1 / 56

James M. Russell III Principal Investigator Hampton University Scott M. Bailey

James M. Russell III Principal Investigator Hampton University Scott M. Bailey Deputy Principal Investigator Virginia Tech November 17, 2009. AIM End of Prime Mission Review Science Results. Aeronomy of Ice in the Mesosphere (AIM). Unprecedented advances in

caitir
Download Presentation

James M. Russell III Principal Investigator Hampton University Scott M. Bailey

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. James M. Russell III Principal Investigator Hampton University Scott M. Bailey Deputy Principal Investigator Virginia Tech November 17, 2009 AIM End of Prime Mission Review Science Results

  2. Aeronomy of Ice in the Mesosphere (AIM) • Unprecedented advances in observation of noctilucent clouds • - Solar occultation • - Panoramic UV nadir imaging • - In-situ and remotely sensed dust • Major step forward in understanding noctilucent clouds, their formation and variability • - World class science team • - State of the art modeling

  3. Principal Investigator: James M. Russell III Hampton University Deputy PI: Scott M. Bailey Virginia Tech Co-Investigators Gary Thomas, CU Cora Randall, CU David Rusch, CU David Siskind, NRL Michael Taylor,USU Michael Stevens, NRL Larry Gordley, GATSMihály Horányi, CU Patrick Espy, NTNU Michael Summers, GMU Mark Hervig, GATS Christoph Englert, NRL William McClintock, LASP Steven Eckermann, NRL AIM Science Team

  4. Noctilucent Clouds and Polar Mesospheric Clouds are the same phenomenon Tom Eklund, July 28, 2001, Valkeakoski, Finland • Ground-based observers: Noctilucent Clouds (NLCs) • Satellite observers: Polar Mesospheric Clouds (PMCs)

  5. NLCs display complicated structure driven by atmospheric dynamics Billows Bands Timo Leponiemi, 2001

  6. AIM overview and science results outline • Brief mission overview • What we know about NLCs • AIM goals, objectives and Level 1 requirements • AIM instruments and measurements • Science results • Summary

  7. AIM was launched from VAFB by a Pegasus XL rocket • April 25, 2007, 1:26:03 PM PDT launch • Near perfect 600 km orbit • First satellite mission dedicated to the study of NLCs • Observed five seasons thus far • Extended mission approved for June 1, 2009 to September 30, 2012

  8. NLCs have been photographed from the ground Omaha, NB July 14, 2009 Mike Hollingshead Omaha, NB Photo July 14, 2009

  9. NLCs have been photographed from the ground, aircraft Commercial airline NLC Photo John Boardman, Pilot Omaha, NB July 14, 2009 Mike Hollingshead Omaha, NB Photo July 14, 2009 Commercial airline NLC Photo John Boardman, Pilot

  10. NLCs have been photographed from the ground, aircraft and space Commercial airline NLC Photo John Boardman, Pilot Omaha, NB July 14, 2009 Mike Hollingshead Omaha, NB Photo July 14, 2009 Commercial airline NLC Photo John Boardman, Pilot Space Station NLC Photo Donald Pettit, Science Officer Space Station NLC Photo Donald Pettit, Science Officer

  11. NLCs have been photographed from the ground, aircraft and space Commercial airline NLC Photo John Boardman, Pilot Omaha, NB July 14, 2009 Mike Hollingshead Omaha, NB Photo July 14, 2009 Commercial airline NLC Photo John Boardman, Pilot There has been a growing public and scientific interest in these clouds in recent years Space Station NLC Photo Donald Pettit, Science Officer Space Station NLC Photo Donald Pettit, Science Officer

  12. NLCs capture the imagination and concern of the public Mysterious, Glowing Clouds Appear Across America’s Night Skies By Alexis Madrigal, July 16, 2009  |  1:00 pm  |  WIRED SCIENCE “Photographers and other sky watchers in Omaha, Seattle, Paris and other locations have run outside to capture images of what scientists call noctilucent (”night shining”) clouds.” Scientists seek noctilucent cloud enlightenment By Lester Haines, New Scientist, UK June 3, 2009 “According to New Scientist, skywatchers last week snapped the first examples of the clouds, although NASA's AIM spacecraft got the first indications back on 22 May.” Discover Magazine interview to appear in February 2010 CBS Evening News segment (3 minutes) on March 14, 2008 NPR and WTOP-DC radio segments, image in Nature magazine, more than 50 public media articles worldwide

  13. Usually seen poleward of 55O but have been sighted at ~ 40ON in recent years Have been getting brighter and occurring more frequently over the last 27 years SH NH 50o – 82o S 50o – 82o N Average Brightness Average Brightness -80 -60 -40 -20 0 20 ºC Temperature 2000 2000 1980 1980 1995 1995 2005 2005 1985 1985 1990 1990 NLCs are changing in ways we do not understand Earth’s Atmosphere 100 80 60 Altitude (km) 40 20 Troposphere 0 DeLand, Shettle, Thomas, and Olivero (JGR, vol. 112, D10315, 2007)

  14. What could be causing the observed PMC changes? Three things are needed for PMC formation • Water vapor • Presence of particles • Cold temperatures

  15. While not proven, the most plausible reasons for long-term NLC change are CO2 and CH4 increases • CO2 increases in the lower atmosphere cause the the atmosphere to warm • The same increases at 83km cause cooling • CH4 increases lead to more water vapor in the atmosphere • Both effects make conditions more favorable for NLCs to form

  16. NLCs are ice clouds that occur more than 70km above tropospheric clouds • Why do these clouds form and vary? • Why are long-term changes • occurring? • Is there a connection with • global change? AIM July 4, 2008

  17. 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

  18. H2O H HO2 CH4 O1D, hn OHO1D hn O2, M O3 O O OH The fundamental question: Why do PMCs form and vary? AIM is providing the answers 1. Microphysics 2. Gravity Wave Effects 3. Temperature Variability 5. Nucleation Environment 6. Long-term Mesospheric Change - What is needed? 4. Chemistry

  19. AIM Level 1 science baseline and minimum missions *CDE instrument is not included in the minimum mission

  20. Three Instruments on the AIM observatory Cosmic Dust Experiment (CDE) measures the input of cosmic dust into the atmosphere Solar Occultation for Ice Experiment (SOFIE) T, H2O, Ice mass, cosmic dust Cloud Imaging Particle Size (CIPS) Nadir images Cloud particle size

  21. CIPS: Cloud Imaging and Particle Size Experiment Four CCD cameras image NLCs at ~ 83 km •   0.265 µm; 1 X 2.5 km pixel size • Cloud morphology and particle sizes

  22. SOFIE: Solar Occultation for Ice Experiment A 16-band differential absorption radiometer (UV to IR) to simultaneously measure cloud properties and the PMC environment • Operates over 0.3m to 5.3 m range • T, NLCs, CO2, H2O, CH4, NO, O3, aerosols, cosmic smoke • 2 km vertical resolution

  23. CDE: Cosmic Dust Experiment 14 polyvinylidene fluoride detectors to measure the incoming cosmic dust flux • Differential mass measurements for masses, 10 -11<m < 10 -8 g • Cumulative mass measurements for masses, m > 10 - 8 g • Data span June 2007 to Feb 2008 - CDE data showed increased noise after February 2008 S/C safehold • Data loss mitigated by SOFIE cosmic smoke measurements

  24. SOFIE H2O, Ice, T, Chemistry AIM observing approach: SOFIE

  25. AIM observing approach: SOFIE, CIPS CIPS Ice images 6 min

  26. AIM observing approach: SOFIE, CIPS, CDE o o CDE o o o o o o o o o Cosmic Dust 6 min

  27. A space view gives an entirely new picture of what the clouds look like: 60N Tom Eklund, July 28, 2001, Valkeakoski, Finland Ground AIM Jul 8, 2008 NH • NLCs occur all the time • Highly variable orbit-to-orbit and day-to-day • More structure than expected

  28. One orbit of CIPS data in July 2008

  29. 11-Jul-2008 Three successive orbits on July 15, 2007 NP NP Min Lat = 60N 60N

  30. 6-Jul-2008 NP NP Min Lat = 60N 60N

  31. AIM science focus before launch was on a narrow visible NLC layer centered around 83 km 92 90 88 86 Altitude 84 82 80 78 1-Jun 1-Jul 1-Aug 1-Sep 2007 Ice Void

  32. AIM observed subvisible ice particles for the first time 92 90 88 86 Altitude 84 82 80 78 1-Jun 1-Jul 1-Aug 1-Sep 2007 Ice Void • High SOFIE sensitivity SNR ~106 • Ice exists from 78km to ~ 90km • Visible layer centered at ~ 83km

  33. AIM observed subvisible ice particles for the first time and showed NLCs are highly variable with “Ice Voids” 92 90 Ice Void 88 86 Altitude 84 82 80 78 1-Jun 1-Jul 1-Aug 1-Sep 2007 • CIPS shows the presence of • “Ice voids” • An entirely new mechanism for • NLC formation • Not known before the AIM launch Ice Void • High SOFIE sensitivity • Ice exists from 78km to ~ 90km • Visible layer centered at ~ 83km

  34. What is the role of temperature and water vapor in the formation of PMCs?

  35. Temperature is a controlling factor in PMC formation CIPS PMC frequency at 77º latitude and SABER temperature Merkel et al., 2007

  36. SOFIE PMC altitude and SABER mesopause - 3.5 km for 2007 - 2008 NH/SH seasons 10d Mesopause temperature is a driver for PMC peak altitude formation Russell et al., 2009

  37. SOFIE PMC ice mass density and MLS saturation vapor pressure and vapor pressure Sharply decreasing saturated vapor pressures at season start and rapidly rising values at the end point to temperature as the dominant factor in controlling the beginning and ending of PMC season Black dots: Mesopause vapor pressure Red dots: Mesopause saturated vapor pressure Blue line: Ice mass density

  38. The NLC season turns on and off like a geophysical light bulb providing clues to why NLCs form Northern Hemisphere Southern Hemisphere

  39. How do planetary waves and gravity waves affect PMC formation and destruction?

  40. CIPS sequenceofdaily images showing the influence of the 5-day wave on PMCs June 5 June 3 June 4 June 7 June 6 June 8 June 9 June 10 June 11 June 12 Merkel et al., 2007 Sequence of CIPS Daisies showing 5-day wave June 3 June 4 June 5 June 6 June 7 Merkel et al., 2007

  41. NRL NOGAPS model and SOFIE data show that dynamics can extend the length of the PMC season Time Temperature wavelet amplitudes (grey and black) Observed SOFIE clouds for ice >30 ng/m3 (white dots) The atmospheric 5-day wave modulates PMC occurrence and can effectively extend the period of PMC occurrence by providing many days of localized regions of saturated air in the trough of the wave. Nielsen et al., 2009

  42. Gravity wave frequency, PMC frequency and SABER temperature amp for 2007/2008 SH season CIPS PMC observations Correlation with PMC -0.94 Correlation with SABER temperature0.72 Chandran et al., 2009

  43. What are the mechanisms leading to hemispheric coupling effects on PMC formation?

  44. CIPS NH frequency of PMC occurrence AIM NH PMC data and MLS SH Temp show that the atmosphere is a coupled global system Karlsson et al., 2009

  45. What is the role of cosmic dust in PMC formation?

  46. SOFIE has provided the first satellite observations of meteoric smoke particles 2007 2008 2009 Cosmic smoke flux into the atmosphere is constantly changing and is at a minimum during the PMC season. (White area extinction < 6 x 10-9 km-1) Hervig et al., 2009

  47. SOFIE cosmic smoke particles and models at ~ 60 km show excellent agreement 2008 2009 10-D average cosmic smoke particle extinctions normalized to the respective peak value in each time series Hervig et al., 2009

  48. What is needed to establish a physical basis for the study of mesospheric climate change and its relationship to global change?

  49. Significant progress has occurred in multi-dimensional PMC modeling On the left are shown 30 years of PMC brightness observations by SBUV at three latitudes (DeLand et al. 2007). On the right are modeled PMC brightness for the same time and locations by Marsh and Merkel (2009). The model results are in excellent agreement with observed trends. 27 Year PMC Data Set 30 Year WACCM Model Run

More Related