Global Compact International Yearbook 2017

around its area; a smaller city might
have two or three.
These stations are good at providing
information over the long term, but
their monitoring is limited to too few
parameters to give a good picture of the
atmosphere, and they are too far apart
to provide local air-quality information.
Another factor is that pollution in cities
is highly local and made worse by traffic,
weather phenomena, and buildings.
Ideally, large stations would measure
hundreds of parameters and be supported
by a great number of smaller
units to provide information locally. This
would help in finding the real hotspots,
making it possible to warn residents of
air-quality problems and to start taking
measures to mitigate the situation.
Naturally, the smaller units do not need
to be as sophisticated or accurate; their
power lies in their numbers and locality.
This is the market Vaisala serves with
its new products.
Decision-making support
When a network of air-quality observation
devices is dense enough, it
can provide relevant information for
decision-makers. Even right now, data
on local conditions could be used to
redirect traffic, temporarily close polluting
manufacturing plants, or switch
from coal to other sources of electricity.
Over the long term, observations help
to achieve a more thorough understanding
of the atmosphere and the interplay
between the weather and air pollution.
It is widely known that weather affects
air quality. Rain, for instance, can wash
away air pollutants and improve air
quality momentarily. Wind can either
bring in pollutants or remove them,
depending on the source and its location.
What is less understood is air quality’s
impact on the weather.
Weather can intensify pollution
Air pollutants are mostly created and
spread in the planetary boundary layer,
whose height varies with location,
season, time of day, weather – and
pollutants. The thinner the boundary
layer is, the higher the concentration of
pollutants, which, of course, intensifies
their impact.
Usually, the air near the ground is warmer
than the air above it, which is heated
by solar radiation, directly and indirectly,
when the Earth’s warm surface heats the
air above it. However, when the air has
high concentrations of pollutants, they
VAISALA
Vaisala is a global leader in
environmental and industrial
measurement. Building on 80
years of experience, Vaisala
provides observations for a better
world, offering a comprehensive
range of innovative observation
and measurement products and
services.
will reflect some of the sun’s radiation,
which leads to a cooling of the ground,
and hence the air near it.
This creates a warmer layer – or even
inversion – that consequently cools
down the Earth’s surface and traps the
pollutants in the boundary layer, raising
their concentration.
So, weather phenomena should be monitored
alongside air quality to determine
their interaction, locally and in general.
This understanding is essential if we
are to solve air-quality problems and
mitigate their impact.
First metropolitan monitoring system
being built
In the Helsinki region, steps are being
taken to increase this understanding. A
new air-quality measurement network
will be built in 2017 and 2018 by the
Smart & Clean project parties – Vaisala,
the Finnish Meteorological Institute, the
Helsinki Region Environmental Services
Authority HSY, the University of Helsinki,
Pegasor, and the Helsinki Metropolitan
Smart & Clean Foundation.
The network will be the first air-quality
monitoring system of such accuracy in
the world to cover a whole city.
Even in Finland, where air quality is
generally good, 40 percent of city dwellers
get symptoms from street dust, and
air pollution is estimated to cause about
1,600 premature deaths per year.
The new monitoring network will help
compile much more comprehensive
information about the air quality in different
parts of the Helsinki region. The
Smart & Clean project aims at improving
air quality in the region as well as
creating new, innovative applications,
and piloting solutions suitable for export.
With the help of Vaisala’s new instruments,
it is possible to significantly
improve local coverage of the measurements
for a very reasonable cost.
Global Compact International Yearbook 2017 149