A diagnostic analysis reveals that on the interannual time scale the southeast-northwest movement is a dominant feature of the South Asian high (SAH), and it is closely related to the Indian and East Asian summer monsoon rainfall. The southeastward (northwestward) shift of the SAH is closely related to less (more) Indian summer monsoon rainfall and more (less) rainfall in the Yangtze River valley (YRV) over the East Asian summer monsoon region. An anomalous AGCM is utilized to examine the effect of latent heat anomalies associated with the Asian summer monsoon rainfall on the SAH. The negative latent heat anomalies over the northern Indian Subcontinent associated with a weak Indian summer monsoon stimulates an anomalous cyclone to its northwest and an anticyclone to its northeast over the eastern Tibetan Plateau and eastern China in the upper troposphere, which is responsible for the east-west shift of the SAH and more rainfall in the YRV. The positive latent heat release associated with rainfall anomalies in the YRV excites a southward-located anticyclone over eastern China, exerting a feedback effect on the SAH and leading to a southeast-northwest shift of the SAH.

One-point correlation analysis on upper-level meridional wind identified the existence of a teleconnection pattern in July, which emerges from North Africa to East Asia along the westerly jet in the middle latitudes. We examined the spatial and temporal structures of this teleconnection pattern, and found the unique characteristics rather different from the patterns in other elements such as geopotential height, streamfunction and vorticity. We also investigated the relationship between this teleconnection and precipitation, and suggested that the teleconnection is a possible linkage of the EASM to the Indian monsoon, and even to subtropical heating anomalies over Atlantic. * Corresponding author. elements are zonally elongated at the upper tropo-Address: Institute of Atmospheric Physics, Chinese sphere, because of great seasonal and interannual Academy of Sciences, PO Box 2718, Beijing 100080, variabilities in meridional position of the westerly China.

In this study the statistical relationship between winter-spring Soviet snow depth and summer monsoon rainfall over South Korea has been investigated by lag correlation coefficients and composite analysis. Data for the 1966-95 period are used. Results reveal that the winter/springtime snow depth over western Eurasia (over Kazakhstan) is negatively related, whereas the snow depth over eastern Eurasia (over Manchuria-eastern Siberia) is positively related with Korean monsoon rainfall. The dipole correlation pattern suggests that heavy snow over eastern Eurasia and light snow over western Eurasia is favourable, whereas the reverse situation is unfavourable for monsoon activity over South Korea. The NCEP-NCAR re-analyses data reveal that the dipole correlation configuration is indicative of a mid-latitude long-wave pattern with an anomalous ridge over north Asia during the winter prior to a weak Korean monsoon and an anomalous trough prior to a strong monsoon. The re-analyses data further suggest that the position, shape, and strength of the summertime North Pacific subtropical high and the low-level jet over the East Asian sector could be considerably influenced by the snow distribution over Eurasia.

This study investigates the relationship between the summer monsoon rainfall over Korea and India, by using correlation analysis and Singular Value Decomposition (SVD).Results reveal that summer monsoon rainfall over Korea is negatively (significant at the 99% level) correlated with the rainfall over the northwest and central parts of India. In addition, coupled spatial modes between the rainfall over Korea and India have been identified by the SVD analysis. The squared covariance fraction explained by the first mode is 70% and the correlation coefficient between the time coefficients of the two fields is significant at the 99% level, indicating that the coupled mode reflects a large part of the interaction between the summer monsoon rainfall over Korea and India. The first mode clearly demonstrates the existence of a significant negative correlation between the rainfall over the northwest and central parts of India and the rainfall over Korea.Possible mechanisms of this correlation are investigated by analyzing the variation of upper-level atmospheric circulation associated with the Tibetan high using NCEP/NCAR Reanalysis data.

Oak pollen is a major respiratory allergen in Korea, and the distribution of oak trees is expected to increase by ecological succession and climate change. One of the drivers of climate change is increasing CO, which is also known to amplify the allergy risk of weed pollen by inducing elevated allergenic protein content. However, the impact of CO concentration on tree pollen is not clearly understood due to the experimental difficulties in carrying out extended CO treatment. To study the response of pollen production of sawtooth oak trees (Quercus acutissima) to elevated levels of ambient CO, three open-top chambers at the National Institute of Forest Science in Suwon, Korea were utilized with daytime (8 am-6 pm) CO concentrations of ambient (× 1.0, ~ 400 ppm), × 1.4 (~ 560 ppm), and × 1.8 (~ 720 ppm) treatments. Each chamber had three sawtooth oak trees planted in September 2009. One or two trees per chamber matured to bloom in 2016. Five to six catkins were selected per tree and polyethylene bags were attached to collect pollen grains. The total number of catkins per tree was counted and the number and weight of pollen grains per catkin were measured. Oak allergen-Que a 1 (Allergon Co., Uppsala, Sweden)-was extracted and purified to make an ELISA kit by which the antigen levels in the pollen samples were quantified. Total pollen counts per tree of the × 1.4 and × 1.8 treatments showed significant increase of 353 and 1299%, respectively, from the × 1.0 treatment (p < 0.001). Allergenic protein contents at the × 1.4 and × 1.8 treatments also showed significant increase of 12 and 11%, respectively (p = 0.011). The × 1.8 treatment induced significant difference from the × 1.0 treatment in terms of pollen production and allergenic protein content, whereas the × 1.4 treatment showed mixed significance. In summary, the oak trees under the elevated CO levels, which are expected in the changing climate, produced significantly higher amount of pollen and allergenic protein than under the present air conditions.

This study examined the relationship between the western North Pacific monsoon (WNPM) and the tropical cyclone (TC) activity over western North Pacific during the summer (June to August) in a period from 1977 to 2013. According to the western North Pacific monsoon index (WNPMI), 10 years with high indices (referred to as the positive WNPMI phase) and 10 years with low indices (referred to as the negative WNPMI phase) were chosen. TCs frequently formed in the southeast quadrant of the subtropical western North Pacific in the positive WNPMI phase, and in the northwest quadrant in the negative phase. With respect to the TC track, TCs tended to move northward from the distant sea off the east coast of the Philippines towards Korea and Japan past the East China Sea in the positive WNPMI phase, whereas the characteristic pattern of the negative phase was the TC movement from the Philippines to southern China and the Indochinese peninsula over the South China Sea. As for the TC intensity, the TCs were stronger in the positive WNPMI phase than in the negative WNPMI phase. The anomalous cyclonic circulations in the south of the 30 ∘ N signified strong convection, causing the high TC genesis frequency in the positive WNPMI phase. In addition, the East China Sea, Korea and Japan were shown to be influenced by the anomalous southeasterly, which contributed as the anomalous steering flows and was favourable for the TCs to move into these regions in the positive WNPMI phase. Meanwhile, the positive anomaly of 600 hPa relative humidity and sea surface temperature as well as the negative anomaly of vertical wind shear presented in most regions of the subtropical western North Pacific, creating an environment that facilitated the generation of TCs in the positive WNPMI phase.

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