著者

清水 茂

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.20, no.2, pp.69-73, 1964-11-05 (Released:2010-02-25)

被引用文献数

1 1

著者

Minseok KANG Sungsik CHO

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.77, no.1, pp.2-23, 2021 (Released:2021-01-10)

参考文献数

229

被引用文献数

1 12

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The eddy covariance (EC) technique-based observation system allows for researchers to determine latent and sensible heat fluxes, which are key components of the surface energy balance. The number of water and energy flux studies in Asia has increased as the number of flux measurement sites and the length of the observation periods have grown. To retrace the footprints of the AsiaFlux network and predict future research directions, we reviewed the progress in water and energy flux studies in Asia from the 1990s to the present day. This included studies on continuous evapotranspiration (ET) and surface energy balance measurements in various ecosystems, from the tropics to the polar regions. We also reviewed comparative experiments between the EC technique and other observation techniques including the use of a lysimeter or scintillometer, data processing techniques, connections between carbon and water fluxes, and multi-site syntheses. This paper discusses three remaining challenges that are hindering the derivation of scientific knowledge for ET and the surface energy balance, namely: the non-closure of the surface energy budget, imperfect compatibility between open- and closed-path gas analyzers, and difficulty in partitioning ET into evaporation and transpiration. If we leverage the advantages of the EC technique (i.e., high sampling rates of ≥ 10 Hz and continuous measurement capabilities), standardized methods for correcting and partitioning can be developed in the near future.

著者

卜藏 建治

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.54, no.3, pp.267-274, 1998-09-15 (Released:2010-02-25)

参考文献数

37

被引用文献数

1 1

著者

宮本 硬一

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.13, no.4, pp.147-152, 1958-05-31 (Released:2010-02-25)

参考文献数

24

被引用文献数

1 1

---

The auther classified in the previous paper the paddy fields in the Shichigashuku Village, Miyagi Prefecture from the standpoint of the temperature of irrigation water into the following four groups:paddy area irrigated with water of low temperature (Max. water temp. below 20°C on Aug. 18)do. of semi-low temperature (Max. 20-23°C on Aug. 18)do. of medium temperature (Max. 23-25°C on Aug. 18)do. of high temperature (Max. over 25°C on Aug. 18)In each area, the representative paddy fields irrigated continuously with water or respective temperature were selected and the growth and yield of rice-plant therein were observed in relation to the water temperature. The results obtained were described and discussed in this paper.(1) In each paddy field of all the area, the growth and yield of rice increased as the distance from the inlet of water became larger, just same as the temperature of water rose. But the ratio of the increase became less, so that the correlation curve between the increase of growth or yield and the distance from the inlet was parabolic, not linear.(2) On the growth and yield of rice, the area of high water temperature predominated particularly over the other three. From the point of temperature, water of below 20°C gave serious cold injury to the plant and made almost all of spikelets sterile. The plant was also affected considerably by the water of 20 to 25°C, and especially the temperature of 20 to 22°C was distinguished with the remarkable falling down of the grouth and yield. Incidentally, it was conseivable that that this extent of water temperature would be critical to the growth of rice-plant. On the other hand, water of over 26°C influenced very little and that of over 28°C wo uldnt be troubled about the injurious effect to the plant under somewhat bad climatic conditions.(3) The fertility of heads was also affected by the temperature of water irrigated. Dividing all the kernels into complete grains (wholly ripened) and incomplete ones (the others), the number or percentage of the former was increased in proportion to the distance from the inlet with just same patterns as mentioned in (1), and the tendency was particularly distinct in the area of low water temperature.And besides, the ripening appearences in corresponding parts, for instance, water inlet of fields in each area were related with the water temperature; say, excellent in the the high temperature area and in turn.On the contrary, the incomplete grains did not show so distinct tendency as the complete ones.(4) Water temperature influenced differently on each tillering of the plant. By a certain degree of low temperature the main culm was injured the least; the higher the order of the tillering, the more the cold injury, general.At the part of fields where water temperature was about 25°C, heads of both main culm and 1st-ordered tillers had almost same fertillity. Where it was about 24°C, heads of main culm had almost all of complete grains and a little of incomplete ones, while those of 1st-ordered tillers had about half of complete and incomplete grains. Below 23°C, the majority of grains remained to ripen incompletely.(5) The above-mentioned results of field observations on the relation between the water temperature and the growth or yield of riceplant seemed to concur with many results of laborateory experiment already reported.

著者

植田 亨

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.55, no.2, pp.179-185, 1999-06-10 (Released:2010-02-25)

著者

北村 修

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.50, no.1, pp.33-41, 1994-06-10 (Released:2010-02-25)

被引用文献数

1 1

著者

Takeshi IZUTA

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.75, no.1, pp.1-2, 2019 (Released:2019-01-10)

参考文献数

5

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In the 21st Century, air pollution and climate change are very serious environmental problems for forest ecosystems all over the world. Therefore, many researches are needed for understanding the responses of forest ecosystems to air pollutants such as ozone (O3), a main component of photochemical oxidants, and climate change such as elevated atmospheric CO2 and air temperature. The 28th IUFRO (International Union of Forest Research Organizations) Biennial Conference of Research Group 7.01 (Impacts of Air Pollution and Climate Change on Forest Ecosystem) entitled “Actions for Sustainable Forest Ecosystems under Air Pollution and Climate Change” was held in Fuchu, Tokyo, Japan (Tokyo University of Agriculture and Technology) on 22-26 October, 2017. At this biennial conference, we had an excellent opportunity to discuss close relationships among air pollution, climate change and forest ecosystems. This special issue of Journal of Agricultural Meteorology is dedicated to the original articles derived from the organized sessions of the 28th IUFRO Biennial Conference of Research Group 7.01 as follows: (1) Asian forest ecosystem under changing environment, (2) Developing detection, monitoring and evaluation, (3) Ecophysiological and genetic understanding of plant responses, (4) Water and nutrient cycles in forest ecosystems, (5) Modelling and risk assessment, and (6) Forest ecosystems under multiple stressors. The following briefly introduces the 5 original articles in this special issue.

著者

高橋 英紀 山本 博 鈴木 啓助 守屋 開

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.34, no.2, pp.77-82, 1978

被引用文献数

3

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人為的な湖の形成 (ダム等) や消滅 (干拓等) が周辺の自然や農業に及ぼしている影響を質的に量的に把握することを目的として湖周辺の局地気候に関する研究を開始した。今回観測を行なった洞爺湖は直径が約10km, 周長46kmの円形に近いカルデラ湖である。観測は1977年1月20・21日に行なった。自動車の屋根にとりつけた直径0.3mmの銅・コンスタンタン熱電対により気温を測定し, ペンレコーダーに記録しながら湖岸にそって周回した。得られた結果を要約すると次のごとくとなる。<br>(1) 観測期間中の水温は1~5℃であったのに対し, 気温は最高約-2℃, 最低-15℃で水温-気温差は最大10℃であった。<br>(2) 湖周辺の風向は昼間には一般風の影響をうけていたが夜間には周辺から湖に向って風が吹き込んでいた。<br>(3) 湖周辺の気温は一般風の影響の強い昼間には湖の風下では風上に比べ約2℃高温であった。<br>(4) 夜間の気温分布は昼間に比べ場所による変動が大きく地域により約5℃の差があった。

著者

関 平和 小森 友明

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.41, no.3, pp.257-264, 1985-12-10 (Released:2010-02-25)

参考文献数

8

被引用文献数

2

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Experiments for extraction and accumulation of the heat generated in composting process were performed using a buried-tube-type heat exchanger and an accumulator. Water was circulated between the heat exchanger and the accumulator as a heat transfer medium. The following results were obtained.1) The compost bed maintained its average temperature at 50°C or higher for about 60 days of the whole period of composting reaction in the first stage (72 days). During this high temperature period, the experiments for heat extraction and accumulation were made by circulating water intermittently or continuously. In the case of the intermittent water-circulation, the water temperature of the accumulator attained to a designed temperature, 30°C, when the room temperature was higher than 10°C, but never did the water temperature when the room temperature was lower than 5°C. With the continuous water-circulation, the water temperature at the steady state condition was in average of 16 through 24°C.2) The apparent rate of heat generation in the compost bed was 200 through 300kcal/m3hr during an early period of about 40 days, which included a turning of the compost bed. The composting reaction was therefore not likely to be inhibited by extracting heat from the bed during the period of intermittent water-circulation experiments.3) The efficiency of heat extraction was 17-26% in the intermittent water-circulation, while the efficiency of heat collection at the steady state condition was 27-32% in the continuous water-circulation. These efficiencies could increase by the well designed arrangement and the increased number of the buried tubes.4) It is necessary to investigate the method for deciding the optimum scale or size of the container for the compost and the heat accumulator on the basis of the theoretical analysis of heat transfer processes.

著者

岩田 拓記 浅沼 順 大谷 義一 溝口 康子 安田 幸生

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.65, no.1, pp.1-9, 2009

被引用文献数

2

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サーフェスリニューアル法を顕熱輸送モデルとして用いて,日中の平坦なマツ林上における複数高度での乱流観測から算出した鉛直長さスケールと乱流輸送の関連性を調べた。鉛直方向の積分長さスケールは大気不安定が強くなるに従い大きくなる傾向を示したが,Raupach <i>et al.</i> (1996, Boundary-Layer Meteorol., 78, 351-382) のシア長さスケールは大気安定度に比較的依存しなかった。これらの長さスケールを輸送渦の高さとして用い,サーフェスリニューアル法によって顕熱フラックスを算出した。渦相関法で算出したフラックスと比較した結果,異なる長さスケールを用いたサーフェスリニューアル法のパフォーマンスは不安定条件下で大きく異なり,積分スケールを用いた場合のフラックスの精度が最も良かった。これらの相違は長さスケールの安定度依存に関係していると考えられる。この結果は,渦のスケールを直接測定した積分スールをサーフェスリニューアル法において用いることが妥当であることを示している。また,乱流生成において浮力の影響が大きいときには,シア長さスケールは粗度層の渦スケールを表すのに制限がある可能性が示唆された。

著者

大政 謙次

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.48, no.2, pp.181-186, 1992-09-10 (Released:2010-02-25)

参考文献数

20

被引用文献数

1

著者

仁科 弘重 高倉 直

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.39, no.3, pp.201-211, 1983-12-10 (Released:2010-02-25)

参考文献数

12

被引用文献数

2 2

---

As the first step of a study on solar greenhouses with latent heat storage systems, thermal properties of phase change materials (PCMs) were tested and solar heating experiments applying these PCMs to small greenhouses were performed.Several PCMs which have melting points between 10-30°C were selected from the literatures (e.g. Hale et al., 1971), and measurements of melting points and heats of fusion were made. Considering these test results (Table 1 and Fig. 1), and because of the extremely high price of paraffin, we chose polyethylene glycol (PEG) and calcium chloride hexahydrate as the most suitable PCMs for solar heating greenhouses at the present time.Three types of solar greenhouse systems were constructed, and solar heating experiments were performed in both 1979 and 1980. We used two small identical glasshouses (floor area is 7.2m2, surface area 25.2m2) with the north wall (4.8m2) insulated.In the Type I solar greenhouse (without thermal screen), polyethylene tubes (3.0cm in diameter) were filled with 600kg of PEG (# 600 and # 400) and hung by steel bars in the insulated heat storage unit. Air was circulated by a fan between the greenhouse and the heat storage unit, and solar heat was collected from the air inside the greenhouse (Fig. 2). Typical patterns of diurnal changes in temperatures in the Type I solar greenhouse on a clear day are shown in Fig. 3. Solar heat stored in the daytime was 9, 900kcal and heat released in the nighttime was 11, 060kcal. The average efficiency of heat storage on clear days was 20%, based on the outside solar radiation.In the Type II solar greenhouse (with one layer thermal screen), three 1.6m2 air-type solar collectors were attached. PCMs, 300kg of CaCl2⋅6H2O and 200kg of PEG (# 600), were encapsulated in double-layered polypropylene panels (1.2cm in thickness) and were installed in the heat storage unit. In the daytime, air was sucked from the greenhouse to the collectors, and heated air was then sent to the heat storage unit and was returned to the greenhouse. In the nighttime, the path to the collectors was closed by a damper, and air was circulated between the greenhouse and the heat storage unit, although the direction of the air flow through the heat storage unit was opposite to that in the daytime (Figs. 4 and 5). The heat collected in the collectors was 12, 060kcal, and the heat stored in the heat storage unit was 8, 380kcal (7, 520kcal to CaCl2⋅6H2O, 860kcal to PEG) on Feb. 3, 1980. The temperatures of CaCl2⋅6H2O and PEG were kept almost at the melting point of each, which indicated that the storage capacity of latent heat was not yet filled. The inside air temperature was kept at 8.0°C in the early morning on Feb. 4, when the outside air temperature was -0.6°C. The average efficiency of heat storage on clear days was 17%, taking into account the receiving area of both the collectors and the greenhouse.In the Type III solar greenhouse (with one layer thermal screen), double-layered polypropylene panels (1.5cm in thickness) which contained 56kg of CaCl2⋅6H2O were installed in front of the inside surface of the north wall. They could be called a heat storage panel. In addition to this, 200kg of PEG (#600) was encapsulated in PVC pipes (3.2cm in diameter) and was installed in the small heat storage unit. The heat storage panel can store heat from direct solar radiation. In the heat storage unit, heat was collected from the inside air by circulating air between the greenhouse and the heat storage unit. Typical patterns of diurnal changes in temperatures in the Type III solar greenhouse on a clear day are shown in Fig. 6. The heat stored in the heat storage panel and the heat storage unit was 2, 860kcal and 7, 560kcal, respectively.

著者

坂上 務

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.15, no.2, pp.59-63, 1959-09-15 (Released:2010-02-25)

被引用文献数

1 1

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The author investigated the microclimate on the waste heap from the forest point of view. That is, the slopes were favourable to the sliding down of cold air and the rising of warm air, on the slopes, the layer of air near the ground had the peculiar meteorological properties.Like a skin of air it clothes and determined the climatic habitate of the plants growing thereon. There were 10 observation points located on the slopes of different direction and high degree.The sketch map (Fig. 1) shows by the configuration of the contours how regular the cone is on all sides, and it lies at an average inclination of 30°. All the points of maximum and minimum temperature readings were taken at a height of 30cm in winter, and vertical distribution of temperature and humidity readings were taken at o-150cm height in spring & summer. Fig. 6-9.Fig. 1-Fig. 4 show the distribution of maximum and minimum temperature on the waste heap on average for winter days.It was to be found that the lowest temperature and maximum temperature range would be found on the south slope, and results of humidity measurement on the south slope, had dry air layer, so the plants did not easy grow there.

著者

小元 敬男 青野 靖之

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.45, no.1, pp.25-31, 1989-06-10 (Released:2010-02-25)

参考文献数

21

被引用文献数

22 15

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An attempt is made to estimate blooming dates of Prunus yedoensis for 21 meteorological stations in Japan by using DTS (the number of days transformed to standard temperature). The starting date for computation at each station is determined by correlation analysis. At many stations the date lies between 40 and 55th day from January 1st.The number of days transformed to a standard temperature (in this study 25°C is used) at each station is computed by adding characteristic temperature of each day from a starting date to blooming date for various temperature characteristic (Ea). The estimated blooming date is the date when accumulated value of DTS reached at that of mean observed blooming date for the site.It is found that 17kcal mol-1 for Ea gives minimum error when averaged over all sites. Using this Ea and D2 which is the starting date determined from error analysis, computations are made to estimate blooming dates at each station between 1961 and 1985. It is shown that at stations in Hokkaido and Tohoku districts, RMS errors between the observed and the calculated blooming dates fall between 1 and 2 days. At stations in other areas, the errors range between 2 and 3, except for Hachijo where it becomes 6.7 days. The large error at this southernmost station seemed to be attributed to year to year change of degrees of rest completion of Prunus yedoensis, which affect effectiveness of temperature just before blooming.

著者

長谷場 徹也

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.32, no.1, pp.27-31, 1976-06-15 (Released:2010-07-01)

参考文献数

14

被引用文献数

1 1

著者

蔵田 憲次 大原 源二

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.1, pp.33-36, 1988-06-10 (Released:2010-02-25)

参考文献数

2

著者

蔵田 憲次

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.3, pp.181-186, 1988-12-10 (Released:2010-02-25)

参考文献数

6

被引用文献数

1 3

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Computers have been applied to crop management in protected cultivation and have proved to be of great use. However, in the present computer systems, control algorithm is fixed and users can only change the setpoints of the controlled variables. Crop management is strongly influenced by the local conditions of climate, soil, etc. and well trained and eager growers manage their crops in the way which is suitable under the given local conditions and is obtained through the long period experience.This study aims at developing a system which learns grower's managing methods (rules, hereafter) through measuring environmental factors, crop status, if possible, and grower's behavior.After learning the grower's rules, the learned rules will be applied to the automatic management.Thus, the grower will be released from the management labor without losing their own personal preference and principles in crop management. This system can also be applied to the rule aquisition and analysis of well trained growers. This report presents considerations on the characteristics of the growers' rules and the possibilities and problems of the simple learning algorism developed (K-algorithm, hereafter), which will be the framework of the system we aim at. Details of K-algorithm are given in another report (Kurata, 1988).Considerations on the grower's rules revealed that there are many difficult aspects for the computer in learning, for examples, the problem of fuzziness associated with the human feelings, the problem of noise and how to find out a function which the grower's rule has but not directly measurable. All these points are omitted in the present study and left for the future study.A simple simulation revealed that K-algorithm is very powerful in imitating the grower's behavior but the learned rules are somewhat longer than the assumed grower's rules, examples of which are listed Table 1. This redundant expression of the learned rule is due to some correlations among environmental factors, crops status and time. If we assume stochastic stationary state of these functions and their correlations, this brings about no problem in applying the learned rules to the automatic management.

著者

小中原 実

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.39, no.4, pp.315-322, 1984-03-10 (Released:2010-02-25)

参考文献数

69

被引用文献数

2 2

著者

孫 禎翼 高倉 直

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.44, no.4, pp.253-258, 1989-03-10 (Released:2010-02-25)

参考文献数

14

被引用文献数

9 10

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For investigation of the relationship between plant growth and environmental factors in a plant factory, an experimental plant factory has been built and some experiments have been carried out. Leaf lettuce was grown in a hydroponic system under artificial light condition. Arial environment such as air temperature, humidity and CO2 concentration were controlled. Root environment such as EC and pH were monitored and controlled by a microcomputer.In the first experiment, EC level was maintained at a constant set-point and the difference between the set-point and the actual value was summed up when the latter value was corrected. Transpiration was also calculated from the water depression in the tank. Then it was summed up through the growing period.Following results were obtained:(1) The EC decrement showed high correlation with the transpiration, regardless of light intensity and (2) the transpiration rate per EC decrement decreased as the EC of nutrient solution became higher.In the second experiment, the effects of light intensity, lighting cycle and EC of nutrient solution on tipburn injury were examined.Following results were obtained: (3) The tipburn occurrence became later under the conditions that the EC was low and the duration of a lighting cycle was short and (4) the tipburn occurrence became later under the conditions that the light intensity was low and the duration of a lighting cycle was short.Effect of the duration of a lighting cycle on the tipburn occurrence showed larger as the light intensity increased. From the results of Tibbitts et al (1985), it is, therefore, considered that the pressure of laticifer or the Ca concentration in the wall of laticifer increases with the increase of the duration of lighting cycle and this could cause the tipburn.

著者

Akihiko ITO Shimpei INOUE Motoko INATOMI

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.78, no.2, pp.56-65, 2022 (Released:2022-04-10)

参考文献数

62

被引用文献数

8

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Evaluating regional budgets of methane (CH4), a potent greenhouse gas and short-lived climate forcer, is an important task for future climate management. This study estimated historical CH4 emissions from paddy fields in East Asia by using a process-based terrestrial biogeochemical model driven by climate and land-use data. To capture the range of estimation uncertainty, this study used two CH4 emission schemes, four paddy field maps, and two seasonal inundation methods for a total of 16 simulations. The mean CH4 emission rate during 2000-2015 was estimated to be 5.7 Tg CH4 yr-1, which is similar to statistical inventories and other estimates. However, the large standard deviation (± 3.2 Tg CH4 yr-1) among the simulations implies that serious estimation uncertainties remain. Three factors - CH4 emission scheme, paddy field map, and inundation seasonality - were responsible for the disparity of the estimates. Because of the lack of historical management data, the model simulation did not show a decreasing trend in the agricultural CH4 emissions. A sensitivity analysis for temperature indicated that a 1-2 °C temperature rise (typical warming in mitigation-oriented scenarios) would substantially enhance CH4 emissions. However, a sensitivity analysis for water management indicated that a lower water-table depth would largely mitigate the emission increase. Additional studies to improve agricultural datasets and models for better paddy field management are still needed.