全文获取类型
收费全文 | 78篇 |
免费 | 2篇 |
国内免费 | 7篇 |
专业分类
大气科学 | 39篇 |
地球物理 | 24篇 |
地质学 | 10篇 |
海洋学 | 11篇 |
天文学 | 1篇 |
自然地理 | 2篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 7篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 8篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1991年 | 2篇 |
排序方式: 共有87条查询结果,搜索用时 343 毫秒
1.
文中研究了耦合海-气环流模式中的双热带辐合带(Double ITCZ)现象,并对这一现象的成因从海洋热量收支的角度进行了初步分析。Double ITCZ现象是在热带太平洋赤道南北两侧各出现一条ITCZ的现象,这是耦合海-气环流模式中的较为普遍的一种异常现象,与实际气候中出现的Double ITCZ现象并非指同一问题。文中对比观测和模式结果,指出了Double ITCZ现象的主要特征,针对它的出现过程进行细致分析,再利用模式输出的热量收支各项进行统计,得到了从海洋热收支分析得到的海表温度变化原因。与观测到的正常模态相比,Double ITCZ是一个异常的模态,它的特征突出地表现为西太平洋暖池区的降温和东南太平洋10°S附近的升温。海洋热量收支分析表明,暖池区的降温主要是受到扩散的作用,而表层平流的异常增暖在决定异常辐合带区升温过程中占第一位的作用。 相似文献
2.
An experimental micrometeorological set-up was established at the CARBOEURO-FLUX site in Tharandt, Germany, to measure all relevant variables for the calculation of the vertical and horizontal advective fluxes of carbon dioxide. The set-up includes two auxiliary towers to measure horizontal and vertical CO2 and H2O gradients through the canopy, and to make ultrasonic wind measurements in the trunk space. In combination with the long-term flux tower an approximately even-sided prism with a typical side-length of 50 m was established. It is shown that under stable (nighttime) conditions the mean advective fluxes have magnitudes on the same order as the daily eddy covariance (EC) flux, which implies that they play a significant, but not yet fully understood, role in the carbon budget equation. The two advective fluxes are opposite and seem to cancel each other at night (at least for these measurements). During the day, vertical advection tends to zero, while horizontal advection is still present implying a flow of CO2 out of the control volume. From our measurements, a mean daily gain of 2.2 gC m–2 d–1 for the horizontal advection and a mean daily loss of 2.5 gC m–2d–1 for the vertical advection is calculated for a period of 20 days. However the large scatter of the advective fluxes has to be further investigated. It is not clear yet whether the large variability is natural or due to measurement errors and conceptual deficiencies of the experiment. Similar results are found in the few comparable studies. 相似文献
3.
4.
5.
再论水平和垂直分辨率之间的协调 总被引:5,自引:1,他引:5
在计算域面积为常数的约束下,给出了几种不同精度的平流方程和ω方程的“最优垂直网格距”,以及在极限情况下的“协调垂直网格距”的表达式。还讨论了在水平和垂直分辨率不协调时数值解对能量传播和计算稳定性的影响。 相似文献
6.
Several schemes for scalar advection on unstructured triangular grids are assessed for possible use in ocean modelling applications.
Finite element, finite volume and finite volume–element approaches are evaluated. A series of tests, including a numerical
order of convergence analysis, idealized rotating cone and cylinder experiments, and transport of a tracer through the Stommel
Gyre representation of ocean basin-scale circulation, are carried out. Volume element Eulerian–Lagrangian and third-order
Runge-Kutta discontinuous Galerkin schemes are recommended for use in tracer studies. Taylor–Galerkin and second-order Runge–Kutta
discontinuous Galerkin are found to be robust and accurate second-order schemes. When positivity is required, a fluctuation
redistribution scheme was found to be an easily implemented, accurate, and computationally efficient approach.
Responsible editor: Phil Dyke 相似文献
7.
James R. Christian 《Ocean Dynamics》2007,57(1):63-71
As ocean biogeochemical models evolve to permit the elemental composition of plankton populations and dissolved organic matter
to vary, each element is normally assigned a separate state variable, which is advected and mixed independently of the others.
In a population of cells with varying elemental quotas, the proper currency of the advection operator is subpopulations of
similar cells. The spatial gradient in total C, N, or P summed over the spectrum of such subpopulations is identical to that
calculated for the population means, so treating the various elements as independent should generally be a valid approximation.
However, errors can arise in high-order advection schemes with nonlinear corrector terms, which are not additive across the
subpopulations. Some numerical examples indicate that these errors are relatively small [O(10−3–10−4)] but can be as high as O(10−2) in certain cases. As grid resolution varies, the error scales approximately to the Courant number. 相似文献
8.
This note describes a numerically stable version of the improved Mellor–Yamada (M–Y) Level-3 model proposed by Nakanishi and Niino [Nakanishi, M. and Niino, H.: 2004, Boundary-Layer Meteorol. 112, 1–31] and demonstrates its application to a regional prediction of advection fog. In order to ensure the realizability for the improved M–Y Level-3 model and its numerical stability, restrictions are imposed on computing stability functions, on L/q, the temperature and water-content variances, and their covariance, where L is the master length scale and q
2/2 the turbulent kinetic energy per unit mass. The model with these restrictions predicts vertical profiles of mean quantities such as temperature that are in good agreement with those obtained from large-eddy simulation of a radiation fog. In a regional prediction, it also reasonably reproduces the satellite-observed horizontal distribution of an advection fog. 相似文献
9.
Unsteadiness as a cause of non-equality of eddy diffusivities for heat and vapour at the base of an advective inversion 总被引:8,自引:8,他引:0
This paper examines the effect of non-stationarity of the wind on similarity of the eddy diffusivities for heat and vapour within a stable layer at the bottom of an internal boundary layer formed downwind of a dry-to-wet transition. First, we present some experimental data taken above a rice crop downwind of very extensive dry range lands at Warrawidgee, NSW, Australia. These data establish that periods of higher wind speed were associated with periods of higher saturation deficit in the canopy of the rice crop, and lower Bowen ratio. It is shown that Bowen ratios calculated for 30-second sub-intervals varied three-fold within a single 20-minute averaging period. Thus periods of higher wind speed corresponded to periods of higher moisture flux and smaller sensible heat flux.An idealized situation is then analysed theoretically. It is assumed that the time scale of the slow variations of the wind is long compared with the surface-layer time scale and that fetch is sufficient that the air near the ground is in continuous equilibrium with the surface. Using a two-scale Reynolds decomposition of the fluctuating wind and scalar variables into active and inactive components, it is shown that unsteadiness can lead to an eddy diffusivity for saturation deficit, calculated as the ratio of average flux to average gradient, that is larger than that for total energy calculated in a similar way. Using this ratio to calculate the ratio of diffusivities for temperature and humidity, KT/Kq, it is found that the latter can be much larger than one if the Bowen ratio is small and negative. Despite this, assuming KT = Kq and using the Bowen ratio method to calculate surface energy fluxes will usually incur only minor errors. 相似文献
10.
A Spectrum-Independent Procedure for Correcting Eddy Fluxes Measured with Separated Sensors 总被引:1,自引:0,他引:1
We investigate flux underestimates in eddy correlation measurements that are caused by horizontal separation of the sensors. A common eddy correlation setup consists of a sonic anemometer and a humidity sensor which, because of its bulk, must be placed some distance away from the sonic path, leading to a flux loss (of latent heat). Utilizing an additional fast temperature sensor placed near the humidity sensor, we develop a procedure for correcting for this loss. The procedure simultaneously corrects the sensible heat flux for the difference between true temperature and sonic temperature. Our correction procedure, which does not depend on the shape of the cospectrum, is then compared to the widely-used procedure following Moore (1986), which assumes a cospectral model ('Kansas Model). Both correction methods are applied to data collected within the internal boundary layer over a rice paddy, downwind of arid land. Under conditions of good fetch, they were found to agree well. Under poor fetch conditions, the model-based correction tended to be too small, while the spectrum-independent combined correction was robust. The latter is thus recommended for situations where the cospectral shape can be expected to deviate from the 'Kansas shape. 相似文献