The improvement of the one-dimensional Mellor-Yamada and K-profile parameterization turbulence schemes with the non-breaking surface wave-induced vertical mixing

Both the level 2.5 Mellor-Yamada turbulence closure scheme （MY） and K-profile parameterization （KPP） are popularly used by the ocean modeling community. The MY and the KPP are improved through including the non-breaking surface wave-induced vertical mixing （Bv）, and the improved schemes were tested by using continuous data at the Papa ocean weather station （OWS） during 1961-1965. The numerical results showed that the Bv can make the temperature simulations fit much better with the continuous data from Papa Sta- tion. The two improved schemes overcame the shortcomings of predicting too shallow upper mixed layer depth and consequently overheated sea surface temperature during summertime, which are in fact com- mon problems for all turbulence closure models. Statistical analysis showed that the Bv effectively reduced the mean absolute error and root mean square error of the upper layer temperature and increased the corre- lation coefficient between simulation and the observation. Furthermore, the performance of vertical mixing induced by shear instability and the Bv is also compared. Both the temperature structure and its seasonal cycle significantly improved by including the Bv, regardless of whether shear instability was included or not, especially for the KPP mixing scheme, which suggested that Bv played a dominant role in the upper ocean where the mean current was relatively weak, such as at Papa Station. These results may provide a clue to improve ocean circulation models.

Exact solution and approximate solution of irregular wave radiation stress for non-breaking wave

Wave radiation stress is the main driving force of wave-induced near-shore currents. It is directly related to the hydrodynamic characteristics of near-shore current whether the calculation of wave radiation stress is accurate or not. Irregular waves are more capable of reacting wave motion in the ocean compared to regular waves. Therefore,the calculation of the radiation stress under irregular waves will be more able to reflect the wave driving force in the actual near-shore current. Exact solution and approximate solution of the irregular wave radiation stress are derived in this paper and the two kinds of calculation methods are compared. On the basis of this,the experimental results are used to further verify the calculation of wave energy in the approximate calculation method. The results show that the approximate calculation method of irregular wave radiation stress has a good accuracy under the condition of narrow-band spectrum,which can save a lot of computing time,and thus improve the efficiency of calculation. However,the exact calculation method can more accurately reflect the fluctuation of radiation stress at each moment and each location.

全程无缝隙护理在儿童阻塞性睡眠呼吸暂停低通气综合征手术室护理中的应用观察

目的探讨全程无缝隙护理在儿童阻塞性睡眠呼吸暂停低通气综合征(OSAHS)手术室护理中的应用效果。方法将2017年6月~2019年3月湛江中心人民医院收治的80例OSAHS患儿随机分为观察组和对照组。观察组采用手术室全程无缝隙护理,对照组采用传统护理。统计对比两组焦虑程度、疼痛程度和躁动发生情况。结果观察组入手术室前和术后24h的焦虑评分明显低于对照组(P<0.05)。观察组术后6h和术后24h的疼痛程度明显轻于对照组(P<0.05)。观察组躁动总发生率明显低于对照组(P<0.05)。结论手术室全程无缝隙护理可降低OSAHS患儿的焦虑和疼痛程度,同时可减少术后躁动的发生率。

全程无缝隙护理模式在手术室优质护理服务中的应用效果

目的:探讨全程无缝隙护理模式在手术室优质护理服务中的应用效果。方法:收治接受手术治疗患者70例,均分为护理组和对照组,采用不同护理方法,对比各自疗效情况。结果:对照组护理后SAS 36.3分,SDS 37.9分;护理组护理后SAS 29.6分,SDS 30.3分。对比发现心理状态护理组在护理后明显优于对照组,差异具有统计学意义(P<0.01)。结论:全程无缝隙护理是一种有效改善手术患者心理状态的优质服务模式。

A comparison of two global ocean-ice coupled models with different horizontal resolutions

A global eddy-permitting ocean-ice coupled model with a horizontal resolution of 0.25° by 0.25° is estab- lished on the basis of Modular Ocean Model version 4 （MOM4） and Sea Ice Simulator （SIS）. Simulation results are compared with those of an intermediate resolution ocean-ice coupled model with a horizontal resolution of about 1° by 1°. The results show that the simulated ocean temperature, ocean current and sea ice concentration from the eddy-permitting model are better than those from the intermediate resolu- tion model. However, both the two models have the common problem of ocean general circulation models （OGCMs） that the majority of the simulated summer sea surface temperature （SST） is too warm while the majority of the simulated subsurface summer temperature is too cold. Further numerical experiments show that this problem can be alleviated by incorporating the non-breaking surface wave-induced vertical mixing into the vertical mixing scheme for both eddy-permitting and intermediate resolution models.

Can Langmuir Circulations Solve the Problem of Insufficient Upper-Ocean Mixing?

Insufficient vertical mixing in the upper ocean during summer is a common problem of oceanic circulation and climate models.The turbulence associated with non-breaking waves is widely believed to effectively solve this problem.In many studies,non-breaking surface wave processes are attributed to the effects of Langmuir circulations(LCs).In the present work,the influences of LCs on the upper-ocean thermal structure are examined by using one-and three-dimensional ocean circulation,as well as climate,models.The results indicated that the effect of vertical mixing enhanced by LCs is limited to the upper ocean.The models evaluated,including those considering LC effects alone and the combined effects of LCs and wave breaking,failed to produce a reasonable summertime thermocline,resulting in a large cold bias in the subsurface layer.Therefore,while they can slightly reduce the biases of mixed layer depths and sea surface temperatures in models,LCs are insufficient to solve the problem of insufficient vertical mixing.Moreover,restriction of non-breaking surface wave-induced processes in LCs may be questionable.

Theoretical analysis and experimental study of oxygen transfer under regular and non-breaking waves

The dissolved oxygen concentration is an important index of water quality, and the atmosphere is one of the important sources of the dissolved oxygen. In this paper, the mass conservation law and the dimensional analysis method are employed to study the oxygen transfer under regular and non-breaking waves, and a unified oxygen transfer coefficient equation is obtained with consideration of the effect of kinetic energy and wave period. An oxygen transfer experiment for the intermediate depth water wave is performed to measure the wave parameters and the dissolved oxygen concentration. The experimental data and the least squares method are used to determine the constant in the oxygen transfer coefficient equation. The experimental data and the previous reported data are also used to further validate the oxygen transfer coefficient, and the agreement is satisfactory. The unified equation shows that the oxygen transfer coefficient increases with the increase of a parameter coupled with the wave height and the wave length, but it decreases with the increase of the wave period, which has a much greater influence on the oxygen transfer coefficient than the coupled parameter.