DEVELOPING NOCS SCIENCE STRATEGY
CHALLENGE 1: HOW
FOR 2050 AND
54. Under this challenge we want to understand
the patterns, rates and causes of change in atmospheric CO2 levels
over geologic time; the consequences of changes in palaeo CO2
levels for ocean temperature, sea water acidity and oxygenation;
the processes (and feedbacks) in addition to CO2 change (eg, ocean
circulation strength and mode) that control (amplify) rapid changes
in climate; the impact of these past changes on continental ice
volume (sea level), biogeochemical cycling and global biodiversity.
CHALLENGE 2: WILL
55. The present Atlantic Ocean circulation
carries warm upper waters northward through the Atlantic, the
waters gradually cool on their journey northward giving up heat
to the atmosphere; in the subpolar and polar regions the surface
waters become cold enough and salty enough to sink to the bottom
forming cold deep waters; and this cold deep water returns southward
through the Atlantic. This circulation is called the meridional
overturning circulation (MOC); its size is estimated to be about
17 Sv and it transports 1.3 PW of heat northward, heat that is
given up to the atmosphere leading to the equitable climate of
56. There is a clear need for observations
of the Atlantic MOC and how it is changing over time. Recent analysis
of five hydrographic sections suggested that the MOC at 25(°N
has slowed by 30% over the past 50 years.
But how variable is the MOC on seasonal to interannual time scales?
Is the 30% slowdown within the range of natural variability? Has
the change been gradual as suggested by models or was it abrupt,
occurring over a decade or less? It is essential to establish
a baseline measure of the MOC strength and its seasonal to interannual
variability to put wide-ranging and longer time series of Atlantic
observations into an overall context of Atlantic (and global)
57. Recent results from the NERC RAPID Programme
have shown the necessity to acquire data with sufficient temporal
and spatial resolution (4D) in order to be able to extract long
term trends from short term variability. In particular it demonstrates
the needs for continuous measurements (long term observatories)
and the development of autonomous survey.
CHALLENGE 3: HOW
58. The Palaeo record clearly shows how
species have changed with climatic conditions and we expect the
same to be true in the future and there are implications for organisms
both in the upper water column and the deep ocean. What will be
the responses of biota (eg coral reefs) to ocean acidification?
CHALLENGE 4: WHAT
59. The long term ocean stations in the
North Pacific (HOT) and Atlantic (BATS), and zooplankton collection
(SAHFOS) have demonstrated how patterns of ecosystem change in
the surface ocean can emerge from high quality long term records.
The RAPID programme has shown the potential to follow important
changes in heat fluxes at an ocean scale. Additionally, continuous
records are the only way to effectively assess the impact of episodic
events such as plankton bloom events that may account for much
of the C flux at a particular site. Therefore there is a need
for collection of long time series data, with station locations
and sampling/data collection strategies need to be carefully optimised,
and there is scope for international cooperation.
CHALLENGE 5: WHAT
60. The production of organic C and biogases
in the upper ocean are anticipated to have important impacts on
atmospheric gas concentrations (eg carbon dioxide, dimethyl sulphide
and halocarbons). Vertical transfer to deeper long residence time
waters of organic carbon (the biological pump) and carbon dioxide
physically dissolved at the surface, through mixing and vertical
particle transfer will remove carbon from the atmosphere and upper
ocean. Key biogases produced in the ocean and released to the
atmosphere are proposed to have important feedbacks on climate
so knowledge of their production and fate is essential.
CHALLENGE 6: WHAT
12. Presently the challenge is to integrate
ocean physics models with models of biology at increasing resolution
in order to provide more rigorous predictions of the behaviour
of the ocean system. Mesoscale processes have been identified
as important and hence the need for higher resolution. Models
of atmospheric inputs of gases and particles to the ocean, and
release of climatically important gases, need to be effectively
interfaced with models describing the atmosphere and terrestrial
components of the planet. There is an increasing need to incorporate
the role of shelf seas/coastal oceans in larger-scale modelling.
CHALLENGE 7: WHAT
62. Sea-level change is important since
it would directly affect coastal regions. In addition, it has
an often overlooked impact on inland flood hazards, since sea-level
rise elevates the base-level of rivers. The melt-water influxes
into the oceans that cause sea-level rise can also affect oceanographic
circulation, and hence heat-transport to high latitudes (notably
NW Europe). It is therefore imperative that we develop an understanding
of both the longer-term history of sea-level change and its modern
variabilityincluding the various processes that govern
regional and global sea-level changeto underpin evaluations
of the large-scale impacts of global (greenhouse) climate change.
We especially need to constrain the magnitude and rate of potential
global ice-volume reduction and hence sea-level rise. There is
a need to be able to translate global predictions to local scales
to be used by government to plan and prepare for environmental
CHALLENGE 8: WHAT
63. Although originally thought to be of
low biodiversity, the deep ocean is now known to be very biodiverse,
this diversity composed of species in the small macrofaunal and
meiofaunal size range. Such biodiversity is supplemented by the
very different faunas found at, inter-alia, hydrothermal
vents and cold seeps. Our knowledge of this biodiversity is increasing
but ecosystem functioning is still imperfectly understood, particularly
at temporal scales. Recent studies of the Atlantic have shown
large regime shifts but we can only speculate as to their causes.
Deep-sea technology has now advanced sufficiently that, for the
first time, experimental manipulations in the deep ocean are now
possible. This provides an important opportunity to address fundamental
questions relating to the functionality (trophic, respiratory,
reproduction and competition) in deep ocean ecosystems.
CHALLENGE 9: HOW
64. Microbes are central to ecosystem processes.
Their genetic biodiversity is immense yet their tiny size means
"out of sight is out of mind". Recent research has identified
physiological functions and genes that code for these functions.
Many functions are strategically important; for instance, genes
for nitrogen fixation, and other uniquely prokaryotic aspects
of the marine nitrogen cycle, are now known to be diverse, originating
from several different bacterial and archaeal groups. We do not
know the implications of this and we do not know how these relate
to similar processes in other ecosystems. Is there a common phenotypic
or genotypic microbial diversity across terrestrial, freshwater
and marine ecosystems?
CHALLENGE 10: WHAT
65. The growth of mega-cities, particularly
in Asia, means that the first natural event causing over a million
deaths due to a large earthquake or Tsunami in the next 30 years
is now highly likely. We need to invest in the science to tackle
the questions related to earthquakes, tsunami, continental slope
slumping and volcanic hazards. NOCS believes (and as also articulated
in the Natural Hazards Working Group report chaired by Sir David
King in response to the 2004 earthquake and tsunami) that hazard
assessment is necessary for the implementation of early warning
systems, that we must understand the threats and processes underpinning
these hazards, and that greater support is needed to improve scientific
methods used to assess risk.
CHALLENGE 11: CAN
GEOLOGICAL CO2 SEQUESTRATION
What is a sustainable energy budget for the
earth? What are the implications for human society?
How do we responsibly exploit geological energy
How do we improve hydrocarbon exploration methods?
How do we improve recovery from known oil and gas resources? How
do we better exploit geothermal energy? How should we exploit
37 Bryden, H L, Longworth, H R and Cunningham, S A
2005 Slowing of the Atlantic meridional overturning circulation
at 25N. Nature, 438, 655-657. (doi:10.1038/nature04385). Back