1. National Research Council of Italy Roberto Bozzano, Sara Pensieri
SA7.1 Ligurian Sea Heat Budget and Water Quality Analysis Ocean physics and climate change
National Research Council of Italy
Roberto Bozzano, Sara Pensieri
W1-M3A
Western 1 – Mediterranean Moored Multi-sensor Array
General Assembly 2017
Vilanova i la Geltrú, Spain; 27 – 29 June 2017

2. SA7.1 POSSIBLE APPLICATIONS Air-sea interaction:
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
The service activity of the W1M3A observatory relies on:
open access graphical representations of near surface water quality and heat budgets of the Ligurian Sea (north-western Mediterranean Sea).
open access to near real-time data.
The service “officially” runs for 3 years (Sep. 1st, 2014 – Aug. 31st, 2017).
Data in the portal are available since the beginning of the project.
SA products are based on near real-time data available to the FixO3 community in the ftp site of the observatory (Medatlas format) and, with different formats, in MONGOOS Data Centre, in EMODnet Physics, in Copernicus/ MEMS.
POSSIBLE APPLICATIONS
Air-sea interaction:
Atmospheric boundary layer
Wind-wave coupling
Air pollution transfer modeling
Ocean physics and biochemistry
Water mass transport
Primary productivity
Biomass migration
Ocean acidification
Plots of selected derived parameters
Transects and isosurfaces collected during annual cruises.

3. SA7.1 SA product access (Monthly products) Sections
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
SA product access (Monthly products)
Sections
Heat fluxes
Water quality
Monthly time series
Sensible and latent heat fluxes, net long-wave and short-wave fluxes, evaporation, wind stress
Dissolved oxygen, chlorophyll-a, turbidity, pCO2
Graphs are updated in near real-time as soon as a new subset of data is received and processed ashore.

4. SA7.1 SA product access (Cruises)
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
SA product access (Cruises)
R/V Dallaporta
R/V Minerva Uno
Basin-wide investigation of thermohaline variability and mesoscale dynamics.
Analytical determination of dissolved oxygen and CO2.

5. SA7.1 One-click data access (NetCDF format / 1)
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
One-click data access (NetCDF format / 1)
Selection period spans the entire project timeline:
Link to the “Service Level Agreement” of CMEMS
Monthly
data files
Daily
data files of the current month

6. Link for downloading plots
SA7.1
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
One-click data access (Graphs / 2)
For the selected year, monthly plots of parameters are available for download.
Link for downloading plots

7. SA7.1 SA production Single-day missions Research cruises
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
SA production
Single-day missions
The availability of SA products throughout the project timeline was made possible through:
the continuous management of the observatory;
the periodic maintenance of scientific payloads onboard the buoy;
the cross-check of measurements from marine sensors with analytic determinations from water samples;
the reliability of the data management architecture.
May 9, 2014
June 7, 2016
March 19, 2015
June 29, 2016
June 29, 2015
July 11, 2016
August 6, 2015
March 31, 2017
November 13, 2015
May 24, 2017
Research cruises
Aug. 28 – Sep. 3, 2015: R/V Dallaporta
Aug. 23 – 31, 2016: R/V Dallaporta
Apr. 19 – 26, 2017: R/V Minerva Uno

8. SA7.1
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
SA1/2: Heat budget
ITALY
FRANCE
CORSICA
Ligurian sea consists of two distinct parts:
deep (>2600m) western part;
shallow and relatively flat eastern part, located east of a seamount area and the seaward extension of Cape Corso.
Basin-wide cyclonic circulation with noticeable seasonal variability.
Narrow continental shelf, mostly bordered by a steep and high mountainous coast.
Negative water balance (evaporation >> precipitations and river supplies that are almost absent).
Signals of met-ocean variability can be catch through an ocean reference station with:
well instrumented and sustained payloads;
redundant sets of bulk meteorological sensors;
high resolution continuous set of time series.
average net fluxes
ERA40 corrected climatology
Narrow continental shelf, mostly bordered by a steep and high mountainous coast.
Complex interaction between the orography of Liguria and the contrast between cold and humid air mass and warmer water of the Ligurian Sea.

9. SA7.1 Case study 1 - High precipitation events
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
Case study 1 - High precipitation events
Transition area for passing cyclones, but also an area of frequent cyclogenesis.
HPE
Oct. 9/10, 2014 Genoa
Nov. 25, 2016 Genoa
Nov. 28, 2012 Carrara
Sep. 14, 2015 Val Trebbia
Nov. 11, 2012 Massa, Carrara
Nov. 15, 2014 Genoa
Nov. 4, 2011 Genoa
Nov. 10, 2014 Chiavari
Oct. 25, Terre, Lunigiana
Nov. 5, 2014 Carrara
Oct. 4, 2010 Genoa
strong
southerly wind
cold
wind Po
valley
forced
convection
stationary
LANDSLIDE FLOOD
VICT EVAC VICT EVAC.
North
East
South
West
These HPEs are consequence of the formation of quasi stationary mesoscale convective systems over the Ligurian Sea, triggered and maintained by complex mesoscale features, in particular low-level temperature and wind gradients associated with orographically induced flows.
Specifically, the onset of convective systems leading to severe rainfall events over the region is favored by the convergence between two different flows: a warm and moist south-easterly low-level jet on the eastern side, channeled between Corsica and Central Italy and impinging over the Ligurian Apennines, and a northerly shallow cold flow coming from the Po Valley through the lowest orography gaps and affecting the western part of Liguria.
The magnitude of the low-level temperature gradient between the Po Valley and the Ligurian Sea seems to have a significant influence on the extension and intensity of the cold northerly outflow and, as a consequence, on the exact position of the convergence line triggering the convective development.
Northerly winds blowing from the land and carrying cold air masses when reach the warm sea surface, increase the instability of the marine atmospheric boundary layer.
Measurements at sea collecting wind speed/direction measurements and estimating heat fluxes can contribute to understand the space and time evolution of convective systems with particular attention to convergence lines whose position could virtually trigger violent storms and play a fundamental role in forecasting the coastal areas that can be potentially flooded.
The intense episodes are more frequent in autumn when strong wind flows are supported by the release of the ocean heat content after summer.
Alone, heat transfer from the sea to the atmosphere is not sufficient to trigger HPEs. Wind speed and direction play a fundamental role: the greatest amount of precipitation is recorded when the wind turns to north-north-east.

10. SA7.1 SA2/2: Sea water quality
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
SA2/2: Sea water quality
July 2015 – July 2016
Ligurian Sea is characterized by a noteworthy high productivity and a rich and complex ecosystem.
Dissolved oxygen into the sea water, concentration of chlorophyll-a, turbidity and CO2 are some of the measurable parameters that can contribute to assess the good status of health of the ocean.
The observatory maintains a suite of sensors which are regularly replaced for maintenance.
Measurements are cross-checked against reference measurements obtained with CTD casts and/or with water samples analysis.
July – December 2015
Dissolved oxygen in the ocean provides a sensitive early warning system for the trends that climate change is causing. Indeed, an adequate supply of dissolved oxygen gas is essential for the survival of aquatic organisms and the amount of dissolved oxygen is directly connected to the type and abundance of organisms that can live. Oxygen enters the water through diffusion from the atmosphere and/or photosynthesis by aquatic plants, and dissolved oxygen levels are influenced by temperature and salinity (with an inverse proportional relationship).
Calibrated chlorophyll-a concentration is an indicator of phytoplankton abundance and biomass. An understanding of the phytoplankton population and its horizontal and vertical distribution in the ocean can contribute to draw conclusions about the ocean’s health, composition, and ecological status.
Turbidity is a measure of the amount of cloudiness in sea caused by a great variety of scattering particulates (i.e., sediment, plankton, organic by-products). Turbidity affects the depth that sunlight penetrates in water, thus defining the depth of the photic zone, the zone in which photosynthetic production can potentially occur.

11. SA7.1 Case study 2 – Monitoring of zooplankton
Ligurian Sea Heat Budget and Water Quality Analysis
WP 10 – Service Activities
Case study 2 – Monitoring of zooplankton
Study of the zooplankton distribution and its variability on different temporal and spatial scales:
Acoustic backscatter data from moored and vessel-mounted ADCPs.
WP2 catchments at constant depths during cruises.
Diel vertical migration: nocturnal (or normal) pattern characterized by the swimming upward at the sunset and downward at the sunrise of the macroplanktonic/micronektonic component
Other cycle (i.e., 12 h period) can be attributable to the twilight migration.
sunset
sunrise
Backscatter strength values show a seasonal variability with low values in winter from 70 m depth down to 127 m and a gradual increase till 100 m in early spring in correspondence with increment of the net primary productivity that, in turn, implies more availability of food in the water column and less need for zooplankton population to reach the surface to feed themselves.
Analysis of Sv time series clearly evidences a circadian cycle with a quite perfect agreement between the decreasing of backscatter intensity and the hour of sunrise, and, vice versa, an increase of Sv in correspondence to the hours of sunset.
The analysis of corresponding vertical speed presents negative values around dusk and positive ones at dawn showing a well defined nocturnal DVM pattern with a rapid ascent of zooplankton from bottom to sea surface during dusk and a rapid descent from surface to deep water at dawn.
Usually a delay of 1 month exists between peaks of surface production and the increase in zooplankton biomass values of NPP.
DVM is influenced by moonlight: during full moon nights and clear sky, the backscatter strength decreased in the surface layers whilst greater values extended in the water column down to the maximum analyzed depth, making the values acquired at different depth quite homogenous along the water column. This behavior, in contrast with the common nocturnal DVM of new moon periods can be interpreted as a way to escape from visual predators.
Taxonomy
Dry weight
Carbon content
sunrise
sunset
July 2016
Winter
Acoustic backscatter
Vertical velocity