Numerical Simulations of Multiphase Winds and Fountains from
  Star-Forming Galactic Disks: I. Solar Neighborhood TIGRESS Model
  Gas blown away from galactic disks by supernova (SN) feedback plays a key
role in galaxy evolution. We investigate outflows utilizing the solar
neighborhood model of our high-resolution, local galactic disk simulation
suite, TIGRESS. In our numerical implementation, star formation and SN feedback
are self-consistently treated and well resolved in the multiphase, turbulent,
magnetized interstellar medium. Bursts of star formation produce spatially and
temporally correlated SNe that drive strong outflows, consisting of hot
(T>5x10^5K) winds and warm (5050K < T < 2x10^4K) fountains. The hot gas at
distance d>1kpc from the midplane has mass and energy fluxes nearly constant
with d. The hot flow escapes our local Cartesian box barely affected by gravity
and is expected to accelerate up to the terminal velocity of
v_wind~350-500km/s. The mean mass and energy loading factors of the hot wind
are 0.1 and 0.02, respectively. For warm gas, the mean outward mass flux
through d=1kpc is comparable to the mean star formation rate, but only a small
fraction of this gas is at velocity >50km/s. Thus, the warm outflows eventually
fall back as inflows. The warm fountain flows are created by expanding hot
superbubbles at d< 1kpc; at larger d neither ram pressure acceleration nor
cooling transfers significant momentum or energy flux from the hot wind to the
warm outflow. The velocity distribution at launching near d~1kpc better
represents warm outflows than a single mass loading factor, potentially
enabling development of subgrid models for warm galactic winds in arbitrary
large-scale galactic potentials.
