Águas de Março (the waters of March) - CLIVAR · Águas de Março (the waters of March) Brian...
Transcript of Águas de Março (the waters of March) - CLIVAR · Águas de Março (the waters of March) Brian...
Águas de Março (the waters of March)
Brian Mapes, with Patrick Kelly University of Miami
The song
• "The inspiration for "Águas de Março" comes from Rio de Janeiro's rainiest month. The lyrics and the music have a constant downward progression much like the water torrent from those rains flowing in the gutters, which typically would carry sticks, stones, bits of glass, and almost everything and anything" (Wikipedia)
• after dry February for these things to accumulate?
• Poignant, end of summer feeling
Antônio Carlos Jobim
Águas de Março
Source: CPTEC Web site
Brant Liebmann’s (NOAA-PSD)
gridded gauge data daily clim.
• East side of SACZ
CMAP (obs)
(pentad)
Deviation from clim. Fourier 0+1+2 (high frequency part of anomalies)
CMAP (obs) Ensemble
mean of 10 AGCMs
(pentad)
The dry air of February
Year to year correlation of March-Feb differences data
Northern hemisphere <[u]> and North Atlantic u850 @ 25-30N
NCEP1 daily climatology (1969-
1996)
v850 at 30N
<[u]>
m/s
latitude (N)
Barotropic zonal mean flow and TCs
• High-Low tercile <[u]>10-40N composite (ASO)
iBTracs we gridded a TC count variable
• High-Low tercile <[u]>10-40N composite (ASO)
Barotropic zonal mean flow and TCs
-
-
u*v*
-d/dy(u*v*)
-d/dy(u*v*) in 20-30°N
200mb
Western edge of Tibetan High at 200mb is the main momentum pump for <[u]>
JJA climatology
Patrick Kelly PhD thesis – summer 2012
CAM4 does it (overdoes it; due to wet
bias in W. monsoon?)
Monsoon on steroids: Make soil progressively darker
• Thermal forcing • Change soil color in this box which affects surface albedo •Following figures are differences for “strong minus weak” monsoon
forcing
Mean JJA changes in forcing region
forcing
Forcing
Biggest change in Eddies on SW corner of Tibetan High
- Δ EMFD at 200mb
Enhanced eddy torque aloft at 20-30°N
Monsoon strength
Δ zonal EMFD ΔMMC
Forcing
Δ zonal mean zonal wind
Enhanced easterlies at 20-30°N Vertical Average
latit
ude
NASH extends west with stronger Tibetan High
Monsoon forcing
Mean JJA Ψ850
global (both hemispheres) [u200]
zonal mean vertical mean <[u]>
JFM u*v* and its -d/dy
Summary • SH: Dry Feb – Wet March signal in SE Brazil • Appears related to <[u]> easterlies
– dry advection? – PV advection/ Ro wave critical line?
• Like N. Atl. July-Aug midsummer drought • Driven by NW corner of Tibetan High
• Bolivian High stationary wave [u*v*]?