检索结果-南通市图书馆

Retrieving Soil Water Contents from Soil Temperature Measurements by Using Linear Regression

在线全文

学校读者我要写书评

暂无评论

引用

Advances in Atmospheric Sciences 2003年第6期20卷 849-858页

作者： Qin XU Binbin ZHOU NOAA NationalSevereStormsLaboratoryNormanOklahomaUSA NOAAJNWSflNationalCentersforEnvironmentalPrediction CampSpringsMarylandUSA

A simple linear regression method is developed to retrieve daily averaged soil water content from diurnal variations of soil temperature measured at three or more depths. The method is applied to Oklahoma Mesonet soil temperature data collected at the depths of 5, 10, and 30 cm during 11–20 June 1995. The retrieved bulk soil water contents are compared with direct measurements for one pair of nearly collocated Mesonet and ARM stations and also compared with the retrievals of a previous method at 14 enhanced Oklahoma Mesonet stations. The results show that the current method gives more persistent retrievals than the previous method. The method is also applied to Oklahoma Mesonet soil temperature data collected at the depths of 5, 25, 60, and 75 cm from the Norman site during 20–30 July 1998 and 1–31 July 2000. The retrieved soil water contents are verified by collocated soil water content measurements with rms differences smaller than the soil water observation error (0.05 m3 m−3). The retrievals are found to be moderately sensitive to random errors (±0.1 K) in the soil temperature observations and errors in the soil type specifications.

关键词： retrieval soil water content

Nonlinear Oscillations of Semigeostrophic Eady Waves in the Presence of Diffusivity

在线全文

学校读者我要写书评

暂无评论

引用

Advances in Atmospheric Sciences 2005年第1期22卷 49-57页

作者： QinXU WeiGU 高守亭 nationalseverestormslaboratory NormanOK73069 CooperativeInstituteforMesoscaleMeteorologicalStudies UniversityofOklahoma／ScienceApplicationsInternationalCorp.GlobalModelingandAssimilationOfficeNASAGoddardSpaceFlightCenterMD20771 InstituteofAtmosphericPhysics ChineseAcademyofSciencesBeifing100029

Analyses are performed to examine the physical processes involved innonlinear oscillations of Eady baroclinic waves obtained from viscous semigeostrophic models withtwo types of boundary conditions (free-slip and non-slip). By comparing with previous studies forthe case of the free-slip boundary condition, it is shown that the nonlinear oscillations areproduced mainly by the interaction between the baroclinic wave and zonal-mean state (totalzonal-mean flow velocity and buoyancy stratification) but the timescale of the nonlinearoscillations is largely controlled by the diffusivity. When the boundary condition is non-slip, thenonlinear oscillations are further damped and slowed by the diffusive process. Since the free-slip(non-slip) boundary condition is the zero drag (infinite drag) limit of the more realistic dragboundary condition, the nonlinear oscillations obtained with the two types of boundary conditionsare two extremes for more realistic nonlinear oscillations.

关键词： nonlinear oscillation semigeostrophic eady wave diffusivity

在线全文

学校读者我要写书评

暂无评论

海洋与干旱

引用

干旱气象 2004年第3期22卷 90-94页

作者： Martin Hoerling Arun Kumar 王涓力 ClimateDiagnosticsCenter NationalOceanicandAtmosphericAdministration(NOAA) ClimatePredictionCenter NOAA

在1998～2002年期间,发生在美国、欧洲南部以及亚洲西南部的干旱事件,都与海洋的影响有关。在此期间,热带东太平洋海表温度(SSTs)明显持续偏冷,而热带西太平洋及印度洋SSTs明显持续偏暖。气候模式表明由这些不同海域海温强迫的气候响应... 详细信息

在1998～2002年期间,发生在美国、欧洲南部以及亚洲西南部的干旱事件,都与海洋的影响有关。在此期间,热带东太平洋海表温度(SSTs)明显持续偏冷,而热带西太平洋及印度洋SSTs明显持续偏暖。气候模式表明由这些不同海域海温强迫的气候响应是相互作用的,对于中纬度地区广泛分布的、同步持续干旱,每一个海域都有所贡献。印度洋和西太平洋的增温是少见的,且这种增温与温室气体的强迫一致。本文也对未来的干旱趋势提出了一些看法。

关键词：海洋学干旱太平洋温室气体