What is space weather like today? The solar wind, or
the particle flow radiated towards us by the Sun, gives
rise to this question as it collides with Earth's
magnetosphere. Geomagnetic storms can cause various phenomena,
of which the aurora are most familiar to us. They
occur in the ionosphere of the Earth at a height of 80-300
Tuija Pulkkinen at the Finnish Meteorological Institute has
studied auroral storms and their connection to
near space phenomena since 1980s. Despite her youth,
she has already advanced a long way in her research career.
Pulkkinen says that she wanted to choose an area of research
that was not purely theoretical, but in which she could
make observations and develop the theory further.
Because of its geographical location at the equatorward
edge of the auroral zone, Finland is well suited for the
study of aurora. The magnetic field of
the Earth and its changes have already been monitored since the
early 19th century. A comprehensive network of measuring instruments
has been built all over Finland and Scandinavia. From the 1980s on, it
has also become possible to place instruments in space satellites
that orbit the Earth. Finns have a good reputation as
designers of such instrumentation.
Tuija Pulkkinen (née Mali) was considering future studies
either in Finnish or in natural sciences while in school.
She didn't, however, want to become a teacher of Finnish,
and thus she chose physics instead. The gifted young woman made
rapid academic progress. She completed her Master's degree in
just five years. In 1992, she became the first Finnish woman
to complete a Ph.D. degree in theoretical physics. The topic
of her dissertation was Magnetic field modeling during dynamic
In her research for the doctoral dissertation, Pulkkinen
developed a method for modeling the near space magnetic field.
She has applied this model to auroral storms. Earth's
magnetic field has a 'tail' pointing away from the direction
from where the solar wind is arriving (i.e., away from the Sun).
Pulkkinen started with the electric current systems prior to
auroral storms, and later also included the recovery phase
current systems in her model. In this way, it becomes possible
to find out the causal relationships between the electric
current systems of the tail of the magnetic field, and the
Researchers at the Finnish Meteorological Institute have also
developed a magnetohydrodynamic simulation model. With it,
it is possible to simulate phenomena occurring in connection of
auroral storms solely on basis of what kind of solar wind the
Sun is emitting. In other words, it is like a space weather
forecast. The results of this simulation model are compared
with observations, e.g., ground based or satellite photographs
of the aurora and with the magnetic field models developed by
Pulkkinen. The simulation code used at the Finnish
Meteorological Institute is unique in Europe. Other codes
are in use in the U.S.A. and in Japan. Pulkkinen is also
familiar with these, as she has worked with American research
groups involved with modeling.
The research projects in which Tuija Pulkkinen is a participant
are quite international, which makes daily contacts to various
parts of the world a necessity. She is a research professor
at the Finnish Meteorological Institute. Among the current
challenges for Pulkkinen and the space plasma physics
group at the Finnish Meteorological Institute
is the idea of establishing a European space weather
program. Apart from basic research, its activities would
include space weather forecasts. Particle eruptions taking place
in space can damage satellites, and correct weather forecasts
can help to avoid this damage. Space weather also affects
transcontinental telephone traffic and transmissions of
satellite tv channels. Its ground based effects include
damage to transformers of power transmission lines, and the
intensified corrosion of long gas pipelines.
Tuija Pulkkinen's research has received well-deserved
recognition. In 1998, she was the Macelwane medalist of the
American Geophysical Union. The medal is given to a promising
young researcher in the field of geophysics. In 1999, Pulkkinen
received the science prize of the City of Helsinki.
The workdays of a research scientist can be long, and one must
travel often. The mother of one has to balance work and family
life. However, Tuija Pulkkinen calls her family one of her
1 Public defense of dissertation 1992. Georg Gustafsson from
Uppsala University as opponent.
2 Finnish women physicists at the party after Tuija Pulkkinen's public
defense of her dissertation.
3 Tuija Pulkkinen is talking to visiting children from a day care centre
at the Finnish Meteological Institute about the Sun and solar wind,
using a torch and a hairdryer to demonstrate.
4,5 In 1998, Tuija Pulkkinen received the Macelwane medal of the
American Geophysical Union in Boston. The medal is given to a promising
young researcher in the field of geophysics.
6 Tuija Pulkkinen's favourite aurora: a heart-shaped aurora, with the
Earth seen in the background.
Photos: Tuija Pulkkinen
Tuija Pulkkinen's homepage
"Pulkkinen Receives James B. Macelwane Medal".