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The total ozone reduction in the Arctic during the winters of 1993/94 acid 1994/95 has been evaluated using the ground-based total ozone measurements of five SAOZ spectrometers distributed in the Arctic and from number density profiles of a balloon-borne version of the instrument. The ozone change resulting from transport has been removed using a 3D Chemistry Transport Model (CTM) run without chem
Polar stratospheric clouds (PSC) were observed with the multi-wavelength lidar of the MOANA project (Modelling and Observations of Aerosols in the Northern Atmosphere) during SESAME (Second European Stratospheric Arctic and Mid-latitude Experiment). The physical state, liquid or solid, of the cloud particles can be inferred from the lidar data. Using isentropic back-trajectories to obtain the ther
A Lagrangian approach has been used to assess the degree of chemically induced ozone loss in the Arctic lower stratosphere in winter 1991/1992. Trajectory calculations are used to identify air parcels probed by two ozonesondes at different points along the trajectories. A statistical analysis of the measured differences in ozone mixing ratio and the time the air parcel spent in sunlight between th
The absence of LIDAR depolarization in a polar cirrus observed above Sodankyla (Finland) showed the presence of spherical particles at -65°C. The presence of pure liquid water is excluded, since homogeneous freezing should occur at or above -40°C. The cirrus layer was detected at the tropopause, during the horizontal and vertical advection above northern Scandinavia of warm and wet oceanic air. Tw
Balloon borne frost-point hygrometers and backscatter sondes were launched at Sodankylä, Finland in January and February of 1996. These instruments measure water vapor and the backscatter ratio of light due to polar stratospheric clouds in the Arctic stratospheric vortex. Here we report the results of a hygrometer sonde and a backscatter sonde launched within 3.5 hours of each other on January 22/
It is well established that extensive depletion of ozone, initiated by heterogenous reactions on polar stratospheric clouds (PSCs) can occur in both the Arctic and Antarctic lower stratosphere. Moreover, it has been shown that ozone loss rates in the Arctic region in recent years reached values comparable to those over the Antarctic. But until now the accumulated ozone losses over the Arctic have
A Finnish national climate research programme, SILMU, has funded three projects in the field of ozone and UV radiation research during 1990-1995. The results of these projects are summarised here. The study of temperature sounding records made in Finland 1958-94 has revealed a warming trend in the lower and middle troposphere (up to 0.3 K/decade) and a cooling of similar order of magnitude in the
Measurements of tropospheric ozone at three sites at the Arctic Circle in the Finnish Lapland are presented. The variability of ground-level ozone over the diurnal and seasonal cycles in 1992-93 is discussed for the sites of Oulanka and Pallas. The variability with height and over the annual cycle in 1989-94 is discussed for the Sodankyla aerological Observatory, which has the longest record on th
LONG-TERM depletion of ozone has been observed since the early 1980s in the Antarctic polar vortex, and more recently at mid-latitudes in both hemispheres, with most of the ozone loss occurring in the lower stratosphere1. Insufficient measurements of ozone exist, however, to determine decadal trends in ozone concentration in the Arctic winter. Several studies of ozone concentrations in the Arctic
In this study we address the question of temporal ozone trends on isentropic surfaces within the Arctic polar vortex during EASOE. We have combined ozone sonde data from twelve campaign stations distributed throughout the European sector of the Arctic. The development of ozone at the 425, 475, 550 and 700K levels is presented, using analysed fields of isentropic potential vorticity and isentropic
This special issue of Climatic Change contains a series of research articles documenting co-ordinated work carried out within a 3-year European Union project 'Prediction of Regional scenarios and Uncertainties for Defining European Climate change risks and Effects' (PRUDENCE). The main objective of the PRUDENCE project was to provide high resolution climate change scenarios for Europe at the end o
The Swedish Regional Climate Modelling Programme, SWECLIM, was a 6.5-year national research network for regional climate modeling, regional climate change projections and hydrological impact assessment and information to a wide range of stakeholders. Most of the program activities focussed on the regional climate system of Northern Europe. This led to the establishment of an advanced, coupled atmo
While delays in human-robot encounters can harm perceptions of competence, they can also enhance engagement and relatability, making timing a crucial factor in the design of robot behaviors for effective human-robot interaction. Previous research has primarily focused on how robots’ pauses or errors impact perceptions of competence, but it has not adequately addressed the complexity of timing in s
Amid growing geopolitical tensions and the shift toward a multipolar world, research security has emerged as a critical concern for academic institutions and national governments. While efforts to protect science from foreign interference and intellectual property theft are increasing, many current measures lack empirical grounding, clear objectives, or proven effectiveness. This paper discusses t
When children exercise their right to political participation through climate activism and litigation, they demonstrate that an ethics of care is a core component of the postpaternalist era. Children’s ethics of care, however, is not only about care toward their immediate human relations, but also toward other species, the environment they live in and generations to come. They thereby develop the
Thanks to its ability to form a lattice of self-ordered nanosized pores, nanoporous anodic aluminum oxide (NP-AAO) is a promising material with diverse applications, for example, as membrane for the controlled deposition of catalysts. NP-AAO is obtained by the anodization of an aluminum substrate under specific pH and voltage conditions. However, the growth mechanism of the oxide is still under de
It is widely believed that Friedrich Hayek's first encounter with Gunnar Myrdal involved the latter's last-minute contribution, as a replacement for Erik Lindahl, to a Sammelband edited by the former in 1933, and that Hayek was lukewarm toward Myrdal and his ideas from the very beginning. Correspondence between the two shows that, in fact, their interaction about this contribution began two years
Passivity refers to spontaneous formation of a passive film on the surface of metals. High stability of the passive film on advanced alloys relies on the repassivation ability of the alloys in corrosive environments. Two Ni-base superalloys (Ni-22Cr-9Mo-5Fe-2Nb and Ni-18Cr-3Mo-20Fe-5Nb) are studied to elucidate the mechanism of repassivation through a combination of multimodal in-situ synchrotron
