B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Remote Sensing I Atmospheric Microwave Remote Sensing Summer 2007 Björn-Martin Sinnhuber Room NW1 - U3215 Tel

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Contents Chapter 1Introduction Chapter 2Electromagnetic Radiation Chapter 3Radiative Transfer through the Atmosphere Chapter 4Weighting Functions and Retrieval Techniques Chapter 5Atmospheric Microwave Remote Sensing: A short review of spectroscopy Chapter 6Atmospheric UV/visible Remote Sensing Chapter 7Radar and Sea Ice Remote Sensing Chapter 8Remote Sensing of Ocean Colour

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Chapter 5 Atmospheric Microwave Remote Sensing Ground-based microwave remote sensing A short review of microwave spectroscopy

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Radiometer for Atmospheric Measurements (RAM)

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 NDSC Stadion at Ny-Alesund, Spitsbergen (79°N)

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Observations in Spitsbergen (79°N)

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007

Principle of the Radiometer for Atmospheric Measurements

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Measured Microwave Spectrum by the RAM

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Pressure Broadening of Spectral Lines 50km / 0.5 hPa 20km / 50 hPa 10km / 200 hPa

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Weighting Functions for Ozone Retrieval

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Retrieval techniques / Inverse Modelling Assume that the measured spectrum y is a known function of the atmospheric profile x plus some noise ε. Linearize F (also known as the forward model):

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 However, can not be directly inverted (ill-posed problem) Optimal Estimation A-priori profile A-priori profile covariance matrix Measurement error covariance matrix Best guess profile Best estimate given by Optimal Estimation solution:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Example Ozone Profile: RAM vs. Ozonesonde

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Optimal Estimation: Averaging Kernels Optimal estimation solution: Define: Then: Define Averaging Kernel Matrix A = GK:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Averaging Kernel Functions

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Chapter 5 Atmospheric Microwave Remote Sensing Ground-based microwave remote sensing A short review of microwave spectroscopy

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Molecular Rotations Diatomic molecule:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Energy (classical) rotational Energy angular momentum moment of inertia

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Molecular Rotations: Moments of Inertia Diatomic molecule:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Molecular Rotations: Moments of Inertia

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Molecular Rotations: Moments of Inertia reduced mass:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Energy (classical) classically:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Energy (quantum mechanics) Quantum mechanics: For linear molecules:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotation: Energy Levels Angular momentum is quantized:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotation: Energy Levels Express energy in terms of wave numbers: remember:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotation: Energy Levels with Rotational Constant B: write as

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Energy Levels JF(J)

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Transitions

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Transitions allowed transitions:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Microwave Spectrum of HCl

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Rotational Constant with μ the (reduced) mass of the molecule and r the bond length. Difference between two rotational lines given by 2B, where B is the rotational constant:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Microwave Spectrum of ClO

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Intensities of Rotational Lines Probability for transition between level l and level u depends on the difference of molecules in level l and u In thermal equilibrium given by Boltzmann distribution: (tends to decrease with increasing J)

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Intensities of Rotational Lines Depends also on degenaracies of the levels: (tends to increase with increasing J) Why?

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Degeneracies of Rotations posible orientations J=1

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Degeneracies of Rotations J=2 J=3

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Intensities of Rotational Lines Depends also on degenaracies of the levels: (tends to increase with increasing J) Overall proportional to:

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Intensities of Rotational Lines May be used to derive temperature from observed spectrum

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Microwave Spectrum of ClO

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Microwave Spectrum of N 2 O

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Microwave Spectrum of H 2 O

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 The N2O Molecule NNO N2O is a linear molecule

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 The Water Molecule O HH nm °

B.-M. Sinnhuber, Remote Sensing I, University of Bremen, Summer 2007 Microwave Spectrum of Ozone