• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Convection: a neglected pathway for downward transfer of wind energy in the oceanic mixed layer*

    2018-08-02 02:50:48ZHANGYu張鈺WANGWei王偉
    Journal of Oceanology and Limnology 2018年4期
    關(guān)鍵詞:王偉

    ZHANG Yu (張鈺), WANG Wei (王偉)

    Physical Oceanography Laboratory/CIMST, Ocean University of China and Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China

    Abstract Upper-ocean turbulent mixing plays a vital role in mediating air-sea fluxes and determining mixed-layer properties, but its energy source, especially that near the base of the mixed layer, remains unclear. Here we report a potentially signi ficant yet rarely discussed pathway to turbulent mixing in the convective mixed layer. During convection, as surface fluid drops rapidly in the form of convective plumes,intense turbulence kinetic energy (TKE) generated via surface processes such as wave breaking is advected downward, enhancing TKE and mixing through the layer. The related power, when integrated over the global ocean except near the surface where the direct effect of breaking waves dominates, is estimated at

    Keyword: convective mixed layer; convecting plumes; turbulent kinetic energy (TKE); wind energy;surface waves

    1 INTRODUCTION

    Turbulent mixing in the oceanic mixed layer is very important to circulation and climate. It regulates fluxes across the air-sea interface, facilitates the takeup of excessive heat and CO2from the atmosphere,and more importantly affects properties of water masses that greatly contribute to the large-scale transport of climatically important tracers in the ocean interior (Macdonald and Wunsch, 1996; Sloyan and Rintoul, 2001a, b; Sabine et al., 2004). Formation of various water masses through processes like subduction or deep convection, takes place within the mixed layer and near its base, so turbulent mixing in the deeper part of the mixed layer is of critical importance to water mass properties and hence the Meridional Overturning Circulation. Despite its signi ficance, progress in understanding the mixedlayer turbulent mixing has been relatively slow(D’Asaro, 2014). One of the fundamental questions,the energy source of mixing in the mixed layer,especially near its base, remains unclear, severely impairing our ability to properly represent the related processes in numerical models and predict changes of climate in the future (Iudicone et al., 2008; Cerove?ki et al., 2013).

    For many decades the dominant paradigm of the upper ocean turbulent mixing consists of three paths(Thorpe, 2005). The first one is the generation of turbulent kinetic energy (TKE) from instability of wind-driven shear, in association with the classical logarithmic boundary layer obeying “the law of the wall”. The second one is the TKE generation at the cost of potential energy in the process of convective instability. The third path is linked to surface gravity waves. Upon generation, they receive most of the wind energy input to the ocean (60 out of 63 TW(1 TW=1012TW), (Wang and Huang, 2004)), and transfer most of the energy to TKE via breaking.Considering that maintaining the deep circulation requires only about 2–3 TW of power (Wunsch and Ferrari, 2004), the ocean circulation would be affected if only a small fraction of the TKE could somehow escape from the surface entering the ocean interior.However according to the conventional understanding TKE generated through wave breaking is concentrated near the surface, declining rapidly downward and approaching the classical “wall-law” scaling within only a few signi ficant wave heights. In this regard, the ocean surface is a large reservoir of TKE that is untapped.

    In the past few decades, two mechanisms by which surface wave energy is converted to TKE have been proposed. One is Langmuir circulation which is closely related to Stokes drift of surface waves and is capable of rapidly moving fluid vertically, thereby enhancing turbulence (Langmuir, 1938; Leibovich,1980; McWilliams et al., 1997; Thorpe, 2004).However its maximum effect is well above the base of the boundary layer. The other one is the interaction between non-breaking waves and turbulence, which is argued to be able to greatly improve global model performance (Huang and Qiao, 2010), but its validation and effect are under debate (Kantha et al.,2014). What we discuss here is a “non-local” transport mechanism, that is, strong TKE generated near the surface is carried downward and redistributed through the layer by sinking convective plumes during convection. We begin with a brief discussion of oceanic convective boundary layer in Section 2. The mechanism is discussed with a simple analytical model in Section 3; conclusions are given in Section 4.

    2 A RECONSIDERATION OF THE OCEANIC CONVECTIVE BOUNDARY LAYER

    Convection is a process whereby surface water parcels undergoing buoyancy loss become dense enough to sink to a depth dependent on local strati fication. The sinking motion is in the form of convective plumes (Thorpe, 2005), converting potential energy to small-scale turbulence, a process that has long been recognized as one major path to turbulent mixing in the oceanic convective boundary(CBL hereinafter) layer, along with other ways such as shear production.

    In numerical models, turbulent properties of both the atmospheric and oceanic boundary layers are usually represented by the TKE equation, which describes the budget of TKE (Stull, 1988; Burchard,2002). For the oceanic CBL, we can write the equation as follows (Endoh et al., 2014):

    where the time dependency of TKE, which is denoted by b, is related to the production of shear, P, to the production by buoyancy, Bu, to a term T that collectively represents effects of TKE transport, and to the dissipation rate of TKE, ε. Usually, it is assumed that the steady-state TKE is balanced “l(fā)ocally”between source terms, P and Bu, and the sink term, ε(Osborn, 1980; Anis and Moum, 1994). For strongly convecting boundary layer, one would naturally expect a close balance between the buoyancy generation and dissipation. However, as shown by a recent observational study of TKE budget in the oceanic CBL (Endoh et al., 2014), the generation by buoyancy is relevant in the upper part of the layer, but declines quickly downward and becomes a sink,rather than a source of TKE, in the lower half of the layer. The shear generation term, though comparable with Bunear the surface, decays quickly downward as well, being small and positive in the large portion of the layer. Meanwhile, the dissipation rate, estimated by the use of the microstructure data, shows a more or less uniform distribution through the layer. Obviously it is the transport term, T, that dominates the TKE budget in at least the deeper part of the layer, implying that the “l(fā)ocal” assumption is not proper. Actually, the similar conclusion has been obtained by both observational studies for the atmospheric CBL and studies of large eddy simulations (Lenschow, 1974;Moeng and Sullivan, 1994; Mironov et al., 2000), but the mechanism behind remains unsettled.

    Here we propose a transport mechanism that is related to the downward motion of convective plumes.The convective plumes can have strong vertical velocities, as large as about 0.01 m/s in nighttime mixed layer (Shay and Gregg, 1984) and 0.1 m/s in open ocean convection events (Marshall and Schott,1999). It is thus worth noting that as dense surface water parcels drop, they carry along not only heat, salt and other passive tracers but also their kinematic properties, i.e., the TKE generated via processes such as wave breaking at the surface or Langmuir Cell at intermediate depth. The mechanism, which has been long overlooked, and its effects on turbulent mixing will be discussed with a simple model in following sections.

    3 A MODIFIED TURBULENCE MODEL FOR THE OCEANIC CONVECTIVE BOUNDARY LAYER

    Convection occurring in the upper ocean is a complicated process in fluenced by many factors. As suggested by rather limited observations in the ocean or in the lab, a convective patch usually consists of multiple convective plumes. The vertical velocity is big and negative within each plume, but weak and positive between plumes. While sinking, plumes entrain and mix with the external fluid, changing density as they go and being strongly in fluenced by rotation of the earth.

    We simplify the actual convection process by ignoring mass exchanges with the surrounding fluid while plumes sink and ignoring energy sources of TKE other than wave breaking at the surface. By assuming the related dynamics is axisymmetric about the vertical axis of the convective plume (Fig.1), we consider a two-dimensional “cell” consisting of two limbs: a downward limb composed of downwelling parcels carrying intense TKE in the plume, and an upward limb consisting of slowly upwelling parcels carrying little TKE outside the plume. The two limbs are connected within two very thin sub-layers near the top and the bottom of the mixed layer, where horizontal convergence/divergence occurs to balance vertical motion.

    Since TKE is negligible outside plumes, only its distribution inside the plume is of interest. For dynamics in the interior and outside the top and bottom sub-layers, we consider a classical, one dimensional, second-order turbulence closure model(Mellor and Yamada, 1974, 1982; Craig and Banner,1994), which has been widely used in studies of the mixed-layer turbulence and incorporated into general circulation models of ocean and atmosphere.

    Here we further simplify the model by only considering the quasi-equilibrium state and modify it by adding an extra term representing vertical advection:

    where b is TKE and w is the vertical velocity of sinking plumes and is prescribed for simplicity as a constant of depth, q the turbulent velocity ( b= q2/2), l the turbulent length scale, Sqand B are empirical constants, and the product lqSqrepresents eddy diffusivity. The second term in Eq.2 represents vertical diffusion of energy whereas the final term is the TKE dissipation rate, ε.

    Fig.1 Schematic of a cylindrical “cell” consisting of a convecting plume at the center and upward compensating motion outside

    Rather than a “bilinear” form including both the top and bottom boundaries (Craig and Banner, 1994),l( z) is instead assumed to be simply a linear function of depth,

    where κ is von Kámán’s constant and z0is the roughness length.

    At the surface and the base of the mixed layer we employ the following boundary conditions,

    where α is referred to as the “wave energy factor” and u*is the oceanic friction velocity. The former is found quite insensitive to sea state while the latter is closely related to the strength of surface wind stress. The two boundary conditions represent respectively the energy input from breaking waves at the surface and zero flux of energy at the bottom.

    It is important to note that the model described above is for the interior of the plume excluding the two sub-layers near the top and bottom of the layer.Therefore, budgets for mass or energy cannot be closed by only considering Eqs.2–5. For example,integrating Eq.1 through the layer and using boundary conditions lead to a budget of the total TKE dissipation:

    Fig.2 Vertical structure of the dissipation rate, ε, for different magnitude of vertical velocity

    where [ b]0denotes the value of b at the surface and its value at the bottom has been ignored. What is basically suggested by Eq.6 is that in addition to TKE induced by wave breaking directly on top of the sinking plume,an extra source term, | w|[ b]0, arises as surface water parcels at nearby horizontal locations converge to compensate for the local sinking motion, and contributes to the turbulence budget of the plume. In this sense, the surface convergence induced by convective sinking makes it possible for the non-local source to enhance the TKE dissipation.

    To solve the nonlinear Eqs.2–5, we use the shooting method (see Appendix) with values of those parameters, Sq, B, α, κ, and z0fixed as in Craig and Banner (1994).

    As the result of the balance between advection,diffusion, and dissipation, the TKE dissipation rate is large near the surface and decays quickly downward,but the decay tendency is drastically abated with the strengthening sinking motion (Fig.2), suggesting its homogenization or redistribution effect on TKE. In addition, the overall magnitude of TKE through the layer is enhanced by advection, as suggested by Eq.6,and its value at deeper mixed layer is increased by more than five orders as | w| increases from 0 to 0.1 m/s. For mixed layers driven by intermediate to strong convection, the dissipation rate could be as large as 10-7W/kg at the base of the layer, roughly two orders of magnitude higher than that usually found in the seasonal pycnocline.

    Turbulence measurements in the upper-ocean have been very scarce, limiting progress of understanding and modeling of convection. As suggested by a few available vertical pro files obtained in the oceanic convective boundary layer, TKE dissipation rate is almost vertically homogeneous (Shay and Gregg,1984; Lombardo and Gregg, 1989), a feature also found prominent in the atmospheric convective boundary layer, except near the sea surface where effects of other processes such as wave breaking are dominant (Anis and Moum, 1995; Noh et al., 2004).The first direct turbulence measurements in oceanic convective boundary layer was made in 1983 (Shay and Gregg, 1984), along which detailed measurements of both atmospheric forcing, including the work of surface wind stress, Ew, and buoyancy flux, Jb0, and boundary layer pro files of temperature, salinity, and velocity, were also obtained, providing a good opportunity to test results of our simpli fied turbulence model (see Appendix).

    The friction velocity is readily obtained from measurements of Ew. As to the vertical velocity, we adopt the result of scaling argument, w= a( Jb0H)1/3,where “ a” is a coefficient of proportionality. Few values of “ a” existing in the literature, for example,0.52 was once chosen in a study of deep convection in the Labrador Sea (Steffen and D’Asaro, 2002). Using u*, w, and H as model input, we obtain three curves of TKE dissipation rate and plot them on top of observations. Obviously, model results and observations agree well to each other. Though the highly simpli fied model lacks many elements such as time dependency, generation of turbulence by buoyancy, shear instability or Langmuir circulation,and proper treatment of the two sub-layers, it successfully captured the uniform distribution of TKE with depth. In contrast, model estimates without vertical transport (black lines in Fig.3) are far less than observed values, and decay much more quickly with depth.

    The model is further applied to the globe using observations and reanalysis data of air-sea fluxes and mixed layer depth (see Appendix). First of all, the sinking velocity of plumes, estimated as ( Jb0H)1/3, in the convective mixed layer of September is as high as a few cm/s over large regions in the Southern Hemisphere especially along the Antarctic Circumpolar Current (ACC) (Fig.4c), indicative of potential relevance of the proposed mechanism.Distributions of strong convection show similar spatial patterns to that of strong surface wind stress(Fig.4a), yielding large values of the dissipation rate through the mixed layer as a consequence of downward advection of TKE (Fig.4d, e).

    Fig.3 Comparison of TKE dissipation rate between observations (black dots) and model results (solid lines)

    To have a general idea of the pattern and magnitude of mixing, we tentatively translate ε at the mixed layer base into a turbulent mixing rate, κv, using the Osborn relation (Osborn, 1980) (Fig.4f). All quantities in Fig.4 show similar patterns, and the most remarkable feature is a yellow-red band extending quasi-zonally in the ACC. In the austral (Southern Hemisphere)winter, the ACC region is characterized with strong westerlies, and intensi fied surface buoyancy loss (not shown), both of which help to generate excessively deep mixed layer over a few hundred meters in many regions. Presumably through downward motion during convection, strong TKE is carried downward from the surface, sustaining enhanced mixing through the entire layer with the amplitude as large as 10-1m2/s.Noteworthily, the area with maximum turbulent mixing is roughly coalesced with regions of mode water distributions such as the Subtropical Mode Water and Subantarctic Mode Water (Siedler et al.,2001), implying the potential signi ficance of the turbulent mixing to the formation/transformation of water masses. As deep winter mixed layer shoals in the austral spring, the strong mixing near the base of the mixed layer may exert an important in fluence on diffusion of mode water located just below.

    Fig.4 Distribution of TKE dissipation rate and mixing coefficient in September

    When integrated globally from the mixed layer base to the 10-m depth, above which the direct effect of breaking surface waves is presumably dominant,the resultant TKE dissipation is about 0.7 TW, over 1% of the total power from wind to surface waves which is, according to our calculation, about 52 TW.Since only monthly climatology for mixed-layer depth is used in above estimates, strength of convection is probably compromised, so is the estimate of the sinking velocity. Hence there is a good reason to expect that the real ratio is probably even higher than what is obtained.

    4 CONCLUSION

    As demonstrated by both observational and numerical studies, the assumption of a “l(fā)ocal”equilibrium of TKE budget for the oceanic or atmospheric CBL is not appropriate and transport of TKE can be relevant, especially in the lower half of the layer. We propose here a potentially important mechanism whereby TKE is redistributed and enhanced in the oceanic convective boundary layer.By sinking convective plumes, intense TKE generated near the surface through processes such as wave breaking can be brought downward to enhance mixing in the middle and deeper mixed layer. Signi ficance of the mechanism was veri fied and evaluated by comparison between in-situ turbulence measurements and results of the widely used one-dimensional Mellor-Yamada second-order turbulence model with an extra term representing the downward advection of TKE by convecting plumes. Applying the model to the global ocean, we found the mechanism is potentially important for water mass properties during its formation/transformation process. By inducing entrainment from below the mixed layer, it may also cause diffusion of mode water, a problem that has attracted much attention in recent years (Oka and Qiu,2012). On the other hand, through the mechanism wind effect reaches great depth of the ocean, especially in regions of open-ocean convection, thus impacting deep ocean circulation.

    In spite of its relevance for ocean and climate, the proposed mechanism has long been overlooked and our consideration in this paper is only the first step toward a proper understanding of the process. It is important to note that the applicability of our idealized model can be affected by its assumptions. As pointed out by one reviewer, the linear assumption of the turbulent length scale as a function of depth could lead to questionably large values in deep mixed layer.Some studies also suggested the importance of accounting for the effect of density strati fication in estimating the length scale around the base of the mixed layer (Galperin et al., 1988, 1989; Furuichi and Hibiya, 2015). Further studies are expected to more thoroughly investigate effects of convection in downward transport of surface TKE to the deeper area. For example, the numerical approach using large eddy simulation models (Harcourt, 2013, 2015;Furuichi and Hibiya, 2015) may help us elucidate important issues such as the relation between the local generation of TKE by buoyancy and its non-local advection by convective plumes, the spatial structure and temporal evolution of vertical velocity in the convective mixed layer, and the relative importance of the mechanism compared with other processes that may also induce vertical transport of TKE. Answering these questions can eventually help to improve parameterization of upper-ocean turbulent mixing,and improve our ability to accurately predict climate variation in the future.

    5 DATA AVAILABILITY STATEMENT

    The sources of the data involved in this paper are contained in the Appendix.

    6 ACKNOWLEDGEMENT

    The authors would like to thank the anonymous reviewers for their valuable suggestions.

    APPENDIX

    1 Solution of the turbulence model

    Following Craig and Banner (1994), we assume l is a linear function of depth:

    where κ is von Kámán’s constant and z0is the roughness length. In the current study, values of these variables are the same as in Craig and Banner (1994) ( Sq=0.2, B=16.6, α=100, κ=0.4, and z0=0.1 m).

    To solve above set of equations, we use the shooting method and consider the following system, in which for kthiteration q, as the function of the vertical coordinate z and an unknown boundary condition tksatis fies the following equation with Cauchy conditions at the base of the mixed layer z=-1,

    and an extra condition q2(0, tk) q'(0, tk)=1 at the surface z=0.

    If the system is well converged, the following condition should be satis fied:

    which leads to

    and so

    De fining two functions Y= ?q/ ? t and Y'= ?q'/ ? t, we have

    Hence with an initial guess of the boundary value t1of the turbulent velocity at the base of the mixed layer,we solve respectively q and Y from following equations:

    Then use Eq.A11 to get the value of t2, from which a new set of equations can be obtained. The cycle goes on tillis smaller than a prescribed small number.

    2 Comparison of model results against observations

    Black dots in Fig.3 denote dissipation rate calculated from dissipation-scale velocity fluctuations made with airfoil lift probes mounted on the Advanced Microstructure Pro filer (AMP) within a warm-core Gulf Stream ring during a cold-air outbreak (Shay and Gregg, 1984). These pro files were formed of seven bursts of drops taken during the cold air-break; each burst contained 4–12 pro files and was taken during an interval of between 1 and 3 h. The seven bursts spanned a period of 27 h when the mixed layer depth increased from 70 m to 170 m. Based on closeness of observed data for the atmospheric forcing including the work of surface wind stress and surface buoyancy flux, we obtain three sets of Ew, Jb0and H, and use each of them to estimate u*and w, which were subsequently used as input to our simple turbulence model. The three blue lines in Fig.3 are for the three sets with a=0.52, the three red lines are for a=1, and the three black lines are for w=0.

    3 Global distribution of TKE dissipation rate and mixing coefficient

    猜你喜歡
    王偉
    “平行線及其判定”初試鋒芒
    CHARACTERIZATION OF RESIDUATED LATTICES VIA MULTIPLIERS*
    Effects of heterogeneous adoption thresholds on contact-limited social contagions
    小 蝌 蚪 的 尾 巴
    王偉:寄情山水?dāng)⑧l(xiāng)愁
    藝術(shù)百家 王偉
    警察街頭“捉”小孩“捉”住就開點贊單
    這個英國人在長城撿垃圾22年
    新西蘭地震震出上萬只超級大鮑魚
    王偉宋 勇者的重生
    久久精品影院6| 国产91精品成人一区二区三区| 韩国av一区二区三区四区| 欧美日本中文国产一区发布| 国产成人精品在线电影| 极品教师在线免费播放| 亚洲国产欧美一区二区综合| 久久性视频一级片| 男人操女人黄网站| 国产欧美日韩综合在线一区二区| 女人被狂操c到高潮| 国产成人啪精品午夜网站| 国产精品一区二区在线不卡| 中文字幕av电影在线播放| 久久精品亚洲精品国产色婷小说| 欧美精品啪啪一区二区三区| 成人特级黄色片久久久久久久| 日本免费一区二区三区高清不卡 | 岛国在线观看网站| 丰满饥渴人妻一区二区三| 午夜视频精品福利| 久久久久久免费高清国产稀缺| 女同久久另类99精品国产91| 成年版毛片免费区| 午夜福利在线观看吧| 天堂√8在线中文| 日韩 欧美 亚洲 中文字幕| 久久精品aⅴ一区二区三区四区| 一a级毛片在线观看| 少妇被粗大的猛进出69影院| 亚洲,欧美精品.| videosex国产| 国产精品偷伦视频观看了| 欧美中文综合在线视频| 麻豆成人av在线观看| 日韩精品免费视频一区二区三区| 一级片免费观看大全| 成人国语在线视频| 熟女少妇亚洲综合色aaa.| aaaaa片日本免费| 最新在线观看一区二区三区| 制服人妻中文乱码| 高清欧美精品videossex| 午夜91福利影院| 国产精品一区二区精品视频观看| 久久人人97超碰香蕉20202| 午夜影院日韩av| av天堂在线播放| 天天影视国产精品| 一进一出好大好爽视频| 久久久久久久午夜电影 | 国产高清国产精品国产三级| 极品人妻少妇av视频| 国产欧美日韩一区二区三| 老司机靠b影院| av天堂在线播放| 久久中文看片网| 国产精品九九99| 99国产综合亚洲精品| 免费看十八禁软件| 日本wwww免费看| 大码成人一级视频| 国产精品一区二区在线不卡| 成人永久免费在线观看视频| 亚洲五月色婷婷综合| 自线自在国产av| 搡老岳熟女国产| a级片在线免费高清观看视频| 成人亚洲精品一区在线观看| 交换朋友夫妻互换小说| 真人一进一出gif抽搐免费| 亚洲免费av在线视频| 久久午夜综合久久蜜桃| 亚洲av片天天在线观看| 变态另类成人亚洲欧美熟女 | 亚洲精品国产区一区二| 成人三级黄色视频| www.999成人在线观看| 黄频高清免费视频| 欧美日韩视频精品一区| 成年女人毛片免费观看观看9| 欧美久久黑人一区二区| 亚洲一区二区三区不卡视频| 黄网站色视频无遮挡免费观看| av中文乱码字幕在线| www.999成人在线观看| 日韩欧美免费精品| 91国产中文字幕| 亚洲免费av在线视频| 黄片播放在线免费| 国产精品乱码一区二三区的特点 | 国产亚洲精品第一综合不卡| 欧美日本亚洲视频在线播放| 久久天堂一区二区三区四区| 亚洲九九香蕉| 欧美成狂野欧美在线观看| 可以免费在线观看a视频的电影网站| 国产在线精品亚洲第一网站| 国产精品久久久久成人av| 不卡一级毛片| 99re在线观看精品视频| 国产亚洲欧美在线一区二区| 久久精品91无色码中文字幕| 国产区一区二久久| 人人妻人人添人人爽欧美一区卜| 亚洲一区中文字幕在线| 大型黄色视频在线免费观看| 精品国产美女av久久久久小说| 叶爱在线成人免费视频播放| 国产av又大| 久久伊人香网站| 黑人操中国人逼视频| 精品一区二区三区视频在线观看免费 | 女同久久另类99精品国产91| 日韩成人在线观看一区二区三区| 99在线人妻在线中文字幕| 亚洲aⅴ乱码一区二区在线播放 | 精品卡一卡二卡四卡免费| 国产视频一区二区在线看| 亚洲国产精品999在线| 99在线人妻在线中文字幕| 国产色视频综合| 成人三级做爰电影| 真人做人爱边吃奶动态| 精品福利观看| 国产又爽黄色视频| 成人免费观看视频高清| www.www免费av| 久久久久国产一级毛片高清牌| 亚洲精品av麻豆狂野| 亚洲精品成人av观看孕妇| 无遮挡黄片免费观看| 天堂√8在线中文| 久久精品成人免费网站| 精品久久蜜臀av无| 亚洲中文日韩欧美视频| 精品国产亚洲在线| 国产高清激情床上av| 天天添夜夜摸| 99riav亚洲国产免费| 精品午夜福利视频在线观看一区| 久久国产亚洲av麻豆专区| 中文亚洲av片在线观看爽| 亚洲国产看品久久| 99精国产麻豆久久婷婷| 久久香蕉激情| 久久国产精品人妻蜜桃| 亚洲色图av天堂| 亚洲国产精品999在线| 淫秽高清视频在线观看| 欧美日韩视频精品一区| 级片在线观看| 精品福利观看| 一a级毛片在线观看| 性色av乱码一区二区三区2| 国产成人一区二区三区免费视频网站| 久久国产精品人妻蜜桃| 亚洲欧美精品综合一区二区三区| 天天影视国产精品| 俄罗斯特黄特色一大片| 国产极品粉嫩免费观看在线| 人妻丰满熟妇av一区二区三区| 国产视频一区二区在线看| 精品一品国产午夜福利视频| 日本免费a在线| 97超级碰碰碰精品色视频在线观看| 亚洲 欧美一区二区三区| 一级片免费观看大全| 性欧美人与动物交配| 一区二区三区国产精品乱码| 午夜视频精品福利| 中文字幕人妻丝袜一区二区| 电影成人av| 人妻久久中文字幕网| 成人永久免费在线观看视频| 波多野结衣高清无吗| 日本黄色日本黄色录像| 久久精品亚洲av国产电影网| 亚洲欧洲精品一区二区精品久久久| 不卡av一区二区三区| 亚洲精品在线观看二区| 欧美激情极品国产一区二区三区| 桃红色精品国产亚洲av| 多毛熟女@视频| 女性被躁到高潮视频| 国产av在哪里看| 女生性感内裤真人,穿戴方法视频| 国产色视频综合| 欧美久久黑人一区二区| 国产精品亚洲一级av第二区| 亚洲精品久久成人aⅴ小说| 亚洲av第一区精品v没综合| 欧美黄色淫秽网站| 热re99久久国产66热| 免费在线观看影片大全网站| 午夜福利,免费看| 老鸭窝网址在线观看| 欧美丝袜亚洲另类 | 亚洲av美国av| 欧美中文日本在线观看视频| 黄色 视频免费看| 亚洲av第一区精品v没综合| 久久久久久久久免费视频了| 国产又色又爽无遮挡免费看| 色婷婷av一区二区三区视频| 黄色 视频免费看| 亚洲七黄色美女视频| 国产在线精品亚洲第一网站| 亚洲国产精品sss在线观看 | 国产精品乱码一区二三区的特点 | 欧美日韩福利视频一区二区| 欧美日韩精品网址| 久久中文字幕一级| 国产精品电影一区二区三区| a级片在线免费高清观看视频| 两人在一起打扑克的视频| 麻豆成人av在线观看| 久久天躁狠狠躁夜夜2o2o| 国产av一区在线观看免费| 一二三四在线观看免费中文在| 亚洲精品在线观看二区| 国产精品九九99| 男人操女人黄网站| 久久热在线av| 亚洲欧美精品综合一区二区三区| 国产免费av片在线观看野外av| 国产欧美日韩综合在线一区二区| 亚洲熟女毛片儿| 中文字幕另类日韩欧美亚洲嫩草| 欧美最黄视频在线播放免费 | 很黄的视频免费| 女同久久另类99精品国产91| 国内毛片毛片毛片毛片毛片| 丁香六月欧美| 黄片小视频在线播放| 国产97色在线日韩免费| 成人国产一区最新在线观看| 男人操女人黄网站| 黄网站色视频无遮挡免费观看| 性色av乱码一区二区三区2| 精品国内亚洲2022精品成人| 日韩欧美三级三区| svipshipincom国产片| 最好的美女福利视频网| 久99久视频精品免费| 国产精品98久久久久久宅男小说| 亚洲七黄色美女视频| 久久国产亚洲av麻豆专区| 亚洲视频免费观看视频| 亚洲第一欧美日韩一区二区三区| 亚洲精品在线观看二区| 国产精品美女特级片免费视频播放器 | 日本黄色视频三级网站网址| 欧美在线一区亚洲| 亚洲一区二区三区不卡视频| 露出奶头的视频| 丰满迷人的少妇在线观看| 巨乳人妻的诱惑在线观看| 国产欧美日韩一区二区精品| 亚洲中文日韩欧美视频| www.自偷自拍.com| 国产亚洲欧美在线一区二区| 日本vs欧美在线观看视频| 久久精品亚洲熟妇少妇任你| 亚洲成人精品中文字幕电影 | 亚洲欧美精品综合久久99| 精品福利观看| 免费高清在线观看日韩| 免费在线观看日本一区| 日本精品一区二区三区蜜桃| 制服人妻中文乱码| 自线自在国产av| 久久人妻熟女aⅴ| 国产单亲对白刺激| 欧美日韩精品网址| 亚洲片人在线观看| 中国美女看黄片| 50天的宝宝边吃奶边哭怎么回事| 成人av一区二区三区在线看| 黄色视频不卡| 99热国产这里只有精品6| 亚洲国产欧美网| 免费看a级黄色片| 日本a在线网址| 日韩欧美在线二视频| 久久欧美精品欧美久久欧美| 亚洲五月婷婷丁香| 黑人巨大精品欧美一区二区mp4| 黄频高清免费视频| 中文字幕精品免费在线观看视频| av在线天堂中文字幕 | 免费av毛片视频| 成人三级做爰电影| 欧美在线黄色| 婷婷丁香在线五月| 国产xxxxx性猛交| 久久这里只有精品19| 国产成人欧美| 久久久国产成人免费| 亚洲欧美激情在线| 国产黄色免费在线视频| 麻豆成人av在线观看| 亚洲av熟女| 女性被躁到高潮视频| 国产成人精品在线电影| 国产成人精品久久二区二区免费| 国产精品九九99| 淫妇啪啪啪对白视频| 日韩精品免费视频一区二区三区| tocl精华| 男男h啪啪无遮挡| 男人舔女人的私密视频| 欧美日韩乱码在线| 伦理电影免费视频| 纯流量卡能插随身wifi吗| 久久99一区二区三区| 亚洲欧洲精品一区二区精品久久久| 女人被躁到高潮嗷嗷叫费观| 黄色视频,在线免费观看| 成人三级做爰电影| 热re99久久精品国产66热6| 亚洲av日韩精品久久久久久密| 成人三级做爰电影| 亚洲一区二区三区色噜噜 | 国产精品亚洲av一区麻豆| 亚洲精品成人av观看孕妇| 久久香蕉国产精品| 国产激情久久老熟女| 中文亚洲av片在线观看爽| 淫秽高清视频在线观看| 日本三级黄在线观看| 欧美日韩亚洲高清精品| 18禁美女被吸乳视频| 成人影院久久| 亚洲av成人不卡在线观看播放网| cao死你这个sao货| 夜夜躁狠狠躁天天躁| 欧美av亚洲av综合av国产av| 18禁裸乳无遮挡免费网站照片 | 深夜精品福利| 首页视频小说图片口味搜索| 中文亚洲av片在线观看爽| 国产成人精品在线电影| 久久伊人香网站| 91字幕亚洲| 夜夜爽天天搞| 免费一级毛片在线播放高清视频 | 亚洲成av片中文字幕在线观看| 夜夜夜夜夜久久久久| 欧美成人午夜精品| 女性生殖器流出的白浆| 久久伊人香网站| 国产深夜福利视频在线观看| 黄频高清免费视频| 成人影院久久| 韩国精品一区二区三区| 夜夜爽天天搞| 美女福利国产在线| 国产主播在线观看一区二区| 国产欧美日韩综合在线一区二区| 亚洲午夜精品一区,二区,三区| 亚洲av成人av| 少妇的丰满在线观看| 妹子高潮喷水视频| 日本a在线网址| 国产99久久九九免费精品| 国产xxxxx性猛交| 国产欧美日韩一区二区精品| 免费日韩欧美在线观看| 国产欧美日韩一区二区三| 日本撒尿小便嘘嘘汇集6| 亚洲中文字幕日韩| 免费观看人在逋| 夜夜躁狠狠躁天天躁| 欧美在线黄色| 视频区图区小说| 精品福利观看| 成人亚洲精品一区在线观看| 国产片内射在线| 伊人久久大香线蕉亚洲五| a级毛片在线看网站| 欧美最黄视频在线播放免费 | 国产精品久久视频播放| 热re99久久国产66热| 国产欧美日韩一区二区三| av片东京热男人的天堂| 亚洲精品一卡2卡三卡4卡5卡| 露出奶头的视频| 欧美大码av| 丁香欧美五月| 女警被强在线播放| 侵犯人妻中文字幕一二三四区| 中文字幕人妻丝袜制服| 夜夜躁狠狠躁天天躁| 精品一区二区三卡| 三级毛片av免费| 精品国产亚洲在线| 最近最新中文字幕大全免费视频| 怎么达到女性高潮| 日本 av在线| 两人在一起打扑克的视频| 999久久久精品免费观看国产| 最近最新中文字幕大全免费视频| 日日爽夜夜爽网站| 他把我摸到了高潮在线观看| 成人国语在线视频| 999久久久国产精品视频| 久久精品成人免费网站| 国产免费男女视频| 99国产精品免费福利视频| 多毛熟女@视频| 最好的美女福利视频网| 69精品国产乱码久久久| 777久久人妻少妇嫩草av网站| 亚洲狠狠婷婷综合久久图片| 久久久久久久久免费视频了| 日韩精品免费视频一区二区三区| 免费在线观看亚洲国产| 亚洲精品国产区一区二| 亚洲五月天丁香| 日韩免费高清中文字幕av| 亚洲精品粉嫩美女一区| 级片在线观看| 天天影视国产精品| 精品一区二区三区四区五区乱码| 国产视频一区二区在线看| 性色av乱码一区二区三区2| 亚洲精品久久午夜乱码| 午夜福利一区二区在线看| 18禁黄网站禁片午夜丰满| 黑人巨大精品欧美一区二区mp4| 一夜夜www| 午夜日韩欧美国产| 亚洲精品美女久久av网站| 午夜成年电影在线免费观看| 亚洲国产毛片av蜜桃av| bbb黄色大片| 又紧又爽又黄一区二区| 亚洲人成电影观看| 91字幕亚洲| 首页视频小说图片口味搜索| 黄色女人牲交| 亚洲色图综合在线观看| 少妇裸体淫交视频免费看高清 | 五月开心婷婷网| 国产亚洲精品一区二区www| 男女下面插进去视频免费观看| 国产精品98久久久久久宅男小说| 欧美色视频一区免费| 黑人巨大精品欧美一区二区蜜桃| 91麻豆av在线| 亚洲精品久久成人aⅴ小说| 久久人妻av系列| 亚洲精品粉嫩美女一区| av电影中文网址| 69av精品久久久久久| 麻豆成人av在线观看| 69精品国产乱码久久久| 日韩成人在线观看一区二区三区| 伦理电影免费视频| 国产亚洲欧美在线一区二区| 精品国产国语对白av| 午夜福利,免费看| 欧美另类亚洲清纯唯美| 久久人人精品亚洲av| 69精品国产乱码久久久| 精品一区二区三区视频在线观看免费 | 日韩av在线大香蕉| 又黄又爽又免费观看的视频| 久久久久久久精品吃奶| 国产亚洲精品久久久久久毛片| 日韩有码中文字幕| 一级a爱片免费观看的视频| 天堂影院成人在线观看| 色综合站精品国产| 手机成人av网站| 国产精品成人在线| 新久久久久国产一级毛片| 国产激情久久老熟女| 99国产精品免费福利视频| 99国产精品99久久久久| 少妇裸体淫交视频免费看高清 | 亚洲成人久久性| 久9热在线精品视频| 欧美日韩精品网址| 亚洲一码二码三码区别大吗| 欧美乱色亚洲激情| 欧美日本中文国产一区发布| 最近最新中文字幕大全电影3 | 99久久国产精品久久久| 亚洲精品一卡2卡三卡4卡5卡| 91av网站免费观看| 91在线观看av| 亚洲精品国产精品久久久不卡| 脱女人内裤的视频| 99国产精品免费福利视频| 91老司机精品| 欧美午夜高清在线| 精品欧美一区二区三区在线| 亚洲国产精品999在线| 国产区一区二久久| 亚洲伊人色综图| 精品久久久久久电影网| 亚洲少妇的诱惑av| 免费在线观看亚洲国产| 亚洲伊人色综图| 最新在线观看一区二区三区| 涩涩av久久男人的天堂| 亚洲人成伊人成综合网2020| 乱人伦中国视频| 性少妇av在线| 国产三级在线视频| 日本wwww免费看| 亚洲av成人不卡在线观看播放网| 国产成人一区二区三区免费视频网站| 日韩精品青青久久久久久| 黄色片一级片一级黄色片| 久久久久久人人人人人| 别揉我奶头~嗯~啊~动态视频| 国产成人欧美| 亚洲人成电影免费在线| 欧美一区二区精品小视频在线| 亚洲一卡2卡3卡4卡5卡精品中文| 99久久久亚洲精品蜜臀av| 欧美日韩一级在线毛片| 一进一出抽搐gif免费好疼 | 纯流量卡能插随身wifi吗| bbb黄色大片| 新久久久久国产一级毛片| 久久久国产成人精品二区 | 亚洲精品国产一区二区精华液| 天天躁狠狠躁夜夜躁狠狠躁| 99久久综合精品五月天人人| 国产一区在线观看成人免费| 欧美日韩亚洲国产一区二区在线观看| 男女下面进入的视频免费午夜 | 日韩精品免费视频一区二区三区| 黑人猛操日本美女一级片| 国产一卡二卡三卡精品| 淫妇啪啪啪对白视频| 国产黄a三级三级三级人| 国产成人精品久久二区二区免费| 露出奶头的视频| 免费在线观看视频国产中文字幕亚洲| 黄频高清免费视频| 老司机深夜福利视频在线观看| 18禁美女被吸乳视频| 欧美激情久久久久久爽电影 | 又大又爽又粗| 亚洲精品在线美女| 欧美日韩一级在线毛片| 日韩欧美国产一区二区入口| 十分钟在线观看高清视频www| 日本欧美视频一区| 国产精品 欧美亚洲| 亚洲,欧美精品.| 人人澡人人妻人| 日本黄色日本黄色录像| 精品高清国产在线一区| 免费高清在线观看日韩| 欧美 亚洲 国产 日韩一| а√天堂www在线а√下载| 老司机在亚洲福利影院| 日韩大码丰满熟妇| 身体一侧抽搐| 很黄的视频免费| 久久国产精品男人的天堂亚洲| 午夜成年电影在线免费观看| 国产精品免费一区二区三区在线| 久久久久久久久免费视频了| 国产精品九九99| 国产亚洲精品一区二区www| 日日干狠狠操夜夜爽| 一二三四在线观看免费中文在| 成人手机av| 纯流量卡能插随身wifi吗| 操美女的视频在线观看| 亚洲国产看品久久| 成人18禁高潮啪啪吃奶动态图| 亚洲久久久国产精品| 看黄色毛片网站| 51午夜福利影视在线观看| 国产精品免费视频内射| 制服诱惑二区| 国产精品影院久久| 91麻豆av在线| a级片在线免费高清观看视频| 亚洲色图综合在线观看| 99国产综合亚洲精品| 手机成人av网站| 两性夫妻黄色片| 亚洲全国av大片| 精品无人区乱码1区二区| 国产不卡一卡二| 日韩大尺度精品在线看网址 | 视频在线观看一区二区三区| 色哟哟哟哟哟哟| 97超级碰碰碰精品色视频在线观看| 啦啦啦免费观看视频1| 欧美大码av| 久久久国产精品麻豆| 在线十欧美十亚洲十日本专区| 18禁裸乳无遮挡免费网站照片 | av福利片在线| 欧美av亚洲av综合av国产av| 国产av一区在线观看免费| 国产一区二区在线av高清观看| 又黄又粗又硬又大视频| 又大又爽又粗| 91字幕亚洲| 成人三级做爰电影| 日本精品一区二区三区蜜桃| 黑人操中国人逼视频| 日韩人妻精品一区2区三区| 亚洲成人久久性|