3,579 research outputs found
Trans-Eurasian transport of ozone and its precursors
No full textLong-range transport of air across the European and Asian continents brings substantial quantities of ozone and other oxidants to northeast Asia from upwind sources over Europe and North America. This transport differs significantly from that over the Pacific and Atlantic Oceans because of weaker and less frequent frontal systems over the continent and because of weaker convective lifting over European sources. Slower O-3 formation, faster destruction at low altitudes, and greater deposition over continental regions lead to Europe having a smaller impact on O-3 than other source regions. We present chemical transport model studies of the formation and transport of O3 from European precursor sources and investigate the extent of their impacts over Eurasia. We focus on measurement sites at 100degreesE, representing the inflow to east Asia on which regional pollutant sources build, and on northeast Asia, which may be directly affected by transport across Eurasia. The seasonality in O-3 production over Europe is simulated well, and transport principally in the boundary layer propagates these changes in O-3 over Eurasia, leading to monthly mean impacts at Mondy, Siberia, of 0.5-3.5 ppbv. Impacts over Japan are smaller, 0.2-2.5 ppbv, and are very similar to those from North American sources, which dominate at higher altitudes. By following the effect of daily emissions independently, we clearly demonstrate that this greater North American impact is associated with lifting over the Atlantic. European and North American sources contribute to background O-3 over Japan in the anticyclonic conditions that favor regional O-3 buildup and are thus expected to have a small but significant effect on regional air quality. Finally, we demonstrate that location and transport lead to European sources having a different impact on OH, and hence on tropospheric oxidizing capacity and climate, from other major Northern Hemisphere source regions
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Indirect long-term global radiative cooling from NOx emissions
No full textAnthropogenic emissions of short‐lived, chemically reactive gases, such as NO x and CO, are known to influence climate by altering the chemistry of the global troposphere and thereby the abundance of the greenhouse gases O3, CH4 and the HFCs. This study uses the characteristics of the natural modes of the tropospheric chemical system to decompose the greenhouse effect of NO x and CO emissions into (i) short‐lived modes involving predominantly tropospheric O3 and (ii) the long‐lived mode involving a global coupled CH4‐CO‐O3 perturbation. Combining these two classes of greenhouse perturbations—large, short‐lived, regional O3 increases and smaller, long‐lived, global decreases in CH4 and O3—we find that most types of anthropogenic NO x emissions lead to a negative radiative forcing and an overall cooling of the earth
The Spirit to “Survive” the War – a Play by Akimoto Matsuyo, Hitachibō Kaison (Kaison, the Priest of Hitachi)
No full textAkimoto Matsuyo (1911–2001) is one of the few female playwrights of the Shōwa Period. Her master was Miyoshi Jūrō, a renowned figure of the proletarian theater. He taught Akimoto the art of detailed realism. Akimoto’s great fascination with folklore, an obvious influence of Yanagida Kunio, drove her meticulous fieldwork. In places forgotten and irrelevant to the main course of history, she explored the sensitivity of those in deep connection with local traditions and used this research in her plays. Her play Hitachibō Kaison (Kaison, the Priest of Hitachi) is based on a legend that featured Yoshitsune. Kaison first betrays his lord, later changes his life completely – goes about retelling his sins, and in the end refuses to eat and becomes a virtuous living incarnation of Buddha (ikibotoke). The story opens with the scene of Tokyo children being evacuated at the end of the Pacific War. The children unexpectedly become absorbed into the world of Kaison’s legend. The comeback of the folk magic theme, posing a contrast with postwar Japan’s modern rationalization, is a unique phenomenon in the literature of the late 1950’s. It also somehow relates to the interest in Japanese folklore and sensuality present in the works of the playwrights of the 1960’s, like Tarayama Shūji or Kara Jūrō. Akimoto, however, does not see Japanese folklore only in contrast to modernity. In her play Muraoka Iheijiden (The Life of Muraoka Iheiji, 1960) she describes a simple man from the countryside, Muraoka, who initially dedicates himself to helping women sold abroad to China and South-East Asia, but later, due to misguided patriotism, changes his approach and by the end abandons all the “deceived” women. In the play Kasabuta Shikibukō (Meditation on Our Lady of Scabs, 1969) Akimoto deals with the pain and suffering of the common people. Basing her story on folk beliefs glorifying the figure of Izumi Shikibu, Akimoto shows the suffering of a mother and a wife that both long for the recovery of a mentally handicapped man who lost his faculties due to a coal-mining accident. Although not explicitly, the play addresses the topic of the psychological construct of selfish patriotism that throughout the 20th century allowed Japan to slip further and further into military conflict starting with the Russo-Japanese War. After the wars were over it still brought suffering to people, who now became victims of a quasi-war, that is, the rapid economic development. In Muraoka Iheijiden the sincere, whole-hearted modern day love of the common countryside people towards their home areas, the neighborly love, all become abused by the power of the state. In Kasabuta Shikibukō, the anti-modern world of myth and folktale – with all its relations, including male-female relationships, eventually ends up twisted by the greed for power that comes with economic development (the national system). Both on the surface and in the inner depths of society, salvation (meaning to live like a human being) becomes an empty slogan (symbol), repeated by simple people devoid of any escape, whose only rescue is in the faith that salvation will come. The author shows it most vividly in one of the scenes from Hitachibō Kaison. The children who are beingevacuated from Tokyo start evoking the name of “Lord Kaison” (Kaison-sama) unaware of the meaning behind those words. In the article I would like to examine how theater plays portray the similarities between the belief in kishuryūritan tales glorifying the defeated, and the imperial system that supported Japanese wars during the era of militarism
Contributions of regional and intercontinental transport to surface ozone in the Tokyo area
No full textJapan lies downwind of the Asian continent and for much of the year air quality is directly influenced by emissions of ozone precursors over these heavily-populated and rapidly-industrializing regions. This study examines the extent to which oxidant transport from regional and distant anthropogenic sources influences air quality in Japan in springtime, when these contributions are largest. We find that European and North American contributions to surface ozone over Japan in spring are persistent, averaging 3.5 +/- 1.1 ppb and 2.8 +/- 0.5 ppb respectively, and are greatest in cold continental outflow conditions following the passage of cold fronts. Contributions from China are larger, 4.0 +/- 2.8 ppb, and more variable, as expected for a closer source region, and are generally highest near cold fronts preceding the influence of more distant sources. The stratosphere provides a varying but ever-present background of ozone of about 11.2 +/- 2.5 ppb during spring. Local sources over Japan and Korea have a relatively small impact on mean ozone, 2.4 +/- 7.6 ppb, but this masks a strong diurnal signal, and local sources clearly dominate during episodes of high daytime ozone. By examining the meteorological mechanisms that favour transport from different source regions, we demonstrate that while maximum foreign influence generally does not occur at the same time as the greatest buildup of oxidants from local sources, it retains a significant influence under these conditions. It is thus clear that while meteorological boundaries provide some protection from foreign influence during oxidant outbreaks in Tokyo, these distant sources still make a substantial contribution to exceedance of the Japanese ozone air quality standard in springtime
Measurements of Surface Temperature and Emissivity by Two-dimensional Four-color Thermometry with Narrow Bandwidth
No full textAbstract To study characteristics of heated material surface over 600 K, non-contact measurements of two-dimensional (2D) distributions of temperature and emissivity are very useful for process monitoring in engineerings, because of remote sensing in short time. The 2D temperature distributions enable us to monitor the surface temperature quantitatively with high spatial resolution. The 2D emissivity distributions give us a capability to judge thermal degradations or defects of surfaces. In our previous studies, 2D distributions of temperature and emissivity determined by two-color method with a CCD camera and two optical filters have been reported. In this study, a four-color method is proposed to improve accuracy and precision in measurements of the 2D distributions. Four optical filters with narrow bandpass of 10 nm were used for our measurements, because the thermometry with them is advantageous over that with wide ones in terms of *Corresponding author, phone: +81-52-789-5982, fax: +81-52-789-2919. E-mail: [email protected] (Fumie Akimoto) accuracy in temperature determination. As the wavelengths of these narrow bandpass filters are selected to be free from atmospheric absorption, it gives negligibly small errors in the temperature measurement. Distributions of temperature and emissivity determined by two-color method are also discussed for comparison. The results obtained by the four-color method have high accuracy and precision and the resultant 2D emissivity distribution indicates that several conditions of surfaces are clearly illustrated
Observation of Top Quark Production in ¯pp Collisions with the CDF Detector at Fermilab
No full textWe establish the existence of the top quark using a 67 pb \Gamma1 data sample of ¯ pp collisions at p s = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those we previously published, we observe a signal consistent with t ¯ t decay to WWb ¯ b, but inconsistent with the background prediction by 4:8oe. Additional evidence for the top quark is provided by a peak in the reconstructed mass distribution. We measure the top quark mass to be 176 \Sigma 8(stat:) \Sigma 10(sys:) GeV/c 2 , and the t ¯ t production cross section to be 6:8 +3:6 \Gamma2:4 pb. The CDF Collaboration F. Abe, 14 H. Akimoto, 32 A. Akopian, 27 M. G. Albrow, 7 S. R. Amendolia, 24 D. Amidei, 17 J. Antos, 29 C. Anway-Wiese, 4 S. Aota, 32 G. Apollinari, 27 T. Asakawa, 32 W. Ashmanskas, 15 M. Atac, 7 P. Auchincloss, 26 F. Azfar, 22 P. Azzi-Bacchetta, 21 N. Bacchetta, 21 W. Badgett, 17 S. Bagdasarov, 27 M. W. Bailey, 19 J. Bao, 35 P. ..
High-Pressure Research Applications Seminar
No full textThe United States‐Japan seminar on “High‐Pressure Research Applications in Geophysics and Geochemistry” was held in Honolulu, Hawaii, January 13–16, 1986, under the auspices of the National Science Foundation (NSF) and the Japan Society for the Promotion of Science (JSPS). The seminar, the third in a series, was cocovened by Murli H. Manghnani (University of Hawaii, Honolulu) and Syun‐iti Akimoto (University of Tokyo). Coming together for this symposium were 25 researchers from Japan, 22 from the United States, and four others, from Australia, the People's Republic of China, the Netherlands, and the Federal Republic of Germany. Of the 52 papers presented, 38 were presented orally at seven scientific sessions, and the rest were displayed at a poster session
Seasonal variation of carbon monoxide in northern Japan: Fourier transform IR measurements and source-labeled model calculations
No full textTropospheric carbon monoxide (CO) was measured throughout 2001 using ground-based Fourier transform IR (FTIR) spectrometers at Moshiri (44.4°N) and Rikubetsu (43.5°N) observatories in northern Japan, which are separated by 150 km. Seasonal and day-to-day variations of CO are studied using these data, and contributions from various CO sources are evaluated using three-dimensional global chemistry transport model (GEOS-CHEM) calculations. Seasonal maximum and minimum FTIR-derived tropospheric CO amounts occurred in April and September, respectively. The ratio of partial column amounts between the 0–4 and 0–12 km altitude ranges is found to be slightly greater in early spring. The GEOS-CHEM model calculations generally reproduce these observed features. Source-labeled CO model calculations suggest that the observed seasonal variation is caused by seasonal contributions from various sources, in addition to a seasonal change in chemical CO loss by OH. Changes in meteorological fields largely control the relative importance of various source contributions. The contributions from fossil fuel (FF) combustion in Asia and photochemical CO production have the greatest yearly averaged contribution at 1 km among the CO sources (31% each). The Asian FF contribution increases from winter to summer, because weak southwesterly wind in summer brings more Asian pollutants to the observation sites. The seasonal variation from photochemical CO production is small (±17% at 1 km), likely because of concurrent increases (decreases) of photochemical production and loss rates in summer (winter), with the largest contribution between August and December. The contribution from intercontinental transport of European FF combustion CO is found to be comparable to that of Asian FF sources in winter. Northwesterly wind around the Siberian high in this season brings pollutants from Europe directly to Japan, in addition to southward transport of accumulated pollution from higher latitudes. The influences are generally greater at lower altitudes, resulting in a vertical gradient in the CO profile during winter. The model underestimates total CO by 12–14% between March and June. Satellite-derived fire-count data and the relationship between FTIR-derived HCN and CO amounts are generally consistent with biomass burning influences, which could have been underestimated by the model calculations
Intercontinental transport of ozone and its precursors in a three-dimensional global CTM
No full textThe coupling of chemistry with atmospheric transport processes provides a mechanism for local and regional pollution from heavily populated continental regions to influence tropospheric composition at hemispheric and global scales. In this study we use the FRSGC/UCI 3-D chemical transport model to quantify the impact of ozone precursors from anthropogenic sources in the United States, Europe and East Asia on regional and global ozone budgets and to identify the key controlling processes. We find that the East Asian region has the greatest potential to affect tropospheric ozone due principally to efficient vertical transport, but that Europe experiences the greatest intercontinental effects due to rapid, short-distance transport from North America. In addition to significant boundary layer ozone production in each region, we find that 25-40% of the total net regional production occurs above 730 hPa in the free troposphere, and that on a hemispheric scale 70-85% of ozone from anthropogenic sources in the upper troposphere, above 400 hPa, is due to in-situ chemistry rather than direct vertical transport. Increased surface ozone concentrations over remote continents are largest in spring and autumn at northern mid-latitudes; while this seasonality is driven by horizontal transport in the free troposphere followed by subsidence, boundary layer and upper tropospheric chemical production make a substantial contribution. Although the effects are greatest in periodic episodes when meteorological conditions are favourable, there is significant enhancement in background ozone concentrations. We suggest that increasing emissions will significantly impact the oxidizing capacity of the troposphere by leading to greater polarization between ozone production and destruction environments
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