Large-scale and synoptic meteorology in the south-east Pacific during the observations campaign VOCALS-REx in austral Spring 2008 1NCAS, Department of Meteorology, University of Reading, RG6 6BB, UK
27 May 2011
2Met Office, Exeter, UK
3University of Washington, Seattle, USA
4UCLA, Los Angeles, USA
5University of Manchester, UK
Received: 30 November 2010 – Published in Atmos. Chem. Phys. Discuss.: 06 January 2011 Abstract. We present a descriptive overview of the meteorology in the south eastern
subtropical Pacific (SEP) during the VOCALS-REx intensive observations
campaign which was carried out between October and November 2008.
Mainly based on data from operational analyses, forecasts, reanalysis,
and satellite observations, we focus on spatio-temporal scales from
synoptic to planetary.
A climatological context is given within which the specific conditions
observed during the campaign are placed, with particular reference to
the relationships between the large-scale and the regional circulations.
The mean circulations associated with the diurnal breeze systems are also
We then provide a summary of the day-to-day synoptic-scale circulation,
air-parcel trajectories, and cloud cover in the SEP during VOCALS-REx.
Three meteorologically distinct periods of time are identified and
the large-scale causes for their different character are discussed.
The first period was characterised by significant variability associated
with synoptic-scale systems interesting the SEP; while the two
subsequent phases were affected by planetary-scale disturbances with a
The changes between initial and later periods can be partly explained
from the regular march of the annual cycle, but contributions from
subseasonal variability and its teleconnections were important.
Across the whole of the two months under consideration we find a
significant correlation between the depth of the inversion-capped
marine boundary layer (MBL) and the amount of low cloud in the area of
We discuss this correlation and argue that at least as a crude
approximation a typical scaling may be applied relating MBL and cloud
properties with the large-scale parameters of SSTs and tropospheric
temperatures. These results are consistent with previously found
empirical relationships involving lower-tropospheric stability.
Revised: 26 April 2011 – Accepted: 05 May 2011 – Published: 27 May 2011
Citation: Toniazzo, T., Abel, S. J., Wood, R., Mechoso, C. R., Allen, G., and Shaffrey, L. C.: Large-scale and synoptic meteorology in the south-east Pacific during the observations campaign VOCALS-REx in austral Spring 2008, Atmos. Chem. Phys., 11, 4977-5009, doi:10.5194/acp-11-4977-2011, 2011.