FN Archimer Export Format
PT J
TI Ocean-Atmosphere Coupling in the Monsoon Intraseasonal Oscillation: A Simple Model Study
BT 
AF BELLON, Gilles
   SOBEL, Adam H.
   VIALARD, Jerome
AS 1:1;2:1,2;3:3;
FF 1:;2:;3:;
C1 Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA.
   Columbia Univ, Dept Earth & Environm Sci, New York, NY USA.
   Univ Paris 06, Inst Rech Dev, Lab Oceanog Expt & Approches Numer, Inst Pierre Simon Laplace, Paris, France.
C2 UNIV COLUMBIA, USA
   UNIV COLUMBIA, USA
   IRD, FRANCE
IF 4.307
TC 31
UR https://archimer.ifremer.fr/doc/00185/29637/27987.pdf
LA English
DT Article
CR CIRENE 2007
   VT 102 / CIRENE
   VT 75 / CIRENE
BO Le Suroît
   Marion Dufresne
DE ;madden julian oscillation;tropical circulation model;sea surface temperature;asian summer monsoon;convective perturbations;walker circulation;radiation budget;indian ocean;variability;simulation
AB A simple coupled model is used in a zonally symmetric aquaplanet configuration to investigate the effect of ocean-atmosphere coupling on the Asian monsoon intraseasonal oscillation. The model consists of a linear atmospheric model of intermediate complexity based on quasi-equilibrium theory coupled to a simple, linear model of the upper ocean. This model has one unstable eigenmode with a period in the 30-60-day range and a structure similar to the observed northward-propagating intraseasonal oscillation in the Bay of Bengal/west Pacific sector. The ocean-atmosphere coupling is shown to have little impact on either the growth rate or latitudinal structure of the atmospheric oscillation, but it reduces the oscillation's period by a quarter. At latitudes corresponding to the north of the Indian Ocean, the sea surface temperature (SST) anomalies lead the precipitation anomalies by a quarter of a period, similarly to what has been observed in the Bay of Bengal. The mixed layer depth is in phase opposition to the SST: a monsoon break corresponds to both a warming and a shoaling of the mixed layer. This behavior results from the similarity between the patterns of the predominant processes: wind-induced surface heat flux and wind stirring. The instability of the seasonal monsoon flow is sensitive to the seasonal mixed layer depth: the oscillation is damped when the oceanic mixed layer is thin (about 10 m deep or thinner), as in previous experiments with several models aimed at addressing the boreal winter Madden-Julian oscillation. This suggests that the weak thermal inertia of land might explain the minima of intraseasonal variance observed over the Asian continent.
PY 2008
PD OCT
SO Journal Of Climate
SN 0894-8755
PU Amer Meteorological Soc
VL 21
IS 20
UT 000260012200006
BP 5254
EP 5270
DI 10.1175/2008JCLI2305.1
ID 29637
ER

EF