Installation of tide gauges, collection and processing of water level data and

geodetic measurements in Nunavik

• The anticipated temperature warming leads to ice sheet melting and

thermal expansion of the oceans contributing to mean sea level rise

(IPCC, 2013).

• Coastal areas in northern Quebec are particularly vulnerable to

climate change impacts (Ouranos, 2010).

General context

IPCC (2013) Climate Change 2013: The Physical Science Basis. Working Group I contribution to the

IPCC Fifth Assessment Report (WGI AR5)

Ouranos (2010) Savoir s’adapter aux changements climatiques, Montréal, Qc, Canada 128 p.

• «Nunavik’s Marine Infrastructures and Climate Change Research

Project – Impacts and Adaptation»

– developed and led by the Nord-du-Québec Coordination Office of the

Ministère Transports du Québec

• Study of the vulnerability of the Nunavik Marine Infrastructure to

Climate Change:

– Water level data and geodetic measurements program

– Three year duration

• Identify adaptation strategy to ensure durability and safefy of the

marine infrastructures in the 14 northern villages in Nunavik within

the context of climate change

Transport Québec research project

Source : http://www.inframaritimes-nunavik-cc.mtq.gouv.qc.ca

• Mandate of Environnement Illimité : «Acquisition and installation of

gauges, data collection and survey»

– Purchase of equipment (instrumentation, moorings);

– Installation of tide gauges and barometers,

– Geodetic levelling of the instruments,

– Static surveys using high-precision GPS for monitoring isostatic

rebound,

– Implantation of complementary markers if needed,

– Maintenance, monitoring and recovery of equipments (2010, 2011,

2012),

– Control and processing of data on a annual basis,

– Production of annual reports,

– Harmonic analysis of sea level data.

Project Context

• Water level and tide data:

– All the data are the propriety of Transports Québec;

– Inputs to the efforts of propagation of storm wave modelling;

– Definition of average levels in studied villages;

– Validation of existing tide tables for these regions;

– Study of extreme water levels.

General Objectives

General Objectives

• High-precision GPS geodetic survey data:

– All the data are the propriety of Transports Québec;

– Implantation of new high-precision markers and validation older

markers;

– Monitoring isostatic rebound;

– Help to define the new reference system:

• NAD83 SCRS V5

• Ellipsoid NAD83 (GRS-80, WGS84)

• Geoide CGG2005NAD83

Study Area

• Campaign: 15 days (Sept. 23 to Oct. 7, 2009)

• Visit of 4 sites:

– Umiujaq, Ivujivik, Kangiqsujuaq and Quaqtaq

– After a selection among the seven villages to be instrumented

• At each village:

– Installation of two tide gauges and one barometer;

– 3-h water level surveys and CTD (conductivity, temperature, depth)

profile measurement;

– Geodetic surveys of three markers in static GPS mode (>48 hours)

Activities carried out in 2009

• Second visit to Umiujaq site on Nov. 18-19, 2009 :

– Tide levelling prior the freeze-up for verification

• Campaign: 30 days (Aug. 15 to Sept. 23, 2010 with interlude of 11

days from Sept. 3-14)

• Visit of the four already instrumented villages:

– Maintenance of moorings and data recovery;

– 3-h water level surveys and CTD profile measurement;

– Geodetic surveys of three markers in static GPS mode (>48 hours).

• Instrumentation of the 3 other villages:

– Kuujjuaq, Akulivik and Puvirnituq

Activities carried out in 2010

• Second visit to Kangiqsujuaq site on Oct. 16-17, 2010:

– Search for an unrecovered tide gauge and install a replacement new

tide gauge

Activities carried out in 2011

• Campaign: 31 days (Aug. 22 to Sept. 21, 2011)

• Visit of the seven villages:

– Maintenance of mooring and data retrieval;

– 3-h water level surveys and CTD profile measurement;

– Geodetic surveys of three markers in static GPS mode (>48 hours).

Activities carried out in 2012

• Campaign: 27 days (Aug. 20 to Sept. 15, 2012)

• Visit of the seven villages:

– Maintenance of mooring and data retrieval;

– 3-h water level surveys and CTD profile measurement;

– Geodetic surveys of three markers in static GPS mode (>48 hours);

– Dismantling and return of all equipment.

Material and instrumentation

• Tide gauges, barometers and CTD profiler:

– Submersible tide gauges RBR TGR-2050 : recording of the absolute

pressure

– Barometers RBR DR-1050: recording of the atmospheric pressure

– CTD profilers RBR XR-620: recording of the Conductivity (salinity),

Temperature and Depth in the water column

Material and instrumentation

• Calibration certificates supplied by the manufacturer RBR Ltd.

• Performance tests performed on instruments before each installation

• Configuration of tide gauges:

– Read frequency: 1 Hz ;

– Read period: 15 min ;

– Averaging: 1 min. period

Material and instrumentation

• Performance tests on tide

gauges

– Inter-comparison before

each installation

• Protection structure of TGR-2050 tide gauge

Tide gauge installation

Tide gauge installation

• Schematic representation of a mooring

Tide gauge installation

Tide gauge installation

Location of instruments and markers

Village of Umiujaq

(instrumented in 2009)

• 2 tide gauges

• 3 markers – 2 new implatations

• 1 barometer

Location of instruments and markers

Village of Puvirnituq

(instrumented in 2010)

• 2 tide gauges

• 3 markers – 3 new implantations

• 1 barometer

Location of instruments and markers

Village of Akulivik

(instrumented in 2010)

• 2 tide gauges – Aku-02 unrecovered in 2012

• 3 markers – 2 new implantations

• 1 barometer

Location of instruments and markers

Village of Ivujivik

(instrumented in 2009)

• 2 tide gauges – Ivu-04 accidently moved

over a period of 12 days en July 2011

• 3 markers – 3 new implantations

• 1 barometer

Location of instruments and markers

Village of Kangiqsujuaq

(instrumented in 2009)

• 2 tide gauges – Kan-03 unrecovered in 2010

and replaced with Kan-02

– Kan-01 unrecovered in 2012 and accidently moved in Nov. 2010

• 3 markers – 2 new implantations

• 1 barometer

Location of instruments and markers

Village of Quaqtaq

(instrumented in 2009)

• 2 tide gauges

• 3 markers – 2 new implantations

• 1 barometer

Location of instruments and markers

Village of Kuujjuaq

(instrumented in 2010)

• 2 tide gauges

unrecovered in 2011 → no data

• 3 markers – 3 new implantations

• 1 barometer

• Instrument: automatic level LEICA DNA03

– precision of 1 mm per kilometer double leveling

– all paths were made in return in order to calculate closure

• Connection made:

– At the installation

– At the retrieval

Installation: geodetic leveling

• Water level survey:

– Period: 3 hours, centered on high tide

– Frequency: 5 minutes

Installation: water level survey

Installation of barometers

• Installation of a barometer at the airport of each village

• Geodetic leveling of barometers:

– Connection of barometers measured at each site from a temporary point

outside the airport;

– Positionning of the elevation of the using GPS in RTK mode;

– Connecting in the airport with the electronic level

Installation of barometers

• Environment Canada barometer available for comparison:

– manually recorded time series

– minimal interval of 1 hour

– usually available during the day only

• GPS station: – Stabilized and anchored to the

ground (winds of 80 km/h)

– 3 measurement of the height

• Before and after

– Data validation

• Recording time (>24 h)

• Trimble 5700 or R7 receptor: – 24 dual-frequency channels

L1/L2

– Static mode

– Period

• 2 times 24 hours

• without reset

• Trimble Zephyr Geodetic Antenna

Instrumentation of geodetic surveys

Geodetic surveys

• Use of the same 3 markers per village and the same configurations of receptors for all the 4 monitoring campaigns

• Installation of new markers (support points) and validation of existing markers

• Barometers – Verification of the number of records

– Verification of the clock drift: consistent with the specifications of the

instrument and negligible

– Comparison with local data from Environment Canada

• Tide gauges

– Verification of the the number of records (expected vs. obtained)

– Verification of the clock drift: consistent with the specifications of the

instrument and negligible

– Validation of the signal to detect any accidental movement: comparison

of two recordings of the same site

– Transformation of absolute pressure data in geodetic elevation

Data processing

• Transformation of tide gauge data:

– Calculation of the hydrostatic pressure

• Input: atmospheric pressure

– Transformation of the pressure in water height

• Density profile (CTD)

• Variation of the density according to the temperature

• Gravity constant according to the latitude

– Connection of the water height to geodetic elevation

• Connection before (leveling of time serie)

• Connection after (verification)

Data processing

Data processing

Data processing

• Raw time series (tidal pressures) to villages of Ivujivik, Kangiqsujuaq

and Quaqtaq

Data processing

• Validation of tide gauge data

– Comparison of recorded signals for the same site

– Evaluation of the stability of the difference between measurements • Small distance between the respective moorings: little or no phase difference and

amplitude of the tide

• Residues from the respective averages (calculated on the same time period) must be

identical

• Correction of the signal of a tide gauge if needed

– Correction according to the difference between the residues at the time

of dicontinuity and adjustment for the remainder of the time series

– Repetition of the procedure if necessary

– Confirmation of the correction by comparing the geodetic elevation

calculated for the second water level survey before retrieval

Data processing

• Examples of discontinuities in the records at Ivujivik in July 2011

Data processing

• Calculation of the hydrostatic pressure

with

• Atmospheric pressure of the barometer

– Validation of the signal: drift and comparison with the signal from Environment

Canada barometer → generally, very good correlation ( R2 > 0.9)

– Correction at sea level:

Data processing

• Difference between barometric data from Environnement Illimité inc. and

Environment Canada at Ivujivik, Sept. 9, 2011 to Sept. 3, 2012

• Comparison of RBR

barometric records vs EC

at Ivujivik, Sept. 9, 2011 to

Sept. 3, 2012

Data processing

• Calculation of water height

with

• Gravitational constant depending on the latitude of the site:

• Density of water

– Based on measurements of salinity and temperature achieved during

the installation and recovery of moorings (vertical profiles)

– Homogeneous, mixed or stratified profile

– homogeneous: variation of the density (σT) less of 2 units

– mixed: σT from 2 to 5 units

– stratified: σT superior to 5 units

Data processing

• Ivujivik: homogeneous profile • Puvirnituq: stratified profile

Data processing

with

• Correction of the density of water for the seasonal variation of the

temperature

• Calculation of the density (2 layers model)

with

Data processing

• Conversion of water height in geodetic elevation

– Use of the 1st water level survey (after installation of mooring) for the

conversion

– Validation with the 2nd water level survey (before retrieval): verification of

the absence of drift

Geodetic water level

• Water level surveys at Ivujivik in 2011 (reinstallation) and 2012

(retrieval)

Geodetic water level

• Water level surveys at Umiujaq in 2011 (reinstallation) and 2012

(retrieval)

Geodetic measurements

• Implementation of

the GPS receiver

to the existing

marker 84KP121,

Umiujaq

Geodetic measurements

• Implementation of

the GPS receiver

to the new

implanted marker

AT2009-04,

Ivujivik

Geodetic measurements

• All GPS data collected by Environnement Illimité inc. in 2009,

2010, 2011 and 2012 were forwarded and compiled by the

Geodetic Survey Division of Natural Resources Canada

• Compilation of the results of isostatic rebound from 2009 to 2012

by Natural Resources Canada

Harmonic analysis of water levels

• Study for the Ouranos consortium

• Objectives:

– determine the amplitude and phase of the largest tidal constituents

– estimate the residual signal unrelated to the tide and the mean water

level on an annual basis

Harmonic analysis of water levels

• Principle: – Decomposition of the total variance of the fluctuations of the water level

in a set of variances associated with the known harmonics of the tide

• Tool:

– Model T_Tide under MATLAB (Pawlowicz et al., 2002)

MATLAB is commercial software developped by MathWorks

PAWLOWICZ, R., B. BEARDSLEY ET S. LENTZ. 2002. Classical tidal harmonic analysis including

error estimates in MATLAB using T-TIDE, Computers & Geosciences, 28 (8), 929-937

y(t) = Σ Aj cos (2π (σj t – φj))

with

Results

• Results of the harmonic analysis of hourly data of water level at Ivujivik station for 2011-2012 (Z0 = -0.34 m)

Results

• Results of the harmonic analysis of hourly water level at Ivujivik station for 2011-2012 (Z0 = -0.34 m)

• Responsible of the mandate et advisers:

– Anick Guimond (MTQ, project leader)

– Yann Ropars (CIMA+, senior adviser)

– Jean-Pierre Savard (Ouranos, scientific adviser)

• Work team (Environnement Illimité):

– Stéphane Lorrain (project manager)

– Robert Mathieu (land surveyor)

– Patrice Delisle (mooring technician)

– Sébastien Cloutier (geographer)

– Sébastien Bety (land survey technician)

– Marco Drouin (land survey technician)

– Jean Fleury (land surveyor)

– Geneviève Tremblay (logistics)

– Travis Arychuk (Private Sky Aviation)

– Sara Dubosq (oceanographer)

– Yvonnick Le Clainche (oceanographer)

Team

• A.R.K. :

– Serge Payer

– Jack Papak

• Umiujaq

– Emily Sappa (Landholding)

– Peter Novalinga (guide)

• Ivujivik

– Annie Kristensen (city hall)

– Lucassie Kanarjuaq (guide 2009)

– Johny Lunku (guide 2010)

• Kangiqsujuaq

– Aquujaq Qisliq, Johnny Annahatak (guides 2009)

– Ikkiarialik Nappaaluk / Tiivi Alaku (guides 2010)

– Peter Arngak and Markusi Qisiiq (divers 2010)

• Quaqtaq

– Robert Deer (Landholding)

– Josepi and Billy Keleutak (guides)

• Kuujjuaq – Jason Aitchison

• Akulivik

– Matewsie Qiluqi

• Puvirnituq

– Thomasi Tukalak

Team

Thank you!