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OLD NEWS from the
Ocean Loading Provider
BUG REPORTS
Aug. 13, 2012: An error in the post-processor (used for
sites near coasts) caused small errors (sub-mm) in loading
coefficients. The problem was fixed today. From Nov. 26,
2012, on, the sites are marked on the charts.
Nov. 28, 2012: olgt.pl
had another error. Updated today, please download again.
Nov. 8, 2011: olgt.pl
had an error. Please download again.
Please re-issue requests if both of the following
two criteria apply
- The BLQ record indicates that OLMPP was used
("Computed by OLMPP")
- The job was carried out between June 15 and July 25,
2011
Consider to re-issue requests for stations in the Pacific
area if your results have been computed before June 15,
2011, even long before.
Our sincere thanks go to Andreas Richter and Mathias
Fritsche who brought the problem to our attention.
Hans-Georg and Machiel
Read here the details.
OLD NEWS
November 10,
2017: New tide model added: GOT.4.10c
February 12, 2017: Speedier service for jobs forwarded to
Segal.
Clients who request calculations with the high-resolution
models FES2014b, FES2012 and TPXO8-Atlas
had previously to wait in the queue at OSO until their job
was in the top position. Now, the job queue is processed
separately, and high-resolution jobs are relayed to Segal
immediately (i.e. with 10 seconds delay at maximum).
November 1 and September 26, 2016: New Tide Models.
As eagerly awaited in the user community, we have added
FES2014b, FES2012 and TPXO8-Atlas to
the available range of Ocean tide models, thanks to the
efforts of Machiel.
The computations are automatically forwarded to SEGAL at
UBI/IDL in Portugal, so that the
receivers of the parameter files would notice as small
changes as possible, and - if the machines
and their connections are working - none at all as regards
basic user interaction and delivery.
As of yet, a few options won't work with the relayed jobs:
There's no plot option and no live job activity-and-queue
report.
SEGAL is a facility at the University of Beira Interior and
Institute Dom Luiz.
July 20, 2012: Time series from BLQ-files -
Program ttimm
June 20, 2011: mGal is not an SI unit,
and the numbers in the BLQ
result files lack numerical resolution.
Thus a change in conventions was made:
Henceforth, if you select
Gravity, the results are presented in μm/s2.
A new option is offered is you prefer values in nm/s2
However, you can select "mGal" if you still prefer that.
June 13, 2012: New
tide models (all have a resolution of
1/8°×1/8°)
GOT4.8 from NASA
Goddard Space Flight Center and University of Maryland
(Richard Ray).
In this update of GOT4.7 only the S2 tide is
affected.
July 29, 2011:
Centre-of-mass coefficients: text
added and a wager issued.
July 29, 2011: A note
on mass conservation: It should be noted that from
the earliest beginnings of this site, the parameters
(gravity, tilt, displacements) imply a correction to obtain
a global mass balance. We may consider to offer you an
alternative, a radio button to switch it off.
June
20, 2011: mGal is not a metric unit, and the
numbers in the BLQ result files lack numerical resolution.
Thus a change in conventions was made:
Henceforth, if you select Gravity, the results are
presented in μm/s2.
However, you can select "mGal" if you still prefer that.
Aug 27, 2009:
BUG REPORT
An error in the refinement stage OLMPP was detected. Results
are affected at the 10% level in the case of stations near
the coast with increasing error toward high latitudes. The
problem started after a revision on July 07,
2009. Affected results are recognizable on
behalf of a signature Computed by OLMPP
or Computed by OLCMC/OLMPP in the
BLQ output.
Thanks to Kristian Breili and Matt King to point out the
problem.
The problem has been solved ar UT 13:45 today, Aug 27, 2009.
Dec. 24, 2008:
BLQ-files format
BLQ format, header record #5 changed:
$$
ONSALA
$$ GOT00.2_PP ID:
2008-12-23 23:54:30
$$ Computed by
OLCMC/OLMPP by H G Scherneck, Onsala Space Observatory,
2008
$$
Onsala,
lon/lat:
11.9264 57.3958 10.00
------------------------------------------------^column
49
--------------------------------------------------------------------^column
69
Column 69: Station height (F8.2)
June 30, 2008: New tide
model
New tide model: EOT08a from DGFI Munich
with Acknowledgments to Roman Savcenko and Wolfgang Bosch
May 7, 2008: New tide
models
New tide models implemented: GOT4.7 and Andersen 2006
References are not shown yet on our reference page - in
progress (promise!)
April 10, 2008: Article
Published
January 22, 2008: New tide model
New ocean model implemented (TPXO.7.1)
January 22, 2008: A short-cut
A message to the frequent ocean loaders, those who find it
tiresome to go through our web interface. Click here
August 19, 2007: Mass
redistribution
IMPORTANT INFORMATION
To all users who engage in comparisons between model results
and need most accurate loading parameters:
We have changed the Mass Redistribution policy.
It concerns stations near the coast, particularly where
coastlines are complicated and tides are high.
The policy is now that
Mass redistribution due to higher coastline
resolution is carried out in the cases of the
hydrodynamically closed models (SCHWiderski, FES94 and
FES95), and only in these cases.
Previously, mass redistribution was always carried out, i.e.
also in the cases of the empirical models (based on ocean
observations).
If a user recognises differences between empirical loading
signals (from e.g. GPS) and the empirical models, our
suggestion is to recompute the modelling results.
We gratefully acknowledge Nigel Penna for pointing this
problem out to us.
February 4,
2007: Welcome to a new machine
10 times faster. FES2004 takes a few minutes per station
now.
December 19, 2006 -
ALTERNATIVE SITE AVAILABLE
The backup site at
GEODAC , Porto, Portugal, is ready to accept requests,
offering the full suite of ocean tide models.
January 2006: Centre
of mass tides
CMC-files
available - giving you a look under the hood of
centre of mass correction. For experimental use. See the CMC
page .
Previous news and bug reports:
19 Dec 2006
Hans-Georg
Scherneck, Chalmers, Onsala Space Observatory
Page updated 2011-06-20
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