Transcript 100304Nowhere_ATrainInformationSlidesForNASA_YuanHouze.ppt

Mesoscale Convective System Anvils
from A-Train Satellite Data
by
Jian Yuan and Robert A. Houze, Jr.
University of Washington
Motivation
• Mesoscale Convective Systems (MCSs) are major
precipitating cloud systems of the tropics
• MCSs strongly affect heating patterns in the
tropics
• The raining and non-raining portions have
different effects
• Until A-Train, it has been nearly impossible to
distinguish the non-raining “anvil” portions,
which reflect and transmit radiation
• This study solves the problem!
A-Train Strategy for the Study
• MCSs are characterized by wide and cold cloud
tops—MODIS shows these.
• MCSs also characterized by large rain areas with
some portions of very heavy rain—AMSR-E shows
these.
• Large “anvils” can be distinguished by looking at the
MODIS cloud tops not over the AMSR-E rain areas.
• CloudSat shows the internal structure of the anvil.
• From the internal structure we can compute the
radiation in the anvil.
Visual of the strategy
Step 1:
MODIS identifies the wide cold cloud tops, which
characterize MCSs.
Step 2:
AMSR-E distinguishes the raining cores of the MCSs
from the non-raining anvil clouds.
Result of Steps 1 & 2:
Combination of MODIS & AMSR-E show,
for the first time, the global frequency of
occurrence of MCS anvil clouds.
Step 3:
CloudSat detects the top, bottom, and interior
structure of the non-raining anvils.
ANVIL
ANVIL
Results of Step 3:
CloudSat analysis allows comparison of anvil clouds
in different regions of the world.
What comes next:
We will now be able to determine
the radiative effects of tropical MCSs
on the global circulation.
Here, some estimated radiative heating rates have been applied as
a test case to our A-Train derived global distribution of anvil cloud
This research is sponsored by NASA grant NNX07AQ89G and DOE
grant ER64752