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J. R. Carpenter and M.-L. Timmermans

DNS show support for the Kelley condition in determining the location of a rotation-induced transition to significantly reduced heat fluxes. Given this support, we can now address the question raised in the title of this paper, of whether rotation influences double-diffusive fluxes in polar oceans. This was previously discussed in Kelley (1987) using typical order-of-magnitude values from known double-diffusive staircases at that time, however, we revisit this question in light of recent

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Zhijuan Liu, Xiaoguang Yang, Xiaomao Lin, Kenneth G. Hubbard, Shuo Lv, and Jing Wang

substantially improved if the growing demand of food continues because of the population increases in China. Potential yield is the ceiling of the yield for a certain place, which is largely determined by the particular combination of solar radiation, temperature, soil, and plant density at a specific location ( van Ittersum and Rabbinge 1997 ). However, actual farmers’ yields in a region or country are smaller than potential yields because the latter requires nonlimiting management throughout the crop

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Ilker Fer

respect to azimuth. The instrument sampled velocity profiles at 3-s intervals in 8-m-thick cells with the first cell centered at about 13 m. Data recorded in beam coordinates were referenced to geographic north using time series of precise differential global positioning satellite (DGPS) measurements of the local ice orientation. Absolute water velocity was obtained by adding the DGPS-derived ice velocity vector to the relative velocity profile. For the analysis, the velocity profiles were averaged in

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Ryu Saiki and Humio Mitsudera

horizontal plane. Black line denotes the location representing the vertical sections of Figs. 12a and 12b . Red vector denotes τ ai and blue vector denotes τ iw , where | τ ai | = 10.5 × 10 −1 kg m −1 s −2 and | τ iw | = 9.63 × 10 −1 kg m −1 s −2 , respectively. The homogeneous wind starts blowing over the initial sea ice field. As a result, the ice-band patterns emerge all over the domain as in Fig. 11b . The ice bands in this simulation exhibit a regular, 10-km-scale band spacing ( Fig. 11c

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Linlin Zhang and Tangdong Qu

). Another feature at the sea surface is a low dynamic height tongue at about 10°S between the western boundary and the date line, indicating a weak eastward current on its northern flank, which appears to be the South Equatorial Countercurrent (SECC). Fig . 1. Mean steric height (m) relative to 1800 m at (a) the sea surface, (b) 200, (c) 500, and (d) 1000 m derived from Argo data during 2004–13. Two white dashed lines in each panel indicate locations of 170° and 150°W. Below the surface layer at 200 m

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Jérôme Sirven and Bruno Tremblay

Abstract

Analytic solutions of a mechanical sea ice model are computed in idealized configurations. They are then used to study the properties of this model. It classically assumes that the ice behaves at large scale as an isotropic viscoplastic medium. The plastic regime is characterized by a Mohr–Coulomb yield curve. The flow rule corresponds to the one used in granular mediums and depends on a parameter δ that characterizes the expansion properties of the medium. Using simple model configurations, this study first shows that a sliding of the ice along the coast must be permitted; otherwise, the model generally has no solution when the plastic regime is active. This study then shows that the viscous regime is reached only if the stress remains nearly uniform over a large area. For a stress having no particular properties, the plastic regime acts everywhere. In this case, the compressive stress may reach the maximum value allowed by the model close to the coastline. The extension of the domain where the compressive stress is at its maximum depends on δ and the direction of the forcing field. Over this domain, the ice behaves as a fluid material with a small negative viscosity. Last, the authors found that neither the existence of the solution nor its unicity are guaranteed in this stationary model. This result does not imply that the unicity is lost in the transient problem; it suggests that the evolution of sea ice depends not only on the forcing, but also on the initial conditions or history of the system.

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Jinyoung Rhee and Jaepil Cho

, four major river basins were also examined individually, in addition to an analysis of the entire area (ENT). 2. Data and methodology a. Study area and observation data The study was performed in South Korea, in northeastern Asia ( Fig. 1 ). There are four major river basins in the southern part of the peninsula: the Han, Nakdong, Geum, and Yeongsan–Sumjin River basins. The locations of the river basins and the number of Automated Surface Observing System (ASOS) weather stations in each basin are

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Nicholas J. Weber, Matthew A. Lazzara, Linda M. Keller, and John J. Cassano

wind. The top 12 EWE events chosen for the additional dynamical analysis are listed in Table 3 . Table 3. The start date, maximum speed, average speed, resultant direction (vector average), and duration of the top 12 McMurdo Station EWEs. Note that the May 2004 EWE data were obtained from the SPAWAR Arrival Heights AWS data. The winds are considerably stronger because Arrival Heights is at a higher, more exposed location inland above McMurdo Station. Forecast back trajectories are computed for

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Mark R. Jury

−1 ) and rain (mm h −1 ) values (both with a standard deviation of ~5) for 3 successive days in three successively westward locations across the eastern Sahel (cf. Figure 1c ), such that high values refer to a convective vortex propagating westward at >10 m s −1 . Various indices to identify AEW are reviewed in Fink (2012) . The 600-hPa streamfunction over the northern Red Sea (15°–25°N, 30°–45°E) was used to further screen cases ( Spinks and Lin 2015 ), and 25 August 2009 had the highest rank

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Jun Ying and Ping Huang

deviation will induce a similar deviation in the surface wind stress pattern (vectors in Fig. 3c ), which will enhance (suppress) the equatorial cold advection over the eastern (western) Pacific (shaded in Fig. 3c ) through the Bjerknes feedback ( Fig. 4b ). Under these two feedback processes, the original SST warming induced by the CSFI deviation through Δ Q SW will shift westward relative to the location of the CSFI deviation ( Fig. 4c ). The westward-moved SST warming will further induce positive

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