Adventures with the First Law from the Earth’s Surface to the Edge of Space Dr. Marty Mlynczak, (B. S. Physics, 1981) NASA Langley Research Center May 5, 2006 Univ. of Missouri – St. Louis

Introduction of Co-Author

Collaborators Astronomy 001Prof. Richard Schwartz Physics 10Prof. Frank Moss Physics 111Prof. John Ridgen Physics 112Prof. John Rigden Physics 200Prof. Said Agamy Physics 201Prof. Wayne Garver Physics 221Prof. Jacob Leventhal Physics 223Prof. Bernard Feldman Physics 225Prof. Bernard Feldman Physics 231Prof. Peter Handel Physics 232Prof. Robert Hight Physics 241Prof. Dan Kelley Physics 310Prof. Bernard Feldman Physics 311Prof. Bernard Feldman Physics 331Prof. Dan Kelley Physics 356Prof. Dan Kelley Physics 381Prof. Jacob Leventhal Hallway discussionsProf. Jerry North

OUTLINE Overview of some aspects of Atmospheric Science The first law with respect to radiation and chemistry Energy conversion in the atmosphere Observing the first law from space Real-life examples! –Thermostats in the Thermosphere –Hot reactions in the Mesosphere –Cool radiation in the Troposphere – the future challenge Summary

Standard Atmosphere Profile

What is a major goal of Atmospheric Science?? To know what the atmosphere will be like at a future date and To understand the atmosphere of the past

What will the atmosphere be doing…?? Nowcasting Climate Change Weather Forecasting Atmospheric Chemistry In a few hours….In a few days…. In a few years…. In a few decades….

Atmospheric Science – A Fusion of Physics! Relevant processes cover 15 orders of magnitude Thermodynamics Quantum Mechanics Fluid DynamicsChemistry Computer Science Solar Physics Observations Computation of Atmospheric State computer model

Atmospheric Models General Equations Momentum Equation (F = ma) Conservation of Mass (Continuity) Conservation of Energy –a.k.a. the first law of thermodynamics Relates change of temperature to energy flux in a volume of atmosphere Focus on how to determine  Q /  t in the atmosphere

What is  Q /  t ? The rate at which a volume of atmosphere gains or loses energy as a result of: – Radiative processes (absorption, emission) Infrared emitters: CO 2, O 3, H 2 O, NO, O – Latent energy gain or loss Water vapor; exothermic reactions – Heat conduction Atmosphere/surface Molecular heat conduction in thermosphere

Thermospheric Energy Balance Solar EUV, UV Solar Particles e.g., CMEs Thermosphere T, , q 100 – 200 km Infrared Cooling NO, CO 2, O Airglow O( 1 D), O 2 ( 1  ), etc. Conduction Tides, Waves

Thermospheric Energy Balance Thermosphere T, , q 100 – 200 km Infrared Cooling NO, CO 2, O

Observing the Infrared Energy of the Thermosphere TANGENT POINT Ho Z } Ho N(Ho) SABER Measures Limb Radiance (W m -2 sr -1 ) km to Earth Surface - SABER Measurements NO (5.3  m) CO 2 (15  m)

Thermostats in the Thermosphere A look at radiation from Nitric Oxide (NO) during an intense geomagnetic storm How does a thermostat work?

Concept of Infrared ‘Natural Thermostat’ Solar Storm Energy Enters Atmosphere Atmosphere Strongly Radiates

April 18 April 15 SABER NO (5.3  m) Limb Radiance Before and During Storm 80 S, 350 W

Thermospheric Infrared Response NO 5.3  m enhancement by far the most dramatic in terms of overall magnitude and radiative effect Increases by over an order of magnitude in ~ 1 day Changes in NO emission are due to changes in: –NO abundance –Kinetic temperature –Exothermic production of NO vibrational levels –Atomic Oxygen Examine the Thermospheric NO response [ Mlynczak et al., GRL, 2003 ] –Energy loss profiles (W/m 3 ) (vertical profiles) –Energy fluxes (W/m 2 ) from thermosphere

Vertical Profile of Energy Loss by NO Latitude 77 S Before StormDuring Storm This is  Q/  t !

Another Perspective of the Energy Loss Rate First Law of Thermodynamics: Can express total energy loss (W m -3 ) in units of K/day Use MSIS as background atmosphere (for now) for  C p Emphasize: Energy loss rate in K/day does not necessarily equal the radiative cooling rate True Cooling Rate < Energy Loss Rate

NO Energy Loss Rates Expressed in K/day Prior to StormDuring Storm

Example: Cooling Rates at 52 N – April 2002 Quiescent Storm

Vertical Profile of Energy Loss by NO Latitude 77 S Before StormDuring Storm Vertically integrate these to get energy fluxes

Animation Vertically Integrated Thermospheric Energy Loss (W/m 2 ) Southern Hemisphere Polar Projection NO Radiated Energy W m mW/m mW/m mW/m 2 After Mlynczak et al. 2003

Thermospheric NO Radiated Energy W m -2 Day 105

Thermospheric NO Radiated Energy W m -2 Day 106

Thermospheric NO Radiated Energy W m -2 Day 107

Thermospheric NO Radiated Energy W m -2 Day 108

Thermospheric NO Radiated Energy W m -2 Day 109

Thermospheric NO Radiated Energy W m -2 Day 110

Thermospheric NO Radiated Energy W m -2 Day 111

Thermospheric NO Radiated Energy W m -2 Day 112

Thermospheric NO Radiated Energy W m -2 Day 113

Thermospheric NO Radiated Energy W m -2 Day 114

Thermospheric NO Radiated Energy W m -2 Day 115

Thermospheric NO Radiated Energy W m -2 Day 116

Thermospheric NO Radiated Energy W m -2 Day 117

Thermospheric NO Radiated Energy W m -2 Day 118

Thermospheric NO Radiated Energy W m -2 Day 119

Thermospheric NO Radiated Energy W m -2 Day 120

NO “Thermostat” Summary Dramatic increase in NO 5.3-  m emission observed in April 2002 storms (and in October 2003 storms as well) Emission increases by up to factor of 10 in ~ 1 day Effects observed from pole to equator Enhancement lasts ~ 3 days and dies out Radiative loss comparable to energy inputs – estimates being refined Physics of NO enhancement still being sorted out – –Temperature increase? –Atomic Oxygen increase? –NO increase? –Exothermic reaction emission?

Mesospheric Energy Balance Solar EUV, UV Infrared Cooling NO, CO 2, O Airglow O( 1 D), O 2 ( 1  ), etc. Heat Quantum internal Chemical potential

Hot Reactions in the Mesosphere

Latent Energy in the Thermosphere and Mesosphere UV energy absorbed primarily by O 2 or O 3 Energy goes into three separate pools initially: - Chemical potential energy Energy used to dissociate molecule O 2 + hv  O + O - Internal energy O 3 + hv  O 2 ( 1  ) + O( 1 D) - Heat Internal energy radiated to space or quenched to heat Chemical potential energy realized by exothermic reactions

Key Exothermic Reactions in the Mesosphere “The Magnificent Seven” H + O 3  OH + O 2 H + O 2 + M  HO 2 + M HO 2 + O  OH + O 2 OH + O  H + O 2 O + O 2 + M  O 3 + M O + O + M  O 2 + M O + O 3 +  O 2 + O 2

Total Solar Heating and Heating Due to Reaction of H and O 3 – Photochemical Theory After Mlynczak and Solomon, JGR, 1993 How do we measure the rate of heating due to a chemical reaction??

Chemical Heating Rates from the OH Airglow A key reaction is that of atomic hydrogen (H) and ozone (O 3 ) H + O 3  OH + O 2  H f = 76.9 kcal/mole This reaction (fortunately) preferentially populates the highest-lying vibrational quantum states,  = 9, 8, 7, 6 Due to the low density in the mesosphere, these states radiate copious amounts of energy Rate of emission from OH proportional rate of reaction Measure emission rate, readily derive rate of heating

Time-Lapse Movie Zonal Mean, Night May through July Energy Deposition Rate H + O 3  OH(  ) + O 2

H + O 3  OH + O 2 Energy Deposition

Cool Radiation in the Troposphere Development and Flight of FIRST Far-Infrared Spectroscopy of the Troposphere

Far-Infrared Spectroscopy of the Troposphere Far-IRMid-IR Top of Atmosphere – Nadir View

Far-Infrared Spectroscopy of the Troposphere Annual mean TOA fluxes for all sky conditions from the NCAR CAM Reference: Collins and Mlynczak, Fall AGU, 2001

Far-Infrared Spectroscopy of the Troposphere Mid-IR Far-IR Clear-Sky Spectral Cooling Rate Reference: Mlynczak et al; 1998

Far-Infrared Spectroscopy of the Troposphere Observed Unobserved Spectrally Integrated Cooling – Mid-IR vs. Far-IR Reference: Mlynczak et al; 1998

FIRST – Overview Program developed under NASA Instrument Incubator Program (IIP) Develop technology necessary for routine measurement from space of the far-infrared spectrum 15 to 100  m Many compelling science issues (greenhouse effect; cirrus etc.) FIRST is a Michelson cm -1 spectral resolution IIP requires technology to be demonstrated in a relevant environment FIRST successfully demonstrated June on high altitude balloon from Ft. Sumner, NM

FIRST Balloon Payload System Interferometer Cube Aft Optics LN2 Volume Beamsplitter Polypropylene Vacuum Window Remote Alignment Assembly Scatter Filter Scene Select Mirror Scene Select Motor Interdewar Window Active LN2 Heat Exchanger Passive LN2 Heat Exchanger

FIRST on the Flight Line June

FIRST “First Light” Spectrum H2OH2O O3O3 CO 2 window Preliminary Calibration

FIRST Spectra Compared with L-b-L Simulation Demonstration of FIRST Recovery of Spectral Structure Note: FIRST, LbL spectra offset by 0.05 radiance units

FIRST Lands Safely after a Successful Flight

Closing Thoughts Atmospheric energetics and radiation remain a frontier of research Unique space-based assets now observing the heat balance of the mesosphere and lower thermosphere New technology being developed to allow a more comprehensive determination of the tropospheric energy balance and climate PHYSICS RULES!

Extras

FIRST – Status and Summary FIRST successfully completed technology demonstration flight 6/2005 –Met or exceeded technology goals Preliminary calibration applied here from flight blackbody Measured entire thermal emission spectrum on one focal plane with one instrument Agreement in window with CERES, AIRS is excellent Fidelity of measured far-IR spectra with L-b-L codes is outstanding Continuing to improve calibration: –Absolute cal. using laboratory and flight blackbodies –Improved phase corrections Anticipate deployment in future campaigns and science opportunities

FIRST, AIRS, and CERES Window Radiance Comparisons Four AIRS footprints very close to FIRST Several CERES Window channel footprints close to FIRST FIRST Radiance at 900 cm -1 is 0.15 W m -2 sr cm -1 –Corresponds to a skin temperature of K –Air temperature at Ft. Sumner ~ 90 F or 305 K AIRS skin temperature closest to FIRST is K CERES Window Channel (844 to 1227 cm -1 ) –Measured radiance is W m 2 sr -1 closest to FIRST –Computed radiance using ABQ sonde, 318 K skin Temp is W m 2 sr -1 –Computed radiance for 297 K skin temp is W Conclude that within 1 K both CERES and AIRS support FIRST skin temperature, and hence, absolute calibration of the FIRST instrument

SOLAR HEAT QUANTUM INTERNAL CHEMICAL POTENTIAL N( 4 S), N( 2 D), ions e -, O, etc. O 2 ( 1  ), OH(  ) O 2 ( 1  ), CO 2 ( 2 ) NO( , O 3  3  O  1 D  UV, Visible & Infrared Loss Airglow LossTrue Cooling Energy Flow in the Upper Atmosphere

SEE TIDI SABER GUVI TIDI

SABER Instrument 75 kg, 77 watts, 77 x 104 x 63 cm, 4 kbs

SABER Experiment Viewing Geometry and Inversion Approach TANGENT POINT Ho Z } Ho N(Ho) VMR (q) known, infer J, infer TJ known, infer q (O 3, H 2 O, etc.) Determine Volume Emission Rate, Derive  T/  t

The SABER Experiment on TIMED ChannelWavelength Data Products Altitude Range CO  mTemperature, pressure, cooling rates km CO  mTemperature, pressure, cooling rates km O  mDay and Night Ozone, cooling rates km H 2 O6.3  mWater vapor, cooling rates km CO  mCarbon dioxide, dynamical tracer km NO5.3  mThermospheric cooling km O 2 ( 1  )1.27  mDay O 3, solar heating; Night O km OH(  ) 2.0  mChemical Heating, photochemistry km OH(  )1.6  mChemical Heating, photochemistry km Observing the First Law from Space

Far-Infrared Spectroscopy of the Troposphere Up to 50% of OLR (surface + atmosphere) is beyond 15.4  m Between 50% and 75% of the atmosphere OLR is beyond 15.4  m Basic greenhouse effect (~50%) occurs in the far-IR Clear sky cooling of the free troposphere occurs in the far-IR Radiative feedback with H 2 O and greenhouse gas increase is in the far-IR Cirrus radiative forcing has a major component in the far-IR Longwave cloud forcing in tropical deep convection occurs in the far-IR Improved water vapor sensing is possible by combining the far-IR and standard mid-IR emission measurements Direct Observation of Key Atmospheric Thermodynamics Compelling Science and Applications in the Far-Infrared

FIRST – Sensitivity to Cirrus Clouds Brightness temperature difference between two channels 1 =250.0 cm -1 and 2 =559.5 cm -1 as a function of effective particle size for four cirrus optical thicknesses FIRST spectra can be used to derive optical thickness of thin cirrus clouds (  < 2). Reference: Yang et al., JGR, Reference: Yang et al; 2003

74.1° inclination 625 km circular 4 remote sensing instruments Mission Lifetime: 2 years (Jan Jan. 2004) Extended Mission: 2 years (Jan Jan. 2006)

Concept of Infrared ‘Natural Thermostat’ Solar Storm Energy Enters Atmosphere Atmosphere Strongly Radiates

SOLAR HEAT QUANTUM INTERNAL CHEMICAL POTENTIAL N( 4 S), N( 2 D), ions e -, O, etc. O 2 ( 1  ), OH(  ) O 2 ( 1  ), CO 2 ( 2 ) NO( , O 3  3  O  1 D  UV, Visible & Infrared Loss Airglow LossTrue Cooling Solar Energy Deposition in the Atmosphere

Radiative Energy within the Atmosphere Radiant energy from the Sun is absorbed and may heat the atmosphere Also is the source of latent energy in the atmosphere Infrared energy emitted by atmospheric species takes energy from thermal field and it is eventually lost to space – true cooling of the atmosphere Infrared emitters: CO 2, O 3, H 2 O, NO, O

Release of Latent Energy within the Atmosphere Besides electromagnetic radiation, release of latent energy within the atmosphere causes it to heat 1.Condensation of water vapor – troposphere 2.Exothermic reactions in the upper atmosphere In many regions, latent energy release is the dominant mechanism for heating the atmosphere

Major Atmospheric Heating and Cooling Mechanisms Thermosphere –UV absorbed by O 2 –Exothermic reactions Mesosphere –UV absorbed by O 3, O 2 –Exothermic reactions Stratosphere –UV, visible absorbed by O 3, NO 2 –Exothermic reactions Troposphere –UV, VIS. absorbed by O 3, NO 2, O 2 –Condensation of H 2 O –Conduction with surface Thermosphere –NO at 5.3  m –O at 63  m –Heat conduction Mesosphere –CO 2 at 15  m Stratosphere –CO 2 at 15  m –O 3 at 9.6  m –H 2 O  > 15  m Troposphere –H 2 O > 15  m –CO 2 at 15  m –O 3 at 9.6  m HeatingCooling

Major Atmospheric Heating and Cooling Mechanisms Mesosphere –Exothermic reactions Thermosphere –NO at 5.3  m Troposphere –H 2 O > 15  m HeatingCooling How do we observe these from space?

FIRST Flight Specifics Launched on 11 M cu ft balloon June Float altitude of 27 km Recorded 5.5 hours of data 1.2 km footprint of entire FPA; 0.2 km footprint per detector 15,000 interferograms (total) recorded on 10 detectors Overflight of AQUA at 2:25 pm local time – AIRS, CERES, MODIS Essentially coincident footprints FIRST, AQUA instruments FIRST met or exceeded technology development goals –Optical throughput demonstrated by spectra from center and edge of focal plane detectors –Exceeded spectral bandpass – 20 to 1600 cm -1 demonstrated vs. 100 to 1000 cm -1 required FIRST, AIRS, CERES comparisons in window imply excellent calibration (better than 1 K agreement in skin temperature) FIRST records complete thermal emission spectrum of the Earth at high spatial and spectral resolution

FIRST Spectra Comparisons with L-B-L using AIRS Retrievals L-b-L does not yet include FIRST Instrument Response Functions