Emission metrics under the 2 °C climate stabilization target

In multi-gas climate policies such as the Kyoto Protocol one has to decide how to compare the emissions of different greenhouse gases. The choice of metric could have significant implications for mitigation priorities considered under the prospective negotiations for climate mitigation agreements. Several metrics have been proposed for this task with the Global Warming Potential (GWP) being the most common. However, these metrics have not been systematically compared to each other in the context of the 2 °C climate stabilization target. Based on a single unified modeling framework, we demonstrate that metric values span a wide range, depending on the metric structure and the treatment of the time dimension. Our finding confirms the basic salient point that metrics designed to represent different aspects of the climate and socio-economic system behave differently. Our result also reflects a complex interface between science and policy surrounding metrics. Thus, it is important to select or design a metric suitable for climate stabilization based on an interaction among practitioners, policymakers, and scientists.     

Generalized Lyzenga's Predictor of Shallow Water Depth for Multispectral Satellite Imagery

Multispectral satellite remote sensing can predict shallow-water depth distribution inexpensively and exhaustively, but it requires many in situ measurements for calibration. To extend its feasibility, we improved a recently developed technique, for the first time, to obtain a generalized predictor of depth. We used six WorldView-2 images and obtained a predictor that yielded a 0.648 m root-mean-square error against a dataset with a 5.544 m standard deviation of depth. The predictor can be used with as few as two pixels with known depth per image, or with no depth data, if only relative depth is needed.     

On-line sensing system of dynamic ship's attitude by use ofservo-type accelerometers

For an accurate automatic measurement of ship's attitude the paper proposes an intelligent online sensing system which uses four servo-type accelerometers and one servo-type inclinometer appropriately located on the ship. Through an adequate location of the accelerometers, the heaving, rolling, and pitching signals of the ship are separated from each other with adequate linear combinations of the four sensors' outputs. Furthermore, the inclinometer is utilized to extract a bias signal of the pitching. By introducing linear dynamic models and linear observation equations on the three signals, their online measurement is reduced to the state estimation of the linear dynamic systems. A bank of Kalman filters are used to execute the online state estimation and to overcome changes in parameters in the dynamic models with time     

Modern Numerical Schemes for Solving Magnetohydrodynamic Equations

In this paper several modern shock-capturing schemes for solving hydrodynamic and magnetohydrodynamic equations are reviewed. This review covers a wide range of explicit and implicit schemes as well as those in which adaptive mesh refinement methods are adopted. As these numerical schemes are based on Riemann solvers which use Godunov-type techniques, they are well suited for strong shocks and other discontinuities without oscillations in the flow variables. Some other numerical issues as grid generation, divergence cleaning, and an application of MHD schemes to several problems in coronal and interplanetary physics are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

A near-infrared fabry-perot imager at CRL 1.5m telescope and the structure and velocity field of shocked H2 emission in orion KL region

We have developed a near-infrared Fabry-Perot imager at the Nasmyth focus of the Communications Research Laboratory (CRL) 1.5 m telescope at Tokyo. Using this wide field Fabry-Perot imager, we obtained continuum-subtracted images of the H₂ v=1–0 S(1) line for the Orion KL region.     

A comparison of cumulus parameterization schemes in a numerical weather prediction model for a monsoon rainfall event

In order to evaluate cumulus parameterization (CP) schemes for hydrological applications, the Pennsylvania State University–National Center for Atmospheric Research's fifth‐generation mesoscale model (MM5) was used to simulate a summer monsoon in east China. The performances of five CP schemes (Anthes–Kuo, Betts–Miller, Fritsch–Chappell, Kain–Fritsch, and Grell) were evaluated in terms of their ability to simulate amount of rainfall during the heavy, moderate, and light phases of the event. The Grell scheme was found to be the most robust, performing well at all rainfall intensity and spatial scales. The Betts–Miller scheme also performed well, particularly at larger scales, but its assumptions may make it inapplicable to non‐tropical environments and at smaller scales. The Kain–Fritsch scheme was the best at simulating moderate rainfall rates, and was found to be superior to the Fritsch–Chappell scheme on which it was based. The Anthes–Kuo scheme was found to underpredict precipitation consistently at the mesoscale. Simulation performance was found to improve when schemes that included downdrafts were used in conjunction with schemes that did not include downdrafts. Copyright © 2005 John Wiley & Sons, Ltd.     

A study of the groundwater cycle in Sri Lanka using stable isotopes

The characteristics of the groundwater cycle were researched using stable isotope technology in western Sri Lanka where climatic conditions change greatly within a relatively short distance. The effects of local climate, surface water and topography on the groundwater cycle in the study area with similar geological conditions were investigated. Sri Lanka can be divided spatially into a dry zone, an intermediate zone and a wet zone, and also temporally into the rainy season and the dry season. The zonal characteristics of the groundwater cycle were also elucidated using stable isotopic technology. As an input δ diagram of precipitation in the study area, there are obvious seasonal changes in the isotopic composition and a magnitude effect, both in the wet zone and dry zone. In the wet zone, the slope of the regression line between δ D and δ ¹⁸O and deuterium excess is close to 8 and 10, respectively. However, in the dry zone, the slope of the regression line between δ D and δ ¹⁸O and deuterium excess is much less than 8 and 10, respectively. In the wet zone, there is an obvious seasonal change in the isotopic composition of groundwater. The groundwater was recharged by precipitation during the whole year. The isotopically lighter groundwater was found at the valley bottom in the rainy season there. Under the very heavy precipitation conditions, the slope of the regression line between δ D and δ ¹⁸O and deuterium excess for groundwater was close to 8 and 10, respectively. In other cases, the slopes of the regression lines are less than 8. In the dry zone, the groundwater was recharged by precipitation only in the rainy season. The isotopically lighter groundwater was found on the ridge of the valley in the rainy season. The slope of the regression line between δ D and δ ¹⁸O and deuterium excess for groundwater was much less than 8 and 10, respectively. Copyright © 1999 John Wiley & Sons, Ltd.     

Biotic response of benthic foraminifera in Aso-kai lagoon,central Japan,to changes in terrestrial climate and ocean conditions (~AD 700–1600)

We investigated responses of shallow-water benthic foraminifera to changes in climate and ocean conditions, using sediment core ASC2 from Aso-kai lagoon, central Japan. Six AMS ¹⁴C dates reveal that the studied interval corresponds to sediments deposited from ~AD 700 to 1600. Sulfur content of the bulk sediment and multi-dimensional scaling (MDS) axis 1 of fossil benthic foraminifera indicate that the composition of the benthic foraminifera community was closely related to dissolved oxygen (DO) concentration in the hypolimnion. The sulfur content and MDS axis 1 also revealed two shifts over the 900-year interval. In the first phase (~AD 700–1250), the Shannon–Wiener Index (H′), E (S₂₀₀), evenness and rank abundance curve (RAC) kurtosis indicate a gradual deterioration in structure of the benthic foraminifera community. In that period, there are statistically significant correlations between the faunal composition (MDS axis 1) and faunal structure [Shannon–Wiener (H′), E (S₂₀₀), evenness and RAC kurtosis]. In the second phase (~AD 1250–1600), however, faunal composition and structure show no marked correspondence. Instead, abundance of benthic foraminifera fluctuated on a scale of ~200 years. Thus, a shift in the biotic response of benthic foraminifera in Aso-kai lagoon occurred in ca. AD 1250. Gradual deterioration of benthic foraminifera, with taxonomic losses, is consistent with declining DO in the first phase, possibly associated with the increasing influence of the Tsushima Warm Current. The possibility that closure of Aso-kai lagoon and development of the sand bar affected benthic foraminifera cannot, however, be ruled out. No corresponding response was observed in the second phase, during which there was no distinct taxonomic loss. Large variations in abundance, however, were a consequence of strength of the East Asian summer and winter monsoons. The shift in the biotic response of benthic foraminifera in Aso-kai lagoon during the period AD 700–1600 was apparently a result of changes in climate and ocean conditions on the East Asian continental margin.