The interface between land surfaces and the atmosphere is a key area in cli
mate research, where lack of basic knowledge prevents us from reducing the
considerable uncertainties about predicted changes. Boreal forests play an
important, but not well known, role in the global hydrological and biogeoch
emical cycles. NOPEX (a NOrthern hemisphere climate Processes land surface
EXperiment) is devoted to the study of land surface-atmosphere interaction
in a northern European forest-dominated landscape. The main NOPEX region re
presents the southern edge of the boreal zone. It consists of a highly hete
rogeneous landscape, with forests, mires, agricultural land and lakes. A se
cond study site, in northern Finland, representing the northern edge of the
boreal zone, will be introduced into NOPEX in connection with its coming w
inter-time field activities. Field activities, dominating the initial phase
of NOPEX, are conceived to strike a balance between the need to cover mult
i-annual observations and the resources required to carry out measurements
covering all relevant spatial scales. The long-term data collection activit
ies, the Continuous Climate Monitoring (CCM), form the backbone of the fiel
d programme. A suite of Concentrated Field Efforts (CFEs) covering periods
of summer, spring and winter brings together scientists from more then 20 c
ountries during month-long campaigns. CFEs have been carried out in May-Jun
e 1994 and April-July 1995. A third, winter-time CFE is planned for 1998-99
. The System for Information in NOPEX (SINOP) is the database which forms a
backbone for modelling and analysis work, dominating the second stage of N
OPEX. A series of PhD courses are run in parallell to the research activiti
es. Analysis and modelling are done in four interacting areas, including lo
cal-scale processes, meso-scale surface-atmosphere coupling and remote sens
ing techniques. The fourth area, regionalization methods, aims at bringing
the previous three together in order to provide improved parameterization s
chemes for exchange of energy, momentum, water and CO2 between land and atm
osphere in hydrological and meteorological models from the meso to the glob
al scale. (C) 1998 Elsevier Science B.V. Ail rights reserved.