Methodic of measurement Methodic of measurement the greenhouse gasesthe greenhouse gases

Gnedykh V.Gnedykh V.,, and work team and work team of experiments: RUSALKA and ORAKULof experiments: RUSALKA and ORAKUL

Main speciesMain species

- water vapor, strong time variation- water vapor, strong time variation - CO2 contents from - CO2 contents from 280 280 toto 370 ( 370 (ppmppm) )

40 years measurements show - half 40 years measurements show - half anthropogenic CO2 rest in atmosphere rest anthropogenic CO2 rest in atmosphere rest absorbed by ocean and continental absorbed by ocean and continental ecosystems. ecosystems.

- CH4. It is estimates that emission CH4 in - CH4. It is estimates that emission CH4 in atmosphere is atmosphere is 500 м500 мtt per per yearyear now. now.

Differential absorption methodDifferential absorption method

These technique requires These technique requires knowledge knowledge of reference spectrum and the absorption of reference spectrum and the absorption spectra of atmospheric species. For the spectra of atmospheric species. For the case of direct solar spectra measurements case of direct solar spectra measurements the reference spectrum is extraterrestrial the reference spectrum is extraterrestrial spectrum. spectrum.

The measurement with small spectra The measurement with small spectra resolution not permit get high precision for resolution not permit get high precision for contents the CO2. contents the CO2. ((Dufour and BreonDufour and Breon, , 2000). 2000).

Solar spectraSolar spectra

Sketch of measurementSketch of measurementWWe select next bands for e select next bands for

measurements :measurements :

CO2 - 1.58 mkm, CH4 CO2 - 1.58 mkm, CH4 - 1.64 mkm.- 1.64 mkm.

- solar occultation - solar occultation method (satellite)method (satellite)

- space measurement - space measurement solar light reflected by solar light reflected by the surface (ISS)the surface (ISS)

- direct solar - direct solar measurement frommeasurement from

For clear atmosphere For clear atmosphere

The law :The law :

II00 – extraterrestrial flux– extraterrestrial flux

ll – path the solar – path the solar lightlight in atmosphere in atmosphere

– – optical thicknessoptical thickness

))(exp()( 0 lIlI

z

dzzz ')'()(

Real look from spaceReal look from space

Solar Solar glareglare on India on India ricerice fields fields

Initial dataInitial data - - solar spectra with resolution high than NIR solar spectra with resolution high than NIR

HRS resolutionHRS resolution,, - - line line position and position and strengthstrength for selected for selected

spectra bands ,spectra bands , - time of measurement,- time of measurement, - coordinate the searching point- coordinate the searching point,, - coordinate ISS,- coordinate ISS, - sun angels- sun angels - - pressurepressure and temperature in searching and temperature in searching

points .points .

Numerical model for CO2Numerical model for CO2

Absorption lines of molecular oxygenAbsorption lines of molecular oxygen OO22 at at 00..76 76 µm bandµm band, ,

recorded during ground- based solar observations recorded during ground- based solar observations (Tarusa town, Industrial division of IKI(Tarusa town, Industrial division of IKI, 11:39, 24.06.20, 11:39, 24.06.20005)5)

The causes of errorThe causes of error

1. High-altitude distribution:1. High-altitude distribution:humidity humidity cloudscloudsaerosol ( dimension)aerosol ( dimension) temperaturetemperature..

2. In searching points :2. In searching points : - coefficient reflection or scattering the - coefficient reflection or scattering the

surfacesurface

The cloud and aerosol effectThe cloud and aerosol effect

Referent channel Referent channel The O2 A-band is used for assessing The O2 A-band is used for assessing

path length distribution because it offers path length distribution because it offers important practical advantages: the vertical important practical advantages: the vertical profile of O2 is well known; no other known profile of O2 is well known; no other known absorbers interfere with the O2 A-band absorbers interfere with the O2 A-band absorption and the O2 A-band provides a absorption and the O2 A-band provides a number of absorption lines covering a number of absorption lines covering a suitable dynamic range of opacities in the suitable dynamic range of opacities in the atmosphere. (Q.-L. Min, 2004)atmosphere. (Q.-L. Min, 2004)

The 1.27 mkm. band is more The 1.27 mkm. band is more preferable but emission in band effect on preferable but emission in band effect on data accuracy. data accuracy.

Ground measurementsGround measurements

PressurePressure, temperature and humidity in , temperature and humidity in searching points,searching points,

sun angels,sun angels, long time measurements, long time measurements, simultaneous with satellite measurements,simultaneous with satellite measurements, compare with different instruments datacompare with different instruments data..

Pace experiment RUSALKAPace experiment RUSALKA

LLiteratureiterature

Dufour E., F.-M. Breon, 2000. Spaceborne Dufour E., F.-M. Breon, 2000. Spaceborne estimate of atmospheric CO2 column by use estimate of atmospheric CO2 column by use of the differential absorption method: error of the differential absorption method: error analysis. Appl. Opt. analysis. Appl. Opt. 42, 42, 3595-3609.3595-3609.

Q.-L. Min, L. C. Harrison, P. Kiedron, and J. Q.-L. Min, L. C. Harrison, P. Kiedron, and J. Berndt. Berndt. A high-resolution oxygen A-band A high-resolution oxygen A-band and water vapor band spectrometer and water vapor band spectrometer J.G.R. Vol.109, 2004J.G.R. Vol.109, 2004