Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Seasonality and spatial dependence of meso- and submesoscale ocean
  currents from along-track satellite altimetry   Along-track wavenumber spectral densities of sea surface height (SSH) are
estimated from Jason-2 altimetry data as a function of spatial location and
calendar month, to understand the seasonality of meso- and submesoscale
balanced dynamics across the global ocean. Regions with significant mode-1 and
mode-2 baroclinic tides are rejected, restricting the analysis to the
extratropics. Where balanced motion dominates, the SSH spectral density is
averaged over all pass segments in a region for each calendar month, and is fit
to a 4-parameter model consisting of a flat plateau at low wavenumbers, a
transition at wavenumber $k_0$ to a red power law spectrum $k^{-s}$, and a
white spectrum at high wavenumbers that models the altimeter noise. The monthly
time series of the model parameters are compared to the evolution of the mixed
layer. The annual mode of the spectral slope $s$ reaches a minimum after the
mixed layer deepens, and the annual mode of the bandpassed kinetic energy in
the ranges $[2k_0,4 k_0]$ and $[k_0,2 k_0]$ peak $\sim$2 and $\sim$4 months,
respectively, after the maximum of the annual mode of the mixed layer depth.
This analysis is consistent with an energization of the submesoscale by a
winter mixed layer instability followed by an inverse cascade to the mesoscale,
in agreement with prior modeling studies and in situ measurements. These
results are compared to prior modeling, in situ, and satellite investigations
of specific regions, and are broadly consistent with them within measurement
uncertainties.

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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: cmp-lg
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The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: ao-sci