Role of tropical atlantic SST variability as a modulator of El Niño teleconnections

The present study suggests that the off-equatorial North Atlantic (NATL) SST warming plays a significant role in modulating El Niño teleconnection and its impact on the North Atlantic and European regions. The El Niño events accompanied by NATL SST warming exhibit south-north dipole pattern over the Western Europe to Atlantic, while the ENSO teleconnection pattern without NATL warming exhibits a Rossby wave-like pattern confined over the North Pacific and western Atlantic. Especially, the El Niño events with NATL warming show positive (negative) geopotential-height anomalies over the North Atlantic (Western Europe) which resemble the negative phase of the NAO. Consistently, it is shown using a simple statistical model that NATL SSTA in addition to the tropical Pacific SSTA leads to better prediction on regional climate variation over the North Atlantic and European regions. This role of NATL SST on ENSO teleconnection is also validated and discussed in a long term simulation of coupled global circulation model (CGCM).     

天气雷达数字化终端及其应用软件

为解决雷达数据采集、实时显示、数据存储、资料处理自动化等问题，进行了天气雷达数字化终端和应用软件技术的研究和开发。改变了711B-1雷达数据存储、分析自动化程度低的状况。增加和丰富了雷达二次产品，使雷达资料得到了充分的分析和应用，提高了雷达对天气的监测能力。增加了对冰雹、暴雨等强对流天气的预警功能、人工增雨效果检验等功能。     

污染源、气象条件变化对我国SO2浓度及硫沉降量分布的影响

用三维欧拉型污染物长距离输送模式,模拟了中国大陆SOx的分布,并采用不同时期(1975、1980、1987年)的污染源与气象场资料,分析了污染源与气象条件变化对SOx分布产生的影响.研究表明,在该期间中国SOx污染比较严重的地区,气象条件变化导致SO2浓度和硫沉降量的相对变化通常在20%左右;污染源对SO2浓度与硫沉降量的作用通常大于气象条件,污染源变化产生的SO2浓度与硫沉降量的相对变化率为气象条件变化的几倍,甚至1～2个量级,尤其SOx污染比较严重的地区更为明显;但对西北及青藏高原地区,在源排放量变化不大,而气象条件变化较显著时,气象条件的作用通常大于排放源的影响.     

江西三类致灾大风天气活动与回波特征分析

使用常规天气资料、灾情资料、自动气象站、卫星云图和雷达回波等资料,对江西出现的灾害性大风天气进行分析,结果表明：江西致灾大风天气主要有三种类型。（1）与飑线回波带和超级单体等雷达回波系统相伴随的雷雨大风天气,同时还伴随强雷电、强降水、冰雹和龙卷等灾害性天气;（2）与冷锋雷暴回波带和冷空气大风相伴随的混合大风天气,具有雷雨大风天气和冷空气大风天气活动的特征;（3）由雷暴下沉气流触发、中高空动能下传和气压梯度风共同作用产生的无降水致灾大风天气,没有降水、雷电等天气现象伴随。     

Landsat ETM＋数据的武汉市地表温度反演研究

以Landsat ETM＋为主要遥感数据源,辅助以气象数据资料,利用NDVI计算出植被覆盖率,继而计算出地表比辐射率,并利用单窗算法精确反演得到了武汉市2002年夏季地表温度。研究表明,武汉城市热岛由武昌、汉口、汉阳三大城区热岛构成,且几乎集中在城区;城区大热岛区中还存在多数热岛效应更为严重的＂岛中岛＂;武汉热岛分布与...     

赤道涡旋与南海夏季风爆发

文中应用１９７９－１９９５年共１７ａ的８５０ｈＰａ风场资料和ＮＯＡＡ卫星的ＯＬＲ资料，分析了南海夏季风爆发的特征。证实南海夏季风爆发，落后于同纬度的中南半岛和菲律宾岛屿地区。但在南海的东部和西部，季风爆发几乎是同时的，具有某种驻波的特征。文中还证实，大多数年份的４，５月间在１０５°Ｅ附近有赤道涡旋形成，这个涡旋引导它上游的赤道西风或南半球西风进入南海南部，为南海的季风爆发创造有利条件。这种涡旋不活跃的年份，季风爆发往往偏晚。它们之间可能存在某种联系。４月中旬，这个涡旋的形成和１０５°Ｅ越赤道气流的初步建立是同时的。进入５月份，这支越赤道气流逐渐加强。南海夏季风的活动与这支气流可能关系密切。如果称位于１０５°Ｅ附近的赤道涡旋为东亚的爆发涡旋，它显然与南亚季风的情况有较大差别。南亚的爆发涡旋与季风爆发的关系是直接的，而在东亚，则是间接的，这也说明了东亚季风比南亚季风更具有复杂性。     

Temporal variation and source identification of black carbon at Lin’an and Longfengshan regional background stations in China

Black carbon (BC) is a component of fine particulate matter (PM_2.5), associated with climate, weather, air quality, and people’s health. However, studies on temporal variation of atmospheric BC concentration at background stations in China and its source area identification are lacking. In this paper, we use 2-yr BC observations from two background stations, Lin’an (LAN) and Longfengshan (LFS), to perform the investigation. The results show that the mean diurnal variation of BC has two significant peaks at LAN while different characteristics are found in the BC variation at LFS, which are probably caused by the difference in emission source contributions. Seasonal variation of monthly BC shows double peaks at LAN but a single peak at LFS. The annual mean concentrations of BC at LAN and LFS decrease by 1.63 and 0.26 μg m^–3 from 2009 to 2010, respectively. The annual background concentration of BC at LAN is twice higher than that at LFS. The major source of the LAN BC is industrial emission while the source of the LFS BC is residential emission. Based on transport climatology on a 7-day timescale, LAN and LFS stations are sensitive to surface emissions respectively in belt or approximately circular area, which are dominated by summer monsoon or colder land air flows in Northwest China. In addition, we statistically analyze the BC source regions by using BC observation and FLEXible PARTicle dispersion model (FLEXPART) simulation. In summer, the source regions of BC are distributed in the northwest and south of LAN and the southwest of LFS. Low BC concentration is closely related to air mass from the sea. In winter, the source regions of BC are concentrated in the west and south of LAN and the northeast of the threshold area of s_tot at LFS. The cold air mass in the northwest plays an important role in the purification of atmospheric BC. On a yearly scale, sources of BC are approximately from five provinces in the northwest/southeast of LAN and the west of LFS. These findings are helpful in reducing BC emission and controlling air pollution.     

西拉木伦河流域降水和径流特征分析

在搜集整理西拉木伦河流域近30a(1981—2010年)降水资料和同期径流数据的基础上,运用统计方法分析了该流域的降水和径流年内和年际变化特征,并对年降水量和径流二者之间的关系进行了初步探讨。结果表明,西拉木伦河流域年内降水分配不均匀,降水主要集中在夏季,近30a年际降水量呈波动减少趋势。受降水影响,西拉木伦河流域径流年际变化同样也较为强烈。以西拉木伦河流域年降水量、径流量建立数学模型为:Q=-4.624+0.029P年(R=0.706)。     

东北地区旱涝的OLR特征分析

该文选取了东北地区4个典型多雨年和4个典型少雨年, 利用OLR资料对该地区旱涝年OLR场的时空分布规律及其低频振荡的传播特征进行了合成对比分析.结果表明, 东北旱涝与低纬OLR的分布及其变化密切相关, 特别是西北太平洋副热带高压、西太平洋ITCZ和印度ITCZ的位置和强度以及赤道中东太平洋OLR的距平在旱涝年均有显著差别, 并且热带和副热带OLR低频振荡的向北传播对东北地区夏季降水也有至关重要的影响.