From 6e00390872482b69f3db5f4e37189d1ca67a9998 Mon Sep 17 00:00:00 2001
From: ctroupin <charles.troupin@gmail.com>
Date: Wed, 19 Dec 2018 22:27:35 +0100
Subject: [PATCH] instrument description
---
latex/AlborexData.bib | 2 +-
latex/AlborexData_ESSD.tex | 75 ++++++++++++++++++++++++++------------
2 files changed, 52 insertions(+), 25 deletions(-)
diff --git a/latex/AlborexData.bib b/latex/AlborexData.bib
index da09955..10be849 100644
--- a/latex/AlborexData.bib
+++ b/latex/AlborexData.bib
@@ -1748,7 +1748,7 @@ and Larnicol, G.},
}
@TechReport{TROUPIN2018PY,
- Title = {AlborEx-Data-Python},
+ Title = {{AlborEx-Data-Python tools v1.0.0}},
Author = {C. Troupin},
Institution = {University of Liège},
Year = {2018},
diff --git a/latex/AlborexData_ESSD.tex b/latex/AlborexData_ESSD.tex
index 34543c5..870333d 100644
--- a/latex/AlborexData_ESSD.tex
+++ b/latex/AlborexData_ESSD.tex
@@ -207,7 +207,7 @@ When the spike value is above the threshold (depending on the variable), the fla
\item[stationarity:] it aims to checks if measurements exhibit some variability over a period of time, by computing the difference between the extremal values over that period.
\end{description}
-It is worth mentionning the tests described above are not yet applied on the glider data, since their processing is done outside of the general SOCIB processing chain, but the tests have been implemented in the glider toolbox \citep[][and available at \url{https://github.com/socib/glider_toolbox}]{TROUPIN16} and will be made operational once they have been properly tested and validated.
+It is worth mentioning the tests described above are not yet applied on the glider data, since their processing is done outside of the general SOCIB processing chain, but the tests have been implemented in the glider toolbox \citep[][and available at \url{https://github.com/socib/glider_toolbox}]{TROUPIN16} and will be made operational once they have been properly tested and validated.
As the new files will not be available before a full reprocessing of all the historical missions, the decision was taken to provide the data files in their current state. A new version will be uploaded as soon as the processing has been performed.
@@ -246,42 +246,55 @@ The CTD rosette was equipped with:
\item a SBE 43 oxygen sensor,
\item a Seapoint [FTU] fluorescence and turbidity sensor.
\end{itemize}
-The meteorological variables (air pressure, temperature, humidity, wind speed and direction) are acquired using GEONICA METEODATA 2000 weather station.
-The continuous, near-surface measurements of temperature and salinity are provided by a SeaBird SBE21 thermosalinograph.
-\subsubsection{Quality checks}
-
-The general checks described in Sec.~\ref{sec:qctests} (i.e., ranges, spike, gradient and stationarity) are applied on the temperature, salinity, conductivity and turbidity. The threshold values are detailed in the corresponding tables in the QC procedure document \citep{SOCIBQC2018}.
+The GEONICA METEODATA 2000 weather station measured the following variables: air pressure, temperature, humidity, wind speed and direction, with a resolution of 10 minutes. The continuous, near-surface measurements of temperature and salinity are provided by a SeaBird SBE21 thermosalinograph.
+\subsubsection{Quality control}
+The general checks described in Sec.~\ref{sec:qctests} (i.e., ranges, spike, gradient and stationarity) are applied on the temperature, salinity, conductivity and turbidity. The threshold values are detailed in the corresponding tables in the QC procedure document \citep{SOCIBQC2018}. As mentioned in Sec.~\ref{sec:processing}, netCDF files with a correction applied on the salinity and conductivity are also provided (L1\_corr).
\subsection{Gliders}
To collect measurements addressing the submesoscale, two gliders were deployed on May 25 inside the study area. The coastal glider carried out measurements up to 200~m depth and the deep glider up to 500~m. The horizontal resolution was about 0.5~km for the shallow and 1~km for the deep glider. The initial sampling strategy consisted in two 50-km long, meridional tracks, 10 kilometers away one from the other, and to repeat these tracks up to 4 times during the experiment. However, due to the strong zonal currents in the frontal zone, different tracks (Fig.~\ref{fig6:glidertracks}) crossing the front several times were made instead.
-On May 25 at 19:24 (UTC), the deep glider payload suffered an issue with the data logging software, resulting in no data acquisition during a few hours, during which the problem was being fixed. After that the data acquisition could be resumed on May 26 at 08:50 (UTC).
-
-Due to safety concerns, both the deep and coastal gliders had their surfacing limited: the deep glider came to the surface one in every 3 profiles, while the coastal gliders came out one in every 10 profiles. While this strategy might not be considered as optimal in a purely scientific point of view, the priority was set on the glider integrity
+On May 25 at 19:24 (UTC), the deep glider payload suffered an issue with the data logging software, resulting in no data acquisition during a few hours, during which the problem was being fixed. After this event, the data acquisition could be resumed on May 26 at 08:50 (UTC).
\begin{figure}[t]
\includegraphics[width=.5\textwidth]{fig06.png}
\caption{Deployment positions and trajectories of the gliders. Different time instances separated by one day are indicated on the tracks to provide a temporal dimension.\label{fig6:glidertracks}}
\end{figure}
-The total number of valid measurements (i.e., discarding the bad and missing values) acquired are 121513 for the deep glider and 226717 for the coastal. The mean vertical separation between 2 consecutive measurements is around 16~cm. Figure~\ref{fig6:glidersections} displays the temperature and salinity sections obtained with the 2 devices. The high density of measurements makes it possible to distinguish small-scale features on both sides of the front, such as strong lateral gradients, subduction or filament structures.
+The mean vertical separation between 2 consecutive measurements is around 16~cm. Figure~\ref{fig6:glidersections} displays the temperature and salinity sections obtained with the 2 vehicles. The high density of measurements makes it possible to distinguish small-scale features on both sides of the front, such as strong lateral gradients, subduction or filament structures.
\begin{figure*}[t]
\includegraphics[width=\textwidth]{fig07.png}
\caption{Temperature (top) and salinity measured by the two gliders. The approximative front position at the surface is shown as a dashed, grey line.\label{fig6:glidersections}}
\end{figure*}
-The gliders follow a 3-dimensional trajectory in the water column but for some specific usages it is sometimes more convenient to have the glider data as if they were a series vertical profiles. To do so, a binning is applied on the original data, leading to the so-called Level-2 data, further described in Sec.~\ref{sec:processing}.
+The gliders follow a 3-dimensional trajectory in the water column but for some specific usages it is sometimes more convenient to have the glider data as if they were a series vertical profiles. To do so, a binning is applied on the original data, leading to the L2 data, as described in Sec.~\ref{sec:processing}.
\subsubsection{Configuration}
+The information concerning the two gliders is summarised in Tab.~\ref{tab:gliders}. Due to safety concerns, both the deep and coastal gliders had their surfacing limited: the deep glider came to the surface one in every 3 profiles, while the coastal gliders came out one in every 10 profiles. While this strategy does not appear optimal in a scientific point of view (loss of measurements near the surface, meaning of the depth-average currents), the priority was set on the glider integrity.
-\subsubsection{Quality checks}
+\begin{table*}[htpb]
+\caption{Characteristics of the gliderss.\label{tab:gliders}}
+\begin{tabular}{lll}
+\tophline
+ & Coastal glider & Deep glider \\
+\middlehline
+Manufacturer & Teledyne Webb Research Corp. & Teledyne Webb Research Corp. \\
+Model & Slocum, 1st generation, shallow version (200 m) & Slocum G1 Deep \\
+Battery Technology & Alkaline C-Âcell & Alkaline C-Âcell \\
+Software Version & 7.13 (navigation), 3.17 (science) & 7.13 (navigation), 3.17 (science)\\
+On-Âboard Sensors & CTD, Oxygen, Fluorescence-ÂTurbidity & CTD-ÂA4468, Oxygen-Â3830, Fluorescence-ÂTurbidity SLK\\
+
+\bottomhline
+\end{tabular}
+\end{table*}
+
+\subsubsection{Quality control}
Before the deployment, glider compass was calibrated following \cite{MERCKELBACH2008}. The thermal-lag happening on the un-pumped Sea-Bird CTD sensors installed on the deep and coastal gliders is corrected using the procedure described in \citep{GARAU11}.
@@ -289,7 +302,7 @@ The checks not yet applied but planned for the next release of the Glider toolbo
\subsection{Surface drifters}
-On May 25, 25 Surface Velocity Program (SVP) drifters were deployed in the frontal area in a tight square pattern with a mean distance between neighbor drifters around 3~km. In the Mediterranean Sea, they have been shown to provide information on the surface dynamics, ranging from basin scales to mesoscale features or coastal currents \citep{POULAIN13}. Almost all the drifters were equipped with a thermistor on the lower part of the buoy to measure sea water temperature.
+On May 25, 25 Surface Velocity Program \citep[SVP,][]{LUMPKIN2009} drifters were deployed in the frontal area in a tight square pattern with a mean distance between neighbor drifters around 3~km. In the Mediterranean Sea, they have been shown to provide information on the surface dynamics, ranging from basin scales to mesoscale features or coastal currents \citep{POULAIN13}. Almost all the drifters were equipped with a thermistor on the lower part of the buoy to measure sea water temperature.
11 out the 25 drifters, especially those deployed more to the south, were captured by the intense Algerian Current and followed a trajectory along the coast until a longitude about 5$^{\circ}$30'E. The other drifters were deflected northward about 0$^{\circ}$30'E, then veered northwestward or eastward
and described cyclonic and anticyclonic trajectories, respectively. All the drifters moved along the front position (deduced from the SST images), until they encounter the Algerian Current (Fig.~\ref{fig3:drifters}).
@@ -306,6 +319,15 @@ On average the temporal sampling resolution is close to one hour, except for 2 d
\caption{Drifter temperature (left-hand side) and velocity in the area of study.\label{fig7:drifterszoom}}
\end{figure*}
+\subsubsection{Configuration}
+
+The drifters deployed during the experiment are the mini-World Ocean Circulation Experiment SVP drifters. These drifters are made up of a surface buoy that includes a transmitter to relay data and a thermistor to measure the water temperature near the surface; the buoy is tethered to a holey-sock drogue centered at 15~m depth. The possible loss of the drogue is controlled with a tension sensor located below the surface buoy.
+
+15 drifters were manufactured by Pacific Gyre and 10 by Data Buoy instrumentation (DBi). All the drifters contributed to the Mediterranean Surface Velocity Programme (MedSVP).
+
+\subsubsection{Quality control}
+
+Tests are applied on the position, velocity and temperature records (valid ranges and spikes). Checking the platform speed is particularly relevant, as abnormally high values are intermittently encountered.
\subsection{Profiling floats}
@@ -313,39 +335,44 @@ Three profiling floats were deployed in the same zone as the drifters, on May 25
The Arvor-C trajectory closely follows the front position until a latitude of 36$^{\circ}$30'N, accounting for 455 profiles in the vicinity of the front. This is probably due to its configuration: its high frequency temporal sampling makes it possible to spend more time in the near-surface layer and hence the float follows the front better than the 2 other float types. Its last profile was taken on June 14, 2014, at an approximative location of 36$^{\circ}$15'N, 4$^{\circ}E$, then it drifted at the surface.
-The 2 Arvor-type floats provided temperature and salinity profiles. In addition to these variables, the Provor-bio platform measured biochemical and optical properties: colored dissolved organic matter (CDOM), chlorophyll-a concentration, backscattering (650~nm), dissolved oxygen concentration and downwelling irradiance (380, 410, 490~nm) and photosynthetically active radiation (PAR). The profiles were performed around local noon time and were used in combination with the glider measurements to study the deep chlorophyll maximum (DCM) across the front \citep{OLITA17}.
\begin{figure*}[ht]
\includegraphics[width=.9\textwidth]{fig10.png}
\caption{Profiling floats trajectories (top-left panel) and salinity from May 25 to June 15, 2014. \label{fig8:argofloats}}
\end{figure*}
+\subsubsection{Configuration}
+
+The 3 floats provided temperature and salinity profiles thanks to the Sea-ÂBird CTD. In addition to these variables, the PROVBIO (PROVOR CTS4) platform measured biochemical and optical properties: colored dissolved organic matter (CDOM), chlorophyll-a concentration, backscattering (650~nm), dissolved oxygen concentration and downwelling irradiance (380, 410, 490~nm) and photosynthetically active radiation (PAR). Table \ref{tab:argofloats} reports the main deployment characteristics.
+The profiles were performed around local noon time and were used in combination with the glider measurements to study the deep chlorophyll maximum (DCM) across the front \citep{OLITA17}.
\begin{table*}[htpb]
-\caption{Characteristics of the profiling floats.\label{tab:argofloats}}
+\caption{Characteristics of the profiling floats. All the floats are manufactured by NKE (Hennebont, France).\label{tab:argofloats}}
\begin{tabular}{lccllc}
\tophline
-Platform & Initial time & Final time & Maximal depth (m) & Cycle length & Number of profiles \\
+Platform & Final time & Maximal depth (m) & Cycle length & No. of profiles \\
\middlehline
-Arvor-A3 & 2014-05-25 & 2014-06-17 & 2000 & 1 day & 12 \\
-Arvor-C & 2014-05-25 & 2014-06-17 & 400 & 1.5 hour & 455 \\
-Provor-bio & 2014-05-25 & 2014-04-24 & 1000 & 1 day until June 7, then 5 days & 71 \\
+ARVOR-A3 & 2014-06-17 & 2000 & 1 day & 12 \\
+ARVOR-C & 2014-06-17 & 400 & 1.5 hour & 455 \\
+PROVOR CTS4 $^{\ast}$ & 2014-04-24 & 1000 & 1 day until June 7, then 5 days & 71 \\
\bottomhline
\end{tabular}
+\belowtable{$^{\ast}$ Provor-bio was programmed to profile near local noon time.}
\end{table*}
\subsection{Current profiler\label{sec:adcp}}
-The Vessel Mounted-Acoustic Doppler Current Meter Profiler (VM-ADCP) operating at 153 kHz acquired velocity profiles approximatively every 2 minutes during nighttime (22:00--6:00 UTC) at a speed of 10 knots and during the CTD surveys (see Fig.~\ref{fig3:CTD}). The measurement accuracy is on the order of 0.01~m/s. The measurements were vertically averaged over 8~m depth bins.
+The Vessel Mounted-Acoustic Doppler Current Meter Profiler (VM-ADCP) acquired velocity profiles approximatively every 2 minutes during nighttime (22:00--6:00 UTC) at a speed of 10 knots and during the CTD surveys (see Fig.~\ref{fig3:CTD}). The measurement accuracy is on the order of 0.01~m/s. The measurements were vertically averaged over 8~m depth bins.
The velocities exhibit a dominant eastward current with speed locally larger than 1~m/s and that signal is clearly visible in the first 100~m of the water column. The velocity field is illustrated in Fig.~\ref{fig9a:adcp} where each velocity vector is shown as a bar with a color depending on the intensity. The vertical structure is also displayed along with the front position.
\subsubsection{Configuration}
-The current profiler is an Ocean Surveyor ADCP (Teledyne RD Instruments) operating at 150KH
+The current profiler is an Ocean Surveyor ADCP, manufactured by Teledyne RD Instruments and operating at a frequency of 150~KH. This instrument was configured with a 8-m depth bin and a total of 50 bins. Final velocity profiles were averaged in 10-minute intervals.
+
+The position and behavior (heading, pitch and roll) of the research vessel is obtained with an Ashtec 3D GPS 800 ADU positioning system that provides provide geographical positions with a 10-20 cm accuracy and heading, pitch and roll with an accuracy on the order of 1$^{\circ}$.
+
-This instrument was configured with a
-8-m depth bin and a total of 50 bins. Final velocity profiles were averaged in 10-min intervals.
\subsubsection{Quality checks}
@@ -418,7 +445,7 @@ File name & Platform \\
The standard format (netCDF) in which the data files are written makes the reading and visualisation straightforward. A variety of software tools such as ncview, ncBrowse or Panoply are designed to visualised gridded fields. Here the data provided consist of trajectories (surface or 3D), profiles, trajectory-profile, which can be easily read using the netCDF library in different languages (Tab.~\ref{netcdflib}).
-Examples of reading and plotting functions, written in Python, are also provided \citep{??????}. They allow the interested readers to get the data from the files and reproduce the same figures as in the paper, constituting a good starting point to carry out further specific analysis.
+Examples of reading and plotting functions, written in Python, are also provided \citep{TROUPIN2018PY}. They allow users or readers to get the data from the files and reproduce the same figures as in the paper, constituting a good starting point to carry out further specific analysis.
\begin{table*}[h]
\caption{NetCDF libraries for various languages.\label{tab:netcdflib}}
--
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