Numerical Simulation of Long-Term Climate Change in East Asia

A 10-yr regional climate simulation was performed using the fifth-generation PSU/NCAR Mesoscale Model Version 3 (MM5V3) driven by large-scale NCEP/NCAR reanalyses. Simulations of winter and summer mean regional climate features were examined against observations. The results showed that the model could well simulate the 10-yr winter and summer mean circulation, temperature, and moisture transport at middle and low levels. The simulated winter and summer mean sea level pressure agreed with the NCAR/NCEP reanalysis data. The model could well simulate the distribution and intensity of winter mean precipitation rates as well as the distribution of summer mean precipitation rates, but it overestimated the summer mean precipitation over North China. The model's ability to simulate the regional climate change in winter was superior to that in summer. In addition, the model could simulate the inter-annual variation of seasonal precipitation and surface air temperature. Geopotential heights and temperature at middle and high levels between simulations and observations exhibited high anomaly correlation coefficients. The model also showed large variability to simulate the regional climate change associated with the El Nino events. The MM5V3 well simulated the anomalies of summer mean precipitation in 1992 and 1995, while it demonstrated much less ability to simulate that in 1998. Generally speaking, the MM5V3 is capable of simulating the regional climate change, and could be used for long-term regional climate simulation.     

Irrigated area determination: a case study in the Province of San Juan,Argentina

Much of the central-western region of Argentina, where San Juan Province is located, experiences arid to semi-arid climatic conditions with low average annual rainfall accompanied by substantial evapotranspiration. Consequently, a viable crop industry depends to a large extent upon irrigation from major river systems. Increasing demand for water in the lower basin of the San Juan River is emphasizing the need for more accurate estimates of water used for irrigation. Since the water demand for a particular crop is very closely related to crop area, monitoring the area of crop under irrigation is considered a proxy for the amount of water used. Landsat 5 imagery for the growing season, field data and aerial photographs were used to evaluate crop area.     

苍山5.2级地震前十里泉电厂井地下水离子多组分的变化特征及机制讨论

１９９５年９月２０日山东苍山５．２级地震前,山东枣庄十里电厂水化学现观测井（Δ＝ｋｍ）水离子多组分出现了较为同步的异常变化。本文以此为基础,分析研究了这些异常的变化特征,讨论了异常出现的机制,研究认为,枣庄十里泉电厂水化学观测井水离子多组分的异常同步变化及相互印证,提高了异常的可信度;与水中常见离子组分相比,其中水汞的震前异常变化幅度最大,异常特征明显;十里泉电厂水化学观测井水离子多组分的同步异常     

Water balance change for a re-vegetated xerophyte shrub area/Changement du bilan hydrique d’une zone replantée d’arbustes xérophiles

Abstract

Abstract Water balances for a re-vegetated xerophyte shrub (Caragana korshinskii) area were compared to that of a bare surface area by using auto-weighing type lysimeters during the 1990–1995 growing seasons at the southeast Tengger Desert, Shapotou, China. The six-year experiment displayed how major daily water balance components might vary for a bare and a re-vegetated sand dune area. Evapotranspiration from the C. korshinskii lysimeter represented a major part of the water balance. The average annual ET/P ratios varied between 69 and 142%. No seepage was observed for the vegetated lysimeter. For the bare lysimeter, on the other hand, 48 mm or 27% of observed rainfall per year occurred as seepage. These results suggest that re-vegetating large sandy areas with xerophytic shrubs could reduce soil water storage by transpiration. Also, the experimental results indicate that re-vegetating large sandy areas could significantly change groundwater recharge conditions. However, from a viewpoint of desert ecosystem reconstruction, it appears that natural rainfall can sustain xerophytic shrubs such as C. korshinskii which would reduce erosion loss of sand. However, re-vegetation has to be balanced with recharge/groundwater needs of local populations.     

中华绒螯蟹(Eriocheir sinensis)肠道和肝胰腺5-羟色胺(5-HT)和5-羟色胺受体2(5-HTR2)的定位研究

肠道和肝胰腺是中华绒螯蟹(Eriocheir sinensis)重要的消化器官,本文运用组织学技术测量了中肠和后肠长度,并对肠道长与体长进行相关性分析。应用免疫组化技术对5-HT和5-HT受体2进行组织定位和计数。结果表明:(1)中华绒螯蟹的肠道长与体长接近,两者之间呈极显著正相关(P0.01)。后肠长度约为中肠的2倍;(2)5-HT和5-HT受体2在中肠和后肠中的组织定位和数量相似,均分布于黏膜上皮细胞间和肌层与外膜交界处,亦见于后肠的固有膜和黏膜下层与肌层交界处,在肠球外膜中也有大量分布;(3)5-HT和5-HT受体2阳性物质在肝胰腺的四种细胞的胞核中均有分布,在F细胞的胞质中也有分布。5-HT和5-HT受体2在中华绒螯蟹肠道和肝胰腺组织中的分布规律一致,表明中华绒螯蟹消化道5-HT发挥生理功能可能与5-HT受体2有关。此外,5-HT和5-HT受体2在后肠近肌细胞分布的特点可能与肠道收缩有关。后肠在中华绒螯蟹消化生理中的作用应引起重视。     

基于主成分分析的相对重力观测零漂和固体潮提取

利用主成分分析PCA提取2014-08-15~23CG-5相对重力仪静态相对观测的零点漂移和固体潮。结果显示,PCA提取的零点漂移值与最小二乘线性拟合结果非常一致,其差仅在10-2μGal/d量级;PCA估算的固体潮值与CG-5重力仪内部软件提供的固体潮模型计算值统计结果基本一致,两者之差均小于8μGal,均方根均小于5μGal。     

The Project Siberian High in CMIP5 Models

The Siberian high(SH)experienced a decline from the 1970s to 1990s and a recovery in recent years.The evolution of the SH under global warming is unclear.In this study,41 Coupled Model Intercomparison Project Phase 5(CMIP5)climate models are evaluated in terms of their ability to simulate the temporal evolution of the SH in the 19th and 20th centuries and the spatial pattern of the SH during 1981–2005.The results show that 12models can capture the temporal evolution of the SH center intensity(SHCI)for 1872–2005.The linear correlation coefficient between the SHCI from the Twentieth Century Reanalysis and the simulated SHCI from the multi-model ensemble(MME)of the 12 models is 0.3 on annual and inter-annual scales(above the 99%confidence level).On decadal and multi-decadal time scales,the MME also captures the pronounced reduction(between 1981–2000and 1881–1900 period)and the recovery(during1991–2005)of the SH intensity.Finally,the future evolution of the SH is investigated using the MME of the 12models under the+4.5 and+8.5 W m-2 Representative Concentration Pathway(RCP)scenarios(RCP4.5 and RCP8.5).It is shown that the SHCI,similar to the SHCI in the 20th century,has no significant long-term trend in the 21st century under global warming(RCP8.5 scenario).At the end of 21st century(2081–2100),the SH shows stronger interannual variability than the SH at the end of20th century(1981–2000).The increased interannual variability likely favors the increased interannual variability in winter air temperature over midlatitude Eurasia at the end of 21st century.     

CMIP5西北太平洋气候变率的模拟评估

利用观测海温资料和CMIP5模式模拟结果分析西北太平洋(120°E~120°W,20~60°N)海表温度的气候态和年代际变化特征。结果表明,所选22个模式可以较好地模拟出西北太平洋海表温度的气候特征及其年际、年代际变化特征;模式模拟的海表温度总体标准偏差在黑潮延伸体区域最大;绝大多数模式能模拟出海表温度的第一EOF模态;西北太平洋海表温度具有较明显的年代际振荡现象,13/22的模式模拟的海表温度存在明显的年代际振荡,同时海表温度气候态的模拟偏差对其周期振荡模拟的影响较大,尤其在黑潮延伸体区域。     

Simulation of the equatorially asymmetric mode of the Hadley circulation in CMIP5 models

The tropical Hadley circulation (HC) plays an important role in influencing the climate in the tropics and extra-tropics. The realism of the climatological characteristics, spatial structure, and temporal evolution of the long-term variation of the principal mode of the annual mean HC (i.e., the equatorially asymmetric mode, EAM) was examined in model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5). The results showed that all the models are moderately successful in capturing the HC's climatological features, including the spatial pattern, meridional extent, and intensity, but not the spatial or temporal variation of the EAM. The possible reasons for the poor simulation of the long-term variability of the EAM were explored. None of the models can successfully capture the differences in the warming rate between the tropical Southern Hemisphere (SH) and Northern Hemisphere (NH), which is considered to be an important driver for the variation of the AM. Most of the models produce a faster warming in the NH than in the SH, which is the reverse of the observed trend. This leads to a reversed trend in the meridional gradient between the SH and NH, and contributes to the poor simulation of EAM variability. Thus, this aspect of the models should be improved to provide better simulations of the variability of the HC. This study suggests a possible reason for the poor simulation of the HC, which may be helpful for improving the skill of the CMIP5 models in the future.     

Synergistic contribution of precipitation anomalies over northwestern India and the South China Sea to high temperature over the Yangtze River Valley

This study explores the characteristics of high temperature anomalies over eastern China and associated influencing factors using observations and model outputs. Results show that more long-duration (over 8 days) high temperature events occur over the middle and lower reaches of the Yangtze River Valley (YRV) than over the surrounding regions, and control most of the interannual variation of summer mean temperature in situ. The synergistic effect of summer precipitation over the South China Sea (SCS) region (18°-27°N, 115°-124°E) and the northwestern India and Arabian Sea (IAS) region (18°-27°N, 60°-80°E) contributes more significantly to the variation of summer YRV temperature, relative to the respective SCS or IAS precipitation anomaly. More precipitation (enhanced condensational heating) over the SCS region strengthens the western Pacific subtropical high (WPSH) and simultaneously weakens the westerly trough over the east coast of Asia, and accordingly results in associated high temperature anomalies over the YRV region through stimulating an East Asia-Pacific (EAP) pattern. More precipitation over the IAS region further adjusts the variations of the WPSH and westerly trough, and eventually reinforces high temperature anomalies over the YRV region. Furthermore, the condensational heating related to more IAS precipitation can adjust upper-tropospheric easterly anomalies over the YRV region by exciting a circumglobal teleconnection, inducing cold horizontal temperature advection and related anomalous descent, which is also conducive to the YRV high temperature anomalies. The reproduction of the above association in the model results indicates that the above results can be explained both statistically and dynamically.