Session A: Topical Union Session
Conveners: T. Nakajima, R. Ellingson, R. Cahalan, C. Serio and M. Yamasoe
Subjects: Current Problems in Atmospheric Radiation. This session presents plenary lectures on outstanding issues that should be shared by all participants.

Session B: Radiative Transfer Theory and Modeling
Conveners: Bernhard Mayer, Alexander Marshak
Subjects: Radiative transfer (RT) theory including one- and three-dimensional RT applications to the atmosphere and surface (vegetation, land and sea ice). Different aspects of solar and infrared radiation; methods for identifying errors and limits of various RT methods in climate, atmospheric chemistry and remote sensing studies. The use of RT theory for new and advanced active and passive remote sensing techniques including interpretation of hyperspectral measurements. Modeling of cloud-aerosol interaction involving RT theory.

Session C: Molecular Radiative Properties
Conveners: Carmine Serio, Peter Bernath, Claude Camy-Peyret
Subjects: Radiative properties of molecules with application to atmospheric remote sensing. Measurements of molecular line parameters and cross sections for pure rotational (microwave), vibration-rotation (infrared) and electronic transitions (UV-visible); studies on atmospheric continua and non-Voigt line shape functions. Applications to satellite, airborne and ground-based remote sensing: radiative transfer and spectroscopy issues, including those related to the chemistry satellite instruments (ACE, TES, MIPAS, SCIAMACHY, MLS and more) and the most recent meteorological satellite missions such as AIRS and IASI.

Session D: Particle Radiative Properties
Conveners: Tadahiro Hayasaka, Paolo Di Girolamo, Peter Koepke
Subjects: Theoretical, experimental and observational studies on atmospheric particle properties, both aerosols and cloud particles. Radiative properties such as extinction, scattering and absorption coefficients, single scattering albedo, asymmetry factor, and phase function of aerosol and cloud particles (water, ice and graupel) at spectral regions from ultraviolet to microwave; relevant microphysical properties, like size distributions, refractive index, effect of relative humidity, particle shape and mixture of components. Measuring methods, both in situ and remote, and temporal and spatial variations of these properties in the Earth's atmosphere are also important topics in this session.

Session E: General Remote Sensing
Conveners: Allen M. Larar, Yuriy M. Timofeyev
Subjects: Advanced remote sensing measurement systems are being employed for observing a wide variety of geophysical variables from ground-, aircraft-, and satellite-based platforms, enabling a wide range of research and operational applications through retrievals of atmospheric state, dynamics, and composition. Increasing spatial resolutions and coverage areas allow improvement of scientific understanding and predictive capability for geophysical parameters and their response to natural and anthropogenic external forcing. Related topics in this session:

• Determination of atmospheric state, dynamics, and composition
• Geophysical parameter retrieval, error analysis methodology, and the influence of a priori information
• Remote sensing data fusion (multi-sensor, multi-platform, passive & active), and the impact on information content
• Analysis of methods using the spectral, angular, temporal and polarization radiation characteristics
• Sounding of the troposphere, stratosphere, and upper non-LTE atmosphere
• Sounding of 3-D media, tomography and other approaches
• New measurement/instrument concepts and prototype demonstrations
• Remote sensing experiment results
• Laboratory instrument characterization and testing
• Calibration techniques (spectral, spatial, and radiometric)
• Enabling subsystem- or system-level technologies
• New remote sensing data sampling, processing, compression, and telemetry approaches
• Measurement system validation (sensor & data products)
• Environmental research and operational applications.

Session F: Satellite Measurements
Conveners: Michael King, Rolf Stuhlmann, W. Paul Menzel
Subject: Geostationary satellites provide a continuous view of weather systems in tropics and midlatitudes, where they constitute the Global Observing System (GOS) of more than five geosynchronous satellites. Together with polar-orbiting satellites they form a truly global meteorological satellite network that enables measurement of motion, development, and decay of atmospheric phenomena, severe events warning capability, observation of daily global cloud cover and monitoring of surface and vertical variation of temperature and water vapour. The recent addition of new R&D systems to GOS has expanded its spectral, spatial, and temporal remote sensing capabilities dramatically. Related subjects in this Session are:

• Long term calibration of operational sensors
• New and improved algorithms for clear and cloudy sky observations
• Nowcasting applications
• Satellite data and numerical weather prediction
• Climate trends depicted in weather satellite data
• Role of satellite and in situ observations in the Global Observing System
• Applications with new environmental research and operational systems.

Session G: Surface measurements and field experiments
Conveners: G. Shi, J. Vanderlei Martins, Bruce W Forgan
Subjects: All aspects of field measurements of atmospheric radiation including surface networks, aircraft campaigns, and the results of intensive observation periods focused on the measurements of the radiation field or on the components that directly affect the radiation field. In most of these experiments, the optical characteristics of aerosol and clouds, and the chemical composition of the atmosphere are also observed and can be presented in this Section. The presentation of atmospheric radiation data collected by a variety of programs and the modeling and re-analyses of these data sets is also encouraged. Related subjects:

• Results from field experiments including ground based and aircraft measurements
• Results from surface networks
• On-going satellite validation efforts
• New instrumentation for radiation and radiation related properties
• Recent developments in reducing the uncertainty in radiometry at the Earth's surface
• Modeling and re-analysis of atmospheric radiation

Session I: Weather and climate applications
Conveners: Hung-Lung Allen Huang; Bruce McArthur
Subjects:

1. The use of radiative transfer parameterizations for improving weather and climate forecasting.
   • Implementation, validation and comparison of radiative transfer parameterizations within weather and climate models
   • Results of assimilating radiation quantities into forecast and climate models
   • Impacts of radiative processes on weather forecasting and climate model outputs
   • The prediction and validation of radiation quantities from weather and climate models
2. Radiative processes in climate and weather, and their consequences (e.g., cloud-climate interactions, aerosol-chemistry-climate interactions, atmosphere-ocean interactions)
   • Diagnostic analyses of the weather and climate system utilizing model simulations and observations (e.g., satellite, ground-based, aircraft) on a variety of space and time scales.
3. Global and regional radiation climatologies
   • Detection and characterization of climate change
   • Regional changes in radiation regimes and their environmental impacts
4. Other topics such as
   • Design, development, and implementation of future climate sensor systems
   • National and international climate studies that are related to climate variability and changes, such as those on climate analysis method, data quality, new data sets, observation systems, etc.
   • Climate data record management, access, quality control, and stewardship as they impact of climate assessment

Session J: Biosphere-Atmosphere interactions influencing the radiation budget
Conveners: Pedro Leite da Silva Dias, Paulo Artaxo
Subjects: The fluxes of aerosol and trace gases from terrestrial ecosystems to the atmosphere play an important role in influencing the atmospheric radiation balance. In tropical areas, biogenic aerosol and biomass burning emissions inject large amounts of aerosol particles in the atmosphere that have strong direct and indirect radiative forcing. When acting as cloud condensation nuclei (CCN) they can change cloud microphysics, cloud lifetime, and influence atmospheric dynamics and thermodynamics. Some related topics:

• Biogenic aerosol and biomass burning emissions; direct and indirect radiative forcing
• Circulation models; experimental detection and monitoring
• Presence and dynamics of trace gases; secondary organic aerosols in vegetated areas
• Continental and marine CCN, influence on cloud microphysics, dynamical and thermodynamic atmospheric impacts.