Carbon dioxide is the most abundant greenhouse gas emitted due to human activities. Changes in atmospheric columns of carbon dioxide can be measured accurately using ground-based Fourier transform spectrometers, which are operating in the near-infrared spectral region. Our measurements at Sodankylä reveal a significant increase of column carbon dioxide since the start of the column measurements at Sodankylä in early 2009.

Astronauts on board the International Space Station have taken thousands of high-quality images of the northern and southern lights (aurorae). Because the images were not taken as part of a specific research project, no information about exactly where the camera was pointing was available. We have used the stars in the images to reconstruct this information. Now we can tell the latitudes and longitudes of the aurorae in the images and use them for research. The data are publicly available.

In this paper we describe a new method for recognition of digits in seven-segment displays. The method is used for adding date and time information to a dataset consisting of about 7 million auroral all-sky images taken during the time period of 1973–1997 at camera stations centred around Sodankylä observatory in Northern Finland. In each image there is a clock display for the date and time together with the reflection of the whole night sky through a spherical mirror.

This paper describes the laboratory facilities at the Finnish Meteorological Institute – Arctic Research Centre (FMI-ARC). They comprise an optical laboratory, a facility for biological studies, and an office. The facilities are ideal for responding to the needs of international multidisciplinary research, giving the possibility to calibrate and characterize the research instruments as well as handle and store samples.

The objective of this paper is to present a general integrated framework to evaluate land suitability for the optimal placement of solar park, which is based on a combination of a GIS, remote sensing techniques, and multi-criteria decision-making methods. Innovative aspect derives from the proposed tool as currently implemented within a local GIS, which provides a versatile platform of analysis and semi-automation of the operations, which might also extended into full automation.

Solar spectral UV irradiance data measured by the Brewer #037 spectroradiometer in Sodankylä, Finland, in 1990–2014 were examined for their quality flags given by the quality assurance (QA) tools of the European UV DataBase (EUVDB). Statistical analysis on the flags was performed, and five cases were investigated in detail. The results can be used in further development of the quality control/QA tools and selection of cases of exceptional atmospheric conditions for process studies.

The paper described an extensive in situ data set of bulk snow depth, snow water equivalent, and snow density collected as a support of SnowSAR-2 airborne campaign in northern Finland. The spatial and temporal variability of these snow properties was analyzed in different land cover types. The success of the chosen measurement protocol to provide an accurate reference for the simultaneous SAR data products was analyzed in the context of spatial scale, sample size, and uncertainty.

The paper describes the history and the present state of instrumental seismic observations at the University of Oulu and Sodankylä Geophysical Observatory in northern Finland that started in 1950s. This includes both seismic observations at permanent seismic stations and temporary seismic experiments by portable seismic equipment. We describe the instrumentation and major research topics of seismic group at the SGO and discuss the plans for their future development.

Digital photography has become a widely used tool for monitoring the vegetation phenology. The seasonal cycle of the greenness index obtained from photographs correlated well with the CO₂ exchange of the plants at our wetland and Scots pine forest sites. While the seasonal changes in the greenness were more obvious for the ecosystem dominated by annual plants, clear seasonal patterns were also observed for the evergreen forest.

Application of elementary particle physics to the measurements of rock overburden density structures that might be directly applicable to natural resources and undiscovered cave explorations, and even to searching for hidden chambers in historic architectural structures.

A new software coincidence method is shown which can be used to replace conventional coincidence detection with the same effectiveness. Our easy-to-build trial prototype has cost EUR 150 and replaces at least three conventional coincidence modules (over EUR 6000). This has allowed us to carry out experiments that we could not before because of the lack of resources. It detects coincidence, stores timestamp data and transfers them to a PC, allowing easier adjustments and simpler interconnections.

The hardware and software used to collect eddy-covariance ecosystem fluxes of carbon dioxide, heat, and water vapor at a high-elevation subalpine forest site over 17 years are described. Over time, software/hardware improvements have increased the system robustness, leading to a successful 10 Hz data-collection rate of better than 99.98 %. We also provide philosophical concepts that shaped our data system design and are applicable to many different types of environmental data collection.

We have extended the sub-daily, integrated HadISD back to 1931 to double the time coverage of the dataset. We have updated and improved the station selection and merging procedure, which will be rerun on an annual basis to prevent it becoming out of date. The quality-control code has been rewritten from IDL to Python2.7 to make it clearer and more accessible. We have also calculated humidity and heat-stress variables in HadISD.2.0.0. This increases the value and applicability of this dataset.

In order to compare auroral observations, it is necessary to ensure that all instruments are properly calibrated. This can be difficult to achieve with different instruments operated for extended intervals at remote field sites under harsh conditions. Astronomical sources can be used for independent absolute calibration procedures. Under ideal conditions Jupiter is an excellent source, as it can provide more light than the brightest star. We use Jupiter to calibrate an auroral MSP network.

FMI's combined road weather station (RWS) and roadside unit (RSU) in Sodankylä is a unique research platform combining very advanced road weather measurements with a versatile collection of the most common wireless communication methodologies used in a vehicular environment. Together with harsh Arctic road weather conditions it represents an incomparable development environment and pilot RWS station within the field of intelligent transport systems and vehicular networking.

This paper describes frequency and timing calibration, modeling and data processing and calibration for MMS magnetometers, resulting in a merged search choil and fluxgate data product.

Lamp measurements used for the UV irradiance calibration of two Brewer spectrophotometers operated for 20 years in Jokioinen and Sodankylä, Finland, were examined. Temporal development of the responsivity after fixing the irradiance measurements into a specific scale was studied. Both long-term gradual decrease and abrupt changes in responsiveness were detected. Frequent-enough measurements of working standard lamps were found necessary to detect the short-term variations in responsiveness.

This paper presents the results of an investigation into a monument using ground penetrating radar and infrared thermography. The data have been gathered and processed to investigate the presence of multilevel cavities beneath the floor of the monument, and to test an innovative instrument built within the framework of a previous research project. The results show how some features of the underlying environments (partially known, partially unknown) are understood from the upper floor.

Institute of Geophysics and Problems of the Earth Ltd. (Kiev, Ukraine) has developed, patented and been applying in practice for more than 10 years the innovative NMR technology of direct detection of hydrocarbon reservoirs at a depth of up to 5 km without interpretation. Absolute data of deep magтenic resonance sounding are especially in demand during sharp plummeting of oil prices since it significantly reduces exploration risks while saving the exploration budgets of companies.

A new approach, based on the MRB magnetic field measurements radiated by two fixed and spaced RTI three-component magnetic field receivers and the solution of the inverse problem using these measurement results, was proposed and the concept of the MILES equipment for MRB search and localization was developed and successfully tested.

When assessing concrete structures durability, the study of the water penetration is critical, because almost all deterioration reactions require the presence of water. Due to the nondestructive nature of ground-penetrating radar (GPR) technique, the objective of this study is, firstly, to assess water penetration depths in concrete from GPR wave parameters. Secondly, a procedure was developed to be able to determine, from GPR signals, the location of waterfront depths.

Ground-penetrating radar (GPR) is a powerful tool that uses electromagnetic waves to obtain 3-dimensional images of natural or man-made structures and subsoil. It is employed in a large variety of applications in which non-destructive investigations are required. This paper deals with the use of GPR for the evaluation of moisture content in wood. The results of our work are of great interest for the preservation of timber structures, as moisture content is highly relevant to wood deterioration.