Evaluation Dataset for Passive Imager Retrievals

From CrewWiki

Revision as of 08:32, 21 September 2011 by Rob (Talk | contribs)
Jump to: navigation, search


Contents

Common Database

The evaluation of passive imager cloud properties retrievals is part of the CREW. Hereto, a Common Database of cloud retrievals from different algorithms is build, which will be filled with retrievals of the different data providers. Below you will find relevant information for uploading your cloud retrievals to the common database. Note: the selected Golden Days are similar to those selected for CREW-2. Thus, providers that already have provided their data for CREW-2, and that do not want to update their datasets or add new ones, do not need to upload their datasets again.


DATASET SPECIFICATIONS
We have selected five Golden Days that are listed in Table 1. During several hours of the selected Golden Days the A-Train satellites aligned with AVHRR on-board NOAA-18. Our evaluation study will focus on these hours. However, we encourage the data providers to upload their datasets of the five Golden Days for the full 24 hrs. The study area is restricted to the SEVIRI full disk. The following data are desired for the Common Database:

  • SEVIRI 15 minute data of the MSG disk preferably covering the full 24 hrs during the golden days (5x24hrs);
  • MODIS swath data covering the MSG disk preferably covering the full 24 hrs during the golden days (5x24hrs);
  • AVHRR swath data covering the MSG disk during the hours where NOAA-18 was aligned with the A-Train satellites
  • Other instruments (MERIS/POLDER/..) preferably covering the full 24 hrs during the golden days (5x24hrs).

You can upload your data to the Common Database till 31 May 2011 through the FTP server at ICARE, which is assessable for CREW members after registration. During the registration when asked for a “short description of your project”, please write: Account request for the Cloud Retrieval Evaluation Workshop (CREW).


Table 1: Golden Days that have been selected for the (inter)comparison

Day Month Year Hours with alignment between A-Train and NOAA-18
13 June 2008 12:00-15:30
17 June 2008 22:15-24:00
18 June 2008 00:00-01:45
22 June 2008 10:30-12:15
03 July 2008 10:00-12:00


Data Description

The inter-comparison of cloud parameters is done for level 2 products from SEVIRI, MODIS and AVHRR. The products delivered by the different algorithm providers have been converted to a common file format to facilitate direct inter-comparison. Table 2 lists the cloud parameters have been selected for the (inter)comparison:

Table 2: Cloud Parameters that have been selected for the (inter)comparison

Acronym Cloud Parameter
cmk cloud mask
cph cloud phase
ctt cloud top temperature
ctp cloud top pressure
cth cloud top height
cod cloud optical depth
ref effective radius
lwp liquid water path
iwp ice water path

Data Providers and Algorithms

Datasets from 13 retrieval algorithms contributed to the Common Database that was created for the evaluation of cloud properties retrievals in the CREW project. Table 1 lists the provider, the cloud parameters, and the satellites of the 13 datasets in the Common Database. A detailed description of the retrieval algorithms can be found at: here (only for CREW members, password needed).

Table1: List of research groups that provided data for the Common Database. For each groups the satellite instruments and cloud parameters for which data are provided are given. Where the codes from the cloud parameters are: cmk= cloud mask; cph= cloud phase;ctt= cloud top temperature; ctp= cloud top pressure; cth= cloud top height; cod = cloud optical depth; ref= effective radius; lwp= liquid water path; iwp= ice water path; cty= cloud type, and cs= convective signature. The codes for the satellites are: S = SEVIRI, A = AVHRR, M = MODIS,P = POLDER

Acro. Institute Contact Sensor cmk cph ctt ctp cth cod ref lwp cty cs day / night notes
DLR DLR Gesell, Gerhard S F F F F day only
DWD DWD Stenger, Martin; Lockhoff, Maarit S F F FFF day only
ETH ETH de Ruyter Wildt, Martijn S F day only
EUJ Eumetsat Joro, Sauli S F FF night and day
EUL Eumetsat Lutz, Hans-Joachim S F F F night and day
EUW Eumetsat Watts, Phil S F F FF day only
FUB FU Berlin Preusker, Rene S F F night and day
KMR KNMI Roebeling, Rob S,M,AFFF FFF day only
KMV KNMI de Valk, Paul S E E day only
MFR Meteo France Le Gleau, Herve; Derrien, Marcel S F FF F night and day
MOF UK Met Office Francis, Pete S F FF F night and day
MOT UK Met Office Taylor, Ruth S E E night and day
OMA KMI Ipe, Alessandro S FF F day only
IAF Italian Air Force Melfi, Davide S F F
LAR Nasa Langley Patrick Minnis S FFFFFFFF
GSF Nasa Goddard Steve Platnick S,M FFFFFFFF
SMH SMHI Dybbroe, Adam A S SSS
SSH Wisconsin Heidinger, Andrew S,A FFFFFFFF
ULI Univ. Lille Riedi, Jerome P F F


Further Information

For questions related to access and use of ICARE ressources send comments or questions to
Ulrich Hamann and Jerome Riedi