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Seasonal dynamics of soil CO_2 effluxes with responses to environmental factors in lower subtropical forests of china

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Science china Earth sciences 2006年第S2期49卷 139-149页

作者： ZHANG Deqiang, SUN Xiaomin, ZHOU Guoyi, YAN Junhua, WANG Yuesi, LIU Shizhong, ZHOU Cunyu, LIU Juxiu, TANG Xuli, LI Jiong & ZHANG Qianmei South china Botanical Garden, chinese academy of sciences, Guangzhou 510650, china institute of Geographical sciences and Natural Resoureces, chinese academy of sciences, beijing 100101, china institute of atmospheric physics, chinese academy of sciences, beijing 100083, china 1. South china Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China 2. institute of Geographical sciences and Natural Resoureces Chinese Academy of Sciences Beijing 100101 China 3. institute of atmospheric physics Chinese Academy of Sciences Beijing 100083 China

Seasonal metrics and environmental responses to forestry soil surface CO2 emission effluxes among three types of lower subtropical forests were consistently monitored over two years with static chamber-gas chromatograph techniques among three types of lower subtropical forests. Results showed that annual CO2 effluxes (S+L) reached 3942.20, 3422.36 and 2163.02 CO2 g·m-2·a-1, respectively in the monsoon evergreen broadleaf forest, mixed broadleaf-coniferous forest and coniferous forest. All the three types of forests revealed the same characteristics of seasonal changes with the CO2 effluxes peaking throughout June to August. During this peaking period, the effluxes were 35.9%, 38.1% and 40.2% of the total annual effluxes, respectively. The CO2 emission process responding to the environmental factors displayed significantly different patterns in forestry soils of the three types of forests. The coniferous forest (CF) was more sensitive to temperature than the other two types. The Q10 values were higher, along with greater seasonal variations of the CO2 efflux, indicating that the structurally unique forestry ecosystem has disadvantage against interferences. All the three types of forestry CO2 effluxes showed significant correlation with the soil temperature (Ts), soil water content (Ms) and air pressure (Pa). However, stepwise regression analysis indicated no significant correlation between air pressure and the soil CO2 efflux. With an empirical model to measure soil temperature and water content in 5 cm beneath the soil surface, the CO2 effluxes accounting for 75.7%, 77.8% and 86.5% of the efflux variability respectively in soils of BF, MF and PF were calculated. This model can be better used to evaluate the CO2 emission of soils under water stress and arid or semi-arid conditions.

关键词： forestry soil CO2 emission seasonal dynamic metrics environmental factors responses.

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320m气象塔太阳辐射梯度观测

太阳能学报 2003年第3期24卷 295-301页

作者：刘广仁王跃思胡非张文胡玉琼中国科学院大气物理研究所CERN/LAPC 北京100029

该文介绍了利用北京 32 0m气象塔进行太阳辐射梯度测量的仪器装置和初步观测结果。实验表明 ,自行设计制造的太阳辐射自动观测系统 (包括自动太阳跟踪器和数据采集系统 )运行可靠 ,可满足观测要求。初步实验观测结果表明 ,地面与 32 0m... 详细信息

该文介绍了利用北京 32 0m气象塔进行太阳辐射梯度测量的仪器装置和初步观测结果。实验表明 ,自行设计制造的太阳辐射自动观测系统 (包括自动太阳跟踪器和数据采集系统 )运行可靠 ,可满足观测要求。初步实验观测结果表明 ,地面与 32 0m高度之间的辐射衰减明显 ,在极晴好天气下太阳直接辐射在中午时段相差仅 10W/m2 左右 ,而在近地面污染严重的条件下其相对差值最大可达 14 0W/m2 左右。在晴好天气下总紫外辐射高空与地面相对差值很小 ;在大气能见度差时总紫外辐射值减少 ,但是高空与地面的差值相对加大。

关键词：辐射梯度观测太阳自动跟踪装置气象塔太阳辐射

The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking

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Science china Earth sciences 2007年第8期50卷 1266-1272页

作者： YAN BangLiang CMSR, institute of atmospheric physics, chinese academy of sciences, beijing 100029, china CMSR Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking is ex-amined by using a mixed-mode model. The results show that the positive feedback process of the ef-fects of the seasonal variation of the upwelling mean on the Kelvin wave is the mechanism of the locking of the event mature phase to the end of the calendar year. The memory of the Rossby waves for the sign-shifting of the sea surface temperature anomaly from positive to negative 6 months before the cold peak time is the other mechanism of the locking of the La Nia event mature phase to the end of the calendar year. The results here are different from previous ones which suggest that the balance between cold and warm trends of sea surface temperature anomaly is the mechanism involved. The cold trend is caused by the upwelling Kelvin wave from upwelling Rossby wave reflected at the western boundary, excited by the westerly anomaly stress over the central Pacific and amplified by the seasonal variation of the coupled strength in its way propagating westward. The warm trend is caused by the Kelvin wave forced by the western wind stress over the middle and eastern equatorial Pacific. The cause of the differences is due to the opposite phase of the seasonal variation of the upwelling mean to that in the observation and an improper parameterization scheme for the effects of the seasonal varia-tion of the upwelling mean on the ENSO cycle in previous studies.

关键词： Kelvin wave Rossby wave interaction between atmosphere and sea positive feedback

Linear relationship between the interdecadal and interannual variabilities of North china rainfall in rainy season

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chinese Science Bulletin 2003年第10期48卷 1040-1044页

作者： LU Riyu institute of atmospheric physics, chinese academy of sciences, beijing 100080, china institute of atmospheric physics Chinese Academy of Sciences Beijing 100080 China

Interdecadal and interannual timescales are dominant in the North china rainfall in rainy season (July and August). On the interdecadal timescale, the North china rainfall exhibited an abrupt decrease at the end of 1970s. In this study, we examined the effect of this abrupt rainfall decrease on the association between rainfall and circulation on the interannual timescale, and found that the interdecadal variation does not change the physical mechanism responsible for the interannual variation of North china rainfall. There is a linear relationship between the interdecadal and interannual variabilities of North china rainfall in rainy season.

关键词：线性关系中国北部降雨量大气环流

Simulation of the future change of East Asian monsoon climate using the IPCC SRES A2 and B2 scenarios

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chinese Science Bulletin 2003年第10期48卷 1024-1030页

作者： BUEH Cholaw LASG, institute of atmospheric physics, chinese academy of sciences, beijing 100029, china LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

In this paper, we applied the newest emission scenarios of the sulfur and greenhouse gases, i.e. Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2 and B2 scenarios, to investigating the change of the East Asian climate in the last three decades of the 21st century with an atmosphere-ocean coupled general circulation model. The global warming enlarges the land-sea thermal contrast and, hence, enhances (reduces) the East Asian summer (winter) monsoon circulation. The precipitation from the Yangtze and Huaihe river valley to North china increases significantly. In particular, the strong rainfall increase over North china implies that the East Asian rainy area would expand northward. In addition, from the southeastern coastal area to North china, the rainfall would increase significantly in September, implying that the rainy period of the East Asian monsoon would be prolonged about one month. In July, August and September, the interannual variability of the precipitation enhances evidently over North china, meaning a risk of flooding in the future.

关键词：模拟亚洲东方季风气侯变化大气循环模型

An improved δ-Eddington approximation

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chinese Science Bulletin 1999年第4期44卷 304-309页

作者： QIU Jinhuaninstitute of atmospheric physics , chinese academy of sciences , beijing 100029, china institute of atmospheric physics Chinese Academy of Sciences Beijing China

Based on an accuracy analysis of two-stream approximations, an improved δ-Eddington ap-proximation is developed. The approximation has much better accuracy than all exiting two-stream ap-proximations as the optical depth is less than unity. As the surface reflectance is zero and the opticaldepth is less than unity, errors in both transmission and reflection calculated by the present approxima-tion are more one time less than those by other two-stream approximations. In the case of aerosol opti-cal depth of<1, surface reflectance of < 0.6, solar zenith angle of < 78°and aerosol imaginary indexof < 0.05, transmission and reflection errors calculated by the improved δ-Eddington approximationare generally less than 3.5% and 2.6%, respectively. The errors are over 41% and one times lessthan those by Eddington or δ-Eddington.

关键词： radiation flux fractional factor of δ-function Eddington approximation.

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B_c Meson Studies

高能物理与核物理 2002年第Z1期26卷 1-10页

作者： CHANG Chao-Hsi (institute of Theoretical physics, chinese academy of sciences, beijing 100080, china) Inst. of Theor. Phys. Chinese Acad. of Sci. Beijing 100080 China

Our studies on the meson Bc arc briefly *** decays of the meson Bc to a P-wave charmonium Xc or hc are reported comparatively precisely because they are fresh

关键词：高能物理核物理增刊张肇西 B_c Meson Studies Rev

2002:The extra-strong warm winter event in North Asia and its accompanying anomalous atmospheric circulation

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chinese Science Bulletin 2003年第10期48卷 1031-1033页

作者： WANG Huijun LASG, institute of atmospheric physics, chinese academy of sciences, beijing 100029, china LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Features of an extra-strong warm winter event in North Asia in 2002 and its accompanying anomalous atmospheric circulation were studied through diagnosis on the atmospheric reanalysis data set. Results show that the winter of 2002 is of the warmest in the recent 54 years in North Asia, which was caused by both decadal scale and interannual scale variability. The interannual variability is proved to be as the main cause for the event, and it is related to the global scale atmospheric circulation anomalies, with the strongest of them in the Eastern Hemisphere and in the middle and high latitude region of the Southern Hemisphere.

关键词：大气环流亚洲北部高强度暖冬现象天气资料

North Pacific sea ice cover, a predictor for the Western North Pacific typhoon frequency?

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Science china Earth sciences 2007年第8期50卷 1251-1257页

作者： FAN Ke institute of atmospheric physics, chinese academy of sciences, beijing 100029, china Department of atmospheric Science, Yun-nan University, Kunming 650091, china institute of atmospheric physics Chinese Academy of Sciences Beijing China Department of atmospheric Science Yunnan University Kunming China

The relationship between the sea ice cover in the North Pacific and the typhoon frequency has been studied in this paper. It follows that the index for the sea ice cover in the North Pacific (ISA) both in December-January-February (DJF) and in March-April-May (MAM) is negatively correlated with annual typhoon number over the western North Pacific (TNWNP) during 1965―2004, with correlation coeffi-cients of -0.42 and -0.49 respectively (above 99% significant level). Large sea ice cover in the North Pacific tends to decrease TNWNP. Positive ISA (MAM) is associated with the tropical circulation and SST anomalies in the North Pacific, which may lead to unfavorable dynamic and thermal conditions for typhoon genesis over WNP from June to October (JJASO). The variability of the atmospheric circula-tion over the North Pacific, associated with the ISA anomaly in MAM is connected to the tropical at-mospheric circulation variability in MAM via the teleconnection wave train. Besides, as the tropical circulation has strong seasonal persistency from the MAM to JJASO, thus, the ISA in MAM-related variability of the tropical atmospheric circulation as well as the SST can affect the typhoon activity over the western North Pacific.

关键词： typhoon sea ice cover North Pacific teleconnection