At NIOZ, we are often looking for students to help us out with our sea-level research.
Note that the project below is no longer available, but may serve as an example of what would be possible. If you are interested in doing your thesis with us, please get in touch!
~~~~~~~
Present-day sea-level change
along the coast of Brazil
Project Summary
Sea-level
change is not a spatially uniform process. On the contrary, regional
differences from the global mean sea-level change (~3 mm/yr from 1993-2017),
can be large, reaching up to 15 mm/yr depending on the study region. Thus,
understanding sea-level change regionally is critical for adaptation policies.
Contrasting
with the high number of studies focusing on European and North-American sea-level
change, sea-level change at the coast of Brazil has been poorly investigated
over the last decades. One of the reasons is the lack of data available in the
region. Along the 7491 km of the Brazilian coast, there are only 12 tide gauges
registered at the Permanent Service for Mean Sea Level (PSMSL), of which only
two have been updated in the last 3 years. In face of this issue, several
Brazilian universities set up SIMCosta1, a project that aims to improving
coastal monitoring using oceanographic buoys and tide gauges. Currently, the
project has installed 7 tide gauges (Figure 1), from which the data is freely
available at the project website.
While
these tide gauge time series are too short to describe the long term present-day
sea-level change at the coast of Brazil (most of the records now cover 2 years),
the satellite altimetry record (since 1993) is long enough to be used in such
studies. However, sea-levels from satellite altimetry may be contaminated by
the presence of land in the near-shore region, and thus are limited to 20-50km
from the coast. Furthermore, the coastal ocean has a more complex dynamic than
the open ocean, and the geophysical corrections (inverse barometer, sea state
bias, wet and dry troposphere and ionosphere, wind and tides effect) normally
applied to the altimetry record can be less accurate in shallow waters. However,
recent efforts from the coastal altimetry community2 have shown that
altimetry observations can be reprocessed for coastal regions. An example is
the X-TRACK product from AVISO (Birol et al., 2017), which covers 24 coastal
regions of the world and ranges from 1993-02 until 2019-05. Two of the defined
regions by X-TRACK cover the Atlantic South-American coast (Figure 2).
The aim of this project is to characterize
present-day sea-level change in the coast of Brazil, using the X-TRACK product
in combination with the tide gauge data from SIMCosta. The
student will process the altimetry dataset and validate it with the tide gauge
data, obtaining a regional time-series of sea-level anomalies. The final
time-series will be used to answer the question “How has sea level changed
along the coast of Brazil in the last 28 years?” Other sub-questions, as “Do
different regions present a different trends/behavior?”, can also be
investigated.
While
the X-TRACK processing has been validated in other regions (e.g. Birol et al.,
2017), the altimetry product needs to be validated for the Brazilian and South
American region. For this, we will use the tide gauge data from SIMCosta. To
our knowledge, there is no study that describes present-day sea-level change in
the coast of Brazil. Therefore, this study is innovative, and can bring a
significant contribution to the scientific and policy-makers community.
Expected
project duration:
6 - 9 months (Master thesis)
Requirement: Be familiar with some
programming language (Preferably Python, but also MatLab or R).
Other
Details:
· This project works with data
that are available online (e.g. tide gauges and satellite altimetry). No field work
or experimental work is foreseen, only computer work.
· The project is at
NIOZ-Yerseke.
Supervision
Team:
Daily
supervisor: Carolina Camargo, MSc (PhD candidate)
PI
supervisor: Aimée Slangen / Theo
Gerkema
In
collaboration with SIMCosta
For applications, contact carolina.camargo@nioz.nl
References
·
Birol F., N. Fuller, F. Lyard, M. Cancet, F.
Niño, C. Delebecque, S. Fleury, F. Toublanc, A. Melet and M. Saraceno, F.
Leger, 2017. Coastal applications from nadir altimetry: example of the X-TRACK
regional products. Advances in Space Research, https://doi.org/10.1016/j.asr.2016.11.005.
·
1 http://www.simcosta.furg.br/
·
2https://www.coastalaltimetry.org/
