33 research outputs found

    EVALUATION OF EVAPORATION FLUX UNDER QUASI-UNSTEADY WIND VELOCITY

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    The present paper describes a new method to precisely calculate hourly evaporation flux under quasi-unsteady wind velocity using the wind tunnel that can supply a set of high/low speed winds by turns for every set-up period. Soil columns was used for the evaporation experiment and Chao soil and Toyoura standard sand were used for the experiment. The difference in the hourly evaporation flux, Evh, became no less than 12-18% by changing the combination of the high/low speed winds, regardless of the kind of soil, although the average wind velocity, Vwm was the same for all the wind-velocity combinations. This fact is attributed to the nonlinearity of the relation between the evaporation coefficient, av, and wind velocity. It is found that Evh calculated using av for the high and low wind velocities is more accurate than that calculated using av for Vwm

    Global carbon budget 2022

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    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS increased by 5.1% relative to 2020, with fossil emissions at 10.1±0.5GtCyr-1 (9.9±0.5GtCyr-1 when the cement carbonation sink is included), and ELUC was 1.1±0.7GtCyr-1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9±0.8GtCyr-1 (40.0±2.9GtCO2). Also, for 2021, GATM was 5.2±0.2GtCyr-1 (2.5±0.1ppmyr-1), SOCEAN was 2.9 ±0.4GtCyr-1, and SLAND was 3.5±0.9GtCyr-1, with a BIM of -0.6GtCyr-1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71±0.1ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0% (0.1% to 1.9%) globally and atmospheric CO2 concentration reaching 417.2ppm, more than 50% above pre-industrial levels (around 278ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959-2021, but discrepancies of up to 1GtCyr-1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at 10.18160/GCP-2022 (Friedlingstein et al., 2022b)

    Global Carbon Budget 2022

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    Accurate assessment of anthropogenic carbon dioxide (CO2_2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2_2 emissions (EFOS_{FOS}) are based on energy statistics and cement production data, while emissions from land-use change (ELUC_{LUC}), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2_2 concentration is measured directly, and its growth rate (GATM_{ATM}) is computed from the annual changes in concentration. The ocean CO2_2 sink (SOCEAN_{OCEAN}) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2_2 sink (SLAND_{LAND}) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM_{IM}), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS_{FOS} increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr1^{−1} (9.9 ± 0.5 GtC yr1^{−1} when the cement carbonation sink is included), and ELUC_{LUC} was 1.1 ± 0.7 GtC yr1^{−1}, for a total anthropogenic CO2_2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr1^{−1} (40.0 ± 2.9 GtCO2_2). Also, for 2021, GATM_{ATM} was 5.2 ± 0.2 GtC yr1^{−1} (2.5 ± 0.1 ppm yr1^{−1}), SOCEAN_{OCEAN} was 2.9  ± 0.4 GtC yr1^{−1}, and SLAND_{LAND} was 3.5 ± 0.9 GtC yr1^{−1}, with a BIM_{IM} of −0.6 GtC yr1^{−1} (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2_2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS_{FOS} relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2_2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr1^{−1} persist for the representation of annual to semi-decadal variability in CO2_2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2_2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b)

    TEM Image Analysis and Simulation Physics for Two-Step Recrystallization of Discretely Amorphized C<sub>3</sub>H<sub>5</sub>-Molecular-Ion-Implanted Silicon Substrate Surface

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    In this study, we investigate the initial rapid recrystallization of a discretely amorphized C3H5-molecular-ion-implanted silicon (Si) substrate surface in the subsequent thermal annealing treatment through the analysis of plan-view transmission electron microscopy (TEM) images and technology computer-aided design (TCAD) process simulation. In the approach of the analysis of the plan-view TEM image of the Si substrate surface, we found that initial rapid recrystallization occurs in the intermediate regions between the residual crystalline and discrete amorphous regions formed in the C3H5-molecular-ion-implanted Si substrate surface. In addition, the TCAD process simulation results indicate that the intermediate regions correspond to the amorphous pockets formed around the discrete amorphous regions in the C3H5-molecular-ion-implanted Si substrate surface and are recrystallized preferentially during the short thermal annealing time. These plan-view TEM image analysis and TCAD process simulation results reveal a two-step recrystallization of the discretely amorphized C3H5-molecular-ion-implaned Si substrate surface. After the initial rapid recrystallization of amorphous pockets in the 1st step, the recrystallization of discrete amorphous regions starts in the 2nd step. The incubation period between the 1st and 2nd steps is the time required to recrystallize the amorphous pockets around the discrete amorphous regions completely and redefine the amorphous/crystalline interface

    Reduction of White Spot Defects in CMOS Image Sensors Fabricated Using Epitaxial Silicon Wafer with Proximity Gettering Sinks by CH<sub>2</sub>P Molecular Ion Implantation

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    Using a new implantation technique with multielement molecular ions consisting of carbon, hydrogen, and phosphorus, namely, CH2P molecular ions, we developed an epitaxial silicon wafer with proximity gettering sinks under the epitaxial silicon layer to improve the gettering capability for metallic impurities. A complementary metal-oxide-semiconductor (CMOS) image sensor fabricated with this novel epitaxial silicon wafer has a markedly reduced number of white spot defects, as determined by dark current spectroscopy (DCS). In addition, the amount of nickel impurities gettered in the CH2P-molecular-ion-implanted region of this CMOS image sensor is higher than that gettered in the C3H5-molecular-ion-implanted region; and this implanted region is formed by high-density black pointed defects and deactivated phosphorus after epitaxial growth. From the obtained results, the CH2P-molecular-ion-implanted region has two types of complexes acting as gettering sinks. One includes carbon-related complexes such as aggregated C–I, and the other includes phosphorus-related complexes such as P4–V. These complexes have a high binding energy to metallic impurities. Therefore, CH2P-molecular-ion-implanted epitaxial silicon wafers have a high gettering capability for metallic impurities and contribute to improving the device performance of CMOS image sensors. (This manuscript is an extension from a paper presented at the 6th IEEE Electron Devices Technology & Manufacturing Conference (EDTM 2022))

    キョウシン オ ウケル ジュウソウ ホネグミ ノ ソンショウ ブンプ ニ カンスル キソテキ コウサツ

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    This paper first discusses the general features of distributions of damages in multi-story frames under strong ground motions based on numerical response analyses of shear-type lumped mass models. A basic law that governs distributions of damages is then determined by using seismic load distributions expressed in terms of the second joint moments of story shear forces. The results of response analyses show that, as the strength of a story in a multi-story frame decreases, the damage in that weak story increases sharply while the damages in the other stories close to the weak story decrease suddenly. The proposed damage distribution law captures well these tendencies

    Crisis of Japanese Vascular Flora Shown By Quantifying Extinction Risks for 1618 Taxa

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    <div><p>Although many people have expressed alarm that we are witnessing a mass extinction, few projections have been quantified, owing to limited availability of time-series data on threatened organisms, especially plants. To quantify the risk of extinction, we need to monitor changes in population size over time for as many species as possible. Here, we present the world's first quantitative projection of plant species loss at a national level, with stochastic simulations based on the results of population censuses of 1618 threatened plant taxa in 3574 map cells of ca. 100 km<sup>2</sup>. More than 500 lay botanists helped monitor those taxa in 1994–1995 and in 2003–2004. We projected that between 370 and 561 vascular plant taxa will go extinct in Japan during the next century if past trends of population decline continue. This extinction rate is approximately two to three times the global rate. Using time-series data, we show that existing national protected areas (PAs) covering ca. 7% of Japan will not adequately prevent population declines: even core PAs can protect at best <60% of local populations from decline. Thus, the Aichi Biodiversity Target to expand PAs to 17% of land (and inland water) areas, as committed to by many national governments, is not enough: only 29.2% of currently threatened species will become non-threatened under the assumption that probability of protection success by PAs is 0.5, which our assessment shows is realistic. In countries where volunteers can be organized to monitor threatened taxa, censuses using our method should be able to quantify how fast we are losing species and to assess how effective current conservation measures such as PAs are in preventing species extinction.</p></div
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