Climate simulations for 1880–2003 with GISS modelE     

J. Hansen  M. Sato  R. Ruedy  P. Kharecha  A. Lacis  R. Miller  L. Nazarenko  K. Lo  G. A. Schmidt  G. Russell  I. Aleinov  S. Bauer  E. Baum  B. Cairns  V. Canuto  M. Chandler  Y. Cheng  A. Cohen  A. Del Genio  G. Faluvegi  E. Fleming  A. Friend  T. Hall  C. Jackman  J. Jonas  M. Kelley  N. Y. Kiang  D. Koch  G. Labow  J. Lerner  S. Menon  T. Novakov  V. Oinas  Ja. Perlwitz  Ju. Perlwitz  D. Rind  A. Romanou  R. Schmunk  D. Shindell  P. Stone  S. Sun  D. Streets  N. Tausnev  D. Thresher  N. Unger  M. Yao  S. Zhang 《Climate Dynamics》2007,29(7-8):661-696

We carry out climate simulations for 1880–2003 with GISS modelE driven by ten measured or estimated climate forcings. An ensemble of climate model runs is carried out for each forcing acting individually and for all forcing mechanisms acting together. We compare side-by-side simulated climate change for each forcing, all forcings, observations, unforced variability among model ensemble members, and, if available, observed variability. Discrepancies between observations and simulations with all forcings are due to model deficiencies, inaccurate or incomplete forcings, and imperfect observations. Although there are notable discrepancies between model and observations, the fidelity is sufficient to encourage use of the model for simulations of future climate change. By using a fixed well-documented model and accurately defining the 1880–2003 forcings, we aim to provide a benchmark against which the effect of improvements in the model, climate forcings, and observations can be tested. Principal model deficiencies include unrealistically weak tropical El Nino-like variability and a poor distribution of sea ice, with too much sea ice in the Northern Hemisphere and too little in the Southern Hemisphere. Greatest uncertainties in the forcings are the temporal and spatial variations of anthropogenic aerosols and their indirect effects on clouds. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Variability of Surface Air Temperature in Italy 1870–1980     

T. Nanni  G. Lo Vecchio  S. Cecchini 《Theoretical and Applied Climatology》1998,59(3-4):231-235

Summary The trends and the fluctuations in variability of surface air temperature in Italy has been investigated by statistical analysis of historical data covering the recent 100 years. 27 stations were used for the analysis and these were distributed all over the Italian territory divided into two climatically homogeneous zones. The temperature trends are different in each climatic zone and season, while the interannual variability shows a similar seasonal dependence for the North and South of Italy. In particular, summer temperature shows a characteristic pattern with alternating minima and maxima reaching significant values in the period 1940–1970: a maximum for the North between 1940–1960 and a minimum for the South between 1960–1970. Received February 1, 1996 Revised June 7, 1997  相似文献   

On the determination of boundary-layer parameters using velocity profile as the sole information     

Aloysius K. Lo 《Boundary-Layer Meteorology》1979,17(4):465-484

This paper proposes a numerical technique based on the least-square error method for evaluating fluxes and other surface-layer parameters. The special feature of this method is that it requires no a-priori knowledge of either the temperature profile or the roughness length z ₀. The accuracy of the method has been tested on both the Kansas and the Wangara experimental data. Results obtained compared favourably with those from direct measurements as well as from other studies using conventional approaches.  相似文献   

Oil pollution along coastal areas of Hong Kong     

M.T. Cheung  T.Y. Cheng  S.W. Leung  C.C. Lo  L.M. Mak 《Marine pollution bulletin》1979,10(8):228-231

The level of total hydrocarbon in three chosen sites in Hong Kong was determined over a period of 8 months, September 1977 to April 1978. The range of hydrocarbon content is 3.67 ppb to 11.98 ppb. The level of hydrocarbon in Pacific Ocean is 0.016 ppb. The oil pollution in Hong Kong shoreline waters is 230–750 times higher than deep ocean water, but the level is not yet hazardous.  相似文献   

Stromboli and its 1975 eruption     

G. Capaldi  I. Guerra  A. Lo Bascio  G. Luongo  R. Pece  A. Rapolla  R. Scarpa  E. Del Pezzo  M. Martini  M. R. Ghiara  L. Lirer  R. Munno  L. La Volpe 《Bulletin of Volcanology》1978,41(3):259-285

On November 4, 1975 in the evening, an eruption took place at Mt. Stromboli. On the following day lava flowed on the Sciara del Fuoco downward to the sea, accompanied by an intense explosive activity at the crater plane. Direct observations on the volcanic activity were carried out since November 6 while a seismic survey was made from Nov. 7 to 12. The total volume of the lava outpoured during this period of activity that lasted 21 days, was estimated to be about 10⁴ m³. This paper reports the results of direct observations, and of the petrological, radioactive disequilibria and seismic activity studies performed for this eruption. The eruption was preceded by an insignificant change of seismic activity, which was monitored by a seismic station located about 2 km East of the crater. A shallow seismicity was strietly related to crater explosions accompanying the eruptive phenomenon. Radioactive disequilibria showed a lack of disequilibrium between²²⁸Ra and²³²Th explainable in terms of a fast rising of magma in the conduit. Chemical analyses of lava samples and deep seismic sounding data indicate a correspondence between the depth (10–15 km) at which crystallization pressure of phenocrysts occurs and a low velocity laver.  相似文献   

An analytical-empirical method for determining the roughness length and zero-plane displacement     

Aloysius K. Lo 《Boundary-Layer Meteorology》1977,12(2):141-151

A method based on the principle of the Method of Weighted Residuals for evaluating the roughness-length (z ₀) and zero-plane displacement (d) is presented. This method not only can minimize errors involved during the calculation process but can also smooth and re-distribute the already minimized error in a most favourable manner via using appropriate weighting functions. With the inclusion of d in addition to z ₀, formulae for wind and temperature profiles in the surface layer are presented by:% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4baFfea0dXde9vqpa0lb9% cq0dXdb9IqFHe9FjuP0-iq0dXdbba9pe0lb9hs0dXda91qaq-xfr-x% fj-hmeGabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWGvbGaeyypa0% ZaaSaaaeaacaWG1bWaaSbaaSqaaiaacQcaaeqaaaGcbaGaam4Aaaaa% daWadaqaaiGacYgacaGGUbWaaeWaaeaadaWcaaqaaiaadQhacqGHsi% slcaWGKbaabaGaamOEamaaBaaaleaacaaIWaaabeaaaaaakiaawIca% caGLPaaacqGHRaWkcqaHipqEaiaawUfacaGLDbaaaaa!43FC!\[U = \frac{{u_* }}{k}\left[ {\ln \left( {\frac{{z - d}}{{z_0 }}} \right) + \psi } \right]\]and% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4baFfea0dXde9vqpa0lb9% cq0dXdb9IqFHe9FjuP0-iq0dXdbba9pe0lb9hs0dXda91qaq-xfr-x% fj-hmeGabaqaciGacaGaaeqabaWaaeaaeaaakeaacqaH4oqCcqGHsi% slcqaH4oqCdaWgaaWcbaGaaGimaaqabaGccqGH9aqpcqaH4oqCdaWa% daqaaiGacYgacaGGUbWaaeWaaeaadaWcaaqaaiaadQhacqGHsislca% WGKbaabaGaamOEamaaBaaaleaacaaIWaaabeaaaaaakiaawIcacaGL% PaaacqGHRaWkcqaHipqEdaWgaaWcbaacbmGaa8hvaaqabaaakiaawU% facaGLDbaaaaa!485A!\[\theta - \theta _0 = \theta \left[ {\ln \left( {\frac{{z - d}}{{z_0 }}} \right) + \psi _T } \right]\]where and _T are the integrated diabetic influence functions' for velocity and temperature profiles respectively.Analytical expressions for both and _T as functions of wind shear or, implicitly in terms of the Richardson number have been derived.Presented at the 10th Annual Congress of the Canadian Meteorological Society, Quebec City, Canada, May 26–28, 1976.  相似文献   

西藏高原及其附近的流场结构和对流层大气的热量平衡   总被引：58，自引：16，他引：58  

叶笃正  罗四维  朱抱真 《气象学报》1957,28(2):108-121

本文利用1954—1956年的高空及地面记录,作出了平均流场,并计算了垂直速度、冷暖平流及辐射等,得出下面几点结论:1)冬季在1.5千米及3千米的西风,在高原西边有明显的分支,东边有明显的会合,且在东西两边各有一“死水区”(风速很小),在高原北面形成了高压脊,而在其南面形成了低槽,到了6千米除了二个“死水区”消失以外,其余基本上没有变化。2)夏季1.5千米及3千米在高原附近的流线,绕高原作气旋性旋转,而到了6千米则相反而呈反气旋性旋转,其中心在高原西南部分,且随高度增加而向西偏。3)夏季在高原上基本上是上升运动,可能达到9千米;冬季在高原上估计可能是下沉运动(除西南角有部分上升运动)。4)夏季可以肯定高原是一个热源,而冬季除了西南角有—部分是热源外,其他地区可能是一冷源。  相似文献   

Phreatic Surface in Island Aquifers with Regular Geometry and Time-Independent Recharge and Pumping     

Hugo A. Loáiciga 《Mathematical Geosciences》2008,40(2):199-211

The equation of groundwater flow in marine island aquifers in which there is time-independent, spatially-variable recharge and pumping is solved in closed form for rectangular, circular, and elliptical island geometries. The solution of the groundwater flow equation is expressed in terms of the elevation of the phreatic surface within the flow domain. The depth of the seawater-freshwater interface below mean sea level follows from the Dupuit–Ghyben–Herzberg relation. The method of solution presented in this work relies on expanding the hydraulic head and forcing function (recharge and groundwater extraction) as Fourier series that transforms the two-dimensional Poisson-type flow equations into second-order ordinary differential equations solvable using classical theory. The important case of constant recharge (without groundwater extraction) leads to solutions in which the hydraulic head is expressible as the product of a flow factor equal to the squared root of the ratio of recharge over hydraulic conductivity times a geometric factor involving island shape parameters and flow boundary conditions. Estimability conditions for the hydraulic conductivity are derived for the cases of constant recharge and spatially variable recharge with pumping.  相似文献   

The Late Pleistocene clastic deposits in the Romito Cave,southern Italy: a proxy record of environmental changes and human presence     

Massimiliano Ghinassi  Andrè C. Colonese  Zelia Di Giuseppe  Lisa Govoni  Domenico Lo Vetro  Giulia Malavasi  Fabio Martini  Silvia Ricciardi  Benedetto Sala 《第四纪科学杂志》2009,24(4):383-398

Clastic sediments deposited in caves and rock shelters bear peculiar sedimentological characteristics and have seldom been considered as a high‐resolution proxy record of climatic or environmental changes. The Romito Cave has its entrance at 275 m above sea level, about 25 km from the Tyrrhenian coast of Calabria, southern Italy. New archaeological excavation performed since 2000 has revealed a sedimentary succession spanning the record of Gravettian to Late Epigravettian cultures (Late Pleistocene). The present study focuses on the lower part (2.5 m thick) of the succession, where three main unconformity‐bounded stratigraphic units have been recognised (labelled RM1–3). Each unit consists of water‐lain deposits indicating high‐ to low‐competence flow, capped with anthropogenic deposits. The gradual deactivation and reactivation of the water drainage between 23 475 ± 190 and 16 250 ± 500 cal. a BP is correlated with regional precipitation changes due to the onset of dry climatic conditions of the Last Glacial Maximum. However, the deactivation of cave drainage after the deposition of unit RM3, around 15 400 ± 500 cal. a BP, deviates from the regional hydrological trend of progressively increasing water discharges and is attributed to the drainage cut‐off by probable cave wall collapses. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

中国低碳治理的制约因素和相应对策     

卢笛声 《地理科学》2014,34(3):265-271

作为全球碳排放大国,中国低碳治理的发展方向对全球气候变化有深远的影响,值得深入研究。通过中国低碳治理的制约因素及其成因的分析,提出地方政府行为是中国低碳治理的主要制约因素。这主要表现在地方政府鼓励不符合低碳发展的粗放式经济增长和城市开发及地方政府制定与执行低碳政策的积极性不高。而地方政府行为背后是各种制度环境因素。因此,改善中国低碳治理需要从制度改革入手。对制度改革提出3个建议：① 强化节能目标责任制;② 缓和地方政府过于强烈的发展意愿;③ 加强公民参与低碳治理。  相似文献