1 aim epo teacher workshop, july 24, 2006 scott bailey scott m. bailey aim deputy principal...
TRANSCRIPT
1 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Scott M. BaileyAIM Deputy Principal Investigator
University of [email protected]
907-474-7741
Noctilucent CloudsA miners’ canary for global
change?
2 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Aeronomy of Ice in the Mesosphere (AIM)
Ken Sassen, Alaska
To Ground-based observers:Noctilucent or “night shining”
Clouds (NLCs)
To Satellite observers: Polar Mesospheric Clouds (PMCs)
3 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Why do noctilucent clouds shine at night?
NLC83 km
Clouds occur 50 miles above the earth surface causing them to be illuminated after sunset
4 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
PMCs display complicated structuredriven by atmospheric dynamics
BandsBandsBillowsBillows Timo Leponiemi, 2001
5 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
6 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
7 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
8 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Space Station NLC Photograph Donald Pettit, Space Station Science Officer
9 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
NLCs were NOT observed before 1850.NLCs were NOT observed before 1850.
Fogle, 1965
10 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Krakatoa injected water into the stratosphere
11 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
NLC occurrence is increasing.NLC occurrence is increasing.
Thomas and Olivero, 2001
12 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
NH NLC Occurrence Frequency is Increasing
Northern Hemisphere Observations by SBUVN
LC
Occ
urr
ence
Fre
qu
ency
(%
)
Time
Adapted from Deland et al., 2003
From SBUV
13 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Measurements show bright cloud frequency has increased.Measurements show bright cloud frequency has increased.
Satellite Measurements Reveal Brighter Clouds after Satellite Measurements Reveal Brighter Clouds after SMESME
Shettle et al., 2002
14 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
NLCs usually occur in the polar regions during a 12 week period centered about two weeks after solstice
SME defined the NLC climatology 20 years ago
15 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
A Spectacular but Unexpected Event: June 22, 1999A Spectacular but Unexpected Event: June 22, 1999
An NLC is observed and photographed at 40An NLC is observed and photographed at 40oo latitude for the first time! latitude for the first time!
16 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Low latitude PMC event; June 23, 1999
Aimee MerkelAimee Merkel
SNOE dataSNOE data
17 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
NLC increases at the beginning of the northern season
SBUV data analyzed for:
50oN to 70oN 20 to 40 days before summer solstice
Rusch, 2003
18 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
NLCs are changing
NLCs at 42oN for first time in history (Logan, Utah on June 22-23, 1999)
• Why are NLCs increasing in
frequency and brightness?
• Why were they sighted at
~40oN nearly every year now
when usually they have only been seen
poleward of 55o?
19 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Are NLCs the “miner’s canary” of global change in the upper atmosphere?
NLCs are changing
NLCs at 42oN for first time in history (Logan, Utah on June 22-23, 1999)
• Why are NLCs increasing in
frequency and brightness?
• Why were they sighted at
~40oN for 3 consecutive
summers (1999, 2000 and 2001)
when usually they are seen
poleward of 55o?
20 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
What do we know about NLC formation?
• NLC formation requires cold temperatures; thus global CO2 changes may be one cause of increasing NLCs
- CO2 buildup in the lower atmosphere causes warming, but increases in the upper atmosphere should cause cooling
• H2O chemistry must be important since NLCs consist of water ice
• Poor knowledge exists of how NLCs nucleate, the environment for nucleation and how the mesosphere responds to forcings
21 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Why do they form?
What is the role of temperature, H2O, dynamics, and chemistry?
AIM will address the critical questions
22 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Why do they vary?
Doextraterrestrialforcings suchas cosmic dustor ionizationplay a role?
AIM will address the critical questions
Why do they form?
What is the role of temperature, H2O, dynamics, and chemistry?
23 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Why have they appearedat such low latitudes (~ 40N)in recent NH summers?
AIM will address the critical questions
Why do they vary?
Doextraterrestrialforcings suchas cosmic dustor ionizationplay a role?
Why do they form?
What is the role of temperature, H2O, dynamics, and chemistry?
24 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
Is there a relationship to global change?
AIM will address the critical questions
Why have they appearedat such low latitudes (~ 40N)in 3 recent NH summers?
Why do they vary?
Doextraterrestrialforcings suchas cosmic dustor ionizationplay a role?
Why do they form?
What is the role of temperature, H2O, dynamics, and chemistry?
25 AIM EPO Teacher Workshop, July 24, 2006
Scott Bailey
• Resolve why NLCs form and how and why they vary
• Quantify the connection between the clouds and the meteorology of the polar mesosphere by measuring the thermal, chemical and dynamical environment in which NLCs form
• Provide the basis for study of long-term variability in the mesospheric climate and its relationship to global change
AIM goals are clearly defined