ANDRO: An Argo-based deep displacement dataset
Michel Ollitrault (LPO, IFREMER, France) & Jean-Philippe Rannou (ALTRAN, France)
A world deep displacement dataset, named ANDRO, after a traditional dance of Brittany meaning a swirl, comprising more than 600 000 deep displacements, has been produced from the Argo float data.
Presently this dataset contains Argo float displacements before January 1st 2010. All Argo data prior to that date has been collected from the Data Assembly Centers (DACs): AOML, Coriolis, JMA, CSIRO, BODC, MEDS, INCOIS, KORDI, KMA and CSIO .
One important feature of ANDRO is that the pressures measured during float drifts at depth, and suitably averaged are preserved in ANDRO. To reach this goal, it was necessary to reprocess most of the Argo raw data, because of the many different decoding versions (roughly 100) not always applied by the DACs to the displacement data because they were mainly interested in the p,t,S profiles. The result of our work was the production of comprehensive files, named DEP (for déplacements in French), containing all the possibly retrievable float data.
From the 6302 DEP files thus created (there are one DEP file per float), the ANDRO ASCII file is generated. Although the DEP files are available (DEP_files_20140218.7z or DEP_files_20140218.zip), we think most scientific users will be satisfied with the much simpler and synthetic ANDRO dataset (ANDRO_20140218.dat or in compressed forms ANDRO_20140218.zip or ANDRO_20140218.7z).
Three papers describing precisely the work we have done are available : ANDRO_JAOT_2013.pdf, ANDRO_NL_Coriolis.pdf or Argonautics12_extract.pdf (the latter two being shorter versions of the first one).
ASCII file WMO_DAC_FloatType_TransSystem_20140218.txt catalogs the float information included into the (last version) ANDRO dataset. This file contains four columns:
1. WMO float ID,
2. DAC where float data are stored,
3. Float type,
4. Transmission system.
ASCII filedescribes the notation of the DAC names, as follows:
1. AOML (USA)
2. CORIOLIS (France)
3. JMA (Japan)
5. MEDS (Canada)
6. INCOIS (India)
7. KMA (South Korea)
8. CSIRO (Australia)
9. CSIO (China)
10. KORDI (South Korea)
ASCII filedescribes the notations of the float types, as follows:
6. SOLO SIO
7. SOLO WHOI
ASCII filegives the satellite transmission system used, as follows:
2. IRIDIUM or ORBCOMM
Any remark or error will be welcomed.
Mail to michel.ollitrault_at_ifremer.fr or jean-philippe.rannou_at_altran.com.
Important Note :
Argo public NetCDF files are found on any of the two Global Data Assembly Center websites (http://www.usgodae.org/argo/ or http://www.coriolis.eu.org/).
Using this then available Argo data, Yoshinari, Maximenko & Hacker, at the University of Hawaii first produced an atlas of velocity estimates (YoMaHa’05), in 2006. This atlas is regularly updated (YoMaHa’07) using the latest Argo public NetCDF files (http://apdrc.soest.hawaii.edu/projects/Argo/data/trjctry/). However the parking pressure is given as the nominal pressure, not the measured one, which may result in an error.
Fortunately, the DACs are presently implementing a detailed trajectory file format (for containing all the measured pressure at depth, …), following much of our DEP file format. It is hoped that this will permit, in the future, an easy update of ANDRO as well as a refinement of YoMaHa’07.
Actual contents and format:
DEP files (last version):
Matlab files: (Example programs to read the ANDRO dataset or the DEP files)