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*]?