Analysis of ocean surface heat fluxes in a NOGAPS climate simulation: Influences from convection, clouds and dynamical processes
Analysis of ocean surface heat fluxes in a NOGAPS climate simulation: Influences from convection, clouds and dynamical processes
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NOGAPS 气候模拟中海洋表面热通量分析：对流、云和动力过程的影响
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
T. Hogan
中科院分区：
文献类型：
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作者：
D. Waliser;T. Hogan
本研究探讨了模拟质量的表面热通量场的气候模拟过程中产生的海军业务全球大气预报系统，版本3.4，减少光谱截断T63和18级（以下简称NOGAPS-CL）。比较17年的NOGAPS-CL模拟使用每月的海面温度作为表面边界条件和一些验证数据集组成的船舶，卫星，和/或再分析为基础的表面热通量，降水，顶部的大气辐射收支，水蒸气，云频率，表面风应力，对流层风。在这种扩展的，长期的整合，NOGAPS-CL低估了净表面短波通量在大部分的副热带海洋和高估了净短波通量在西太平洋暖池和中纬度海洋相比，几个卫星派生的气候数据集。此外，NOGAPS-CL预测的潜热通量在大部分的副热带地区，并根据预测的潜热通量在北方海洋西边界流和下的风暴轴区域，从他们向东延伸。这些短波和蒸发偏差联合收割机会在地表净热通量中产生误差，进入亚热带/热带海洋的热量太少，而中纬度海洋的热量损失太多。相关量的检查表明，热带气候偏差耦合到对流云和/或边界层参数化的缺点，导致过早释放的潮湿不稳定性的边界层的区域外的深对流区。在亚热带地区，这导致了气候学云量、降雨和地面蒸发的增强，以及地面短波通量和向外长波辐射（OLR）的减少。此外，由于湿静能的这种提前释放，在深对流区，云、降雨和水汽含量减少，地面短波通量和向外的长波辐射增加。降水的减少和OLR的增强降低了热带大尺度环流的强度，这反过来又降低了副热带地区下沉的强度，而下沉通常会抑制这些地区的对流过程。这些结果的影响进行了讨论的预测模式气候地面通量，对流，云，动力过程之间的关系，以及它们与其他气候模式的相似性和它们可能对瞬态系统的模拟的影响。
This study examines the simulation quality of the surface heat flux fields produced during a climate simulation of the Navy Operational Global Atmospheric Prediction System, version 3.4, with a reduced spectral truncation of T63 and 18 levels (herineafter referred to as NOGAPS-CL). Comparisons are made between a 17-year NOGAPS-CL simulation using monthly sea surface temperatures as surface boundary conditions and a number of validating data sets consisting of ship, satellite, and/or reanalysis-based surface heat fluxes, precipitation, top of the atmosphere radiation budget, water vapor, cloud frequency, surface wind stress, and tropospheric winds. In this extended, long-range integration, NOGAPS-CL underpredicts the net surface shortwave flux in much of the subtropical oceans and overpredicts the net shortwave flux in the western Pacific warm pool and the midlatitude oceans, when compared to several satellite-derived climatological data sets. In addition, NOGAPS-CL over predicts the latent heat flux in much of the subtropics and under predicts the latent heat flux over the northern ocean western boundary currents and under the storm track regions that extend eastward from them. These shortwave and evaporation biases combine to produce errors in the surface net heat flux, with too little heat entering the subtropical/tropical oceans and too much heat loss in the midlatitudes oceans. Examination of related quantities indicates that the tropical climate biases are coupled to shortcomings in the convective cloud and/or boundary layer parameterizations which leads to the premature release of moist instability from the boundary layer in regions just outside the deep convective zones. This leads to enhanced climatological cloudiness, rainfall, and surface evaporation, as well as to a reduction in the surface shortwave flux and outgoing longwave radiation (OLR), in the subtropical regions. Furthermore, because of this early release of the moist static energy, there is a reduction in clouds, rainfall and water vapor content, as well as enhanced surface shortwave flux and outgoing longwave radiation, in the deep convective zones. The reduction in rainfall and enhanced OLR reduces the strength of the tropical large-scale circulation, which in turn reduces the strength of the subsidence in the subtropical regions which normally acts to suppress the convection processes in these regions. The implications of these results are discussed in terms of the relationship among the forecast model climatological surface fluxes, convection, clouds, and the dynamical processes, as well as their similarities to other climate models and their possible impact on the simulation of transient systems.