共查询到10条相似文献，搜索用时 109 毫秒
1.
Seasonal evolution of surface mixed layer in the Northern Arabian Sea (NAS) between 17° N–20.5° N and 59° E-69° E was observed
by using Argo float daily data for about 9 months, from April 2002 through December 2002. Results showed that during April
- May mixed layer shoaled due to light winds, clear sky and intense solar insolation. Sea surface temperature (SST) rose by
2.3 °C and ocean gained an average of 99.8 Wm−2. Mixed layer reached maximum depth of about 71 m during June - September owing to strong winds and cloudy skies. Ocean gained
abnormally low ∼18 Wm−2 and SST dropped by 3.4 °C. During the inter monsoon period, October, mixed layer shoaled and maintained a depth of 20 to
30 m. November - December was accompanied by moderate winds, dropping of SST by 1.5 °C and ocean lost an average of 52.5 Wm−2. Mixed layer deepened gradually reaching a maximum of 62 m in December. Analysis of surface fluxes and winds suggested that
winds and fluxes are the dominating factors causing deepening of mixed layer during summer and winter monsoon periods respectively.
Relatively high correlation between MLD, net heat flux and wind speed revealed that short term variability of MLD coincided
well with short term variability of surface forcing. 相似文献
2.
Evaluation of the Diurnal Warming of Sea Surface Temperature Using Satellite-Derived Marine Meteorological Data 总被引：2，自引：0，他引：2
In order to produce a high-quality sea surface temperature (SST) data set, the daily amplitude of SST (ΔSST) should be accurately
known. The purpose of this study was to evaluate the diurnal variation of sea surface temperature in a simple manner. The
authors first simulated ΔSST with a one-dimensional numerical model using buoy-observed meteorological data and satellite-derived
solar radiation data. When insolation is strong, the model-simulated 1-m-depth ΔSST becomes much smaller than the in situ
value as wind speed decreases. By forcibly mixing the sea surface layer, the model ΔSST becomes closer to the in situ value.
It can be considered that part of this difference is due to the turbulence induced by the buoy hull. Then, on the assumption
that the model results were reliable, the authors derived a regression equation to evaluate ΔSST at the skin and 1-m depth
from daily mean wind speed (U) and daily peak solar radiation (PS). ΔSST is approximately proportional to In(U) and (PS)2, and the skin ΔSST estimated by the equation is not inconsistent with in situ observation results reported in past studies.
The authors prepared maps of PS and U using only satellite data, and demonstrated the ΔSST evaluation over a wide area. The result showed that some wide patchy
areas where the skin ΔSST exceeds 3.0 K can appear in the tropics and the mid-latitudes in summer.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
热带印度洋SST的日变化幅度受到大气季节内振荡(Madden-Julian Oscillation,MJO)的调制,其在MJO对流最强(弱)位相达到极小(大)值,并且在MJO对流增强位相显著强于其对流减弱位相。本文利用逐时的再分析海表通量强迫一维海洋混合层模式,定量地诊断了MJO事件中SST日变化的差异成因。结果表明,SST日变化在MJO对流最强与最弱位相的显著差异主要是由短波辐射的季节内变化所致(40%),其次是风应力(38%)和潜热通量(14%),其他要素的影响较小。而SST日变化在MJO对流增强与减弱位相所呈现的不对称特征,主要是由纬向风应力的不对称性所致,这是MJO扰动结构与背景环流相互作用的结果。 相似文献
4.
大气模式中季节内振荡特征对不同海温强迫场的响应 总被引：2，自引：0，他引：2
利用美国国家大气研究中心 (NCAR)的全球大气模式 (CCM3) ,分别以月平均和周平均海表温度 (SST)为强迫场进行 2个积分试验 (称为 CCMM和 CCMW试验 )。积分结果与观测资料的对比分析发现 ,CCM3模拟大气季节内振荡 (MJO)信号的强度均较观测资料偏弱 ,而其中以CCMW模拟的强度略大而较接近真实。表明 SST强迫场包含更真实的季节内变化信息对提高模拟 MJO强度有作用。 CCMM与 CCMW模拟 MJO活动的时间位相均与观测差别较大 ,直接原因在于 CCM3中降水季节内振荡与 SST变化的相关关系不正确 ,而更根本的问题在于大气模式无法反映资料分析发现的季节内时间尺度的 SST与大气的相互作用。 相似文献
5.
The paper shows that, by virtue of the specific water circulation in the south-eastern Indian Ocean, thermal influx within
the 0–200 m layer exceeds the efflux by 13.5×1015 MJ per year, which, being recalculated for the entire area, is equivalent to about 2200 MJ m−2. Computations of the heat fluxes through the sea surface in that part of the ocean indicate that thermal efflux to the atmosphere
is larger than the influx of solar heat by about 1500 (on average, for the entire area), rather than by 2200 MJ m−2 per year. Hence, about 700 MJm−2 penetrate through the lower boundary of the layer and warm up the deeper ocean layers.
Translated by Vladimir A. Puchkin. 相似文献
6.
基于一个一维湍能海洋混合层模式,发展了一个易于与大气或海洋模式耦合的,可应用于水平二维空间的模块化海洋混合层模式。并加入垂直上翻参数化方案,引入日平均海面温度及气候态松弛项,进行二维海洋模拟理想气旋实验和飓风实例模拟实验。理想气旋强迫实验表明,垂直上翻过程的参数化方案可有效地弥补原有一维海洋混合层模式无法形成气旋中心动力上翻的不足,消除了虚假暖水核心。卡特里娜飓风个例实验的结果表明,加入垂直上翻后,飓风中心附近的海表面温度误差明显减小。海洋混合层模式对海洋表面温度日变化模拟能力在二维应用中依然表现良好。经过上述改进,发展的海洋混合层模式可以较为真实地模拟平常海表温度高频日变化的同时,还对剧烈天气过程也有一定的模拟能力,具有广泛的应用前景。 相似文献
7.
How the role of vertical turbulent mixing (VTM) in sea surface cooling (SSC) varies with the moving speed of a tropical cyclone
was examined for Typhoon Rex (1998) by using the Meteorological Research Institute Community Ocean Model (MRI.COM). The MRI.COM
well reproduced TRMM/TMI three-day mean sea surface temperature (SST) fields along Rex’s track. During the fast-moving phase
of Rex, SSC simulated by the MRI.COM was caused by shear-induced VTM on the right side of the track. During the slowly-moving
phase, on the other hand, the Ekman-pumping area mostly overlapped the VTM area right behind Rex’s center. During the recurvature
phase, cool water transported by the upwelling was more efficiently entrained into a mixed layer by the VTM for nearly a 1
near-inertial period after the passage of Rex. We then modified the entrainment formulation of Deardorff (1983), which was
incorporated into a slab mixed-layer ocean model (SOM) so as to fit to the results simulated by the MRI.COM. The principal
modifications are as follows: (1) consideration of turbulent kinetic energy (TKE) production caused by surface wave breaking;
(2) increase in the coefficient for estimating dissipation to balance with TKE production due to turbulent transport; and
(3) changing the initial guess for the critical Richardson number. These modifications led to an improvement of SST simulations
by the SOM. The impact of the modifications on simulated SSTs turned out to be more significant than the impacts of initial
mixed-layer depth and the difference between diurnally-varying and daily mean short-wave radiation. 相似文献
8.
In order to examine temporal variations of the surface oceanic and atmospheric fCO2 and the DIC concentration, we analyzed air and seawater samples collected during the period May 1992–June 1996 in the northwestern
North Pacific, about 30 km off the coast of the main island of Japan. The atmospheric CO2 concentration has increased secularly at a rate of 1.9 ppmv yr−1, and it showed a clear seasonal cycle with a maximum in spring and a minimum late in summer, produced mainly by seasonally-dependent
terrestrial biospheric activities. DIC also showed a prominent seasonal cycle in the surface ocean; the minimum and maximum
values of the cycle appeared in early fall and in early spring, respectively, due primarily to the seasonally-dependent activities
of marine biota and partly to the vertical mixing of seawater and the coastal upwelling. The oceanic fCO2 values were almost always lower than those of the atmospheric fCO2, suggesting that this area of the ocean acts as a sink for atmospheric CO2. Values varied seasonally, mainly reflecting seasonal changes of SST and DIC, with a secular increase at a rate of 3.7 μatm
yr−1. The average values of the annual net CO2 flux between the ocean and the atmosphere calculated by using the different bulk equations ranged between −0.8 and −1.7 mol
m−2yr−1, and its magnitude was enhanced and reduced late in spring and mid-summer, respectively, due mainly to the seasonally varying
oceanic fCO2. 相似文献
9.
Using the air-sea data set of January, 1983 (the mature phase of the 1982/83 El Nino event), the net radiation on the sea surface, the fluxes of the latent and the sensible heat from ocean to the atmosphere and the net heat gain of the sea surface are calculated over the Indian and the Pacific Oceans for the domain of 35°N-35°S and 45°E-75°W. The results indicate that the upward transfer of the latent and the sensible heat fluxes over the winter hemisphere is larger than that over the summer hemisphere. The sensible heat over the tropical mid Pacific in the Southern Hemisphere is transported from the atmosphere to the ocean, though its magnitude is rather small. The latent heat flux gained by the air over the eastern Pacific is less than the mean value of the normal year. The net radiation, on which the cloud amount has considerable impact, is essentially zonally distributed. Moreover, the sea surface temperature (SST) has a very good correlation with the net radiation, the region of warm SST coinci 相似文献
10.
使用美国夏威夷大学发展的中等复杂程度海洋模式(IOM)在给定表面强迫条件下模拟了热带大西洋上层海洋年际和年代际变率的时空结构.利用NCEP的41a(1958～1998年)逐月平均表面资料作为强迫场,积分海洋模式41a作为控制试验,并利用模式分别做动量(风应力)通量和热量通量无异常变化的平行试验,与控制试验作比较.对3组试验模拟上层海洋变率状况的比较,并按年际和年代际时间尺度分别分析,揭示表面风应力和热通量异常对海表面温度和温跃层深度变化的影响,并比较了其影响的相对重要性.结果表明模式成功地模拟出了热带大西洋上层海洋的变率.模式模拟的海表面温度年际变化主要表现为弱ENSO型,年代际变化表现为南、北大西洋变化相反的偶极子型.在年际时间尺度上,热力强迫和动力强迫对海表温度变化都有贡献,其中赤道外海表面温度异常(SSTA)变化主要由热通量异常引起,而近赤道SSTA的变化主要由动量异常强迫引起.在年代际时间尺度上,热通量强迫的作用远比动量强迫重要.模式不仅能够模拟SST在年际和年代际时间尺度上的变率,还能够模拟温跃层深度在年际和年代际时间尺度上的变率.年际和年代际时间尺度上,温跃层深度的变率主要由动量异常决定,热通量异常强迫的贡献很小. 相似文献