CMIP5全球气候模式对1981—2005年东北地表温度的模拟分析

利用中国东北1981—2005年173个气象台站观测的月平均地表(0 cm)温度资料和参加IPCC第五次评估报告的43个全球气候模式模拟结果,对比分析了CMIP5耦合气候模式对中国东北地区地表温度的模拟性能。结果表明：大部分气候模式模拟结果都能较好的再现研究区域的地表温度时空变化,与月观测的时间相关系数均高于095,对年际变化模拟能力稍差,大部分模式模拟结果在整个研究时段均表现出冷偏差。空间分布显示,CMIP5模式能够模拟出中国东北地区地表温度南高北低的空间分布特征,但不同模式模拟结果之间差异较大,模拟能力较优模式能够较好的模拟出研究区域的冷暖中心,较优模式组和较差模式组在夏季的差距达到最大,较差模式组不能再现地表温度的分布特征。通过模式优选发现FGOALS_s2模式表现最优。总的来说,CMIP5耦合气候模式对中国东北区域地表温度的时空变化特征的模拟性能较好,对气候态年变化的模拟性能好于对年际变化的模拟。     

鄂尔多斯盆地子洲气田上古生界山西组、下石盒子组储集层特征对比研究

鄂尔多斯盆地子洲气田山西组山23段和下石盒子组盒8段是该区天然气的主力储集层, 但其产能却存在很大差异.应用薄片鉴定、扫描电镜、高压压汞、恒速压汞及岩心分析资料, 分别对该地区上古生界山西组山23段和下石盒子组盒8段储集层进行了研究.子洲气田山23储层以石英砂岩为主, 孔隙类型多样, 粒间孔、溶孔、晶间孔发育, 喉道类别以微—细喉为主, 属相对低孔高渗型储层; 盒8储层则以岩屑砂岩为主, 孔隙类型主要为岩屑溶孔和晶间孔, 喉道类别以细—微喉为主, 属于相对低孔低渗型储层.山23段和盒8段储集层岩石类型、孔隙结构差别巨大, 造成了其储集性能的差异性.不同的沉积环境和成岩作用是造成其差异性的主要原因.     

中强地震前山东地下流体地震前兆模糊分维特征研究

采用模糊集理论与分形理论相结合的模糊分维方法，计算山东地下流体在１９８３年菏泽５．９级地震和１９９５年苍山５．２级地震前的变化。分析结果认为，模糊分维值反映了地震前兆时序观测资料的结构变化特征，具有一定的物理意义，为从复杂的地下流体前兆观测值中提取地震异常信息提供了新的方法，但对某些台、测项而言、必须具体分析其模糊分维变化特征及其震前异常变化特征。     

Investigating the uncertainty and transferability of parameters in SWAT model under climate change

ABSTRACT

There is an implicit assumption in most work that the parameters calibrated based on observations remain valid for future climatic conditions. However, this might not be true due to parameter instability. This paper investigates the uncertainty and transferability of parameters in a hydrological model under climate change. Parameter transferability is investigated with three parameter sets identified for different climatic conditions, which are: wet, intermediate and dry. A parameter set based on the baseline period (1961–1990) is also investigated for comparison. For uncertainty analysis, a k-simulation set approach is proposed instead of employing the traditional optimization method which uses a single best-fit parameter set. The results show that the parameter set from the wet sub-period performs the best when transferred into wet climate condition, while the parameter set from the baseline period is the most appropriate when transferred into dry climate condition. The largest uncertainty of simulated daily high flows for 2011–2040 is from the parameter set trained in the dry sub-period, while that of simulated daily medium and low flows lies in the parameter set from the intermediate calibration sub-period. For annual changes in the future period, the uncertainty with the parameter set from the intermediate sub-period is the largest, followed by the wet sub-period and dry sub-period. Compared with high and medium flows/runoffs, the uncertainty of low flows/runoffs is much smaller for both simulated daily flows and annual runoffs. For seasonal runoffs, the largest uncertainty is from the intermediate sub-period, while the smallest is from the dry sub-period. Apart from that, the largest uncertainty can be observed for spring runoffs and the lowest one for autumn runoffs. Compared with the traditional optimization method, the k-simulation set approach shows many more advantages, particularly being able to provide uncertainty information to decision support for watershed management under climate change.

EDITOR Z.W. Kundzewicz ASSOCIATE EDITOR not assigned     

Absorption properties of urban/suburban aerosols in China

The broadband diffuse radiation method is improved to retrieve the aerosol refractive index imaginary part （AIP） and broadband （400-1000 nm mean） single scattering albedo （SSA）. In this method, four sets of SSA selection criteria are proposed for quality control. The method is used to retrieve AIP, SSA and absorptive optical thickness （AbOT） from routine hourly-exposed pyrheliometer and paranometer measurements over 11 sites （meteorological observatories） in China during 1998-2003. Apart from one suburban site （Ejin Qi）, the other urban sites are all located around big or medium cities. As shown in the retrieval results, annual mean SSA during 1998-2003 changes from 0.941 （Wuhan） to 0.849 （Lanzhou）, and AIP from 0.0054 to 0.0203. The 11-site average annual mean SSA and AIP are 0.898 and 0.0119, respectively. SSA during winter is smaller for most sites. There is an evidently positive correlation between SSA and aerosol optical thickness （AOT） for all sites. There is also a positive correlation between SSA and relative humidity for most sites, but a negative correlation for a few sites, such as Kashi and ǚrǚmqi in Northwest China.     

Understanding the implications of the EU-LULUCF regulation for the wood supply from EU forests to the EU

Background

In June 2018, the European Parliament and Council of the European Union adopted a legislative regulation for incorporating greenhouse gas emissions and removals from Land Use, Land Use Change and Forestry (EU-LULUCF) under its 2030 Climate and Energy Framework. The LULUCF regulation aim to incentivise EU Member States to decrease greenhouse gas emissions and increase removals in the LULUCF sector. The regulation, however, does not set a target for increasing the LULUCF carbon sink, but rather includes a ‘no net debit’ target for LULUCF (Forests and Agricultural soils). For Managed Forest Land (MFL) an accounting framework with capped credits for additional mitigation against a set forest reference level (FRL) was agreed for 2021–2030. The FRL gives the projected future carbon sink in the two compliance periods 2021–2025 and 2026–2030 under “continuation of forest management practices as they were in the reference period 2000–2009”. This FRL was disputed by some Member States as it was perceived to put a limit on their future wood harvesting from MFL. Here we simulated with the EFISCEN European forest model the “continuation of forest management practices” and determined the corresponding wood harvest for 26 EU countries under progressing age classes.

Results

The simulations showed that under “continuation of forest management practices” the harvest (wood removals) in the 26 EU countries as a whole can increase from 420 million m³/year in 2000–2009 to 560 million m³/year in 2050 due to progressing age classes. This implies there is a possibility to increase absolute wood harvests without creating debits compared to the forest reference level. However, the manner in which ‘continuation of forest management’ developed with a progressing age class development over time, meant that in some countries the future harvesting exceeded 90% of the increment. Since this generally is considered to be unsustainable we additionally set a harvesting cut-off as max 90% of increment to be harvested for each individual country as a possible interpretation of sustainability criteria that are included in the regulation. Using this additional limit the projected harvest will only increase to 493 million m³/year.

Conclusions

The worry from Member States (MS) that the FRL will prevent any additional harvesting seems unwarranted. Due to differences between Member States concerning the state of their forest resources, the FRL as a baseline for harvesting works out very differently for the different Member States. The FRL may have other unforeseen consequences which we discuss. Under all scenarios the living forest biomass sink shows a decline. This can be counteracted through incentivising measures under Climate Smart Forestry.

     

Ensemble simulation of land evapotranspiration in China based on a multi-forcing and multi-model approach

In order to reduce the uncertainty of offline land surface model(LSM) simulations of land evapotranspiration(ET), we used ensemble simulations based on three meteorological forcing datasets [Princeton, ITPCAS(Institute of Tibetan Plateau Research, Chinese Academy of Sciences), Qian] and four LSMs(BATS, VIC, CLM3.0 and CLM3.5), to explore the trends and spatiotemporal characteristics of ET, as well as the spatiotemporal pattern of ET in response to climate factors over mainland China during 1982–2007. The results showed that various simulations of each member and their arithmetic mean(Ens Mean) could capture the spatial distribution and seasonal pattern of ET sufficiently well, where they exhibited more significant spatial and seasonal variation in the ET compared with observation-based ET estimates(Obs MTE). For the mean annual ET, we found that the BATS forced by Princeton forcing overestimated the annual mean ET compared with Obs MTE for most of the basins in China, whereas the VIC forced by Princeton forcing showed underestimations. By contrast, the Ens Mean was closer to Obs MTE, although the results were underestimated over Southeast China. Furthermore, both the Obs MTE and Ens Mean exhibited a significant increasing trend during 1982–98; whereas after 1998, when the last big EI Ni ?no event occurred, the Ens Mean tended to decrease significantly between 1999 and 2007, although the change was not significant for Obs MTE. Changes in air temperature and shortwave radiation played key roles in the long-term variation in ET over the humid area of China, but precipitation mainly controlled the long-term variation in ET in arid and semi-arid areas of China.     

福州市地表干湿分布特征及其与农业干旱的关系

利用常规资料、NCEP再分析等资料,对0604号强热带风暴碧利斯造成华南持续特强暴雨的特点及成因进行了综合分析.结果表明:虽然碧利斯最强时只达强热带风暴强度,但在其登陆后与强西南季风持续地相互作用,在台风南侧形成强盛的水汽输送和辐合上升机制,且辐合上升运动、高层辐散及水汽辐合中心强度异常强盛,为近年台风少有,且大暴雨区与强水汽辐合上升中心十分吻合;华南持续5天强暴雨与台风低压与西南季风持续结合及副高断裂有密切关系;碧利斯对促使西南季风明显增幅北抬也起了重要作用.     

Measurement of radon exhalation rate in various building materials and soil samples

Indoor radon is considered as one of the potential dangerous radioactive elements. Common building materials and soil are the major source of this radon gas in the indoor environment. In the present study, the measurement of radon exhalation rate in the soil and building material samples of Una and Hamirpur districts of Himachal Pradesh has been done with solid state alpha track detectors, LR-115 type-II plastic track detectors. The radon exhalation rate for the soil samples varies from 39.1 to 91.2 mBq kg^?1 h^?1 with a mean value 59.7 mBq kg^?1 h^?1. Also the radium concentration of the studied area is found and it varies from 30.6 to 51.9 Bq kg^?1 with a mean value 41.6 Bq kg^?1. The exhalation rate for the building material samples varies from 40.72 (sandstone) to 81.40 mBq kg^?1 h^?1 (granite) with a mean value of 59.94 mBq kg^?1 h^?1.     

塔里木盆地塔中低凸起地层水化学特征对不整合的响应

对塔中低凸起地层水化学特征与不整合之间关系的研究结果表明,地层水化学特征对不整合具有很好的响应。在遭受强烈抬升和剥蚀、之间形成不整合的奥陶系和志留系,以及紧靠不整合面附近的石炭系CⅢ油组,其地层水具有矿化度、Cl-含量、K Na 含量和r(Cl-Na)/rMg值相对较小,而HCO3-含量、rNa/rCl值和rSO42-×100/rCl值相对较大的特点,反映出地质历史时期大气降水的影响。在志留系与石炭系之间以及志留系与奥陶系之间的不整合面附近,地层水的矿化度、r(Cl-Na)/rMg值和B3 含量变小,而rNa/rCl值和rSO24-×100/rCl值变大,具有典型的遭受大气淋滤的地层水化学基本特征。