2004/2005年连江县冬季沿坡地地面气温观测和分析研究

中亚热带地区种植南亚热带果树易遭冬季低温冻害, 而坡地逆温的最大增温效应往往比目前所采取的一些防冻措施的效应要好。研究坡地逆温特征、选择适宜的坡位种植果树对避免或减轻低温给果树造成的损失有重要的应用意义。据福建省连江县2004/2005年度冬季低温考察资料分析, 对于相对高差小于50 m的小山坡, 晴天最低气温随高度的增加而增加, 越近坡顶, 最低气温越高; 对于相对高差不足100 m的小山坡, 在相对高差约9/10附近的山坡中上部, 晴天最低气温常出现最高, 逆温效应最明显。汇总几个山坡地的考察资料, 分析得出坡地逆温具有以下两个特征:最大逆温出现的坡位与山坡的总高度差呈反相关; 最大的逆温强度与排汇比和山坡总高度差有关。     

2011年1月黔东南低温雨雪冰冻灾害对农业生产影响分析

利用黔东南州16县市2011年1月气象观测资料,通过与历年同期进行对比分析,得出了黔东南大部地区2011年1月平均气温为1961年以来的最小值,冰冻总日数仅次于2008年,为历年同期第2最多值。并根据黔东南冬种植作物气候适宜性指标,分析了此次冰冻灾害对农业生产的影响,得出以下结论：2011年1月低温雨雪冰冻灾害对大部分地区小麦、油菜、绿肥等的影响相对较小,但对早花早苔的油菜影响大;造成高海拔地区部分莴笋、莲花白、萝卜等蔬菜受灾较为严重,特别是肉质茎或根的莴笋和萝卜;茶叶一般种植在地势高的山坡上,在这次冰冻灾害中,茶叶叶片受损,可能影响首批春茶的上市时间;对特色作物太子参、枇杷、兔眼蓝浆果的影响较小;由于低温期间降雨阶段性明显,因此此次低温雨雪冰冻对黔东南州农业、林业生产造成的损失低于2008年。     

新疆阿勒泰地区冬季低温日数气候特征

利用1961～2012年新疆阿勒泰地区7站1月、2月和12月及冬季日最低气温低于-20℃的日数资料,采用线性回归、经验正交函数分解、Mann—Kendll突变检测、R／S分析等方法,对低温日数的时空变化进行了分析。结果表明：（1）冬季及各月的低温日数具有自东南向西北递减的空间分布特征,且1月出现的低温日数最多,12月出现的最少;（2）冬季低温日数的极值空间分布特征与平均值的一致。其中,年极大值出现的时间集中在1960年代中期至1970年代中期之间,年份差异较大,而年极小值均一致的出现在2006年;（3）各站冬季平均低温日数在近51a内的倾向率为-1．71--4．24d／10a,呈减少趋势,而各月的倾向率（吉木乃站1月除外）同冬季的一致,均为负值,但变化率均小于冬季的;（4）第1特征向量场的分布显示,冬季低温日数在空间上具有较好的一致性,高值区位于阿勒泰市、哈巴河县等高发区,中心值为0．455;（5）西部的哈巴河、吉木乃和布尔津3县及中部的阿勒泰市,均没有发生突变,而南部的福海和东部的富蕴和青河2县均在1980年代有下降趋势的突变发生;（6）各站红季及各月的低温日数的R／S分析的H指数显示,未来的趋势与过去一致,仍呈减少趋势。     

湖北省2008年1月11日至2月3日低温雨雪冰冻天气雪情与灾情

2008年1月11日至2月3日,湖北省出现了一次自1954／1955年以来50年一遇的严重冬季低温、雨雪、冰冻极端气象灾害,期间共出现4次（1月11～15日、18～22日、25～28日、1月30日至2月1日）低温雨雪天气过程。由于雨雪过程频繁、强度大,低温冰冻持续时间长,积雪冰冻范围广,对农业、交通、电力、通讯等行业以及城乡居民的日常生活造成了严重影响。     

安图县的低温冷害发生特点及其防御

安图县位于东北亚北纬43°，属于中温带季风气候区域。由于地处长白山脉腹地的东北坡，大部分耕地分布在海拔500M左右的山坡或山谷之中，气温的垂直梯度大≥10℃活动积温不足2500℃，是农业热量条件最差的县份之一。县内东部主要产粮区域（明月镇地区）由于经常受北日本海回流天气系统的影响，气温的年际变化十分剧烈，夏季频繁发生农作物的低温冷害，导致粮食产量极不稳定。对于气温条件十分敏感的水稻而言，在高温年份，亩产可达700多斤，遇到典型的低温冷害年份，则亩产降到200来斤，年际亩产差异达三倍以上。不难看出，安图县粮食产量…     

低温、干旱胁迫对抽雄期玉米叶片光化效率和光合作用速率的影响

在人工模拟低温、干旱条件下，测定了抽雄期玉米叶片荧光参数（Fo、Fm、Fv／Fm）及光合作用速率。其结果表明：低温、干旱均使光化效率（Fv／Fm）、光合作用速率下降，光化效率与温度的关系：Y=0．002X^2-0．0055X＋0．8032（式中Y为光化效率，X为温度）。低温使光合作用速率下降，温度由25℃降到15℃，光合速率可下降27．8％。土壤湿度由处理5降到处理1，在不同温度下光化效率可降低1％～8％；光合作用速率最大减幅达80％左右。低温、干旱并发对光化效率和光合作用速率的负效应加大，光化效率降幅增大2．5倍，光合作用速率增大15％左右。光化效率与光合作用速率两者呈显著正相关。     

西峡县设置地面燃烧炉的可行性及放置位置研究

根据西峡县1971-2000年的降水资料,12月一次年2月的月平均降水量不足20 mm.降水量偏少,为山区火灾埋下隐患.因此,利用地面燃烧炉实施人工增雨(雪)作业,可抑制森林火灾.西峡县冬季有降水时,桦树盘西南山坡盛行南一西南风,气流在耍荷关开始被山坡抬升,因此桦树盘海拔1424.89 m山顶处放置燃烧炉,沿山坡的上升气流可把碘化银烟粒送至云中-4℃以上高度,实现催化增雨(雪)目的.     

宁夏高、低温天气及环流特征的初步分析

通过宁夏24个测站1960—2000年逐日最高、最低气温资料，对宁夏40年来高、低温天气的时空变化特征进行了分析；并利用NCEP／NCAR(1979—1999年)资料对宁夏高、低温天气典型偏多、少年的大气环流异常特征进行了诊断分析。结果表明：宁夏高、低温天气偏多、少年间极涡的强度及位置和大陆高压、副热带高压的强度和位置具有明显差异，同时，高、低温天气偏多、少年份中，温度场也有相反的分布。     

连翘适宜气候条件与高产栽培技术

连翘又名落壳连翘,青翘,为木樨科落叶灌木,是我国传统常用名贵中药材,也是商洛“地道中药材”,以果实入药,被称为“疮家圣药”,具有清热解毒、消肿散结、抗菌、抗炎、解热、镇吐、利尿强心、抗肝损、镇痛、抗内毒素、抗病毒、降血压等功效。连翘是喜温凉,能耐寒、旱,耐脊薄的植物,适应性较强,分布在海拔800-2000m的半阴山坡或向阳山坡的疏灌木丛中,对土质要求不严,富含腐殖质的沙质壤土对生长有利,进入盛果期年产果实4500～6000kg／hm^2,收入可达2．2～3．0万元／hm^2。     

近50年福建省年度极端最低气温统计特征

把福建省各台站年度极端最低气温统一订正为1950／1951～1999／2000整50年记录,并对其进行标准化处理和评价,继而对其偏冷年景进行特征分析。近50年福建省年度极端最低气温1954／1955为最冷年,1999／2000为第3冷年;冬季月平均气温正常,仍可出现异常或明显偏冷的低温;全省年度极端最低气温年景评价为异常偏冷,有的台站年景却仍属正常,年景等级相差达4级。全省年度极端最低气温的年景评价为异常或明显偏低,该年度福建省果树、花卉和其它冬季作物必然遭受不同程度的冻害和寒害。     

Forest ecosystems, disturbance, and climatic change in Washington State, USA

Climatic change is likely to affect Pacific Northwest (PNW) forests in several important ways. In this paper, we address the role of climate in four forest ecosystem processes and project the effects of future climatic change on these processes across Washington State. First, we relate Douglas-fir growth to climatic limitation and suggest that where Douglas-fir is currently water-limited, growth is likely to decline due to increased summer water deficit. Second, we use existing analyses of climatic controls on tree species biogeography to demonstrate that by the mid twenty-first century, climate will be less suitable for key species in some areas of Washington. Third, we examine the relationships between climate and the area burned by fire and project climatically driven regional and sub-regional increases in area burned. Fourth, we suggest that climatic change influences mountain pine beetle (MPB) outbreaks by increasing host-tree vulnerability and by shifting the region of climate suitability upward in elevation. The increased rates of disturbance by fire and mountain pine beetle are likely to be more significant agents of changes in forests in the twenty-first century than species turnover or declines in productivity, suggesting that understanding future disturbance regimes is critical for successful adaptation to climate change.     

Modern climate-related changes in heat supply,moistening, and productivity of the agrosphere in Russia

Climate changes observed in recent decades are analyzed, and the respective climate-related tendencies of changes in heat supply, moistening, and productivity of the agrosphere that determine the natural resourse of potential Russia are determined. The grain crop yield trends are used additionally as climate change indicators. It is shown that climate changes observed in the last 30 years promote the increase in potential agriculture productivity in most of the Russian Federation, where not less than 85% of agricultural products are produced. At the same time, the increase in climate aridity is observed in several regions of Siberia and Chernozem Center, which results in a reduced productivity of agriculture.     

WRF模式对江苏如东地区风速预报的检验分析

探讨了WRF模式在风电场的风速或者功率预报中应用的可行性, 主要研究和评估了WRF模式对地处东亚季风区及海陆交界的江苏如东地区夏季和冬季风速的短期预报效能。研究发现WRF模式可以比较好地预报如东站冬季的风速, 24 h预报的风速时间序列和观测资料的相关系数可以达到0.61, 通过置信度99%的检验, 48 h和72 h的预报与观测风速相关系数分别为0.54和0.47, 也能通过置信度99%的检验;相对而言, 模式对夏季风速的预报则要差一些, 24 h的相关系数有0.59, 48 h和72 h的相关系数只有0.47和0.30, 但仍能通过置信度99%的检验。在量值上, 模式预报的风速比观测值都略偏大一些。而江苏南通市预报结果显示, 模式的预报效能要比如东稍高一些, 和如东类似, 模式对该地冬季的预报要好于对夏季风速的预报。从更大尺度范围的分析也表明, 模式对不同地区预报的准确度是不一样的, 对海面以及海陆交界的海岸预报精度要高一些, 在平坦的内陆地区预报也比较好, 但在山区预报效能则较差。总体说来, WRF能胜任风速短期预报, 值得进一步研究和应用。     

Climate change,migration and adaptation in Funafuti,Tuvalu

This paper shows the extent to which people in Funafuti – the main island of Tuvalu – are intending to migrate in response to climate change. It presents evidence collected from Funafuti to challenge the widely held assumption that climate change is, will, or should result in large-scale migration from Tuvalu. It shows that for most people climate change is not a reason for concern, let alone a reason to migrate, and that would-be migrants do not cite climate change as a reason to leave. People in Funafuti wish to remain living in Funafuti for reasons of lifestyle, culture and identity. Concerns about the impacts of climate change are not currently a significant driver of migration from Funafuti, and do not appear to be a significant influence on those who intend to migrate in the future.     

云南西双版纳地区闪电活动特征

应用2017—2018年云南省VLF/LF三维闪电定位数据和1987—2006年云南省人工雷暴日观测数据,运用数理统计、空间插值等方法分析"雷都"西双版纳闪电活动的时空分布特征,运用网格法将闪电定位数据转化为网格雷电活动日,研究人工观测雷暴日与闪电定位监测资料的相关性。结果表明:西双版纳地区雷电活动从3月就开始逐渐增多,峰值出现在7—8月。就闪电频次而言,云闪少于地闪、正闪少于负闪,正地闪明显多于云南省其他地区。11月闪电强度较大,但频次较少;7月闪电频次较多,但强度较小。云闪多发生在8 km以下,平均高度为4.914 km。地闪和云闪密度分布一致,北部高而南部和东西部低;云闪的强度明显高于地闪,但在空间分布上均是北部弱而南部和东西部强。人工观测雷暴日与网格雷电活动日的逐月分布特征较一致。研究还表明:西双版纳在云南省范围内是人工观测雷暴日最多区域,也是网格雷电活动日最多区域。     

Local advection of momentum,heat, and moisture in micrometeorology

The local advection of momentum, heat and moisture in micrometeorology due to a horizontal inhomogeneity in surface conditions is numerically investigated by a higher-order turbulence closure model which includes equations for the mean quantities, turbulent fluxes, and the viscous dissipation rate. The application of the two-dimensional model in this paper deals with the simulation of the flow from an extensive smooth dry area to a grassy wet terrain. The mean wind speed, temperature, and humidity distributions in the resulting internal boundary layer downstream of the surface discontinuity are determined such that the energy and moisture balances at the Earth's surface are satisfied.Numerical calculations of the mean temperature and humidity profiles are compared with available observed ones. The results include the advective effects on turbulent flux distributions, surface energy balance, evaporation rate, and Bowen ratio. The sensitivity of the predicted mean profiles and turbulent flux distributions to the surface relative humidity, thermal stratification, and the roughness change is discussed.NRC-NAS Resident Research Associate at AFCRL.     

Trends in Extremes of Surface Humidity, Temperature, and Summertime Heat Stress in China

l. IntroductionPrevious studies have shown climatological and seasonal surface temperature and humld-ity dlstributlons over China (Wang and Gaffen, 200l ) and evaluated trends in seasonal meansof several surface humidity variables, rainfall, temperatures, and apparent temPerature for thelast half century (Easterling et al., 2000, Zhai et al., 1999, Zhai and Eskridge, l997, Zhai andRen, l997, Wang and Gaffen, 200l). However, trends in local temperatures, and particularlytrends in extreme he…     

Wind-driven, double-gyre, ocean circulation in a reduced-gravity, 2.5-layer, lattice boltzmann model

A coupled lattice Boltzmann （LB） model with second-order accuracy is applied to the reduced-gravity, shallow water, 2.5-layer model for wind-driven double-gyre ocean circulation. By introducing the secondorder integral approximation for the collision operator, the model becomes fully explicit. The Coriolis force and other external forces are included in the model with second-order accuracy, which is consistent with the discretization accuracy of the LB equation. The feature of the multiple equilibria solutions is found in the numerical experiments under different Reynolds numbers based on this LB scheme. With the Reynolds number increasing from 3000 to 4000, the solution of this model is destabilized from the anti-symmetric double-gyre solution to the subtropic gyre solution and then to the subpolar gyre solution. The transitions between these equilibria states are also found in some parameter ranges. The time-dependent variability of the circulation based on this LB simulation is also discussed for varying viscosity regimes. The flow of this model exhibits oscillations with different timescales varying from subannual to interannual. The corresponding statistical oscillation modes are obtained by spectral analysis. By analyzing the spatiotemporal structures of these modes, it is found that the subannual oscillation with a 9-month period originates from the barotropic Rossby basin mode, and the interarmual oscillations with periods ranging from 1.5 years to 4.6 years originate from the recirculation gyre modes, which include the barotropic and the baroclinic recirculation gyre modes.     

2009年天津城区空气负离子变化规律

空气负离子成为空气清洁度的重要评价指标。利用2009年天津城区空气负离子观测数据,研究天津城区空气负离子的时空变化规律。结果表明：天津城区空气负离子月变化浓度呈双峰型分布,主峰值出现在9月,次峰值出现在5月,7月份负离子浓度最低;四个季节中负离子的日变化特征存在明显差异;天津市和大连市两个沿海城市的负离子浓度范围相差不大,最低值均出现在7月份,但二者月变化规律趋势不同。     

Population, uncertainty, and learning in climate change decision analysis

The prospect of learning about various uncertainties relevant to analyses of the climate change issue is important because it can affect estimates of the costs of both damages and mitigation, and it can influence the optimal timing of emissions reductions. Baseline scenarios representing future emissions in the absence of mitigation are one of the major sources of uncertainty. Here we investigate how fast we might realistically expect to learn about the outlook for long-term population growth, as one determinant of future baseline emissions. That is, we estimate how long it might take to substantially revise current estimates of the likelihood of various population size outcomes over the twenty-first century. We draw on recent work showing that, because population growth is path dependent, we can learn about the long term outlook by waiting to observe how population changes in the short term. We then explore the implications of uncertainty and of this learning potential for mitigation costs and for optimal emissions. Using a simple model, we show that uncertainty in population growth translates into an uncertainty in the optimal tax rate of about $200/tC by 2050 for a range of stabilization levels. When learning is taken into account, it allows for mitigation strategies to change in response to new information, leading to a slight reduction in the expected value of mitigation costs, and a substantial reduction in the likelihood of high cost outcomes. We also find that while learning can lead to large revisions over the next few decades in anticipated population growth, this potential does not imply large changes in near-term optimal emissions reductions. Results suggest that further work on the potential for learning about other determinants of emissions could have larger effects on expected mitigation costs.