Climatological patterns in wind fluctuations on time scales of 1–10 h are analyzed at a meteorological mast at the Yangmeishan wind farm, Yunnan Province,China, using a 2-yr time series of 10-min wind speed observati...Climatological patterns in wind fluctuations on time scales of 1–10 h are analyzed at a meteorological mast at the Yangmeishan wind farm, Yunnan Province,China, using a 2-yr time series of 10-min wind speed observations. For analyzing the spectral properties of nonstationary wind fluctuations in mountain terrain, the Hilbert-Huang transform(HHT) is applied to investigate climatological patterns between wind variability and several variables including time of year, time of day, wind direction, and pressure tendency. Compared with that for offshore sites, the wind variability at Yangmeishan wind farm has a more distinct diurnal cycle, but the seasonal discrepancies and the differences according to directions are not distinct, and the synoptic influences on wind variability are weaker. There is enhanced variability in spring and winter compared with summer and autumn. For flow from the main direction sector, the maximum wind variability is observed in spring. And the severe wind fluctuations are more common when the pressure tendency is rising.展开更多
Based on a δ180 chronology, rare earth elements （REE） and other typical elements in sediments from core MD06-3047 in the western Philippine Sea were analyzed to constrain the provenances of the sediments and invest...Based on a δ180 chronology, rare earth elements （REE） and other typical elements in sediments from core MD06-3047 in the western Philippine Sea were analyzed to constrain the provenances of the sediments and investigate quantitative changes in the Asian eolian input to the study area over the last 700 ka. Among the competing processes that might affect REE compositions, sediment provenance is the most important one. Provenance analysis suggests that the study sediments have two provenance end-members; local volcanic sources are dominant, and eolian dust from the Asian continent has a smaller contribution. During glacial periods, eolian input to the western Philippine Sea was enhanced. In contrast, material supply from local volcanics in- creased during interglacial periods. Changes in eolian input to the study area were probably related to the strength of the East Asian winter monsoon （EAWM） as well as aridity in the Asian continent on an orbital time scale, and were partly influenced by local control factors on shorter time scales. Therefore, we propose that the present study expands the application of the REE-based method for quantitatively estimating the eolian component from the mid-latitude northern Pacific to the low-latitude western Pacific. Additionally, the study preliminarily confirms the influence of EAWM-transported eolian materi- al on sedimentation in the western Philippine Sea since 700 ka.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 91215302 and 41101045)the "One-Three-Five" Strategic Planning of the Institute of Atmospheric Physics, Chinese Academy of Sciences (Grant No. Y267014601)
文摘Climatological patterns in wind fluctuations on time scales of 1–10 h are analyzed at a meteorological mast at the Yangmeishan wind farm, Yunnan Province,China, using a 2-yr time series of 10-min wind speed observations. For analyzing the spectral properties of nonstationary wind fluctuations in mountain terrain, the Hilbert-Huang transform(HHT) is applied to investigate climatological patterns between wind variability and several variables including time of year, time of day, wind direction, and pressure tendency. Compared with that for offshore sites, the wind variability at Yangmeishan wind farm has a more distinct diurnal cycle, but the seasonal discrepancies and the differences according to directions are not distinct, and the synoptic influences on wind variability are weaker. There is enhanced variability in spring and winter compared with summer and autumn. For flow from the main direction sector, the maximum wind variability is observed in spring. And the severe wind fluctuations are more common when the pressure tendency is rising.
基金supported by the Public Science and Technology Research Funds Projects of the OceanState Oceanic Administration of the People’s Republic of China(Grant No.201005003)+1 种基金the National Natural Science Foundation of China(Grant Nos.41376064,41230959,41106043,and 41076033)the National Basic Research Program of China(Grant No.2007CB815903)
文摘Based on a δ180 chronology, rare earth elements （REE） and other typical elements in sediments from core MD06-3047 in the western Philippine Sea were analyzed to constrain the provenances of the sediments and investigate quantitative changes in the Asian eolian input to the study area over the last 700 ka. Among the competing processes that might affect REE compositions, sediment provenance is the most important one. Provenance analysis suggests that the study sediments have two provenance end-members; local volcanic sources are dominant, and eolian dust from the Asian continent has a smaller contribution. During glacial periods, eolian input to the western Philippine Sea was enhanced. In contrast, material supply from local volcanics in- creased during interglacial periods. Changes in eolian input to the study area were probably related to the strength of the East Asian winter monsoon （EAWM） as well as aridity in the Asian continent on an orbital time scale, and were partly influenced by local control factors on shorter time scales. Therefore, we propose that the present study expands the application of the REE-based method for quantitatively estimating the eolian component from the mid-latitude northern Pacific to the low-latitude western Pacific. Additionally, the study preliminarily confirms the influence of EAWM-transported eolian materi- al on sedimentation in the western Philippine Sea since 700 ka.
