the Odin satellite

Preparations for Metop SG Ice Cloud Imager retrievals

Patrick Eriksson, Robin Ekelund, Jana Mendrok,Chalmers University of Technology—Bengt RydbergMolflow—Stefan Buehler, Manfred Brath,University of Hamburg—Anke Thoss,SMHI—Stuart Fox,UK Met Office—Christophe Accadia and Vinia MattioliEUMETSAT

Overview

I Single scattering databaseI Chalmers + Hamburg

I Radiative transfer basicsI Chalmers + Hamburg

I ISMAR airborne instrumentI UK Met Office/ESA + Chalmers + Hamburg + Paris

I Retrieval schemesI SMHI + Chalmers + EUMETSATI HamburgI Paris

posterR. Ekelund

posterJ. Mendrok

posterA. Thoss (PE)

presentationD. Wang

Ice Cloud Imager (ICI)Part of Metop Second Generation (SG)

(courtesy of ESA)

I Launch Dec 2022I 9:30 orbitI Conical scanner, 53◦

I Footprints:I < 16 kmI > 40 % overlap

ChannelsI 183.3±7.0 GHz V pol.I 183.3±3.4 GHz V pol.I 183.3±2.0 GHz V pol.I 243.2 GHz V + H pol.I 325.2±9.5 GHz V pol.I 325.2±3.5 GHz V pol.I 325.2±1.5 GHz V pol.I 448.0±7.2 GHz V pol.I 448.0±3.0 GHz V pol.I 448.0±1.4 GHz V pol.I 664.0 GHz V + H pol.

I + MWI (18.7 - 183.3 GHz)

Why sub-mm? Some example simulationsBased on NICAM model

I Compared to CloudSat/EarthCARE:I larger swath widthI poorer vertical resolution and coverage

Why sub-mm? Some example simulationsBased on NICAM model

I Bridges the gap between IR and existing microwaves

Why sub-mm? Some example simulationsBased on NICAM model

I Main productsI IWP (ice water path)I mean mass size and height

Basic retrieval approach

Retrieval database(set of [x,y])

Retrieval database(set of [x,y])

Inversion approacha: Neural net(s)b: MCI

Inversion approacha: Neural net(s)b: MCI

IWP, Dm and ZmIWP, Dm and Zm

ObservationObservation

Pre-calculations

Retrieval

Atmospheric data1: Model2: CloudSat + ECMWF

Atmospheric data1: Model2: CloudSat + ECMWF

Single scattering dataSingle scattering data

Assumptions, data, ...Assumptions, data, ...

Radiative transfer toolRadiative transfer tool

for operational algorithm,see poster by A. Thoss (PE)

Database of single scattering properties

OverviewI 18 - 887 GHzI 190, 230 and 270 KI Dmax 20µm to 2 cm / x<10I Amsterdam DDAI Total random orientation

I about 30 habitsI Specific alignments

I ? habitsI Can be extended laterI Will be publicly available

I by ARTS web site

StatusI Random orientation

I 20 habits completedI ∼ 50 000 core hoursI more aggregates

will be addedI Specific alignments

I code being tested

posterR. Ekelund

Scattering data, example results

Radiative transfer

I Improving and extending ARTSI ARTS = Atmospheric Radiative Transfer SystemI DISORT and RT4 have been incorporated

I Information content of dual polarisation?

I Relevance of “beam filling” and 3D radiative transfer

posterJ. Mendrok

Example on 3D simulations186.3 GHz, 53◦

Lookingdirection

⇑

Statistical comparison to GMI186.3 GHz, 20◦S - 20◦N, 7 days in Aug 2015

100 120 140 160 180 200 220 240 260 280

Tb [K]

10 -6

10 -5

10 -4

10 -3

10 -2

10 -1

PD

F [#

/K]

GMI, only mid-dayGMI, 24 hSimulations

I CloudSat dBZ→ 3D scenesI Habit = “Hong aggregate”I PSD = Field et al. 2007, tropicalI ARTS Monte Carlo (3D)

ISMARInternational SubMillimetre Airborne Radiometer

I UK Met Office + ESAI Onboard FAMM aircraftI 118, 243, 325, 448 and 664 GHz

I Dual pol. at 243 and 664 GHzI 875 GHz will be added

I Measures both up and downI Scientific data since Dec 2014

I 17 flightsI UK to Greenland

I Mainly nominal performanceI 664V main exception

I Complemented byI MARSS, 89 to 183 GHzI LidarI In-situ probes and sondes

↑↗↙↓

Flight B897Precipitating front over ocean, 2015-03-18

Flight path

0 to 23 dBZ

B897, example retrievals

IWP

[g/m

2]

0

1000

2000

3000

D [m

icro

ns]

0

200

400

600

median

16-84%

2.5-97.5%

Z [k

m]

0

5

10

Time of day [hours]12.5 13 13.5 14 14.5 15

habi

tpr

obab

ility

[%]

0

50

100

Evans

Hong

Sector

posterA. Thoss (PE)

Summary

I The airborne demonstrator ISMAR is operational

I A single scattering database in preparation

I Full retrieval scheme already in placeI retrieval database generation still on a basic level

I Testing / validationI ISMAR + MARSSI GMI, MHS, . . .I Odin-SMRI IceCube, . . .