A Study of the Extended-range Forecast for the Low Frequency Temperature and High Temperature Weather over the Lower Reaches of Yangtze River Valley in Summer

Based on the observational data, the variations of Intraseasonal Oscillation (ISO) of the daily temperatures and its relationships to the high temperature in summer over the lower reaches of the Yangtze River Valley (LYRV) were studied for the period of 1979-2011. It is found that the daily temperatures over LYRV in May-August was mainly of periodic oscillations of 1525, 3060 and 6070 days, and the interannual variation of the intensity of its 3060-day oscillation had a strongly positive correlation with the number of days with daily highest temperature over 35 ℃ in July-August. Low frequency components of daily temperature in the LYRV, and the principal components of the Eastern Asian 850 hPa low frequency temperature, over a time period ranging from 1979 to 2000, were used to establish the Extended Complex Autoregressive model (ECAR) on an extended-range forecast of the 3060-day low frequency temperature over the LYRV. A 11-year independent real-time extended-range forecast was conducted on the extended-range forecast of low frequency component of the temperature over the LYRV in May-August, for the period ranging from 2001 to 2011. These experimental results show that this ECAR model, which is based on a data-driven model, has a good forecast skill at the lead time of approximately 23 days, with a forecast ability superior to the traditional autoregressive (AR) model. Hence, the development and variation of the leading 3060-day modes for the Eastern Asian 850 hPa low frequency temperatures and temporal evolutions of their relationships to low frequency components of the temperature over the LYRV in summer are very helpful in predicting the persistent high temperature over the LYRV at a 20 to 25 days lead.     

江西兴国均村-高兴地区氟水文地球化学特征研究

氟广泛分布于地下水且与人体健康相关,世界上许多国家和地区均存在高氟水。本文以江西省均村-高兴地区为例,结合区域水文地质调查成果开展地下水中氟水文地球化学特征研究,探讨研究区地下水中F-的分布特征与来源。对研究区4个地下水系统中的442个地下水样品的F-、Ca²⁺、HCO_3^-浓度及pH值、TDS等进行分析,研究认为各地下水系统地下水中的F-浓度与Ca²⁺浓度、HCO_3^-浓度、pH值、TDS正相关,含氟矿物的溶解是地下水中氟的主要来源,较强烈的地下水交替条件及弱酸性的地下水特征是导致地下水中氟浓度低的重要原因。     

IPCC AR6报告解读：未来的全球气候——基于情景的预估和近期信息

依据IPCC第六次评估报告（AR6）第一工作组报告第四章的内容,对未来全球气候的预估结果进行解读。报告对21世纪全球表面气温、降水、大尺度环流和变率模态、冰冻圈和海洋圈的可能变化进行了系统评估,并对2100年以后的气候变化做了合理估计。评估指出全球平均表面气温将在未来20年内达到或超过1.5℃,平均降水也将增加,但随季节和区域而异,同时变率将增大。大尺度环流和变率模态受内部变率影响较大。到21世纪末,北冰洋可能出现无冰期;全球海洋会继续酸化,平均海平面将持续上升,百年内上升幅度依赖不同排放情景,都在2100年后继续升高。在最新的评估中采用多种约束方法,减小了预估不确定性的范围。AR6对于低排放情景以及“小概率高增暖情节”的关注为应对气候变化提供了更多、更完整的信息。综合报告的评估结果指出,未来需要进一步减小区域,特别是季风区气候预估的不确定性,并从科学研究和模式发展两方面加强我国气候预估能力的建设。     

Testing the consistency of Holocene and Last Glacial Maximum spatial correlations in temperature proxy records

Holocene temperature proxy records are commonly used in quantitative synthesis and model-data comparisons. However, comparing correlations between time series from records collected in proximity to one another with the expected correlations based on climate model simulations indicates either regional or noisy climate signals in Holocene temperature proxy records. In this study, we evaluate the consistency of spatial correlations present in Holocene proxy records with those found in data from the Last Glacial Maximum (LGM). Specifically, we predict correlations expected in LGM proxy records if the only difference to Holocene correlations would be due to more time uncertainty and more climate variability in the LGM. We compare this simple prediction to the actual correlation structure in the LGM proxy records. We found that time series data of ice-core stable isotope records and planktonic foraminifera Mg/Ca ratios were consistent between the Holocene and LGM periods, while time series of Uk'37 proxy records were not as we found no correlation between nearby LGM records. Our results support the finding of highly regional or noisy marine proxy records in the compilation analysed here and suggest the need for further studies on the role of climate proxies and the processes of climate signal recording and preservation.     

不同覆盖措施对高寒地区剥离的草皮块堆放温湿度及成活的影响

重大工程建设会扰动高寒草地,法规要求扰动区草皮层应予以剥离,待工程建设后再用于恢复原生植被,当前对剥离草皮堆放成活的影响研究较少。试验设计遮阳网与穿孔膜两种覆盖条件,探讨分析其对剥离的草皮块堆放与铺植利用后土壤温湿度及草皮块返青覆盖度的影响,研究结果表明：遮阳网覆盖堆体较自然地表日均土壤温度显著降低,同时各深度层极大延长冻结期,降水对土壤水分的补充效应延后,并造成堆放期水分大量损失;穿孔膜覆盖堆体较自然地表提高了土壤温度,阻碍了降水对土壤水分的补充,并造成堆放后土壤吸持水能力降低。遮阳网覆盖的草皮块返青覆盖度显著高于穿孔膜覆盖的返青覆盖度,堆放期日平均土壤温度>0 ℃的堆放日数与草皮块返青覆盖度的线性拟合较好。工程建设中应尽量缩短堆放时长,采用透水透气类覆盖材料,增加土壤与空气热量交换,以维持更长的冻结期,并适时补充水分,提高草皮块铺植的恢复成效。     

高山区雪堆储雪的实验和模拟计算

随着全球气候变暖,滑雪运动呈现出对气候变化高度的敏感性和依赖性,各地滑雪季将不同程度地缩短。储雪作为一种应对气候变化的方法在雪务保障中逐渐得到研究和应用。在新疆阿勒泰地区吉木乃县开展储雪实验,应用谐波反应法研究了雪堆融化量与外界空气温度、太阳辐射和绝热保温结构热学性能之间的定量关系。实验中,覆盖两层绝热保温材料雪堆1的平均融化量为18.0 kg·d^-1（相当于初始质量的0.85%）,未覆盖绝热保温材料雪堆2的平均融化量为120.8 kg·d^-1（相当于初始质量的6.67%）。模拟期间观测到的雪堆1质量减少了1 438.0 kg,对应的模拟值为1 520.8 kg。谐波反应法可以为评价绝热保温结构的热学性能和提前确定储雪量提供重要的参考依据。由于许多物理过程都未考虑,导致模拟的雪堆融化量与实际融化量之间存在不确定性。雪堆所用绝热保温结构的性能可以用反射率、总传热系数、衰减度和延迟时间来衡量。     

滑坡碎屑化运动物理模型相似材料特性研究

高速远程滑坡物理模型试验中,岩石相似材料的选择是模型试验成功的关键,然而目前滑坡相似材料强度高、难以在缩尺试验中模拟滑坡破碎过程。以重晶石、石英砂为骨料,石膏为胶结剂,羧甲基纤维素钠、甘油、水作为辅助材料,进行可破碎岩石相似材料的配比试验。采用控制变量法研究重晶石与石英砂比例（重石比）、骨料与胶结物比例（骨胶比）、羧甲基纤维素钠含量、拌合水量、甘油含量对相似材料物理力学性质的影响。试验结果表明:所有配比情况下各相似材料物理力学参数的范围分别为单轴抗压强度为0.12～1.47 MPa,弹性模量为25.51～148.12 MPa,黏聚力为1.63～87.39 kPa,内摩擦角为22.70°～35.89°,脆性指标主要分布在0.033～0.145之间;重石比主要控制岩石相似材料的内摩擦角;骨胶比减小,对应的黏聚力和内摩擦角先增大后减小;羧甲基纤维素钠对材料的单轴抗压强度、弹性模量、黏聚力等材料的力学特性以及材料的脆性指标影响均比较大,其中对单轴抗压强度的影响最大。因此,控制羧甲基纤维素钠和拌合水量的含量,并合理调节重石比与骨胶比,在相似比约为1∶600的试验尺度下,最终确定了适用于高速远程滑坡碎屑化过程模拟的低强度高脆性岩石相似材料的配比区间。     

六种成膜封堵剂的室内实验优选与评价

为更好地服务深部钻探工程,准确了解冲洗液封堵性能,对6种成膜封堵剂开展了砂床实验、API静失水量实验、流变性能实验及抗温实验等室内实验进行优选与评价。实验结果表明,2号和4号成膜封堵剂在6种成膜封堵剂中封堵性能最好,它们在基浆中的最优加量均为2%,100 ℃温度条件下加入这2种封堵剂的冲洗液具有较好的抗温性能;冲洗液中膨润土含量和处理剂是影响冲洗液封堵性能的2个重要因素：膨润土含量越高,冲洗液封堵性能越好,加入聚合物、降滤失剂等处理剂可以提高冲洗液的封堵性能。砂床实验是评价冲洗液封堵性能好坏的重要依据。     

青藏高原复杂地层地质钻探低固相冲洗液试验研究

青藏高原由于地质条件的多样性,分布有松散破碎地层、高应力地层、断层破碎带等复杂地层,在地质钻探中经常遇到塌孔、漏浆、缩径、卡钻、埋钻等问题。同时配套使用的冲洗液形成的泥皮质量差、胶结能力较差、携岩粉能力较弱等不足。冲洗液的性能是实现复杂地层顺利钻进的关键。结合青藏高原复杂地层的地质特点,研发了低固相聚合物新型冲洗液,该冲洗液以钠质膨润土和微泡剂等外加剂为基础,具有流动性好、胶结性强、降失水量适中的特点,适宜在青藏高原复杂地层地质钻探中使用。     

川东北普光地区深层富钾卤水钾资源提取研究

四川盆地地下卤水资源丰富,尤其川东北地区地下卤水富含高品质钾资源。本项目以四川普光地区富钾卤水为研究对象,根据卤水组成,采用模拟计算并结合实验验证的方法,研究了高温蒸发时,氯化钠、氯化钾、光卤石、硼酸等矿物的析出阶段及特点。研究结果表明,当蒸失水率约80%时,体系中约85%的NaCl析出,同时KCl达到饱和,继续蒸发可获取钾石盐。控制总蒸失水率94%~95%时分离,体系中大于80%的钾可在这一阶段析出,且湿基中KCl品位可高达约45%;析出钾石盐后的卤水降至室温可获得NaCl、KCl、KCl·MgCl₂·6H₂O及H₃BO₃的混合物,硼的析出率可达到约80%。同时,研究表明,将蒸失水率约80%时分离石盐后的卤水直接降温可以获得湿基品位约高达70%的钾石盐矿,钾析出率约50%。综合对比分析,提出两条以钾资源开发为主的工艺路线:其一为“高温蒸发析氯化钠-高温蒸发析氯化钾-冷却析钾硼混盐”,通过加工获得KCl及H₃BO₃产品;其二为“高温蒸发析氯化钠-冷却析钾”,通过加工获得高端KCl产品。