Influence Of Monsoon Research Articles

Accelerated mass loss of Himalayan glaciers since the Little Ice Age

Himalayan glaciers are undergoing rapid mass loss but rates of contemporary change lack long-term (centennial-scale) context. Here, we reconstruct the extent and surfaces of 14,798 Himalayan glaciers during the Little Ice Age (LIA), 400 to 700 years ago. We show that they have lost at least 40 % of their LIA area and between 390 and 586 km3 of ice; 0.92 to 1.38 mm Sea Level Equivalent. The long-term rate of ice mass loss since the LIA has been between − 0.011 and − 0.020 m w.e./year, which is an order of magnitude lower than contemporary rates reported in the literature. Rates of mass loss depend on monsoon influence and orographic effects, with the fastest losses measured in East Nepal and in Bhutan north of the main divide. Locally, rates of loss were enhanced with the presence of surface debris cover (by 2 times vs clean-ice) and/or a proglacial lake (by 2.5 times vs land-terminating). The ten-fold acceleration in ice loss we have observed across the Himalaya far exceeds any centennial-scale rates of change that have been recorded elsewhere in the world.

Spatial and temporal variability of satellite sea surface temperature in the Makassar Strait and the Java Sea

Sea surface temperature (SST) data obtained from the Aqua-MODIS satellite from 2002 to 2012 were analyzed to determine the spatial and temporal variability in the key region of small pelagic fisheries between Makassar Strait and the Java Sea. Results of the Empirical Orthogonal Function (EOF) analysis show that the characteristics of this region are described by 60% based on the greatest contribution value respectively. The largest contribution of 52% shows that the SSTs in this region is warm. A strong indicator of these conditions appears in the east through the southern part of Kalimantan Island while the weak indicator is in the south to western part of Sulawesi Island. The temporal variation shows that the annual oscillation is dominant in this area where maximum SSTs occurs in the first transitional monsoon (April), while the minimum occurs in the southeast monsoon period (August). The influence of southeast monsoon formats the minimum SSTs area in the south of South Sulawesi that is generated by parallel wind-driven induces to the coast and the divergent current close to the coast. Due to inter-annual variability, minimum SSTs occurs before the El Nino episode whereas the maximum occurs before the La Nina event.

Analysis of the Radiation Fluxes over Complex Surfaces on the Tibetan Plateau

Analysis of long-term, ground-based observation data on the Tibetan Plateau help to enhance our understanding of land-atmosphere interactions and their influence on weather and climate in this region. In this paper, the daily, monthly, and annual averages of radiative fluxes, surface albedo, surface temperature, and air temperature were calculated for the period of 2006 to 2019 at six research stations on the Tibetan Plateau. The surface energy balance characteristics of these six stations, which include alpine meadow, alpine desert, and alpine steppe, were then compared. The downward shortwave radiation at stations BJ, QOMS, and NAMORS was found to decrease during the study period, due to increasing cloudiness. Meanwhile, the upward shortwave radiation and surface albedo at all stations were found to have decreased overall. Downward longwave radiation, upward longwave radiation, net radiation, surface temperature, and air temperature showed increasing trends on inter-annual time scales at most stations. Downward shortwave radiation was maximum in spring at BJ, QOMS, NADORS, and NAMORS, due to the influence of the summer monsoon. Upward shortwave radiation peaked in October and November due to the greater snow cover. BJ, QOMS, NADORS, and NAMORS showed strong sensible heat fluxes in the spring while MAWORS showed strong sensible heat fluxes in the summer. The monthly and diurnal variations of surface albedo at each station were “U” shaped. The diurnal variability of downward longwave radiation at each station was small, ranging from 220 to 295 W·m−2.The diurnal variation in surface temperature at each station slightly lagged behind changes in downward shortwave radiation, and the air temperature, in turn, slightly lagged behind the surface temperature.

Growth Performance and Profitability of Rice Production in India: An Assertive Analysis

This study assessed the growth trends and instability in area, production and productivity of rice in major rice growing states during the period 2001-02 to 2018-19. The study revealed that compound growth rate of area under rice was almost constant in the country during last two decades, while it was fluctuating across the states. However, growth rates of production and productivity was found positive and significant. Instability in area under rice was less as compared to production and productivity. Although production of rice has increased due to innovations and adoption of new farm technologies, but a greater instability in production, indicated the influence of irregular monsoon on production during the study period. Many of the States registered negative profitability in rice cultivation and farmers get handful returns only when the farm business income was calculated. To provide better protection to the farmers through restriction on purchasing rice below MSP or government may adopt proper mechanism to stop distress sale of farm produces particularly rice.

A river flowing through a desert: late Quaternary environments in the Nile basin – current understanding and unresolved questions

Late Quaternary environments in the Nile Basin reflect the influence of the African summer monsoon upon plant cover, sediment yield and flood discharge in the Ethiopian and Ugandan headwaters of the Nile. Intervals of prolonged and very high Nile flow coincide with times of stronger summer monsoon and have been dated using a combination of 14C, OSL and 10Be methods. Periods of high Nile flow into the eastern Mediterranean coincide with the formation of highly organic sedimentary layers termed sapropels. Ages obtained so far for these times of sustained middle to late Pleistocene high flow in the Blue and White Nile are broadly coeval with sapropel beds S8 (ca 217 ka), S7 (ca 195 ka), S6 (ca 172 ka), S5 (ca 124 ka), S4 (ca 102 ka) S3 (ca 81 ka), S2 (ca 55–50 ka) and S1 (10–6.5 ka). Sapropel 5 (ca 124 ka) was synchronous with extreme Blue Nile floods and the formation of the 386 m lake in the lower White Nile Valley, as well as with a prolonged wet phase in the eastern Sahara. Fluctuations in Nile flow and sapropel formation reflect the influence of the precessional cycle upon the East African monsoon. Between 75 ka and 19 ka the climate in the Nile headwaters region became progressively colder and drier. During the Last Glacial Maximum, Lake Tana in Ethiopia and Lake Victoria in Uganda became dry, flow in the White Nile was reduced to a trickle, and the Blue Nile and Atbara became highly seasonal bed–load rivers. The return of the summer monsoon at 14.5 ka ushered in extreme Blue Nile floods, widespread flooding across the Nile Basin and the formation of the 382 m lake in the lower White Nile Valley. There was a brief return to aridity during the Younger Dryas (12.8–11.5 ka), after which the climate again became wetter and widespread flooding in the Nile Valley resumed. The early Holocene floods were later followed by incision and creation of the modern relatively narrow flood plain.

Khabarovsk Federal Research Center of the Far Eastern Branch of the Russian Academy of Sciences Far Eastern Research Institute (KhFRC FEB RAS FIARI)Features of tomato breeding in the Amur region. Results and perspectives

Relevance. Khabarovsk region is considered to be the zone of risky agriculture. It is characterized by the monsoon climate (july - september), having no analogies in Russia by univen distribution of precipitation, temperature drops and high natural infections background. That is why the search of tomato sorts, responsive to environmental changes, with increased or stable yield is highly relevant. The aim of our perennial researches in the creation of highly productive sorts and hybrids of tomato, most fully realizing natural and climatic conditions of cultivation, having higher stability to the most harmful diseases, stress environmental factors and high productive potential. The most significant limiting factors when growing tomatoes in the region are high natural infections background and sharply variable hydrothermal regime, formed under the influence of the Priamurye monsoon climate.Methods. The selection work had been made on vegetable plot of DV NIISH. The seedlings had been growing by cassette method into film greenhouse, which had been no had heating. Then the seedlings was planted out into open ground in accordance with bed technology recommended in the region by scheme 140 X 35 cm. The main method of selection work of new tomato sorts creation was analytical with continious selection. All the necessary phenological, biometrical and psychopathological observations and accounts had been done by generally accepted methodics.Results. The results in development of tomato selection in DV NIISH was the creation of sorts with different ripening time: early ripe – Zarya Vostokа and middle ripe – Amursky Utios and Dunyasha. They were included in the State registry of selection achievements in 2008 year. Sorts Klad and Galant passed successfully the state sort tests and were included in the state registry of selection achievements in 2017 and 2018 years. All these sorts are recommended for growing in garden plots, private plots and farms.

Paleodietary and Paleoclimatic Reconstruction of Hipparion Fauna at ∼9 Ma From the Xunhua Basin on the Northeastern Tibetan Plateau

Stable isotope analysis is pivotal for investigating the paleodiet and paleoecology of ancient mammals. Recently, a ∼9-Myr-old Hipparion fauna was discovered at an elevation of ∼2,200 m above sea level (a.s.l.) in the Xunhua Basin on the northeastern Tibetan Plateau. These fossils can provide key evidence for the ecosystem structure and regional paleoenvironmental reconstruction. Here we present carbon and oxygen isotopic compositions of 56 bulk and 85 serial tooth enamel samples from this fauna, which includes Hipparion platyodus Selve, Chilotherium sp. and Gazella gaudryi Schlosser. The enamel−δ13°C values display a wide range of variation (−11.4 to −5.0‰), with a mean value of −8.9 ± 1.0‰, indicating that the fauna consumed mainly C3 plants. However, the heaviest δ13C value of Hipparion (−5.0‰) suggests at least some consumption of C4 plants. Combined with pollen records, we infer that the Hipparion fauna in the Xunhua Basin was living in forest-grassland setting at ∼9 Ma. The reconstructed paleo-meteoric δ18O values of the Xunhua Basin at ∼9 Ma are lower than the mean annual δ18O of present-day precipitation in this region, suggesting a wetter climate or stronger monsoonal influence than today. Hipparion fauna in the Xunhua Basin yield significantly higher mean values of δ13C and δ18O than contemporary fossils in the Linxia Basin to the east, which is attributed to rapid uplift of the Jishi Shan, blocking water vapor transport by the East Asian Summer Monsoon and making the climate of the Xunhua Basin relatively drier.

A mid-altitude area in southwestern China experienced a humid subtropical climate with subtle monsoon signatures during the early Oligocene: Evidence from the Ningming flora of Guangxi

The Oligocene marked the beginning of the present ‘icehouse’ epoch and witnessed the development and evolution of the Asian monsoon system (AMS). In this paper, the early Oligocene Ningming flora of Guangxi, southern China, is analysed to investigate the AMS based on climate proxies derived from Climate Leaf Analysis Multivariate Program (CLAMP). CLAMP results suggest that the prevailing climate experienced by the Ningming flora was humid subtropical with hot summers and warm winters. Although the record of precipitation seasonality is muted, it is about half as strong as that seen today in monsoon climates of South China, indicating a very weak monsoonal signal. Despite suggesting weak rainfall seasonality, the position of the Ningming flora in physiognomic space indicates that leaves exhibit monsoon-adapted morphologies, comparable to today's vegetation exposed to the Indonesia–Australia monsoon (I-AM) and the transitional monsoon area (influenced by the East Asia monsoon, South Asia monsoon and I-AM). Leaf architectural signatures reveal that the Ningming flora grew under a humid subtropical climate with subtle monsoon signatures. Although it is difficult to distinguish the different domains of the Asian monsoon under such a subtle monsoon influence, based on leaf signatures from southern Asia, it can be inferred that the Ningming Basin during the early Oligocene was exposed to a climate regime similar to that today influenced by the I-AM. In addition, the moist enthalpy method was applied to quantitatively reconstruct the paleoelevation of the Ningming Basin. This approach suggests a paleoelevation estimate of ~1.24–1.35 ± 0.52 km for the early Oligocene, suggesting that a drop in paleoelevation of the Ningming Basin took place after the early Oligocene (Rupelian). The CLAMP results suggest that the early Oligocene Ningming area was at a mid-altitude and experienced a humid subtropical climate with subtle monsoon signatures.

Monsoonal and spatial influence on zooplankton variation in a tropical bay, North Borneo, Malaysia

The tropical climate is seemingly stable with little variation in environmental factors throughout the year. However, a growing number of studies have reported monsoon-driven changes in zooplankton communities in tropical waters. This study examined the monsoonal and spatial variation in the zooplankton community in Sepanggar Bay, Malaysia. Samples were collected from 9 stations throughout the bay in June and October 2017, March and June 2018, coinciding with the southwest monsoon (SWM), northeast monsoon (NEM) and the intermonsoon periods (INTER). Significant seasonal difference was observed for the measured hydrographic parameters (chlorophyll-a, salinity, temperature) with highest values recorded during INTER for chlorophyll-a, NEM for salinity, and SWM 2 for temperature. Throughout the study, 110 zooplankton taxa were identified, and copepods dominated total zooplankton abundance by 70%. Zooplankton abundance increased from 17925 ± 8616 inds. m−3 during SWM 1 to peak at 47628 ± 55488 inds. m−3 during INTER and reached a minimum of (16136 ± 22334 inds. m−3 during NEM. Zooplankton abundances were relatively higher at nearshore stations compared with offshore stations, but was not statistically significant. Four distinct assemblages were obtained from Hierarchical Cluster analysis (HCA), suggesting the influence of monsoon in shaping the zooplankton community. The dominant zooplankton shifted from copepods during SWM1, INTER, and NEM, to tintinnids during SWM 2. Canonical Correspondence Analysis (CCA) revealed temperature and salinity to be strongly associated with zooplankton community, indicating seasonal variations in these environmental factors driven by monsoon which influenced the zooplankton community structure in the bay. Distinct shifts in the zooplankton composition and abundance relative to the monsoon seasons provide new insights into the seasonal sensitivity of zooplankton in tropical coastal ecosystems.

Spatially differentiated changes in regional climate and underlying drivers in southwestern China

The climate in Southwest China are predominantly under the influences of three contrasting climate systems, namely the East Asian monsoon, the South Asian monsoon, and the westerlies. However, it is unclear if the diversified climate systems, in combination with the complex terrain and varying vegetation types, would result in contrasting patterns of changes in climate across the region. Based on the CRU TS data for the period 1901−2017, we examined the spatiotemporal characteristics of the regional climate, and identified types of climate change patterns and drivers. Overall, the region experienced significant increases in annual mean temperature during 1901−2017, with occurrence of a significant turning point in 1954 for a more pronounced warming (0.16 °C/10 a). The annual precipitation fluctuated greatly over the study period without apparent trend, albeit the occurrence of a significant turning point in 1928 for a slight increase in the later period (1.19 mm/10 a). Spatially the multi-year averages of selective climate variables during 1901–2017 displayed a trend of decreases from southeast to northwest, but with increasing variability. We identified five major climate change types across the study region, including warmer (T+), drier (P−), warmer-drier (T+P−), warmer-wetter (T+P+), and no significant changes (NSC). The type T+P+ mainly occurred in the western parts over the plateau sub-frigid semiarid ecozone (77.0%) and the plateau sub-frigid semihumid ecozone (19.9%). The central parts of the region are characterized by the type T+, corresponding to six ecozones, including the mid-subtropical humid ecozone (33.1%), the plateau temperate humid-semihumid ecozone (28.8%), the plateau sub-rigid semihumid ecozone (9.5%), the southern subtropical humid ecozone (8.1%), the plateau sub-frigid arid ecozone (7.3%), and the plateau temperate semiarid ecozone (6.6%). No significant change in climate was detected for the eastern parts over the mid-subtropical humid ecozone (67.3%), the plateau temperate humid and semihumid ecozone (19.5%) and the plateau sub-frigid semihumid ecozone (8.8%). The types P− and T+P− together accounted for less than 5% of the entire study region, which predominantly occurred in central Yunnan-Guizhou Plateau and south of the southeastern Xizang, corresponding predominantly to the mid-subtropical humid ecozone. Across the region and within the zonal climate change types, vegetation and topography both played a significant role in determining the climate variability and magnitude of changes. Our results suggest that the southwestern China experienced intensified influences of the southeasterly monsoon and the southerly monsoon in the regional climate, while the westerly alpine influences subsided; topography and vegetation affected the magnitudes of the directional changes in climate at a local scale.

Monsoon Influence on the Island Mass Effect Around the Maldives and Sri Lanka

The monsoon circulation in the Northern Indian Ocean (NIO) is unique since it develops in response to the bi-annual reversing monsoonal winds, with the ocean currents mirroring this change through directionality and intensity. The interaction between the reversing currents and topographic features have implications for the development of the Island Mass Effect (IME) in the NIO. The IME in the NIO is characterized by areas of high chlorophyll concentrations identified through remote sensing to be located around the Maldives and Sri Lanka in the NIO. The IME around the Maldives was observed to reverse between the monsoons to downstream of the incoming monsoonal current whilst a recirculation feature known as the Sri Lanka Dome (SLD) developed off the east coast of Sri Lanka during the Southwest Monsoon (SWM). To understand the physical mechanisms underlying this monsoonal variability of the IME, a numerical model based on the Regional Ocean Modeling System (ROMS) was implemented and validated. The model was able to simulate the regional circulation and was used to investigate the three-dimensional structure of the IME around the Maldives and Sri Lanka in terms of its temperature and velocity. Results revealed that downwelling processes were prevalent along the Maldives for both monsoon periods but was applicable only to latitudes above 4°N since that was the extent of the monsoon current influence. For the Maldives, atolls located south of 4°N, were influenced by the equatorial currents. Around Sri Lanka, upwelling processes were responsible for the IME during the SWM but with strong downwelling during the NEM. In addition, there were also regional differences in intra-seasonal variability for these processes. Overall, the strength of the IME processes was closely tied to the monsoon current intensity and was found to reach its peak when the monsoon currents were at the maximum.

Seasonal dynamicity of environmental variables and water quality index in the lower stretch of the River Ganga

Rapid human pressure in semi-urban and urban areas along with increasing industrial activities has resulted in release of untreated sewage and other forms of pollutants into major rivers globally including in the Ganga. In this study, nine sites represented by 59 stations along the lower stretch of the River Ganga were monitored seasonally to understand the effect of monsoonal precipitation on environmental variables and Water Quality Index (WQI). Sampling was undertaken in pre-monsoon, monsoon and post-monsoon seasons (2019). In situ surface water temperature, dissolved oxygen, pH, total dissolved solids (TDS) and electrical conductivity (EC) were measured along with dissolved nutrients and Chlorophyll-a. Both pH and DO were strongly influenced by monsoon and affected WQI. TDS was higher in point source (PS) stations during pre-monsoon (113–538 ppm) compared to surface water (SW) stations (113–248 ppm) with strong influence of monsoon (PS-27.4-310.3 ppm; SW-27-68.9 ppm). Dissolved nutrients including nitrate and o-phosphate concentration showed significant seasonal variation and influenced monsoonal precipitation. In PS stations across studied seasons dissolved nitrate concentration varied from 26.33–646 μM while in SW the range was from 21.22–148.06 μM. In the studied sites, higher concentration of dissolved nutrients in PS stations reflected the release of untreated municipal and industrial sewage directly into the river. The effect of precipitation and resulting environmental variables was clearly evident on biological variable (concentration of Chl-a) with observed values in PS stations (0–21 mg l−1) which were lesser compared to SW stations (0–89.3 mg l−1) during monsoon. Non-metric multidimensional scaling revealed three distinct clusters with greater overlap between PS and SW stations in monsoon. The WQI values (14–52) determined for lower stretch of Ganga revealed very poor water quality in majority stations and monsoonal precipitation did not have any influence on the observed trends.

Seasonal and Long-Term Connections between Trophic Status, Sestonic Chlorophyll, Nutrients, Organic Matter, and Monsoon Rainfall in a Multipurpose Reservoir

Due to rapid eutrophication, sustainable water quality management and supply are essential in drinking water sources and aquatic biota in large reservoirs. We evaluated the potentially crucial factors influencing the algal chlorophyll (CHL-a), nutrients, and the links between the rainfall and other vital elements in a large multipurpose reservoir (Yongdam Reservoir) during 2013–2019. We developed the empirical models on algal CHL-a, total phosphorus (TP), total nitrogen (TN), and TN:TP’s ambient ratios considering the maneuvering influence of Asian monsoons. The intensive rainfall during the monsoon months strongly impacted the nutrient regime and other vital factors. The seasonal patterns of algal CHL-a varied in response to the nutrient contents (TN, TP), suspended solids, and ambient N:P ratios along the longitudinal gradient. The conditional plot analysis, empirical modeling, and observations supported an overall P-limitation scenario, as was evident from the magnitude of N:P ratios (R2 = 0.36, F = 24.9, p < 0.001). Furthermore, the reservoir’s trophic status alluded to the larger particles and blue-green algae during the monsoon and postmonsoon months. The correlation analysis, Mann–Kendall trend test, and principal component analysis illustrated compelling links between CHL-a, TP, and rainfall regime. The outcomes suggested the reservoir was primarily controlled by phosphorus limitation, with an increasing CHL-a tendency along with nitrogen dilution. However, a slight decline in phosphorus was also detected. The Yongdam Reservoir is under the threat of recurrent eutrophication events that could jeopardize this vital drinking water facility due to increasing agricultural and anthropic activities.

Sediment Characterization and Monsoonal Impact on Beach Morphology at the Three Beaches along the Karachi Coast, Pakistan

Sediment characteristics plays important role in the determination and functioning of coastal ecosystems. The present study is an attempt to evaluate the variability in sediment characteristics of the three beaches: Clifton, Sandspit and Buleji, at the Karachi coast. The samples were collected during pre-monsoon and south-west monsoon seasons to evaluate the seasonal differences. The sediments of the three sites showed variations in moisture content, organic matter and grain size. The highest mean moisture (27.17%) and organic contents (3.5 %) were recorded from the sediments of Clifton. The maximum fraction of sediments (> 80 %) consist of fine to very fine sand at all studied sites. The sediments of Clifton were high in very fine sand fraction and low in coarse sand fraction as compared to Sandspit and Buleji. The sediments of all the three studied sites are moderately sorted, negatively coarse-skewed and showed leptokurtic distribution. The studied beaches of Clifton, Sandspit and Buleji shows dissimilarity in sediment characteristics as indicated through Cluster and PCA analysis. The monsoonal influence on sediment characteristics was also observed at all the three studied beaches. The strong wave action during SW monsoon season results in the deposition of the coarser sediments at the high tide level thus increasing the steepness of the beaches.

Wave Characteristics in Northeast Coastal Waters of Zhoushan Island Under the Influence of Winter Monsoon

Waves at 12 m water depth in the northeast coastal waters of Zhoushan Island were measured from November 2014 to February 2015, and the characteristics were described. The study showed that the significant wave height varied from 0.08 to 1.35 m with the average of 0.36 m during the winter monsoon period, but the maximum of the maximum wave height is close to the maximum value of some typhoon waves of the same place. The monthly main wave direction varied from ENE to N to NE to ENE. Relatively high correlations exist between some wave parameters and relationships between them were identified. Most of the waves have a bimodal spectrum and the influence of monsoon on waves is intermittent.

Monsoonal influences on rip current hazards at recreational beaches along Pahang coastline, Malaysia

Rip current is a type of wave-inducing current that forms nearshore and flows towards the sea. It is a major global hazard in the marine environment that had claimed the lives of hundreds of people due to drowning and recorded thousands of rescue missions around the world. In Malaysia, the Pahang coastline recorded over 30 drowning cases due to rip currents from 2006 to 2018. However, studies on rip current especially on the east coast of Peninsular Malaysia are very limited. Therefore, this study was conducted to classify the beach morphodynamics associated with rip current formations during the southwest monsoon (SWM) and northeast monsoon (NEM) along the Pahang coastline. Five recreational beaches were selected along the Pahang coastline, namely Balok (B1), Batu Hitam (B2), Teluk Cempedak (B3), Sepat (B4), and Air Leleh (B5) as the study site. Sediment samples and beach profile were collected for both monsoonal seasons. It was found that the Pahang coastline was composed of rip-dominant intermediate beaches with several beaches categorised as barred (B), low tide terrace with rip (LTTR), and low tide bar and rip (LTBR). As intermediate beaches are known as rip current dominated beaches, most beaches at Pahang coastline are found to be composed of different risk level of rip current such as high risk (B3 and B5), moderate risk (B1 and B2) and mixed risk (B4). The findings in this study provide useful insights for coastal management planning along the Pahang coastline and the development of beach safety and rescue missions in the event of an emergency related to rip current.

A 40,000 year record of vegetation, environment and climate change from Chongqing, Central China

Congping is a wetland at about 2100 m asl in Chongqing Province. It is surrounded by a shrubby grassland which grades into a mixed conifer and deciduous woodland. A record based on pollen, microcharcoal and geochemistry has been used to reconstruct an environmental history covering the last approximately 40 kyr BP. The site was wooded throughout the entire record and there were two relatively warm periods; during Marine Isotope 3 (MIS 3) and for the Holocene from about 9 kyr BP. From 27 to 18 kyr BP a gradual cooling occurred and the coldest part of the record was between 22 and 18 kyr BP when a mixed conifer cool temperate deciduous forest occurred, The warmest part of the record lasted from about 9 to 1.5 kyr BP when mixed evergreen and deciduous forest occurred. The broad pattern of changes is in accord with pollen records from Dajiuhu in Hubei, and demonstrates that this was a regional signal. A moist central China at Last Glacial Maximum (LGM) shows that the East Asian Summer Monsoon was delivering enough moisture on the mainland to sustain forest cover, even at 2120 m asl. The large-scale changes are interpreted as relating to changes in Earth's orbital parameters and sea-level changes in the South China Sea which had an impact on moisture delivery into central China. It is surmised that the westerlies which created dry climates in northeastern China trapped the summer Monsoon influence enough to keep central China moist. The Younger Dryas (YD) is present in the weathering parameters as evident in several changes in elemental abundance delivered to the sediments. The Congping record shows no clear evidence of human impact on its vegetation, and there were no local fires to have caused any vegetation changes. In the last 1.5 kyr BP a slight cooling caused a rise in conifers, a decline in broad-leaved tree taxa and increased weathering rates.

Offshore Wind Resource Assessment of Thailand Using Remote Sensing Technique

This paper presents the evaluation of the offshore wind resource of Thailand (the Gulf of Thailand and the Andaman Sea) using remote sensing technique. The wind speed at height of 10 m above mean sea level (A.M.S.L.) was measured using SeaWinds Scatterometer on QuickSCAT by NASA. The QuickSCAT satellite images in 1999-2009 with resolution of 1ox1o was interpreted and validated using the measured wind speed provided by the ship observation, buoy data and numerical weather prediction models. The wind speed was interpolated for 1 km resolution enhancement and extrapolated to the height of 50 m A.M.S.L.. The monthly and annual mean wind speed maps were presented in order to show the spatial and temporal variation of offshore wind energy potential. Results showed that QuickSCAT satellite images interpretation gave lower bias in the rage of wind speed of 3-18 m/s, however, the bias was high for wind speed more than 20 m/s. It found that offshore mean wind speed at height of 50 m A.M.S.L. was in the range of 3.0-6.0 m/s where the middle part of Thai offshore had the highest potential with the wind speed in the rage of 7.0-10.0 m/s. The offshore wind speed had high potential during June until August due to the influence of southwest monsoon.

Paleoclimate changes over the past 13,000 years recorded by Chibuzhang Co sediments in the source region of the Yangtze River, China

Climate change characteristics in the Qinghai-Tibetan Plateau (QTP) exhibit spatial differences. These differences are due to different large circulation systems, comprising Asian summer monsoons and mid-latitude Westerlies. However, the paleoclimate pattern at the transition zone between the two systems existing since the Late Glacial remains unclear. We present a 13,000-year high-resolution record of climate change and monsoon effects in the source region of the Yangtze River at the modern limit of the Indian Summer Monsoon (ISM) influence, which lies in the interaction zone with the Westerlies. Multi-proxy records—such as grain size (GS), total inorganic carbon (TIC) and element geochemistry—suggest four stages of paleoclimate change since the Late Glacial: 1) relatively cold in the Late Glacial, 2) warm-wet conditions in the early Holocene, 3) cool-dry conditions in the mid- and late Holocene and 4) a warming and wetting trend over the last 2000 years. Correspondingly, the lake experienced a shallow-water phase in the Late Glacial and a deep-lake phase during the Holocene. The cold Younger Dryas (YD) event occurred from 12.7 to 11.0 cal. kyr BP in the core, with extremely low total organic carbon (TOC) and coarse GS. In contrast, the Holocene Megathermal occurred between 10.0 and 9.1 cal. kyr BP, as recorded by the TOC maxima, which had a finer grain size. In this study, the TIC (plus the XRF-Ca and Ca/Si ratio) reflected the combined effects of biochemical processes (e.g., algal photosynthesis) and hydrological changes (e.g., precipitation, evaporation and runoff). Comparisons between regional records and reconstructed paleoclimate indexes suggested that the studied area's effective moisture pattern mostly followed fluctuations in the ISM-dominated region. The monsoonal circulation drove the paleoclimate variations on the central QTP since the Late Glacial, mainly controlled by enhanced summer insolation until the mid-Holocene. Further, the effective moisture variation was influenced by the August insolation (increased evaporation), on which the Westerlies effect (related to intensely cold air) and the meltwater runoff were later superimposed. Recently, the hydro-climatic conditions have acquired a temperate-humid status in the study area, which likely approaches that in the early Holocene's late phase. Therefore, the paleoclimate pattern of the source region of the Yangtze River exhibits a transitional nature (phase) between two circulation regions during the Holocene.

Quaternary environments and monsoonal climate off northwest Australia: Palynological evidence from Ocean Drilling Program Site 765

The bathyal Ocean Drilling Program Site 765 at 5725 m water depth, offshore northwest Australia at 16°S is directly under the influence of the Australian monsoon during the Austral summer and is the recipient of continental dust during the Austral winter. It is downstream of the Indonesian Throughflow, which is a major arm of the global thermohaline circulation. As such it is ideally situated to record the climate and oceanic consequences of Quaternary climate variability. Despite being over 400 km from northwest Australia, palynomorphs (pollen and spores) are relatively common in this section, sourced via aeolian (during the dry winter) and benthic transportation processes and sediment plumes (during the summer monsoon). Detailed palynological analyses of this flora in the upper part of this core reveals intermittent snap shots of environmental and climate change over the last 300 kyrs. Interglacial stages are interpreted to be characterised by palynomorph-rich turbidite and calcareous ooze deposition whereas palynomorph-poor slowly accumulating siliceous oozes (deposited below the Calcium Carbonate Compensation Depth) are present during glacials. The dominance of Poaceae sourced from the Australian mainland in interglacial periods suggests that vegetation during these periods was similar to today. Interglacial palynofloral assemblages suggest a more intense wet season (Australian monsoon) with higher rainfall that allowed more active erosion and deposition onto the shelf. The presence of Indonesian sourced pollen and fern spore taxa, as well as warm water dinoflagellate species suggest enhanced Leeuwin Current and monsoonal intensity during interglacials times. The youngest part of the core is dominated by siliceous ooze, likely deposited during the Last Glacial Maximum and the early Holocene. The lack of calcareous ooze near the top of the core is likely caused by Holocene to Recent erosive processes or core disturbance. The presence of common charcoal in all samples over the last 300 kyrs shows that fire was a constant feature of the landscape in northwest Australia prior to human occupation of the region 65,000 years ago.