, Asian summer monsoon, westerlies, paleoclimate

FENG Yingying, YANG Xiaoping. Moisture sources of the Alashan Sand Seas in western Inner Mongolia, China during the Last Glacial Maximum and mid-Holocene: Interpretation from modern analogues, paleoclimatic simulations and geological records[J].Journal of Geographical Sciences, 2019, 29(12): 2101-2121.

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References 72

1	Agnihotri R, Dutta K, Bhushan R et al., 2002. Evidence for solar forcing on the Indian monsoon during the last millennium. Earth and Planetary Science Letters, 198(3/4):521-527. doi: 10.1016/S0012-821X(02)00530-7
2	Berger A L , 1978. Long term variations of daily insolation and Quaternary climatic changes. Journal of the Atmospheric Sciences, 35(12):2362-2367. doi: 10.1175/1520-0469(1978)035<2362:LTVODI>2.0.CO;2
3	Caley T, Malaizé B, Revel M et al., 2011. Orbital timing of the Indian, East Asian and African boreal monsoons and the concept of a ‘global monsoon’. Quaternary Science Reviews, 30(25/26):3705-3715. doi: 10.1016/j.quascirev.2011.09.015
4	Chen F, Chen X, Chen J et al., 2014 a. Holocene vegetation history, precipitation changes and Indian Summer Monsoon evolution documented from sediments of Xingyun Lake, south-west China. Journal of Quaternary Science, 29(7):661-674. doi: 10.1002/jqs.2735
5	Chen F, Li G, Zhao H et al., 2014 b. Landscape evolution of the Ulan Buh Desert in northern China during the late Quaternary. Quaternary Research, 81(3):476-487. doi: 10.1016/j.yqres.2013.08.005
6	Chen J, Huang W, Jin L et al., 2018 a. A climatological northern boundary index for the East Asian summer monsoon and its interannual variability. Science China Earth Sciences, 61(1):13-22. doi: 10.1007/s11430-017-9122-x
7	Chen L, Wu R , 1998. Relationship between summer rainbelt patterns in the eastern China and 500 hPa circulation anomalies over the Northern Hemisphere. Scientia Atmospherica Sinica, 22(6):849-857. (in Chinese)
8	Chen S, Liu J, Xie C et al., 2018 b. Evolution of integrated lake status since the last deglaciation: A high-resolution sedimentary record from Lake Gonghai, Shanxi, China. Palaeogeography, Palaeoclimatology, Palaeoecology, 496:175-182. doi: 10.1016/j.palaeo.2018.01.035
9	Ding Y H, Li C Y, Liu Y J , 2004. Overview of the South China Sea monsoon experiment. Advances in Atmospheric Sciences, 21(3):343-360. doi: 10.1007/BF02915563
10	Fan Y, Chen F, Fan T et al., 2010. Sedimentary documents and optically stimulated luminescence (OSL) dating for formation of the present landform of the northern Ulan Buh Desert, northern China. Science China Earth Sciences, 53(11):1675-1682. doi: 10.1007/s11430-010-3085-1
11	Fan Y, Wang Y, Mou X et al., 2017. Environmental status of the Jilantai Basin, North China, on the northwestern margin of the modern Asian summer monsoon domain during Marine Isotope Stage 3. Journal of Asian Earth Sciences, 147:178-192. doi: 10.1016/j.jseaes.2017.07.012
12	Fan Y, Zhang F, Zhang F et al., 2016. History and mechanisms for the expansion of the Badain Jaran Desert, northern China, since 20 ka: Geological and luminescence chronological evidence. The Holocene, 26(4):532-548. doi: 10.1177/0959683615612588
13	Fleitmann D, Burns S J, Mangini A et al., 2007. Holocene ITCZ and Indian monsoon dynamics recorded in stalagmites from Oman and Yemen (Socotra). Quaternary Science Reviews, 26(1/2):170-188. doi: 10.1016/j.quascirev.2006.04.012
14	Fleming Z L, Monks P S, Manning A J , 2012. Review: Untangling the influence of air-mass history in interpreting observed atmospheric composition. Atmospheric Research, 104/105:1-39. doi: 10.1016/j.atmosres.2011.09.009
15	Gu Z, Liu J, Yuan B et al., 1993. The changes of monsoon in the Qinghai-Tibet Plateau in the past 12000 years: Evidence of the geochemistry of Selincuo deposits. Chinese Science Bulletin, 38(1):61-64. (in Chinese)
16	Hartmann K, Wünnemann B , 2009. Hydrological changes and Holocene climate variations in NW China, inferred from lake sediments of Juyanze palaeolake by factor analyses. Quaternary International, 194(1/2):28-44. doi: 10.1016/j.quaint.2007.06.037
17	Hastenrath S , 2007. Circulation mechanisms of climate anomalies in East Africa and the equatorial Indian Ocean. Dynamics of Atmospheres and Oceans, 43(1/2):25-35. doi: 10.1016/j.dynatmoce.2006.06.002
18	Herzschuh U , 2006. Palaeo-moisture evolution in monsoonal Central Asia during the last 50,000 years. Quaternary Science Reviews, 25(1/2):163-178. doi: 10.1016/j.quascirev.2005.02.006
19	Herzschuh U, Tarasov P, Wünnemann B et al., 2004. Holocene vegetation and climate of the Alashan Plateau, NW China, reconstructed from pollen data. Palaeogeography, Palaeoclimatology, Palaeoecology, 211(1/2):1-17. doi: 10.1016/j.palaeo.2004.04.001
20	Hodell D A, Brenner M, Kanfoush S L et al., 1999. Paleoclimate of southwestern China for the past 50,000 yr inferred from lake sediment records. Quaternary Research, 52(3):369-380. doi: 10.1006/qres.1999.2072
21	Hong Y T, Hong B, Lin Q H et al., 2003. Correlation between Indian Ocean summer monsoon and North Atlantic climate during the Holocene. Earth and Planetary Science Letters, 211(3/4):371-380. doi: 10.1016/S0012-821X(03)00207-3
22	Huang W, Chen J, Zhang X et al., 2015. Definition of the core zone of the “westerlies-dominated climatic regime”, and its controlling factors during the instrumental period. Science China Earth Sciences, 58(5):676-684. doi: 10.1007/s11430-015-5057-y
23	Ji J F, Shen J, Balsam W et al., 2005 a. Asian monsoon oscillations in the northeastern Qinghai-Tibet Plateau since the late glacial as interpreted from visible reflectance of Qinghai Lake sediments. Earth and Planetary Science Letters, 233(1/2):61-70. doi: 10.1016/j.epsl.2005.02.025
24	Ji S, Yang L Y, Yang X D et al., 2005 b. Lake sediment records on climate change and human activities since the Holocene in Erhai catchment, Yunnan Province, China. Science in China Series D-Earth Sciences, 48(3):353-363. doi: 10.1360/03yd0118
25	Jin M, Li G, Li F et al., 2015. Holocene shorelines and lake evolution in Juyanze Basin, southern Mongolian Plateau, revealed by luminescence dating. The Holocene, 25(12):1898-1911. doi: 10.1177/0959683615591349
26	Lau K M, Kim K M, Yang S , 2000. Dynamical and boundary forcing characteristics of regional components of the Asian summer monsoon. Journal of Climate, 13(14):2461-2482. doi: 10.1175/1520-0442(2000)013<2461:DABFCO>2.0.CO;2
27	Lennard C, Hegerl G , 2014. Relating changes in synoptic circulation to the surface rainfall response using self-organising maps. Climate Dynamics, 44(3/4):861-879. doi: 10.1007/s00382-014-2169-6
28	Leuschner D C, Sirocko F , 2003. Orbital insolation forcing of the Indian monsoon: A motor for global climate changes? Palaeogeography, Palaeoclimatology, Palaeoecology, 197(1/2):83-95. doi: 10.1016/S0031-0182(03)00387-0
29	Li C Y, Wang Q, Liu X Yet al., 1982. Tectonic Map of Asia (scale 1:8000000). Beijing: Cartographic Publishing House.
30	Li J, Zeng Q , 2002. A unified monsoon index. Geophysical Research Letters, 29(8): 115-111-115-114. doi: 10.1111/gcb.13762 pmid: 28513920
31	Li Y U, Wang N A, Cheng H et al., 2008. Holocene environmental change in the marginal area of the Asian monsoon: A record from Zhuye Lake, NW China. Boreas, 38(2):349-361. doi: 10.1111/bor.2009.38.issue-2
32	Li Z, Wang N A, Cheng H et al., 2015 a. Formation and environmental significance of late Quaternary calcareous root tubes in the deserts of the Alashan Plateau, Northwest China. Quaternary International, 372:167-174. doi: 10.1016/j.quaint.2014.11.021
33	Li Z, Wang N A, Li R et al., 2015 b. Indication of millennial-scale moisture changes by the temporal distribution of Holocene calcareous root tubes in the deserts of the Alashan Plateau, Northwest China. Palaeogeography, Palaeoclimatology, Palaeoecology, 440:496-505. doi: 10.1016/j.palaeo.2015.09.023
34	Liang X Z, Wang W C , 1998. Associations between China monsoon rainfall and tropospheric jets. Quarterly Journal of the Royal Meteorological Society, 124(552):2597-2623. doi: 10.1002/(ISSN)1477-870X
35	Liu C, Wang H, Jiang D , 2004. The configurable relationships between summer monsoon and precipitation over East Asia. Chinese Journal of Atmospheric Sciences, 28(5):700-712. (in Chinese) doi: 10.3878/j.issn.1006-9895.2004.05.05
36	Liu X, Shen J, Wang S et al., 2007. Southwest monsoon changes indicated by oxygen isotope of ostracode shells from sediments in Qinghai Lake since the late Glacial. Chinese Science Bulletin, 52(4):539-544. (in Chinese) doi: 10.1007/s11434-007-0086-3
37	Long A , 2001. Mid-Holocene sea-level change and coastal evolution. Progress in Physical Geography, 25(3):399-408. doi: 10.1371/journal.pone.0218430 pmid: 31314758
38	Long H, Lai Z, Fuchs M et al., 2012. Timing of Late Quaternary palaeolake evolution in Tengger Desert of northern China and its possible forcing mechanisms. Global and Planetary Change, 92/93:119-129. doi: 10.1016/j.gloplacha.2012.05.014
39	Long H, Lai Z, Wang N et al., 2010. Holocene climate variations from Zhuyeze terminal lake records in East Asian monsoon margin in arid northern China. Quaternary Research, 74(1):46-56. doi: 10.1016/j.yqres.2010.03.009
40	Lu R , 2001. Interannual variability of the summertime North Pacific subtropical high and its relation to atmospheric convection over the warm pool. Journal of the Meteorological Society of Japan, 79(3):771-783. doi: 10.2151/jmsj.79.771
41	Lu R Y , 2004. Associations among the components of the East Asian summer monsoon system in the meridional direction. Journal of the Meteorological Society of Japan, 82(1):155-165. doi: 10.2151/jmsj.82.155
42	Ma C, Zhu C, Zheng C et al., 2008. High-resolution geochemistry records of climate changes since late-glacial from Dajiuhu peat in Shennongjia Mountains, Central China. Chinese Science Bulletin, 53:28-41.
43	Morrill C, Overpeck J T, Cole J E et al., 2006. Holocene variations in the Asian monsoon inferred from the geochemistry of lake sediments in central Tibet. Quaternary Research, 65(2):232-243. doi: 10.1016/j.yqres.2005.02.014
44	Overpeck J, Anderson D, Trumbore S et al., 1996. The southwest Indian monsoon over the last 18000 years. Climate Dynamics, 12(3):213-225. doi: 10.1007/BF00211619
45	Qian W, Lin X, Zhu Y et al., 2007. Climatic regime shift and decadal anomalous events in China. Climatic Change, 84(2):167-189. doi: 10.1007/s10584-006-9234-z
46	Qiang M, Chen F, Wang Z et al., 2010. Aeolian deposits at the southeastern margin of the Tengger Desert (China): Implications for surface wind strength in the Asian dust source area over the past 20,000 years. Palaeogeography, Palaeoclimatology, Palaeoecology, 286(1/2):66-80. doi: 10.1016/j.palaeo.2009.12.005
47	Shi X, Yu K, Chen T , 2007. Progress in researches on sea level changes in the South China Sea since Mid-Holocene. Marian Geology and Quaternary Geology, 27(5):121-132. (in Chinese)
48	Sun X, Du N, Chen Y et al., 1993. Holocene palynological records in Lake Selincuo, northern Xizang. Acta Botanica Sinica, 35:943-950. (in Chinese)
49	Taylor K E, Stouffer R J, Meehl G A , 2012. An overview of CMIP5 and the experiment design. Bulletin of the American Meteorological Society, 93(4):485-498. doi: 10.1175/BAMS-D-11-00094.1
50	Tian L, Yao T, MacClune K et al., 2007. Stable isotopic variations in west China: A consideration of moisture sources. Journal of Geophysical Research-Atmospheres, 112(D10).
51	Trenberth K E , 1991. Climate diagnostics from global analyses-conservation of mass in ECMWF analyses. Journal of Climate, 4(7):707-722. doi: 10.1175/1520-0442(1991)004<0707:CDFGAC>2.0.CO;2
52	Wang L, Chen W, Huang G et al., 2017. Changes of the transitional climate zone in East Asia: Past and future. Climate Dynamics, 49(4):1463-1477. doi: 10.3390/ijerph13020165 pmid: 26828508
53	Wang N A, Li Z, Li Y et al., 2012. Younger Dryas event recorded by the mirabilite deposition in Huahai Lake, Hexi Corridor, NW China. Quaternary International, 250:93-99. doi: 10.1016/j.quaint.2010.11.017
54	Wang N A, Li Z, Li Y et al., 2013. Millennial-scale environmental changes in the Asian monsoon margin during the Holocene, implicated by the lake evolution of Huahai Lake in the Hexi Corridor of Northwest China. Quaternary International, 313/314:100-109. doi: 10.1016/j.quaint.2013.08.039
55	Wang W, Feng Z , 2013. Holocene moisture evolution across the Mongolian Plateau and its surrounding areas: A synthesis of climatic records. Earth-Science Reviews, 122:38-57. doi: 10.1016/j.earscirev.2013.03.005
56	Wu Y, Zheng X, Zhou L , 2012. The asynchronous nature of Holocene climate variability in China and its linkage to Asian monsoon and the westerly. Research of Soil and Water Conservation, 19(1):27-32. (in Chinese)
57	Xiao J L, Xu Q H, Nakamura T et al., 2004. Holocene vegetation variation in the Daihai Lake region of north-central China: A direct indication of the Asian monsoon climatic history. Quaternary Science Reviews, 23(14/15):1669-1679. doi: 10.1016/j.quascirev.2004.01.005
58	Yang X, Liu T, Xiao H , 2003. Evolution of megadunes and lakes in the Badain Jaran Desert, Inner Mongolia, China during the last 31,000 years. Quaternary International, 104(1):99-112. doi: 10.1016/S1040-6182(02)00138-6
59	Yang X, Ma N, Dong J et al., 2010. Recharge to the inter-dune lakes and Holocene climatic changes in the Badain Jaran Desert, western China. Quaternary Research, 73(1):10-19. doi: 10.1016/j.yqres.2009.10.009
60	Yang X, Williams M A J , 2003. The ion chemistry of lakes and late Holocene desiccation in the Badain Jaran Desert, Inner Mongolia, China. Catena, 51:45-60. doi: 10.1016/S0341-8162(02)00088-7
61	Yuan W, Yang Z , 2015. The Alashan Terrane did not amalgamate with North China block by the Late Permian: Evidence from Carboniferous and Permian paleomagnetic results. Journal of Asian Earth Sciences, 104:145-159. doi: 10.1016/j.lithos.2011.07.026 pmid: 26523072
62	Zhang H C, Ma Y Z, Li J J et al., 2001. Palaeolake evolution and abrupt climate changes during Last Glacial Period in NW China. Geophysical Research Letters, 28(16):3203-3206. doi: 10.1029/2000GL012458
63	Zhang H C, Peng J L, Ma Y Z et al., 2004. Late Quaternary palaeolake levels in Tengger Desert, NW China. Palaeogeography, Palaeoclimatology, Palaeoecology, 211(1/2):45-58. doi: 10.1016/j.palaeo.2004.04.006
64	Zhang S W, Yang Z Y, Cioppa M T et al., 2018. A high-resolution Holocene record of the East Asian summer monsoon variability in sediments from Mountain Ganhai Lake, North China. Palaeogeography, Palaeoclimatology, Palaeoecology, 508:17-34. doi: 10.1371/journal.pone.0146261 pmid: 26730966
65	Zhang X J, Jin L Y , 2016. Association of the Northern Hemisphere circumglobal teleconnection with the Asian summer monsoon during the Holocene in a transient simulation. The Holocene, 2015, 1-12.
66	Zhao H, Li G, Sheng Y et al., 2012. Early-middle Holocene lake-desert evolution in northern Ulan Buh Desert, China. Palaeogeography, Palaeoclimatology, Palaeoecology, 331/332:31-38. doi: 10.1016/j.palaeo.2012.02.027
67	Zhao Y, Yu Z, Chen F et al., 2008. Holocene vegetation and climate change from a lake sediment record in the Tengger Sandy Desert, northwest China. Journal of Arid Environments, 72(11):2054-2064. doi: 10.1016/j.jaridenv.2008.06.016
68	Zheng Q, Zhang H, Ming Q et al., 2014. Vegetation and environmental changes since 15 ka B.P. recorded by lake Lugu in the Southwest Monsoon Domain Region. Quaternary Sciences, 34(6):1314-1326. (in Chinese) doi: 10.3969/j.issn.1001-7410.2014.06.21
69	Zhong W, Xue J, Zheng Y et al., 2010. Climatic changes since the last deglaciation inferred from a lacustrine sedimentary sequence in the eastern Nanling Mountains, South China. Journal of Quaternary Science, 25(6):975-984. doi: 10.1002/jqs.1384
70	Zhu Q, He J, Wang P , 1986. A study of circulation differences between East-Asian and Indian summer monsoons with their interaction. Advances in Atmospheric Sciences, 44(4):466-477.
71	Zhu Z, Wu Z, Liu S et al., 1980. Introduction to the Desert in China. Beijing: Science Press. (in Chinese)
72	Ziv B, Dayan U, Kushnir Y et al., 2006. Regional and global atmospheric patterns governing rainfall in the southern Levant. International Journal of Climatology, 26(1):55-73. doi: 10.1002/(ISSN)1097-0088

Model	Model type	Atmospheric resolution	Length of run analyzed (year)
CCSM4	AOGCM	1.25° ′ ~0.9°, L26	301
FGOALS-g2	AOVGCM	~2.8° ′ 3-6°, L26	100
CNRM-CM5	AOGCM	~1.4° ′ 1.4°, L31	200
MPI-ESM-P	AOGCM	1.875° ′ ~1.9°, L47	100
MRI-CGCM3	AOGCM	1.125° ′ ~1.1°, L48	100

	Eccentricity	Obliquity (°)	Precession (ω-180°)	CO₂(ppm)	CH₄(ppb)	N₂O (ppb)
LGM	0.018994	22.949	114.42	185	350	200
Mid-Holocene	0.018682	24.105	0.87	280	650	270

SiteNo.	Site name	Lat. (°N)	Lon. (°E)	Proxy type	Dating method	Number of dates	References
1	Jilantai	39.74	105.70	Pollen, grain size	OSL	4	Fan et al. (2017)
2	Tengger	39.15	104.16	Lacustrine terraces	¹⁴C	14	Zhang et al. (2004)
3	Southeastern margin of Tengger	37.34	105.23	Grain size, Carbonate content. Elemental composition	OSL	4	Qiang et al. (2010)
4	Southeast of Badain Jaran	-	-	Aeolian deposits	OSL	26	Fan et al. (2016)

SiteNo.	Site name	Lat. (°N)	Lon. (°E)	Proxy type	Dating method	Number of dates	References
1	Badain Jaran	-	-	Lacustrine deposits, Aeolian deposits	¹⁴C,TL	5	Yang and Williams (2003)
2	Badain Jaran	-	-	Shorelines	¹⁴C	9	Yang et al. (2010)
3	Badain Jaran	-	-	Lacustrine deposits, Aeolian deposits, Calcareous cementation layers, cemented plant roots	¹⁴C,TL	7	Yang et al. (2003)
4	Huahai	40.43	98.07	Grain size, C/N, Carbonate, TOC	¹⁴C	17	Wang et al. (2013)
5	Tengger	39.15	104.16	Lacustrine terraces	¹⁴C	14	Zhang et al. (2004)
6	Zhuyeze	37.05	104.67	Grain size, pollen, TOC, T/N	¹⁴C	13	Li et al. (2008)
7	Baijian Hu	-	-	Shorelines	OSL	25	Long et al. (2012)
8	Qingtu Hu	39.05	103.67	Grain size, carbonate, TOC, C/N, δ¹³C	¹⁴C,OSL	16	Long et al. (2010)
9	Qingtu Hu	39.07	103.61	Pollen	¹⁴C	5	Zhao et al. (2008)
10	Ulan Buh	39.77 39.86	105.76 106.39	GPR reflecting, Grain size	OSL	6	Fan et al. (2010)
11	Ulan Buh	-	-	Grain size, Loss on ignition, Pollen analysis	OSL	14	Chen et al. (2014)
12	Ulan Buh	-	-	Grain size, elevation	OSL	19	Zhao et al. (2012)
13	Alashan Sand Sea	-	-	Calcareous root tubes	¹⁴C	34	(Li et al., 2015a, Li et al., 2015b)

No	Start date	Duration (days)	Number of station	Precipitation (min)	Precipitation (max)	Moisture source
1	1958-08-01	1	2	11.4	25.7	Westerlies
2	1958-08-07	1	2	33.2	41.3	Westerlies
3	1960-07-19	3	2	14.5	17	Westerlies
4	1961-07-31	2	2	12	40.4	Westerlies
5	1961-08-06	2	2	26.6	36.5	Westerlies
6	1963-07-20	2	2	14.6	29.9	Westerlies
7	1969-06-15	2	2	11	14	Westerlies
8	1969-08-09	1	2	13.5	14.2	Westerlies
9	1970-08-01	1	2	14	18	Westerlies
10	1970-08-17	2	2	24.2	33.1	Monsoon
11	1973-08-10	4	3	11.9	32.9	Monsoon
12	1973-08-15	2	2	10.2	36.6	Westerlies
13	1974-07-28	3	4	10.6	42.1	Monsoon
14	1977-07-28	1	3	11.6	44	Westerlies
15	1977-08-19	2	3	10.2	34.2	Westerlies
16	1978-07-27	3	4	10.9	20.3	Westerlies
17	1979-07-01	2	2	10.9	15	Westerlies
18	1979-07-18	4	3	13	32.4	Monsoon
19	1979-08-06	2	2	26.5	27.9	Monsoon
20	1980-08-01	2	2	10.3	13.5	Monsoon
21	1981-07-02	1	3	14.6	23.8	Westerlies
22	1983-08-13	1	2	20.1	20.9	Monsoon
23	1984-06-13	1	2	13.8	19.3	Westerlies
24	1993-07-20	2	2	28.4	31.2	Westerlies
25	1993-08-10	1	2	13.4	17.7	Westerlies
26	1993-08-29	1	2	14.2	21	Westerlies
27	1994-07-07	1	2	20.2	28.7	Westerlies
28	1994-08-12	1	3	14	18	Westerlies
29	1995-08-10	1	2	10.4	14.8	Westerlies
30	1995-08-15	2	2	18	24.1	Westerlies
31	1996-07-27	3	3	13.1	24	Westerlies
32	1997-07-30	1	2	12.4	17.6	Monsoon
33	1998-06-11	1	3	10.3	44	Monsoon
34	1999-07-06	1	2	11.1	20.5	Westerlies
35	2000-08-07	1	2	11.9	19.1	Westerlies
36	2002-06-07	2	3	18.9	31.2	Monsoon
37	2002-06-21	1	2	21.3	23	Westerlies
38	2003-06-25	1	3	14.1	24.8	Westerlies
39	2003-08-29	1	2	11.4	14.3	Westerlies