Preface 1. Basic properties of radiation, atmospheres and oceans 2. Basic state variables 3. Interaction of radiation with matter 4. Formulation of radiative transfer problems 5. Approximate solutions of prototype problems 6. Accurate numerical solutions of prototype problems 7. Emission-dominated radiative processes 8. Radiative transfer in spectrally-complex media 9. Solar radiation driving photochemistry and photobiology 10. The role of radiation in climate Appendix 1. A primer on radiative transfer: absorption and scattering opacity Appendix 2. Stokes parameters, Poincare sphere, and the Mueller matrix Appendix 3. Nomenclature: glossary of symbols Appendix 4. Principle of reciprocity for the bidirectional reflectance Appendix 5. Isolation of the azimuth-dependence Appendix 6. The streaming term in spherical geometry Appendix 7. Reflectance and transmittance of the invariant intensity (I n2) Appendix 8. Scaling transformation for anisotropic scattering Appendix 9. Reciprocity, duality and effects of surface reflection Appendix 10. Removal of overflow problems in the intensity formulas.

Radiative Transfer in the Atmosphere and Ocean

https://physicstoday.scitation.org/doi/pdf/10.1063/1.1333301

[1] The new Horizontal Wind Model (HWM07) provides a statistical representation of the horizontal wind fields of the Earth's atmosphere from the ground to the exosphere (0–500 km). It represents over 50 years of satellite, rocket, and ground-based wind measurements via a compact Fortran 90 subroutine. The computer model is a function of geographic location, altitude, day of the year, solar local time, and geomagnetic activity. It includes representations of the zonal mean circulation, stationary planetary waves, migrating tides, and the seasonal modulation thereof. HWM07 is composed of two components, a quiet time component for the background state described in this paper and a geomagnetic storm time component (DWM07) described in a companion paper.

/pdf/an-empirical-model-of-the-earth-s-horizontal-wind-fields-vm989vom4t.pdf

An empirical model of the Earth's horizontal wind fields: HWM07

We report on new global-scale wave model (GSWM) predictions for the migrating solar tide in the troposphere, stratosphere, mesosphere and lower thermosphere The model revision, hereafter GSWM-98, includes an updated gravity wave (GW) stress parameterization and modifications to the background atmosphere based on 6-year monthly averaged Upper Atmosphere Research Satellite (UARS) climatologies UARS Halogen Occultation Experiment and Microwave Limb Sounder ozone data are used to define the strato-mesospheric tidal source, while GSWM-98 background winds are based on UARS High Resolution Doppler Interferometer (HRDI) zonal mean zonal wind data We quantify and interpret differences between previous diurnal and semidiurnal predictions, hereafter GSWM-95, and GSWM-98 results The revised GW stress parameterization accounts for the most profound changes and leads to seasonal variability predictions that are consistent with diurnal amplitudes observed in the upper mesosphere and lower thermosphere Unresolved differences between HRDI and other wind climatologies significantly affect MLT tidal predictions

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/1998JA900125

GSWM-98: Results for migrating solar tides

Our current confidence in 'observed' climatological winds and temperatures in the middle atmosphere (over altitudes approx. 10-80 km) is assessed by detailed intercomparisons of contemporary and historic data sets. These data sets include global meteorological analyses and assimilations, climatologies derived from research satellite measurements, and historical reference atmosphere circulation statistics. We also include comparisons with historical rocketsonde wind and temperature data, and with more recent lidar temperature measurements. The comparisons focus on a few basic circulation statistics, such as temperature, zonal wind, and eddy flux statistics. Special attention is focused on tropical winds and temperatures, where large differences exist among separate analyses. Assimilated data sets provide the most realistic tropical variability, but substantial differences exist among current schemes.

/pdf/the-sparc-intercomparison-of-middle-atmosphere-climatologies-3owjnnye1g.pdf

The SPARC Intercomparison of Middle-Atmosphere Climatologies.

The high-resolution Doppler imager (HRDI) on the Upper Atmosphere Research Satellite is a triple-etalon Fabry-Perot interferometer designed to measure winds in the stratosphere, mesosphere, and lower thermosphere. Winds are determined by measuring the Doppler shifts of rotational lines of the O2 atmospheric band, which are observed in emission in the mesosphere and lower thermosphere and in absorption in the stratosphere. The interferometer has high resolution (0.05/cm), good offhand rejection, aud excellent stability. This paper provides details of the design and capabilities of the HRDI instrument.

The high-resolution Doppler imager on the Upper Atmosphere Research Satellite

A system for measuring properties of a medium includes an electromagnetic generator for forming a CW carrier, a digital encoder for forming a digital message, and a modulator for modulating the CW carrier with the digital message to form a digitally modulated CW carrier. The medium provides a channel for propagating the digitally modulated CW carrier. The system further includes a receiver configured to receive the propagated, digitally modulated CW carrier, and a processor for measuring at least one property of the medium. The medium may be disposed within a gaseous atmosphere, a body of water, or a cell of a laboratory.

Method and system for measuring optical properties of a medium using digital communication processing techniques

A system for sensing a characteristic of a sample may include a tunable source configured to emit optical radiation that varies over a wavelength range at a sweep frequency and a reference source configured to emit optical radiation at a reference wavelength. A first modulator may be configured to modulate the first optical radiation at a first frequency, and a second modulator may be configured to modulate the second optical radiation at a second frequency that is different from the first frequency and the sweep frequency. A science detector may be configured to detect the optical radiation from the first modulator and the second modulator after interaction with the sample and generate a science signal. A number of lock-in amplifiers may be respectively configured to generate components of the science signal that are present at the first and second frequencies. A processor may be configured to determine a characteristic of the sample based on the components of the science signal that are present at the first and second frequencies.

Active remote sensing using a simultaneous spectral sampling technique

A continuous-wave (CW) NIR carbon-dioxide monitoring system, incorporating Wavelength Modulation Spectroscopy (WMS), has been developed and was tested aboard the Spirit of Goodyear airship platform. The data shows sensitivities nearly identical to previous ground-based tests but with much higher information rates (100Hz). These tests were conducted over regions with varying ground albedo and included path lengths up to 1.5 km. The system utilized commercial-off-the-shelf (COTS) components including telecom laser diodes and amplifiers. Currently, the system is limited by Erbium Doped Fiber Amplifier (EDFA) spectral bandwdith, but the ever-increasing average power of quantum cascade lasers coupled with the development of midwave fiber technology could make this CW-based architecture a viable solution for future airborne sensors in the MWIR region.

High-speed CW lidar retrieval using spectral lock-in algorithm

Significant progress has been made in the performance, qualification and validation of Active Remote Sensing systems to address complex questions in climate science from satellites in low earth orbit. During the past year, ITT has completed the design, qualified the components, and validated the performance of sophisticated Tunable Diode Laser Absorption Spectroscopy systems for airborne and space missions. ITT has shown that measurement of total column CO2 to an accuracy of 0.5% can be readily achieved using a 5 watt laser, 1 meter telescope and digital signal processing techniques to reject sunlight and noise. Furthermore, the design exploits the proven high reliability of photonic components developed by the telecom industry. ITT testing validated that these components survive launch and multi-year operation in space without significant degradation. Using a scaled sensor, the ground based validation campaign demonstrated the ability to accurately retrieve the CO2 diurnal cycle as well the automotive induced variations in CO2 observed in urban settings. These data validate the end-end sensor performance model and retrieval algorithms, which have previously been used to design a space based CO2 sensor proposed to NASA. ITT will discuss the application of these technologies to other atmospheric constituents. Combined, these results serve to demonstrate that laser based remote sensing of key components of the atmosphere which address global climate change can be achieved from low earth orbit without further development.

Michael E. Dobbs

Papers

The high-resolution Doppler imager on the Upper Atmosphere Research Satellite

Method and system for measuring optical properties of a medium using digital communication processing techniques

Active remote sensing using a simultaneous spectral sampling technique

High-speed CW lidar retrieval using spectral lock-in algorithm

Validation of design for space-based tunable diode laser absorption spectroscopy payload