Tuesday, August 9, 2016

met data from this buoy now feeding NDBC and the global models

Last week I started a new feed of data to the National Data Buoy Center (NDBC) from the two CREWS/CCCCC buoys in the Dominican Republic. These buoys were deployed last December but both went offline about 3 weeks after initial deployment, for different reasons. A recent check-in with these buoys' data streams reveals that they have both been online and transmitting reliable meteorological data for 2-3 months now and therefore they have become good candidates for NDBC feeds.

Once their data have been cleared by NDBC they will be released into the Global Telecommunications Systems (GTS). Once in GTS those data will become visible to national weather services and researchers worldwide, and they may be used in global forecast models such as those used for tropical cyclone forecasts.

The Catuan Wreck buoy is located near Boca Chica on the southern coast of the Dominican Republic.  We have been informally referring to it as CWDR1 (Catuan Wreck, Dominican Republic, first station) but as a buoy its official GTS designation is entirely numeric and is assigned according to region.  The CWDR1 buoy's official designation will be 42090. Its NDBC home page may be found at the following URL:


This link has also been added to the 'Links' section on the right-hand side of this blog.
Mike J+

Wednesday, August 3, 2016

buoy's return to power, and first four months of data

This post, written in August of 2016, describes what was learned through a careful examination of this buoy's data record following its return to power on March 31st. The buoy had previously lost power on December 30th, three weeks after initial deployment, and remained offline for about three months.

The buoy returned to power at UTC 16:00 (local noon) on March 31st. Neither datalogger had logged any records since the buoy lost power on December 30th, suggesting that the buoy had experienced a complete loss of power to all of its sensors and dataloggers.

Judging from the compass data, the buoy was not at its deployment site when it powered up, but was towed to that site the following day. Based on these data I count its deployment dataset as beginning at UTC 15:00 (11am local) on April 1st, 2016.

Battery voltages were steady both before and after these outages, suggesting that the battery had never been disengaged from the solar panels and the charging systems. This is identical to what was observed at the South Water Caye buoy (November 2015, to be described in a maintenance log post still to come), where the problem was traced to the solar regulator, also known as the "automatic sequencing charger" or ASC. The ASC used at all CREWS buoys to date has a "low voltage disconnect" or LVD feature which cuts power to the system load if it determines that the power supply falls below a certain level, on the theory that continued operation at low voltages may be more damaging to the electronics than an outright power loss. This LVD is said to be designed to kick in at about 11.5V.

Similar problems with the ASC have been known to occur at the Buccoo Reef buoy, where systems were rewired to bypass the LVD protection, and have also factored into some power problems experience by the Little Cayman buoy. Counting CWDR1, BUTO1, SWBZ1 and CCMI2, the ASC may be implicated in power losses experienced at as many as four of the network's eight buoys.

Note that as of this writing I have no direct knowledge of any intervention that may have taken place, either by local DR personnel or by YSI support people. My speculation about the buoy's recovery from its deployment site, an intervention that may or may not have involved the ASC, and the buoy's subsequent redeployment, is just that: speculation.

Based on my examination of the last four months of data some further observations can be made:
  • Buoy performance is generally good: redundant measurements of barometric pressure, air temperature, humidity and wind speeds all show excellent agreement. I have begun work on a feed of this buoy's meteorological data from AOML/CHAMP systems to NDBC.
  • Diagnostics suggest that the 'Main' Junction box is growing unacceptably moist. Humidity levels range diurnally between 45% and 65%. I have previously suggested that 20% humidity would be a reasonable target and that anything exceeding 50% should be considered excessive. The other diagnostic humidity metric (that from the 'Met' junction box) remains well under 20%.
  • The two wind sensors report directions that are consistently offset from one another by 7° to 14°, suggesting that they may not be correctly aligned with one another or with the station compass. A realignment should be attempted during the next maintenance operation, while taking care to note which sensor(s) have been adjusted and by how much. At a wild guess I might trust the RMYoung anemometer directions more, based solely on suggestions at other buoys that the WXT base is not always solidly mounted in place.
  • The EXO's CT2 sensor is doing okay with sea temperatures but its salinity reports appear to be unbelievably low, starting from about one month after redeployment. This may simply be an issue with insufficiently frequent calibrations (the CT2 is said to require in-field recalibrations every 1-2 months), or it could indicate CT2 fouling or failure. There is no suggestion in the data record that the EXO has been calibrated since the buoy returned to power.
  • EXO battery voltages were initially steady at 6V but start dropping lower on about June 13th. It is not known whether this suggests any kind of problem with the EXO or casts any doubt on the accuracy of its sensors.
  Mike J+

Monday, January 4, 2016

Outages continue at both DR buoys

[The following is a back-dated share of an email update I sent out on January 4th, 2016, relating to outages observed at both of the newly-deployed Dominican buoys.]
I thought I should sent a followup, because both Dominican buoys are offline now.

The Catuan Wreck (Boca Chica) buoy went offline at UTC 1030 on December 30th, about five and a half days ago.  In addition to the 30-hour power outage (Dec 27th - 28th) I was describing below, there was one 3-hour power loss the day before (Dec 26th) that I had not noticed.  These two outages were followed by a 5-hour outage the following day (Dec 29th) and then the current multi-day outage which began Dec 30th.

Curiously, all four CWDR1 power outages began at the same time of day, within about 20 minutes of one another, UTC 1020 - 1050 (or Dominican time 6:20am - 6:50am).  I'm wondering if maybe this is the earliest time that sun strikes the solar panels strongly enough to generate some current, and it's knocking out the solar regulator?  But that is unfounded speculation at this point.

The Puerto Plata (PPDR1) buoy went offline on December 30th at UTC1900.  I have not yet examined that buoy's data records in detail.

Note that while I can confirm (by the missing record numbers) that the CWDR1 buoy really was powerless, repeatedly, since deployment, I am not yet certain whether the PPDR1 buoy is suffering power outages as well.  Until/unless I regain contact even briefly with PPDR1 I can't know from record-numbering gaps whether that buoy has power-systems problems or merely communications problems.

Mike J+

Wednesday, December 30, 2015

buoy power failure

This is a back-dated post describing what was known about a power failure at the CWDR1 buoy at the end of 2015. The buoy was deployed on December 10th and lost power just under three weeks later on December 30th. It remained offline for a period of about three months.

The buoy's loss of power on December 30th was preceded by three shorter outages: three hours offline on December 26th, thirty hours from December 27th - 28th, and six hours on December 29th.

The following is an excerpt of an email message that I wrote on December 28th, shortly after the buoy had come back online after the 30-hour outage:
The buoy became unreachable yesterday morning at about 5:30am Miami time (6:30am Dominican time).  It remained unreachable for roughly 30 hours before connecting again some time in the last hour.

However, this was NOT simply a failure of cellular service.  The buoy appears to have been entirely non-operational during this time.  When NOAA reestablished contact, we downloaded all data records that had been created in the intervening time, and we can tell by their record numbers whether our downloads are complete.  Our downloads are complete, but record timestamps jump from UTC 10:50 yesterday to UTC 16:40 today.  This applies to datatables in both dataloggers, Met and Main.

I can't quite explain this, except if perhaps there were a temporary power failure to all systems.  But I don't know what kind of power failure could be remedied except through direct intervention, and I would guess that one day offline is not enough time (especially at this time of year) to be noticed, much less to prompt some kind of boat visit.

The Main datatables that are copied from the Met datatables are now full of duplicated records, which is an artifact of the dual-datalogger programming, and another sign that a power failure might be the cause.

I don't know that I would suggest any immediate action in response but I am curious whether anyone knows anything about this buoy's testing.  Now that I think of it, I remember looking over its pre-deployment data and having to edit out a lot of duplicate records, indicative of power ups and downs like this one.  I just assumed that the buoy's power systems were being manually connected and disconnected in that period, as things were moved around.

There were seven such duplications, now that I look at the pre-deployment records more carefully.  The oldest was Nov 12th, and they continue Nov 22nd, 27th, 28th, 29th, Dec 1st, and Dec 5th.  If these are not traceable to times when the buoy's power systems were intentionally cut by human hands, then this might indicate some kind of power problem that could be expected to cause more intermittent outages.
In retrospect I will note that all four of these power outages (as short as 3 hours and as long as 3 months) began at the same time of day, sometime in the hour after UTC 1000 (approximately 6am local time), which could relate to the time of local sunrise.

A subsequent posting on this maintenance log will discuss what what is known about the buoy's return to power.

Thursday, December 10, 2015


The Catuan Wreck (Boca Chica) CREWS buoy was deployed on December 10, 2015. Its coordinates are said to be:
18° 25.924' N
69° 34.802' W
The following photographs were supplied to me by Juan Salado of ONAMET, Dominican Republic.

(posted by Mike Jankulak)

Friday, July 12, 2013

Site #1 Chosen

After a meeting of stakeholders in the Dominican Republic, the site chosen for the installation of the first CREWS/C5 buoy is the Catuan Wreck mooring ball (18degrees 25.924’N, 069 degrees 34.802’ West).