Archive for November 5th, 2009

On the shelf, Friday

Thursday, November 5th, 2009

There was a blog choke last night, looks like I erased my message. Anyway, lets recap where we are.

Gliders, they are flying really well.  We have broken the ru21 to north to study the interesting features we saw in the mid-shelf.  The University of Delaware's glider was deployed and is heading offshore (we are having an icon issue, should be fixed when John K. today, the glider is the "X").  The other two gliders Ru5 and RU 23 continue in on the shore.  As they reach the shallower waters, chlorophyll values continue to rise. Offshore waters show colder water temperatures and the salinity is is higher in the nearshore waters.  Nice validation for the winter bloom, more below. The glider to the north is seeing similar features despite being in deeper water.  A reminder vertical data for people's interest can be found at http://marine.rutgers.edu/cool/auvs/?page=deployments.

slide111

ru05_091030t1653_091106t0104_osse_temp_xsec1

ru05_091030t1653_091106t1122_osse_sal_xsec

ru05_091030t1653_091106t1122_osse_chla_xsec

ru05_091030t1653_091106t1122_osse_bb470_xsec

What do the current show?

The currents have been calming down, and explains the great progress being made by the gliders.  The path planner is very fun, and we tip the morning coffee to our JPL partners.  The currents are likely to increase in the day as it is projected to whip up.  Good thing the AUV team got their work in yesterday.  The forcatsed currents are predicted to whip mostly offshore, and the inner shelf still is predicted to be calm.  Below is the ROMS forecast from the Rutgers group. The ensemble model is also below with the variance in the  U and V components.   The errors in the ensemble model have decreased with variance being on the order of 5 cm/s on in the inner shelf in the U component, 10-15 cm/s in the V component.

slide26

slide44

slide34

Pictures from the AUV team yesterday in Tuckerton

Thursday, November 5th, 2009

The AUV assetts are in the water today as we speak.  Below are pictures of the teams prepping yesterday.

For those who have not been the field station, below is the pier that you walk out to the field station on.

img_1205

Joe Debarro showing off the plankton pump that can be installed on the REMUS vehicle.

img_1206

The Rutgers REMUS, being charged and getting ready for a days work.

img_1208

JPL Iver, dissected to see all its glory

img_1209

The NUWC Iver assembled and looking fine!

img_1211

JPL Executive Summary 11/05/2009

Thursday, November 5th, 2009

Executive Summary of 11/05/2009

Winds have switched to Southeasterly today as predicted. NAM forecasts indicate weak winds Thursday and Friday. Northwesterly winds will resume Saturday with strong wind as high as 30 knots. Excellent SST images are obtained on Tuesday. In addition to the multiple bands in the SST, there is a strong outflow of cold (and probably fresh) water from the NY harbor into the shelf break (shown in both the GOES and MODIS composite images). The cold water outflow from the NY harbor is evident in some models (e.g., HOPS), although with much weaker amplitude, certainly due to the coarse spatial resolutions. The HF radar data clearly show this strong current near the entrance of the NY harbor. The equal-weighted ensemble model forecast shows a relative weak offshore current in this region, mostly due to the fact that some models (e.g., ESprESSO) have strong current than others. All three gliders are moving along the predicted path.

Waypoint change to east

Thursday, November 5th, 2009

Scarlet's reported ocean currents are much lower the last three surfacings, down to 5 cm/sec.  If this holds, it means we successfully made it out of the swift currents to the south by flying perpendicular to the current.  It also means we can fly the direction we want.  Following the white pathline into Spanish waters calls for an easterly course at this time.  We'll make the change at the 11 am surfacing.

091105_ru27_alt

Thoughts from MIT and WELCOME the AUVs TODAY!

Thursday, November 5th, 2009

Pierre sent on some great info to the team.

By the way, our forecasts are on this web-site: http://mseas.mit.edu/Sea_exercises/OOI-OSSE09/index.html
We have given our model fields to Arjuna and Henrik for the AUV planning tomorrow.

Interesting features that we discussed with Henrik and that can be explored with the AUVs are:

- Tidal effects (which we forecast will dominate at least for the first half of the day tomorrow due to weak wind forecasts), see for example: http://mseas.mit.edu/Sea_exercises/OOI-OSSE09/Tides/index_tides.html.

- The along-shore and cross-shore gradients (more interesting than a thermocline yoyo) since the water column is forecast to be relatively well-mixed in the AUV ops area, excepted mid-afternoon due surface warming (afternoon effect for the acousticians). The along-shore AUV-path to the north should show some colder waters slowly advected from the NY Bay. The cross-shore AUV path will also show a small temperature gradient in the area. Attached is a plot of T at 15m forecast for Nov 5 11am, EST.

- By the way, Oscar, the main mixing on the NJ shelf seems to have happened on Oct 25, with full mixing up to 30m depth (more or less). We just missed it by 1 week. This I think is link to the winter bloom we have observed in the glider data.

- For the curious and for John Wilkin, I also include a plot the the vertical avg 0-200m velocity that explains I think some of the features above the Hudson Valley that Yi talked about. You can see the tidal resonance (the forecast plot attached ccnt_VAV200Z_03Nov15z shows the strong flow conditions, with some internal tides elsewhere in the domain). At other times, the resonance leads to no tidal flow right above the valley, but strong flow on either side.

Evening dialogues, history, and path forward

Thursday, November 5th, 2009

Late last night, even after the Yanks were celebrating their victory, the OSSE dialogue continued.  I am compiling many of the thoughts and language of the dialogue.  It provides a great summary of why we are excited, where we have been, and let's us dream about where we are going.

I begin again with Yi's thoughts after yesterday's telecon:

Yi was excited about a feature observed to the North in the MAB.  He saw an outflow feature from the NY harbor,(satellite images of the features and the model realizations are posted in one of the blogs from last night).  Yi's observation was that all four models are warmer in that outflow region, suggesting a weak or  no outflow from the NY harbor, leading him to want some salinity data and he suggested we send a glider up to verify. This suggestion illcited a comment from the Stevens crowd and began an email dialogue.  I am posting that dialogue.

Nickitas chimed in with some thoughts about the to what degree we can believe the SST for identifying small differences.  His point was SST from satellite has inherent errors of a degree Celsius in our region and he cautioned that it can't be taking as absolute truth.  Nickitas looked at the NDDBC buoys and saw NYHOPS is currently tracking COLDER by 1 degree Celsius, not warmer, at NDBC buoy 44009, and it is right on the money at NDBC 44025 and NDBC 44065 just outside NY/NJ Harbor, and several other stations not shown here but in the www.stevens.edu/maritimeforecast pages. These stations are inside the continental shelf.

As Yi pointed out later in the night, The errors for the various satellite data sets are in the range of 0.5 to 1.0 degree.  Merging them together is certainly a challenge, probably will introduce  more errors, so the SST uncertainty is probably over 1.0 degree. While we cannot say much with those regions with smaller differences, there are areas where the difference is significantly more than 1.0 degree, suggesting the discrepancies among the various models.  As was the theme of the discussion in the cool room yesterday, this was viewed as exciting as it provided something as close to an objective "road map" of where to fly.  He also pointed out here was not look for model model differences but to test how our systems are integrated by the cyberinfrastructure.  He asked for comments, and John Orcutt soon chimed in that while there are examples of real-time assimilation into models (e.g.   SCCOOS and Monterey) this is, he asked it this was the first time that the data  and subsequent models are used to steer gliders.

Yi and Pierre followed.  I add to their list.

In 1998-2001, the HyCODE/COMOP efforts at LEO manually ran models and twice a week provided a four day ensemble of forecasts.  All field assets (REMUS, plane, boat, glider) used those forecast to plan their experiments.  Those experiments were a collection of distributed efforts serving many needs, so scientists scattered "Much like Monty Python's race for people with no sense of direction.

In 2003 when a large experiment was conducted.  The  AOSN experiment in Monterey Bay, data are processed  and models are run manually.  Every day, people have to be in the "control room" in  MBARI giving briefings.  Yi had to fly from LAX to MRY a few times a week.  One Sunday night,  they lost Yi's bag, and he had  give the briefing the second day in day-old T-shirt and short.  Many in the room remember that forecast.....  🙂

Progress evolved during the e ASAP experiment in 2006, scientists were  distributed in a virtual mode.  Models were used to assimilate data collected from the field.  While people were looking at model forecasts, but the end-to-end loop was being developed.  FDuring this effort however models were used to guide the gliders and AUVs, the MB06 group even planned glider paths in real-time as well as horizontal and vertical yoyo's for the AUVs (done for PLUSNet, in real-time).

In 2007, with Pierre & Henrik's teams,  guided the Kayaks directly from model forecasts that posted waypoints in web file on a website that the Kayaks read via iridium, with no human in the loop. These efforts continue  in 2008 and 2009.

In 2008, there was the  MB08 experiment, and the network did collect some EO-1 Hyperion images,  but it was not coordinated with gliders and models.  Scientists  guessed where the was interesting feature (the north bay) was  interesting, so Steve Chien's team uploaded commands to steer the satellite imager toward that general direction.

As you said, this is the first time that we complete the sensor web loop end-to-end, including  in situ and satellite sensors, assimilative and forecasting models, and use 3D forecasted current to  optimize the glider trajectories/waypoints.  The next is couple that to the Hyperion overflight for Saturday.

The take home message the vision of distributed end to end system, all in the team have been working is evolving rapidly.  On a personal note, thinking back to the 1998 experiments, it is exciting to see this evolution, and I would submit this history and present state should be a focus of manuscript by this team.  We should think a nice venue to share that exciting history!

Scarlet\’s 7,000th Kilometer. …

Thursday, November 5th, 2009

Scarlet\'s 7,000th Kilometer. - http://www.i-cool.org/?p=4136

Plans going forward into tomorrow and the weekend

Thursday, November 5th, 2009

Today was an exciting day during the OSSE.  We had friendly debate and lots of great ideas.  This is what the future of oceanography can be, and I feel very lucky to be part of it. We also had give the strategy to the JPL path planner to provide the gliders the next set of waypoints.

The crux of the debate was where do we send the gliders? The AUV? Where should we send the U. Deleware glider? What should be the glider configuration for the saturday Hyperion satellite pass? What science do we want to address?

Several in the group wanted to get gliders to the north to resolve some interesting transport issues.  See Yi's thoughts in the earlier blog.  Others wanted to head the gliders in nearshore to confirm the presence of the winter bloom?  Others wanted to fan out in the mid-shelf in parallel lines to validate models?  Discussion of the way forward continued in discussion in many of the groups late into the afternoon.  Given uncertainities that need to be resolved about shipping lanes, to figure out where are the safe northern zones, the inital decision to give the JPL scientists time to run the path planner, a decision was to fan out the gliders as they head in back to the mid shelf.  Tomorrow we will figure out the distribution to cover uncertainity in the north and anchor the shelf wide modeling efforts. The gliders are making good progress. They are now heading onshore, this path planning is cool!

slide19

In the afternoon, discussion continued for over an hour with Julia Leven, Scott Glenn, Wendell Brown, Oscar Schofield, and Javier Zavaka-Garay. Currently the path planner uses the ensemble model  to guide the path planner.  One issue is that we know all the models have different uncertainities and errors.  We focused our discussion on the variability in the currents as this is what influences the ability of the gliders to fly. Below is ensemble currents, below that are variance in the u and v components between the models.  Our discussion focused on using the gliders to minimize the variance (decrease the red areas),  and how that might be a path forward for how we prioritize missions in the next two weeks.  The cross shore lines tonight should help minimize the uncertianity in the mid shelf where the winter bloom is occuring, and then we plan how to resolve the northern area that is of interest to a bunch of the OSSE science team.  What a great day to be an oceanographer!

slide24

slide32

slide42