Improved methods for estimating equilibrium climate sensitivity from transient warming simulations

Climate Dynamics - Equilibrium climate sensitivity (ECS) refers to the total global warming caused by an instantaneous doubling of atmospheric CO2 from the pre-industrial level in a climate system....     

基于COM组件的单站数值预报结果提取与网络动态发布方法

为实现对海量数值预报产品的高效应用和对单站数值预报结果的网络共享,针对ECMWF、T639等数值预报产品特点,创建了一种单站数值预报结果的提取方法,并基于COM组件实现其结果的网络动态发布.本文给出了网络服务器端单站数值预报结果提取COM组件设计的一般思路和关键程序代码,解决了单站数值预报结果的快速提取、直观显示和网络动态实时发布问题.     

2017年8月萍乡地区连续性雷暴大风过程分析

利用常规观测资料、探空资料、多普勒天气雷达基本产品及导出产品,分析了2017年8月中旬萍乡地区雷暴大风天气过程,并选取了其中最强的一次过程进行了细致的分析。结果表明,“北低槽、南副高”的环流形势是此次长时间雷暴大风的环流背景,萍乡受“上下一致”的西南急流控制,中低层切变线、西南急流导致了强对流不稳定;低层逆温、“上干冷、下暖湿”以及风垂直切变的垂直结构,为雷暴大风的产生提供了层结条件和能量条件;地面热低压和地面辐合线、干线等是此次雷暴大风的触发机制。飑线过境,气象要素变化剧烈,在“人”字形回波附近,回波断裂处等区域容易产生强雷暴大风天气。强回波高度迅速下降、拖曳作用、动量下传、中层干暖空气的夹卷及蒸发作用、一定强度的中层径向辐合等多种因素导致了此次地面大风。垂直累积液态含水量、最大反射率因子、风暴顶高的持续下降,对地面大风天气的预报具有一定的指示意义。     

江西省森林和植被碳汇价值研究

江西生态优势明显,森林覆盖率居全国前列,研究植被生态系统碳汇价值是应对气候变化和生态文明建设的具体体现。基于森林资源清查资料,研究了2001—2016年江西省森林碳汇价值;基于卫星遥感数据反演获取植被生态系统净初级生产力(NPP),评估了2000—2016年江西各设区市(县)植被碳汇分布特征。结果表明:1)2016年江西省森林碳储量价值为980.30亿元,植被和森林碳汇价值均呈上升趋势。2)江西省植被碳汇价值增加率为4.55亿元/a,2016年约为823.53亿元,每公顷所创造的碳汇经济价值为4930.67元,比2000年增加了11%。3)2016年各设区市植被碳汇价值排名前三位的分别是赣州、吉安和上饶,排名后三位的是新余、鹰潭和萍乡,单位面积固碳价值排名前三位的为赣州、吉安和抚州,排名后三位的是南昌、九江和鹰潭,其排名与森林面积和森林覆盖率有较大关系。     

The influence of the inter-decadal Pacific oscillation on US precipitation during 1923–2010

Precipitation over the contiguous United States exhibits large multi-decadal oscillations since the early twentieth century, and they often lead to dry (e.g., 1946–1976 and 1999-present) and wet (e.g., 1977–1998) periods and apparent precipitation trends (e.g., from the 1950s to 1990s) over most of the western and central US. The exact cause of these inter-decadal variations is not fully understood. Using observational and reanalysis data and model simulations, this paper examines the influence of the Inter-decadal Pacific Oscillation (IPO) on US precipitation. The IPO is a leading mode of sea surface temperatures (SSTs) seen mostly in the Pacific Ocean. It is found that decadal precipitation variations over much of the West and Central US, especially the Southwest, closely follow the evolution of the IPO (r = 0.85 during 1923–2010 for the Southwest US), and the dry and wet periods are associated, respectively, with the cold and warm phases of the IPO. In particular, the apparent upward trend from the 1950s–1990s and the dry decade thereafter in precipitation over much of the West and Central US are largely caused by the IPO cycles, which switched to a warm phase around 1977 and back to a cold phase around 1999. An atmospheric model forced with observed SSTs reproduces much of this association of US precipitation with the IPO (r = 0.95 between smoothed observed and simulated Southwest US precipitation during 1950–2009 and r = 0.88 between the simulated Southwest US precipitation and the IPO). Atmospheric reanalysis and model data both show a strong high (low) pressure center and anti-cyclonic (cyclonic) anomaly circulation over the North Pacific in the lower troposphere during cold (warm) phases of the IPO, which lead to dry and cold northwesterly and northerly winds and below-normal precipitation over much of the West US during IPO cold periods. The IPO induced changes are most pronounced during the boreal cold season. The results reinforce the notion that tropical Pacific SSTs (and the accompanying SST anomalies in the North Pacific) have large impacts on US precipitation and highlight the need to understand and simulate the IPO for decadal prediction of US precipitation.     

江西省“三农”服务专项建设现状与思考

通过对江西省24个"三农"服务专项建设实施地的"两个体系"建设情况开展实地调查,分析了江西省"三农"服务专项建设在提高气象为农服务现代化、促进气象工作政府化、惠民利民等三方面取得的成效,总结了各地的建设内容、成功经验、工作亮点和特色,梳理了存在的问题,并结合建设现状和有关要求,对今后江西省"三农"服务专项建设提出了六个方面的具体建议。     

Landau damping of longitudinal oscillation in ultra-relativistic plasmas by analytic function of nonextensive distribution

The analytic function of relativistic nonextensive distribution is given, and employed to solve the Landau damping of longitudinal oscillation in ultra-relativistic plasmas. The unified expression of Landau damping which reduces to the result in relativistic Maxwellian distributed plasmas in the extensive limit is obtained, and find that Landau damping is relevant to both the number and energy of resonant particles, which described by temperature and nonextensive parameters in relativistic nonextensive distribution.     

Records of the Moon‐forming impact and the 470 Ma disruption of the L chondrite parent body in the asteroid belt from U‐Pb apatite ages of Novato (L6)

Novato, a newly observed fall in the San Francisco Bay area, is a shocked and brecciated L6 ordinary chondrite containing dark and light lithologies. We have investigated the U‐Pb isotope systematics of coarse Cl‐apatite grains of metamorphic origin in Novato with a large geometry ion microprobe. The U‐Pb systematics of Novato apatite reveals an upper intercept age of 4472 ± 31 Ma and lower intercept age of 473 ± 38 Ma. The upper intercept age is within error identical to the U‐Pb apatite age of 4452 ± 21 Ma measured in the Chelyabinsk LL5 chondrite. This age is interpreted to reflect a massive collisional resetting event due to a large impact associated with the peak arrival time at the primordial asteroid belt of ejecta debris from the Moon‐forming giant impact on Earth. The lower intercept age is consistent with the most precisely dated Ar‐Ar ages of 470 ± 6 Ma of shocked L chondrites, and the fossil meteorites and extraterrestrial chromite relicts found in Ordovician limestones with an age of 467.3 ± 1.6 Ma in Sweden and China. The lower intercept age reflects a major disturbance related to the catastrophic disruption of the L chondrite parent body most likely associated with the Gefion asteroid family, which produced an initially intense meteorite bombardment of the Earth in Ordovician period and reset and degassed at least approximately 35% of the L chondrite falls today. We predict that the 470 Ma impact event is likely to be found on the Moon and Mars, if not Mercury.     

Tail Emission from a Ring-like Jet: Its Application to Shallow Decays of Early Afterglows and GRB 050709

Similar to the case of pulsars the magnetic axis and the spin axis of gamma-ray burst sources may not lie on the same line. This may cause the formation of a ring-like jet due to collimation of the processing magnetic axis. We analyze the tail emission from such a jet, and find that it has a shallow decay phase with a temporal index of -1/2 if the Lorentz factor of the ejecta is not very high, which is consistent with the shallow decay phase of some early X-ray afterglow detected by Swift. The ring-like jet has a tail cusp with sharp rising and very sharp decay. This effect can provide an explanation for the re-brightening and sharp decay of the X-ray afterglow of GRB 050709.     

Observations on the ovulating process of the red flagellated shrimpAcetes chinensis

Acetes chinensis always ovulate in the dark at night. Two to five hours before ovulation, the mature oocytes change from white to orange. In the meantime, meiosis of the oocytes occurs, and reaches the metaphase just prior to ovulation. If ovarian colour change starts in the dark at night but ovulation does not start by break of dawn, ovulation will be inhibited and meiosis of the cells will be blocked.