CEDAR Frontiers: Climate Change and the Role of the Mesosphere

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CEDAR Frontiers Climate Change and the Role of
the Mesosphere

• Wave interaction with the Mesosphere
• Tidal, planetary, and gravity waves forced in the
  troposphere and stratosphere produce observed
  mesospheric signatures.
• Specific sources of mesosignatures not
  identified.
• Longer term changes are poorly understood.

• Long-term Changes
• The CEDAR database extends at least to 1980s.
• Two solar cycles of mesospheric observations
  available.

• Propose studies
• Identify sources of waves affecting mesospheric
  signatures.
• Document possible long-term changes.

Charles Deehr, Geophysical Institute,
cdeehr_at_gi.alaska.edu
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CEDAR Databases Mesospheric Signatures of Lower
Altitude Processes
Temperatures and Winds Models estimates suggest a
decline in MLT temperature associated with
increases in CO2 and N2O concentrations. Models
have addressed only the thermodynamic and
radiative transfer aspects of the problem for a
global mean. Long-term dynamic changes strongly
affect the filtering of gravity waves, offering a
continuing challenge for modelling efforts.
Long-term observations are ambiguous regarding
the direction of changes. Identification of the
sources of variations on all time scales will
help sort out the relative contribution of these
sources to long-term change.
Clouds Noctilucent clouds (NLC) and polar
mesospheric clouds (PMC) may be an indicator of
long-term global climate change. The new AIM
satellite will provide an incentive for
coordinated observations and identification of
signatures.
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Possible CEDAR Campaign Climate Change and the
Role of the Mesosphere

• Coordinated examination of CEDAR database for
  long-term relevant observations.
• Identification of ongoing observing network.
• Coordinated campaigns of observations with best
  possible coverage of latitude, longitude and
  time.
• Emphasis on observations coordinated with
  relevant satellites (TIMED, AIM).

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CEDAR Frontiers Climate Change and the Role of
the Mesosphere

• GOALS
• Identify sources of waves that couple to the
  mesosphere from below.
• Model dynamic processes.
• Identify long-term variations in the mesospheric
  signatures and by extension the variation in the
  sources of these signatures.