adventures with the first law from the earth’s surface to the edge of space

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 001 Prof. Richard SchwartzPhysics 10 Prof. Frank MossPhysics 111 Prof. John RidgenPhysics 112 Prof. John RigdenPhysics 200 Prof. Said AgamyPhysics 201 Prof. Wayne GarverPhysics 221 Prof. Jacob LeventhalPhysics 223 Prof. Bernard FeldmanPhysics 225 Prof. Bernard FeldmanPhysics 231 Prof. Peter HandelPhysics 232 Prof. Robert HightPhysics 241 Prof. Dan KelleyPhysics 310 Prof. Bernard FeldmanPhysics 311 Prof. Bernard FeldmanPhysics 331 Prof. Dan KelleyPhysics 356 Prof. Dan KelleyPhysics 381 Prof. Jacob LeventhalHallway discussions Prof. 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 ModelsGeneral 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

t

TC

t

Qp

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: CO2, O3, H2O, 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 Particlese.g., CMEs

ThermosphereT, , q

100 – 200 km

Infrared CoolingNO, CO2, O

AirglowO(1D), O2(1), etc.

ConductionTides, Waves

Thermospheric Energy Balance

ThermosphereT, , q

100 – 200 km


Observing the Infrared Energy of the Thermosphere

TANGENT POINT HoZ

}Ho

N(Ho)

ddx

x

qTpJHN

xo

),,,()(

SABER Measures Limb Radiance (W m-2 sr-1)

- 400 km to Earth Surface -

SABERMeasurements

NO (5.3 m)CO2 (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 StronglyRadiates

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/m3) (vertical profiles)

– Energy fluxes (W/m2) from thermosphere

Vertical Profile of Energy Loss by NOLatitude 77 S

Before Storm During 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 Cp

Emphasize:

• Energy loss rate in K/day does not necessarily equal the radiative cooling rate

True Cooling Rate < Energy Loss Rate

t

TC

t

Qp

NO Energy Loss Rates Expressed in K/day

Prior to Storm During Storm

Example: Cooling Rates at 52 N – April 2002

Quiescent

Storm

Vertical Profile of Energy Loss by NOLatitude 77 S

Before Storm During Storm

Vertically integrate these to get energy fluxes

Animation Vertically Integrated Thermospheric Energy Loss (W/m2)

Southern Hemisphere Polar Projection

NO Radiated Energy W m-2

2.5 mW/m2

1.5 mW/m2

0.5 mW/m2

After Mlynczak et al. 2003

Thermospheric NO Radiated Energy W m-2 Day 105

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


AirglowO(1D), O2(1), etc.

Heat

Quantuminternal

Chemicalpotential

Hot Reactions in the Mesosphere

Latent Energy in the Thermosphere and Mesosphere

UV energy absorbed primarily by O2 or O3

Energy goes into three separate pools initially: - Chemical potential energy

• Energy used to dissociate moleculeO2 + hv O + O

- Internal energyO3 + hv O2(1) + O(1D)

- 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 + O3 OH + O2

H + O2 + M HO2 + M

HO2 + O OH + O2

OH + O H + O2

O + O2 + M O3 + M

O + O + M O2 + M

O + O3 + O2 + O2

Total Solar Heating and Heating Due to Reaction of H and O3 – 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 (O3)

H + O3 OH + O2 Hf = 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 statesradiate 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, NightMay 23 2002 through July 16 2002

Energy Deposition RateH + O3 OH() + O2

H + O3 OH + O2 Energy Deposition

Cool Radiation in the Troposphere

Development and Flight of FIRST

Far-Infrared Spectroscopy of the Troposphere


Far-IR Mid-IR

Top of Atmosphere – Nadir View


Annual mean TOA fluxes for all sky conditions from the NCAR CAM

Reference: Collins and Mlynczak, Fall AGU, 2001


Mid-IRFar-IR

Clear-Sky Spectral Cooling Rate

Reference: Mlynczak et al; 1998


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 FTS @ 0.625 cm-1 spectral resolution

• IIP requires technology to be demonstrated in a relevant environment

• FIRST successfully demonstrated June 7 2005 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 7 2005

FIRST “First Light” Spectrum

H2O

O3CO2

window

Preliminary Calibration

FIRST Spectra Compared with L-b-L SimulationDemonstration 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 317.7 K– Air temperature at Ft. Sumner ~ 90 F or 305 K

• AIRS skin temperature closest to FIRST is 318.5 K

• CERES Window Channel (844 to 1227 cm-1) – Measured radiance is 41.75 W m2 sr-1 closest to FIRST– Computed radiance using ABQ sonde, 318 K skin Temp is 41.83 W m2 sr-1

– Computed radiance for 297 K skin temp is 30.76 W

Conclude that within 1 K both CERES and AIRS support FIRST skin temperature, and hence, absolute

calibration of the FIRST instrument

SOLAR

HEAT

QUANTUMINTERNAL CHEMICAL

POTENTIAL

N(4S), N(2D), ionse-, O, etc.

O2(1), OH() O2(1), CO2(2) NO(, O33

O1D

UV, Visible& Infrared

Loss

Airglow LossTrue Cooling

Energy Flow in the Upper Atmosphere

SEE

TIDI

SABERGUVI

TIDI

SABER Instrument

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

SABER Experiment Viewing Geometry and Inversion Approach

TANGENT POINT HoZ

}Ho

N(Ho)

ddx

x

qTpJHN

xo

),,,()(

VMR (q) known, infer J, infer T J known, infer q (O3, H2O, etc.)

Determine Volume Emission Rate, Derive T/t

The SABER Experiment on TIMED

Channel Wavelength Data Products Altitude Range

CO2 15.2 m Temperature, pressure, cooling rates 15-100 km



O3 9.6 m Day and Night Ozone, cooling rates 15 - 95 km

H2O 6.3 m Water vapor, cooling rates 15-80 km

CO2 4.3 m Carbon dioxide, dynamical tracer 90-160 km

NO 5.3 m Thermospheric cooling 100 - 300 km

O2(1) 1.27 m Day O3, solar heating; Night O 50-100 km

OH() 2.0 m Chemical Heating, photochemistry 80-100 km

OH() 1.6 m Chemical Heating, photochemistry 80-100 km

Observing the First Law from Space


• 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 H2O 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 CloudsQuickTime™ and aGraphics decompressorare needed to see this picture.

-50

-30

-10

10

10 30 50 70 90 110 130 150

BT

D (

250-

559.

5cm

-1 )

(K

)

Effective Size (µm)

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, 2003.

Reference: Yang et al; 2003

74.1° inclination625 km circular

4 remote sensing instruments

Mission Lifetime: 2 years (Jan. 2002 - Jan. 2004)Extended Mission: 2 years (Jan. 2004- Jan. 2006)

Concept of Infrared ‘Natural Thermostat’

Solar Storm

Energy Enters

Atmosphere

Atmosphere StronglyRadiates

SOLAR

HEAT

QUANTUMINTERNAL CHEMICAL

POTENTIAL

N(4S), N(2D), ionse-, O, etc.

O2(1), OH() O2(1), CO2(2) NO(, O33

O1D

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 mayheat the atmosphere

Also is the source of latent energy in the atmosphere

Infrared energy emitted by atmospheric speciestakes energy from thermal field and it is eventuallylost to space – true cooling of the atmosphere

Infrared emitters: CO2, O3, H2O, NO, O

Release of Latent Energy within the Atmosphere

Besides electromagnetic radiation, release of latentenergy 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 dominantmechanism for heating the atmosphere

Major Atmospheric Heating and Cooling Mechanisms

• Thermosphere– UV absorbed by O2

– Exothermic reactions

• Mesosphere– UV absorbed by O3, O2


• Stratosphere– UV, visible absorbed by O3, NO2


• Troposphere– UV, VIS. absorbed by O3, NO2, O2

– Condensation of H2O– Conduction with surface

• Thermosphere– NO at 5.3 m– O at 63 m– Heat conduction

• Mesosphere– CO2 at 15 m

• Stratosphere– CO2 at 15 m– O3 at 9.6 m– H2O> 15 m

• Troposphere– H2O > 15 m– CO2 at 15 m– O3 at 9.6 m

Heating Cooling

Major Atmospheric Heating and Cooling Mechanisms

• Mesosphere


• Thermosphere– NO at 5.3 m

• Troposphere– H2O > 15 m

Heating Cooling

How do we observe these from space?

FIRST Flight Specifics

• Launched on 11 M cu ft balloon June 7 2005• 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

adventures with the first law from the earth’s surface to the edge of space

Documents

infrared energy

energy flux

bernard feldmanphysics

infrared coolingno

dan kelleyphysics

o latent energy gain

volume of atmosphere

mesospherecool radiation