# Presentation: 436161

## The publicly available single scattering and radiative transfer codes at IFM-GEOMAR: Example applications from the UV to the MicrowaveAndreas Macke, Ronald Scheirer, Mario Schewski, Steffen Meyer, Ingo Schlimme, Susann KlotzscheLeibniz-Institute for Marine Research, IFM-GEOMARKiel, Germany

## Overview

**Single scattering codes (geometric optics)**
**rt.f90**: ray-tracing at randomly oriented polyhedral particle
**rt-2d.f90**: same for horizontal or partly tilted particle orientation
**rt-mc.f90**: as rt.f90 with internal scattering/absorbing inclusions
**rt-ellipsoid.f90**: ray-tracing at randomly oriented ellipsoid
**rt-raindrop.f90**: ray-tracing at rotational symmetric particle defined by Chebychef polynomial expansion
**Radiative transfer codes (Monte-Carlo)**
**mc-unik.f90**: forward Monte-Carlo, estimate for radiance calc.
**GRIMALDI**: MC package incl. documentation, gas abs., scattering library
**3rad-unik**: MC package for 3d microwave and thermal radiative transfer

## Scattering phase functions

## Cirrus Clouds: Solar broadband fluxes

- - SZA = 65 degree -

## Complete MC package (GRIMALDI)

- forward scheme to solve radiative transfer in 3d scattering and absorbing atmosphere with directed (solar) illumination
**preprocessor for absorption properties of atmospheric gases**
- monochromatic and **spectral band fluxes** and radiances for finite sized angular bins
- photon path length pdf for finite sized angular bins
- data base for scattering phase functions and single scattering albedos for spherical and non-spherical cloud particles

## Forward Local Estimate MC (MC-UNIK)

- forward scheme to solve radiative transfer in 3d scattering and absorbing atmosphere with directed (solar) illumination
**monochromatic fluxes and radiances for discrete directions (Local Estimate scheme)**
- data base for scattering phase functions and single scattering albedos for spherical and non-spherical cloud particles

## Backward Local Estimate MC (MC-UNIK-BW)

- backward scheme to solve radiative transfer in 3d scattering and absorbing atmosphere with directed (solar) illumination
- monochromatic radiances for discrete directions (Local Estimate scheme)
**photon pathlength pdf for predefined viewing geometries and viewing locations**
- data base for scattering phase functions and single scattering albedos for spherical and non-spherical cloud particles

## Backward MC (3RAD-UNIK)

- backward scheme to solve radiative transfer in 3d scattering, absorbing and **emitting** atmosphere
- monochromatic radiances for discrete directions
**preprocessor for gas absorption from the thermal to the microwave**
- data base for scattering phase functions and single scattering albedos for spherical cloud particles

## Codes available at: 

- _[http://www.ifm-geomar.de](http://www.ifm-geomar.de/)_
- _[http://www.ifm-geomar.de/index.php?id=981&L=1](http://www.ifm-geomar.de/index.php?id=981&L=1)_

## Orientation of hexagonal columns

- Theta_tilt

- Klotzsche
- and Macke
-  (2005),
- Appl. Opt.

## Slide 11

## Reflection

- Absorption

- Transmission

**Solar broadband**
**radiative fluxes**
**of oriented**
**hexagonal **
**columns**

- Maximum tilt angle ->

- Solar zenith angle ->

## Tdir+ Tdif

**T**dir+ **T**dif

**R**

**T =**

**A**

**R = Reflection**
**A = Absorption**
**T = Transmission**

- Solar radiation budget

## GESIMA: 3d, non-hydrostatic, bulk cloud physicscloud water, rain, ice, snow/graupel

## Clouds & UV total downward flux

**HOM - 3D**

**ICA - 3D**

## Slide 16

## Slide 17

## Slide 18

## Slide 19

## MTG Infrared Sounder Simulator

- IR-Sounding from Geostationary Orbit ->
- Diffraction induced Point Spread Function

## Slide 21