|
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
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
|