Øyvind Nordli

• PhD
• Senior Researcher at Norwegian Meteorological Institute

The Arctic has experienced prominent climate warming, at the beginning of the 20th century and currently. Comparing the driving mechanism during these periods helps to explain the causes of contemporary climate change. Our study explores the impact of regional circulation on Svalbard's surface air temperature (SAT, 2 m above ground). We used air te...

Spitsbergen has experienced some of the most severe temperature changes in the Arctic during the last three decades. This study relates the recent warming to variations in large-scale atmospheric circulation (AC), air mass characteristics, and sea ice concentration (SIC), both regionally around Spitsbergen and locally in three fjords. We find subst...

Daily temperature measurements from six meteorological stations along the coast and fjords of western Spitsbergen have been digitized and quality controlled in a Norwegian, Russian and Polish collaboration. Complete daily data series have been reconstructed back to 1948 for all of the stations. One of the station’s monthly temperature series has pr...

In 2010 we rediscovered the complete set of meteorological observation protocols made by professor Jens Esmark (1762–1839) during his years of residence in the Norwegian capital of Oslo (then Christiania). From 1 January 1816 to 25 January 1839 Esmark at his house in Øvre Voldgate in the morning, early afternoon and late evening recorded air temper...

In this article, air temperature variability in the Svalbard region (74–82°N, 6–30°E) from 1865 to 1920 is presented based on a large amount of early instrumental land and marine data. Measurements were taken during many exploratory and scientific expeditions to the study area. In addition, changes of air temperature from historical times to the pr...

This chapter describes observed changes in atmospheric conditions in the Baltic Sea drainage basin over the past 200–300 years. The Baltic Sea area is relatively unique with a dense observational network covering an extended time period. Data analysis covers an early period with sparse and relatively uncertain measurements, a period with well-devel...

This chapter summarises the climatic and environmental information that can be inferred from proxy archives of the Baltic Sea area during the past millennium (1000 years). The proxy archives mainly comprise tree-ring analyses together with historical documents on extreme weather events and weather-related disasters. In addition to the reconstructed...

A 175 years long homogenized composite record of monthly mean temperatures is presented for Oslo, the capital of Norway. The early raw data have been digitised and quality controlled, and monthly means have been calculated. Some early original observations carried out in a Wild screen (1877–1936) were found to be spuriously high because of inapprop...

Homogeneity is important when analyzing climatic long-term time series. This is to ensure that the variability in the time series is not affected by changes such as station relocations, instrumentation changes and changes in the surroundings. The subject of this study is a long-term temperature series from the Norwegian University of Life Sciences...

In this article, the results of an investigation into the air temperature conditions on Svalbard in the period 1 September 2010 to 31 August 2011 are presented. For this period, parallel temperature measurements have been made as many as in 30 sites. On the basis of this unique set of data it was possible to study, in detail, the spatial distributi...

One of the few long instrumental records available for the Arctic is the Svalbard Airport composite series that hitherto began in 1911, with observations made on Spitsbergen, the largest island in the Svalbard Archipelago. This record has now been extended to 1898 with the inclusion of observations made by hunting and scientific expeditions. Temper...

The Arctic land areas have experienced greater warming over the last three decades than elsewhere in the world. In Europe the Svalbard archipelago (located in the North Atlantic sector of the Arctic Ocean from 74° to 81°N and 10° to 35°E) have experienced the greatest temperature change during this period. At Svalbard airport the mean annual air te...

In this paper we document changes of Langfjordjøkelen, a small ice cap in northern Norway. Surface mass-balance measurements have been carried out on an east-facing part (3.2 km2) of the ice cap since 1989. Measurements reveal a strong thinning; the balance year 2008/09 was the 13th successive year with significant negative annual balance (≤–0.30 m...

First flowering was observed in some native herbaceous and woody plants in Norway at latitudes of ∼58°N to nearly 71°N from 1928 to 1977. For woody plants, the timing for first bud burst was also often observed. Generally, there were highly significant correlations (0.1% level) between the timing of nearly all spring-early summer observations in pl...

The Twentieth Century Reanalysis (20CR) project is an international effort to produce a comprehensive global atmospheric circulation dataset spanning the twentieth century, assimilating only surface pressure reports and using observed monthly sea‐surface temperature and sea‐ice distributions as boundary conditions. It is chiefly motivated by a need...

We use long instrumental temperature series together with available field reconstructions of sea-level pressure (SLP) and three-dimensional climate model simulations to analyze relations between temperature anomalies and atmospheric circulation patterns over much of Europe and the Mediterranean for the late winter/early spring (January–April, JFMA)...

Recent changes in springtime plant phenological records are likely unprecedented and have been attributed to anthropogenically induced temperature change. In Europe, a major synchronous break in phenological time series in the 1980s was found in numerous studies; however, few of these studies put these breaks into a historical perspective. We prese...

Reconstructing the temporal and spatial climate development on a seasonal basis during the last few centuries, including the ‘Little Ice Age’, may help us better understand modern-day interplay between natural and anthropogenic climate variability. The conventional view of the climate development during the last millennium has been that it followed...

Data series for bud burst, beginning of flowering and petal fall for 20 species of deciduous trees and conifers at four sites in different regions of southern Norway have been analysed and related to temperature series. On average, the spring phenophases occurred 7 days earlier during the period 1971-2005. The most significant linear trends were ob...

Systematic temperature observations were not undertaken in Norway until the early 19th century, and even then only sporadically. Climate-proxy data may be used to reconstruct temperatures before this period, but until now there have not been any climate proxies available for late winter. This situation has recently changed, as a diary containing hi...

Global climate change impacts can already be tracked in many physical and biological systems; in particular, terrestrial ecosystems provide a consistent picture of observed changes. One of the preferred indicators is phenology, the science of natural recurring events, as their recorded dates provide a high-temporal resolution of ongoing changes. Th...

The development of a daily historical European–North Atlantic mean sea level pressure dataset (EMSLP) for 1850–2003 on a 5° latitude by longitude grid is described. This product was produced using 86 continental and island stations distributed over the region 25°–70°N, 70°W–50°E blended with marine data from the International Comprehensive Ocean–At...

By stepwise regression analysis the accumulation, ablation, and equilibrium line altitude (ELA) were modelled by circulation indices and spring-summer temperature on six Norwegian glaciers (Ålfotbreen, Nigardsbreen, Rembesdalsskåka, Storbreen, Hellstugubreen and Gråsubreen). The circulation indices were derived from a gridded monthly mean sea level...

Whereas a number of records from the marine realm have demonstrated Holocene changes regarded to be related to overturning circulation in the North Atlantic region, independent information of atmospherical variability from the terrestrial realm have proven more elusive to capture in palaeo-records. This is a major concern, as several studies have s...

This section describes long-term observed climatic changes in atmospheric parameters. The focus is on surface climate conditions, but changes in atmospheric circulation are discussed as they often are behind climatic variability seen on regional and local scales. For a summary introduction on mean atmospheric states and conditions in the Baltic Sea...