cloud- radiative driving of the madden-julian oscillation as seen by the a-train
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Cloud- Radiative Driving of the Madden-Julian Oscillation as Seen by the A-Train. Tony Del Genio Yonghua Chen , CloudSat /CALIPSO Meeting, 11/3/14. The MJO: Many independent studies that agree High-quality obs The models are t errible They haven’t gotten b etter in a decade. - PowerPoint PPT PresentationTRANSCRIPT
Cloud-Radiative Driving of the Madden-Julian Oscillation as Seen by the A-Train
Tony Del GenioYonghua Chen
, CloudSat/CALIPSO Meeting, 11/3/14
(Flato et al. 2014, IPCC AR5 WG1, Chapter 9)
The MJO:
- Many independentstudies that agree
- High-quality obs
- The models areterrible
- They haven’t gottenbetter in a decade
What makes the MJO? (from Adam Sobel’s 2013 EUCLIPSE lecture)
Let h = moist static energy = cpT + gz + Lq (vertically integrated)S = sources and sinks of h (advection, surface fluxes, radiation)
So dh/dt = S; this is called a “moisture mode”
(depends on sensitivity of convection to moisture)
(depends on correlation of radiative heating or surface evaporation with precip)
10 MJOs,2006-2010
GEOPROF-LIDAR GISS GCM, DYNAMO
No MJO
Good MJO
ECMWF-AUX inputs intoFLXHR-LIDAR heatingappear to be reasonablefor MJO anomalies
OLR a good proxy for net heating anomaly; largest in Indian Oceanand ~5 days in advance of MJO peak
Maximum radiative heating anomaly occurs beforeMJO peak, but positive anomalies continue long after
precipitation returns to normal
peak
s
time
SW anomaly mostly opposes LW, but both stabilize onset region
FLXHR-LIDAR minus FLXHR heating differences vs. MJO phase – thin cirrus matter to onset phase
- Magnitude of observed OLR, rain anomalies comparable to that in good MJO models for 2009 YOTC Event E hindcast
- Strong OLR’-P’ correlation supports idea of cloud-radiative driving of MJO
ISCCP-TMI
(good MJO)
(no MJO)
Summary• GEOPROF-LIDAR convection depth vs. AMSR-E CWV appears to
be a good metric for GCM cumulus parameterizations; consistent with moisture mode ideas about MJO eastward propagation
• OLR a good proxy for total column radiative heating anomaly, but SW absorption affects the profile and reinforces upper level heating near MJO onset
• Cirrus heating also appears to play a role before MJO onset (Kelvin waves?)
• Cloud-radiative feedback likely to be the driver of the MJO; well correlated with precipitation anomalies, though cloud anomalies persist as rain decreases
• It is now possible for GCMs to make MJOs, and even perhaps for the right reason