The effect of health benefits on climate change mitigation policies     

Masako Ikefuji  Jan R. Magnus  Hiroaki Sakamoto 《Climatic change》2014,126(1-2):229-243

This paper studies the interplay between climate, health, and the economy in a stylized world with eleven heterogeneous regions, with special emphasis on USA, Europe, China, India, and Africa. We introduce health impacts into a simple economic integrated assessment model where both the local cooling effect of SO ₂ and the global warming effect of CO ₂ are endogenous, and investigate how these factors affect the equilibrium path. Regions do not respond in the same way to climate change. In particular, emission abatement rates and health costs depend on the economic and geographical characteristics of each region. Two policy scenarios are considered, Nash and Optimal, for which we present both global and regional results. Results for Africa and China are highlighted.  相似文献   

Three‐dimensional structures and elemental distributions of Stardust impact tracks using synchrotron microtomography and X‐ray fluorescence analysis     

A. Tsuchiyama  T. Nakamura  T. Okazaki  K. Uesugi  T. Nakano  K. Sakamoto  T. Akaki  Y. Iida  T. Kadono  K. Jogo  Y. Suzuki 《Meteoritics & planetary science》2009,44(8):1203-1224

Abstract— Three‐dimensional structures and elemental abundances of four impact tracks in silica aerogel keystones of Stardust samples from comet 81P/Wild 2 (bulbous track 67 and carrot‐type tracks 46, 47, and 68) were examined non‐destructively by synchrotron radiation‐based microtomography and X‐ray fluorescence analysis. Track features, such as lengths, volumes and width as a function of track depth, were obtained quantitatively by tomography. A bulbous portion was present near the track entrance even in carrot‐type tracks. Each impact of a cometary dust particle results in the particle disaggregated into small pieces that were widely distributed on the track walls as well as at its terminal. Fe, S, Ca, Ni, and eight minor elements are concentrated in the bulbous portion of track 68 as well as in terminal grains. It was confirmed that bulbous portions and thin tracks were formed by disaggregation of very fine fragile materials and relatively coarse crystalline particles, respectively. The almost constant ratio of whole Fe mass to track volume indicates that the track volume is almost proportional to the impact kinetic energy. The size of the original impactor was estimated from the absolute Fe mass by assuming its Fe content (CI) and bulk density. Relations between the track sizes normalized by the impactor size and impact conditions are roughly consistent with those of previous hypervelocity impact experiments.  相似文献   

Baroclinic circulation and its high frequency variability in Otsuchi Bay on the Sanriku ria coast,Japan     

Kiyoshi Tanaka  Kousei Komatsu  Sachihiko Itoh  Daigo Yanagimoto  Miho Ishizu  Hiroyasu Hasumi  Takashi T. Sakamoto  Shogo Urakawa  Yutaka Michida 《Journal of Oceanography》2017,73(1):25-38

Hydrographic observations were made in Otsuchi Bay on the Sanriku ria coast, Japan, to provide clear images of the baroclinic circulation extending over the bay together with the associated intrusion of lower-layer water (bottom water) from outside the bay. In summer, a prominent baroclinic circulation with flow speeds \({>} 0.1\ \text{ m }\ \text{ s }^{-1} \) extends over the greater part of the bay. A main pycnocline (thermocline), which separates the upper and lower layers, is located at a depth of 15–40 m in and around the bay. The direction of the lower-layer flow (inflow into and outflow from the bay) is opposite to that of the upper-layer flow, which are baroclinically coupled to each other. Moreover, with regard to the lower-layer flow, the inflow tends to occur mainly through the northwestern part of the bay mouth, whereas the outflow tends to occur mainly through the southeastern part. The inflow and outflow alternate on time scales of several to a few tens of hours, and the flow directions are sometimes related to the tidal ones, although the relationship is not applied persistently. In winter, the baroclinic circulation is considerably weaker than in summer, because the stratification breaks down.  相似文献   

Impacts of climate change on growth, migration and recruitment success of Japanese sardine (Sardinops melanostictus) in the western North Pacific     

Takeshi Okunishi  Shin-ichi Ito  Taketo Hashioka  Takashi T. Sakamoto  Naoki Yoshie  Hiroshi Sumata  Yumiko Yara  Naosuke Okada  Yasuhiro Yamanaka 《Climatic change》2012,115(3-4):485-503

We developed a multi-trophic level ecosystem model by coupling physical, biogeochemical-plankton and fish models. An oceanic general circulation model was coupled with a lower trophic level ecosystem model and a Japanese sardine migration model, and applied to the western North Pacific. To investigate the impact of global warming on the pelagic fish ecosystem, such as Japanese sardine, we conducted numerical experiments of growth and migration of Japanese sardine using physical fields for the present day and future with a global warming scenario simulated by a high-resolution climate model. The model results demonstrated possible impacts of global warming on the growth and migration pattern of Japanese sardine. The growths of fish in the current main spawning region under the global warming scenario were significantly slower than those under the present climate scenario. Fish in this region will be at disadvantage for their recruitment under the global warming condition. Prey conditions in the spawning region were projected not to markedly change under global warming condition while water temperature increased. As a result sardine spawning ground was projected to shift towards more north areas. During the feeding migration period in summer, geographical distribution of juveniles fish was projected to shift northwards by one to two degrees latitude under the global warming condition following the change in the distribution of optimal temperature region for feeding. However, this northwards shift of the optimal temperature for feeding was minimized adjacent to the western North Pacific by the cooler water supply by the intensification of the Oyashio.  相似文献   

Gas dynamics and structure of galaxies     

Kazushi Sakamoto 《Astrophysics and Space Science》2008,313(1-3):245-251

Between gas dynamics and structure of galaxies is a two-way relation. On one hand, gas dynamics in a galaxy is largely determined by the structure of the galaxy, and on the other hand, gas dynamics can gradually alter the galaxy structure through redistribution of mass and angular momentum within the galaxy. The first half of this relation should mostly determine gas distribution and regulate star formation in undisturbed spirals, and the second half has been suggested to cause secular evolution of spiral galaxies—a slow mode of galaxy evolution in the absence of major mergers. Our knowledge on this relation is going to be greatly deepened by the ALMA. Focusing on the galaxy evolution through gas dynamics, I briefly review what we know about the subject. Then I try to look out what the ALMA can do to answer open questions in the field. It is pointed out that the ALMA will be able to fully map all the spiral galaxies between 1 and 25 Mpc at 1″ resolution in 1000 hours.  相似文献   

Detection and hydrologic modeling of aquifers in unconsolidated alluvial plains through combination of borehole data sets: a case study of the Arao area, Southwest Japan     

Katsuaki Koike  Hidehumi Sakamoto  Michito Ohmi   《Engineering Geology》2001,62(4):301-317

In addition to spatial distribution of groundwater-flow parameters, aquifer properties of location and shape are also significant for assessing groundwater resources because they strongly affect water flow. We present a selection of geologic data suitable for aquifer analysis, a mathematical method of processing them, and a combination of several maps produced by it. The data used in the analysis are typically obtained by borehole investigation. Our targets are the areas underlain by geologic bodies with different ages and lithologies; the spatial correlation structures of geologic data over the areas tend to change locally. The processing method should be a versatile one that is applicable to areas where geostatistical stationarity is not satisfied. The aquifer analysis consistent with that requirement consists of two steps: the first is the transformation of screen locations, locations of sand and gravel layers, and resistivity by electric logging into indicator values, and the second is three-dimensional interpolation of these using the optimization principle method to produce three kinds of distribution models. A stochastic simulation is also used for modeling the resistivity distribution. The three distribution models are integrated to generate a value for evaluating the possibility of aquifer existence. A case study of an alluvial coastal plain, situated in southwest Japan, describes an aquifer model that contains three permeable layers. Each layer has about 10-m thickness and is lens shaped. To confirm the validity of the model, we have drilled two wells that reached one of the middle and bottom permeable layers, observing the water level change. Low correlation of the temporal changes of levels between the wells indicates that the two layers are hydrologically independent of each other. Additionally, groundwater-flow patterns have been estimated by transforming the simulation model parameter into hydraulic conductivity through a simple function and using a finite difference method for flow analysis. The procedure proposed by this study can be applied to other areas by changing the weights assigned to each geologic and geotechnical factor in the generation of the coefficient for aquifer existence, considering the reliability of each factor and hydrologic properties of study area.  相似文献   

Climate and global grain yield variability     

C. Sakamoto  S. Leduc  N. Strommen  L. Steyaert 《Climatic change》1980,2(4):349-361

Historical grain yields from several countries were analyzed to determine the variability of grain yield. This was accomplished by assuming a linear technology trend and analyzing the deviations from this trend. The deviation was assumed to be primarily an effect of weather. Using 10 percent deviation from trend as a threshold, it was determined that for each of seven countries the probability of a poor yield year ranged from 17 in India and the United States to 33 percent in Canada and the U.S.S.R. The probability of two consecutive poor wheat yield years was highest in Canada (17 percent) and lowest in Argentina (6 percent). The probability of a poor year occurring in the same year in both the United States and the U.S.S.R. was about 7–8 percent. The highest variability in yield has occurred in Canada, but variability in India has increased substantially since the 1960's.  相似文献   

Assessment with agro-climatological information     

Clarence Sakamoto  Norton Strommen  Augustine Yao 《Climatic change》1979,2(1):7-20

Multidisciplinary teamwork can create efficient and effective assessment tools and supply information required for inputs in management decisions. In this paper, illustrations are provided to indicate that much information can be gained from using climatological data to assess the impact of the variability of weather and climate on agriculture. Climatic data have been collected and archived for many areas of the world. These data must not go unused.  相似文献   

Structure of caldera and gravity anomaly     

Izumi Yokoyama 《Bulletin of Volcanology》1963,26(1):67-72

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Seasonal Trend in the Occurrence of Nocturnal Drainage Flow on a Forested Slope Under a Tropical Monsoon Climate     

Hikaru Komatsu  Narimasa Yoshida  Hideki Takizawa  Izumi Kosaka  Chatchai Tantasirin  Masakazu Suzuki 《Boundary-Layer Meteorology》2003,106(3):573-592

Using data for one year, we examined the vertical wind speed profileson a mountain slope covered with forest in northern Thailand undera tropical monsoon climate. We defined two profile patterns: higherwind speeds at greater heights (Pattern 1) and lower wind speeds atgreater heights (Pattern 2). We classified 9.4% of the data as Pattern 2;this pattern tended to occur during the night, at low wind speeds, and with high outgoing longwave radiation. In addition, stable stratification anddecoupling between the canopy surface air and the overlying layers wereobserved when Pattern 2 occurred frequently. These facts suggested thatPattern 2 was caused by a nocturnal drainage flow. The occurrence ofPattern 2 showed a clear seasonal trend, indicating that there is a seasonaltrend in the occurrence of nocturnal drainage flows. Pattern 2 was observedmore frequently between August and February and less frequently betweenMarch and July. This corresponded to the seasonal trend in wind speed, butdid not correspond to the seasonal trend in the outgoing longwave radiation.  相似文献