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OLD NEWS  from the Ocean Loading Provider


January 24, 2024
--- BREAKING NEWS: The problem appears solved.

If you are still waiting for your results, please send details of your request, like
* the approximate time of submission
* the ocean model you requested
* the email address you entered in the text box
* anything else you wonder about to hgs at chalmers.se

Please inspect the queue page.
Most probably, the requests marked "Forward to Cloud Service" have been lost.

The problems were with forwarding requests and email to users at gmail.com.

Requests using the high-resolution ocean models FES2012, FES2014B, TPXO.8* and -atlas are forwarded for computation at a Google Cloud location.

Google's gmail has recently started to request authorizing ciphers in order to reject spoofs and faked email senders. This impedes the forwarding of such requests.

The problem also interfers with messages to users at gmail.com comprising error reports as well as computed results based on the low-resolution models, which are calculated at the computer at OSO.

The work-around currently installed may fail to timely take care of your requests. It's unfortunate that the error reports are affected most severely.

Please reload this page from time to time to follow the unfolding developments.

We lay our hopes in the hands of Chalmers' IT-Support to register our service for cipher provision.


March 11, 2022: Extended parsing of requests
A more thorough parsing of station records has been enacted. Requests that fail the test will not be processed.
Instead, the system sends a notification back to the user with hopefully useful advice.

February 03, 2022: New model TPXO.9.5a
This is a 1/61/6 degree model, an update of TPXO.9.2a

December 2021: Stricter coding requirements for direct email
If you bypass the web page and instead send your requests by email, we refer to updated instructions as users had been experiencing denial of service.

April 25, 2021: New model EOT20
(Hart-Davis et al., DGFI, doi=10.17882/79489)
July 12, 2021: Problems have been found recently. A revised version has been installed today at 10:00 UTC. Please resend your requests issued before this date.

August 9, 2020: Error in GOT4.10c with centre of mass option
Tides Q1 and K2 had erroneous coefficients for centre of mass.
Please resubmit your sites if you have used this combination of options.

June 26, 2020: New model TPXO.9.2a

March 7, 2020: Error in our copies of GOT4.10c, Q1 and K2 amplitudes, corrected.
For high-precision applications, the set of loading coefficients should be recomputed.

January 6, 2019: New model TPXO.9-Atlas
A high-resolution model, 30x30 cells per square-degree. Loading jobs are carried out at SEGAL at UBI/IDL inPortugal.
February 05, 2018: Alternative loading Greens function available
For decades the load convolution used an elastic Greens function based on the Gutenberg-Bullen earth model. You can choose an alternative, a Green's function for an anelastic Earth [...] . Further reading: Bos and Scherneck (2013)
February 05, 2018: A pro-memoriam on BLQ files (updated)
with emphasis on phase and its conversion for reckoning with respect to the local solid earth tide.
February 05, 2018: Revision of service for gravity and tilt
Today the service goes official with tilt parameters [...].
February 05, 2018: Revised version of converter script
for BLQ to TSOFT and g-Software (Micro'g Lacoste), [...]


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.



OLDER 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 1/81/8)

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

N. T. Penna, M. S. Bos, T. F. Baker, and H.-G. Scherneck
Assessing the accuracy of predicted ocean tide loading displacement values
J. Geodesy, DOI 10.1007/s00190-008-0220-2, 2008.


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 2024-02-01