Publications

• Garfinkel, C.I. and D.L. Hartmann(submitted), The Influence of the Quasi-Biennial Oscillation on the Troposphere in Wintertime in a Hierarchy of Models, Part 2-Perpetual Winter WACCM runs, JAS.

  @Article{ GH11b,
  AUTHOR = {Garfinkel, C. I. and D. L. Hartmann },
  YEAR = {submitted},
  TITLE = {The Influence of the Quasi-Biennial Oscillation on the Troposphere in Wintertime in a Hierarchy of Models, Part 2-Perpetual Winter WACCM runs},
  JOURNAL = JAS,
  volume = {},
  summary = {Even in the presence of tropical convection anomalies and a variable polar vortex, the QBO influences the troposphere directly through extratropical eddies. The response to the QBO is greatest in the North Pacific, but is present in other regions with eddy driven variability. Response is stronger in February than in January. Response is consistent with the reanalysis data and a coupled WACCM run. }, }
  

• Garfinkel, C.I. and D.L. Hartmann(submitted), The Influence of the Quasi-Biennial Oscillation on the Troposphere in Wintertime in a Hierarchy of Models, Part 1-Simplified Dry GCMs, JAS.

  @Article{ GH11a,
  AUTHOR = {Garfinkel, C. I. and D. L. Hartmann },
  YEAR = {submitted},
  TITLE = {The Influence of the Quasi-Biennial Oscillation on the Troposphere in Wintertime in a Hierarchy of Models, Part 1-Simplified Dry GCMs},
  JOURNAL = JAS,
  volume = {},
  summary = {The QBO can influence the troposphere even in the absence of tropical convection anomalies and a variable polar vortex. QBO anomalies require a meridional circulation to establish thermal wind balance. This circulation extends downwards into the troposphere and induces zonal wind anomalies in the subtropical troposphere. In the presence of extratropical eddies, the zonal wind anomalies are intensified and extend downward to the surface. The tropospheric response differs qualitatively between a strong subtropical jet and a weaker jet, contrary to the predictions of the fluctuation-dissipation theorem. If the extratropical circulation is zonally asymmetric, the response to the QBO is greatest in the exit region of the subtropical jet. Response in dry model is consitent with the reanalysis data and a coupled WACCM run. }, }
  

• Garfinkel, C.I. and D.L. Hartmann(accepted), The Influence of the Quasi-Biennial Oscillation on the North Pacific and El-Nino teleconnections, JGR.

  @Article{ GH10,
  AUTHOR = {Garfinkel, C. I. and D. L. Hartmann },
  YEAR = {accepted},
  TITLE = {The Influence of the Quasi-Biennial Oscillation on the North Pacific and El-Nino teleconnections},
  JOURNAL = JGR,
  volume = {},
  summary = {EQBO at 70hPa leads to a weaker teleconnection in the North Pacific than WQBO in both a model and reanalysis. Part of this may be due to a direct affect of the QBO on the North Pacific, which does not resemble the vortex response in the North Pacific. Part of it may be due to an indirect mechanism by which wind anomalies associated with the EQBO lead to less supportive conditions for the growth of a North Pacific low. Sampling variability and variability in convection cannot be excluded as contributors, however. }, }
  

• Garfinkel, C.I., D.L. Hartmann, and F. Sassi (2010), Tropospheric Precursors of Anomalous Northern Hemisphere Stratospheric Polar Vortices, J. Clim., 23, doi: 10.1175/2010JCLI3010.1.

  @Article{ GHetal10,
  AUTHOR = {Garfinkel, C. I. and D. L. Hartmann and F. Sassi},
  YEAR = {2010},
  TITLE = {Tropospheric Precursors of Anomalous Northern Hemisphere Stratospheric Polar Vortices},
  JOURNAL = JC,
  volume = {23},
  doi = {10.1175/2010JCLI3010.1},
  summary = {Simple reasoning is used to explain the nature of regional tropospheric variability that affects the vortex. An anomalous low over the North Pacific and an anomalous high over Eastern Europe weaken the vortex nearly immediately, with the effect propagating downwards with time. Perturbations of the vortex due to the two centers add linearly; the two are temporally uncorrelated with each other and with the QBO; the two centers are relevant in both early winter and late winter. Much of the influence of ENSO and October Eurasian snow on the vortex is associated with these two centers. Some 40\% of vortex variance is related to variability of these two and the QBO. },}
  

• Garfinkel, C.I., and D.L. Hartmann(2008), Different ENSO Teleconnections and Their Effects on the Stratospheric Polar Vortex , J. Geophys. Res. Atmos , 113, D18114,doi:10.1029/2008JD009920.

  @Article{ GH08,
  AUTHOR = {Garfinkel, C. I. and D. L. Hartmann },
  YEAR = {2008},
  TITLE = { Different {ENSO} Teleconnections and Their Effects on the Stratospheric Polar Vortex},
  JOURNAL = {J. Geophys. Res.- Atmos.},
  volume = {113},
  eid = {D18114},
  pages = {},
  doi = {10.1029/2008JD009920},
  keywords = {},
  summary = {The crucial mechanism through which WENSO warms the vortex is an enhancement of wave-1 without too large a drop in wave-2. This occurs when WENSO induces a PNA-like pattern in the North Pacific. The reason that ENSO(QBO) doesn't modulate the vortex under EQBO(WENSO) is that the PNA pattern is not excited in WENSO/EQBO months.},}

• Garfinkel, C.I., and D.L. Hartmann (2007), Effects of the El-Nino Southern Oscillation and the Quasi-Biennial Oscillation on polar temperatures in the stratosphere , J. Geophys. Res. Atmos., 112, D19112, doi:10.1029/2007JD008481. Supplementary plots at 30mb for the above paper

  @Article{ GH07,
  AUTHOR = {Garfinkel, C. I. and D. L. Hartmann },
  YEAR = {2007},
  TITLE = {Effects of the {E}l-{N}ino {S}outhern {O}scillation and the {Q}uasi-{B}iennial {O}scillation on polar temperatures in the stratosphere},
  JOURNAL = {J. Geophys. Res.- Atmos.},
  volume = {112},
  eid = {D19112},
  pages = {},
  doi = {10.1029/2007JD008481},
  keywords = {},
  summary = {The effect of ENSO and of the QBO on the vortex can be separated in observational data; the magnitude of the QBO's effect is comparable to that of ENSO. ENSO only modulates the vortex under WQBO and neutral QBO however, not under EQBO. Similarly, QBO only modulates the vortex under CENSO and neutral ENSO, not under WENSO.}, }