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1.
A Bogus Typhoon Scheme and Its Application to a Movable Nested Mesh Model   总被引:1,自引:0,他引:1  
ABogusTyphoonSchemeandItsApplicationtoaMovableNestedMeshModelWangGuomin(王国民)(DepartmentofAtmosphericSciences,NamingUniversity...  相似文献   

2.
Characteristics of the Mean Water Vapor Transport over Monsoon Asia   总被引:6,自引:0,他引:6  
Yi Lan 《大气科学进展》1995,12(2):195-206
CharacteristicsoftheMeanWaterVaporTransportoverMonsoonAsiaYiLan(伊兰)(InshtuteofAtmosphericPhysics,ChineseAcademyofSciences,Bei...  相似文献   

3.
AGCMStudyontheMechanismofSeasonalAbruptChangesWangHuijun(王会军)andZengQingcun(曾庆存)(LASG,InstituteofAtmosphericPhysics,ChineseAc...  相似文献   

4.
A numerical study of geostrophic adjustment and frontogenesis   总被引:1,自引:0,他引:1  
ANumericalStudyofGeostrophicAdjustmentandFrontogenesisMajidM.FarahaniandWuRongsheng(伍荣生)DepartmentofAtmosphericSciences,Nanji...  相似文献   

5.
Comparison of Surface Wind Stress Anomalies over the Tropical Pacific Simulated by an AGCM And by a Simple Atmospheric ModelN...  相似文献   

6.
ATwo-DimensionalZonalyAveragedOceanCarbonCycleModelXuYongfu(徐永福)andWangMingxing(王明星)LAPC,InstituteofAtmosphericPhysics,Chines...  相似文献   

7.
The East Asian Monsoon Simulation with IAP AGCMs-A Composite StudyWangHuijunandBiXunqiang(InstituteofAtmosphericPhysics(IAP),...  相似文献   

8.
MultispectrumMethodandtheComputationofVaporEquation①JiZhongzhen(季仲贞)andWangBin(王斌)LASG,InstituteofAtmosphericPhysics,ChineseA...  相似文献   

9.
AFinite-ModeModelofIdealFluidDynamicsonthe2-SphereWeiMozhengCRCforSouthernHemisphereMeteorologyCSIRODivisionofAtmosphericRese...  相似文献   

10.
SomeAspectsoftheCharacteristicsofMonsoonDisturbancesUsingaCombinedBarotropic-BaroclinicModel¥N.R.ParijaandS.K.Dash(CentreforA...  相似文献   

11.
稻田甲烷排放的初级模式   总被引:11,自引:1,他引:11       下载免费PDF全文
丁爱菊  王明星 《大气科学》1995,19(6):733-740
本文建立了一个区域尺度稻田生态系统CH4排放的初步模式,该模式能从理论上反映稻田CH4产生、传输与排放的机理,并提供了一种估计不同区域气候和土壤条件下稻田生态系统CH4排放总量的有效方法。模式主要包括三个部分:水稻的生长、土壤有机物的分解和CH4的产生、传输及排放过程。模式分别模拟了早稻和晚稻CH4的排放,模拟结果与实测比较接近,CH4的季平均排放量,模拟值与实测值的偏差在10% 左右。模式的敏感性实验表明,温度是稻田CH4排放规律的主要控制因子。  相似文献   

12.
中国南京与美国德克萨斯稻田甲烷排放的比较(英文)   总被引:2,自引:0,他引:2  
稻田甲烷排放试验分别在南京与德克萨斯水稻生长季实施,观测期内测定甲烷排放通量、上壤温度和水稻生物量。结果表明:南京稻田土镶温度的季节性变幅为15.3℃,甲烷排放通量与土壤温度成非线性正相关而与水稻生物量无关;德克萨斯稻田土壤温度的季节性变幅为的2.9℃,甲烷排放通量与土壤温度无关而与水稻生物量成线性正相关。由此得出结论:在持续淹水和无外源有机碳施加的条件下,土壤温度变幅大的地区驱动稻田甲烷排放季节性变化的关键因子为土壤温度,土壤温度变幅小的地区其关键驱动因子则为水稻的生长量。  相似文献   

13.
中国南京与美国德克萨斯稻田甲烷排放的比较   总被引:8,自引:0,他引:8  
Field measurements of methane emission from rice paddies were made in Nanjing, China and in Texas, USA, respectively. Soil temperature at approximately 10 cm depth of the flooded soils was automatically recorded. Aboveground biomass of rice crop was measured approximately every 10 days in Nanjing and every other week in Texas. Seasonal variation of soil temperature in Nanjing was quite wide with a magnitude of 15.3℃ and that in Texas was narrow with a magnitude of 2.9℃. Analysis of methane emission fluxes against soil temperature and rice biomass production demonstrated that the seasonal course of methane emission in Nanjing was mostly attributed to soil temperature changes, while that in Texas was mainly related to rice biomass production. We concluded that under the permanent flooding condition, the seasonal trend of methane emission would be determined by the soil temperature where there was a wide variation of soil temperature, and the seasonal trend would be mainly determined by rice biomass production if there are no additional organic matter inputs and the variation of soil temperature over the rice growing season is small.  相似文献   

14.
In the rice field methane is produced in the soil layer with depths of 2-25 cm. The vertical profile of methane production rate in the paddy soil during the water covering period differs from that in the paddy soil in dry phase. Only a small part, about 30%. of the produced methane is emitted to the atmosphere through rice plant, air bubbles, and molecular diffusion. Therefore, the methane emission rate from the rice field depends not only on the methane production rate in the soil, but also on the transport efficiency of the rice plant, air bubble formation that in turn depends on the production rate, and molecular diffusion.Field measurements show that methane emission rates from a particular rice field have very large diurnal, seasonal and interannual variations, which are related to soil characteristics, water regime, farming procedure, local climate, and rice growing activities. The relationship between the methane emission rate and the above mentioned factors is very complicated. The emission rate  相似文献   

15.
Summary The CH4 emission rates from Chinese rice fields have been measured in five typical areas representing all of the five major rice culture regions in People's Republic of China (P.R. China). Four types of diurnal variations (afternoon peak, night peak, afternoon-night double peaks and random pattern) of CH4 emission rates have been found. The first pattern was normally found in clear weather, the second and the third types were only found occasionally in particular place, while the fourth were found in cloudy or rainy weather. Due to the irregular pattern of the methane production observed in the morning-afternoon comparison experiment, the transport pathway influenced by certain factors, may be the major factor governing the diurnal variation of CH4 emission. Seasonal variation patterns of CH4 emission differ slightly with different field locations, where climate system, cropping system and other factors are different. Two and three emission peaks were generally found during single and early rice vegetation periods, with the peak magnitude and time of appearance differing to small degree in individual sites. A decreasing trend of seasonal variation was always observed in late rice season. A combination of seasonal change of transport efficiency and that of CH4 production rate in the paddy soil explains well the CH4 emission. The role of rice plant in transporting CH4 varied over a large range in different rice growing stages. The reasons for internnual changes of CH4 flux are not yet clear.Great spatial variation of the CH4 emission has been found, which can be attributed to the differences in soil type and soil properties, local climate condition, rice species, fertilizer and water treatment. Experiments showed that while the application of some mineral fertilizers will reduce the CH4 emission and CH4 production in the soil, the application of organic manure will enhance CH4 emission and CH4 production in the soil. Any measures which can get off easily decomposed carbon from organic manure may reduce C supply for CH4 production, and hence reduce CH4 emission. Fermented sludges from biogas generators and farmyard-stored manure seem to be promising. In some parts of China, separate application of the organic and mineral manure instead of mixed application could be another option. Frequent Scientific drainage and ridge cultivation, which are often used water management techniques in Chinese rice agriculture, have been proved in the experiments to be a very efficient mitigation measures to reduce CH4 emission from rice fields.By summarizing the present available data, China's rice fields contribute about 13.3 Tg yr–1 (11.4–15.2) CH4 to the atmosphere. The total methane emission from global rice fields can be estimated 33–60 Tg yr–1, much less than the estimates made before.If we extrapolate the measured data in China with a consideration of measured data in other Asian country, the total global emission of CH4 from rice fields are estimated to be about 35–60 Tg yr–1 With 2 Figures  相似文献   

16.
我国华中地区稻田甲烷排放特征   总被引:12,自引:1,他引:12  
本文主要讨论地处我国华中水稻生态区的湖南红壤稻田的CH4排放特征。稻田CH4排放的日变化都有一致的规律,即在下午16:00左右出现最大值;CH4排放的日变化幅度与天气条件和水稻植物体有关;CH4排放的日变化与温度日变化的相关性很好(R>0.90)。早稻和晚稻的CH4排放季节变化规律有明显的差别,这主要是由于早、晚稻水稻生长期间的天气特别是空气温度变化的差异引起的,早稻CH4排放率在水稻生长中期(6月)略大,而晚稻在水稻移栽后几天内CH4排放就达到整个季节中的最大值,以后随时间逐渐降低;缺水会使CH4排放率明显降低,而且在重新灌水后相当长时间内CH4排放率没有回升;CH4排放在全有机肥的田中最大,然后依次是常规施肥、全沼渣肥及化肥田;尿素、氯化钾和复合肥的多施可降低稻田CH4排放率;不同施肥田中CH4排放率的温度效应不同;施肥是控制CH4排放的一种可行手段;在整个晚稻生长季节中瞬时CH4排放率与瞬时温度呈明显的指数关系;在1991年双季水稻生长季节中,稻田中CH4的排放量为67.96 g·m-2,其中早稻的CH4排放率为0.36 g·m-2·d-1,晚稻为0.48 g·m-2·d-1。  相似文献   

17.
成都平原稻田甲烷排放的实验研究   总被引:9,自引:0,他引:9  
根据1996~1999年四个稻季的观测资料,分析了成都平原单季稻甲烷排放的季节变化和年际变化特征.结果表明:在水稻生长季节甲烷排放通量变化很大,在分蘖期和成熟期一般会出现峰值.年际间的通量变化也很大,其年均排放通量的变化范围在2.35~33.95mg m-2 h-1之间.4年的平均排放通量为12 mg m-2 h-1,与四川乐山的7年平均值30mg m-2 h-1相比,存在着明显的地区差异.同时分析讨论了温度、施肥、水稻品种、土壤氧化还原电位(Eh)以及稻田水位等诸多因素对稻田甲烷排放的影响.结果表明:在成都平原水稻生长季节的平均气温对CH4的平均排放通量影响不大;而气温对CH4排放的日变化有相对重要的影响,但气温对甲烷排放日变化的影响与水稻植物体的生长阶段有关;发现了水稻植物体(根、茎、叶)重量对CH4排放的重要作用.讨论了合理使用肥料和施肥量,控制水位和Eh值对稻田CH4的减排作用,提出优化组合诸影响因子,以充分发挥其减排潜力.  相似文献   

18.
农田生态系统温室气体排放研究进展   总被引:39,自引:0,他引:39  
自1985年起,中国科学院大气物理研究所利用自行设计制造的自动观测仪器系统,历时十六年先后对我国四大类主要水稻产区的甲烷排放规律及其与土壤、气象条件和农业管理措施的关系进行了系统野外观测实验,并对稻田甲烷产生、转化和输送机理进行了理论研究,探讨了控制稻田甲烷排放的实用措施,建立了估算和预测稻田甲烷排放的数值模型.在甲烷排放的时空变化规律和转化率研究方面有一系列新的发现,在稻田甲烷产生率、排放率及其与环境条件的关系方面取得一系列新的成果,以充分证据改变了国际上关于全球和中国稻田甲烷排放总量的估算.在对稻田甲  相似文献   

19.
1990年7—9月,在浙江临安(30°14'N,119°42'E),利用微气象学(梯度廓线)法及箱式技术对水稻田CH4排放通量进行了同步观测,取得了中稻整个生长期内的CH4排放资料。文章仅对箱式技术的观测结果作了介绍与分析。观测发现在整个灌溉期内,稻田CH4释放率为3.67—16.14 mg/m2·h,均值为10.58 mg/m2·h。CH4排放的季节变化明显,日变化也同样很明显。另外还发现,CH4排放通量与水(地)温及其他气象因素,如强风、阴雨等有关。与梯度廓线法的观测结果不同,箱式观测到的CH4排放通  相似文献   

20.
主要介绍了近 2 0年来稻田甲烷排放的模式研究和排放量的估算以及减少稻田甲烷排放的措施。数值模式是估算稻田甲烷排放量的一条有效途径 ,模式的研究现在正处于发展阶段。介绍了几个主要的模型 ,既有物理过程模型也有经验模型。年排放量的估算范围为 6 79~ 4 1 4Tg ,随着技术的发展和大量实验的进行估算值的精度正得到不断的提高。减排措施是减少稻田甲烷排放的必要手段 ,但是目前的减排技术均处于研究阶段 ,应用还不成熟  相似文献   

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