An introduction to wavelet analysis with applications to vegetation time series

Wavelets are relatively new mathematical tools that have proven to be quite useful for analyzing time series and spatial data. We provide a basic introduction to wavelet analysis which concentrates on their interpretation in the context of analyzing time series. We illustrate the use of wavelet analysis on time series related to vegetation coverage in the Arctic region

Extreme weather and climate events in northern areas: A review

The greatest impacts of climate change on ecosystems, wildlife and humans often arise from extreme events rather than changes in climatic means. Northern high latitudes, including the Arctic, experience a variety of climate-related extreme events, yet there has been little attempt to synthesize information on extreme events in this region. This review surveys work on various types of extreme events in northern high latitudes, addressing (1) the evidence for variations and changes based on analyses of recent historical data and (2) projected changes based primarily on studies utilizing global climate models. The survey of extreme weather and climate events includes temperature, precipitation, snow, freezing rain, atmospheric blocking, cyclones, and wind. The survey also includes cryospheric and biophysical impacts: sea ice rapid loss events, Greenland Ice Sheet melt, floods, drought, wildfire, coastal erosion, terrestrial ecosystems, and marine ecosystems. Temperature and sea ice rank at the high end of the spectra of evidence for change and confidence in future change, while drought, flooding and cyclones rank at the lower end. Research priorities identified on the basis of this review include greater use of high-resolution models and observing system enhancements that target extreme events. There is also a need for further work on attribution, impacts on ecosystems and humans, and thresholds or tipping points that may be triggered by extreme events in high latitudes. Key words: climate, weather, extremes, storms, northern region

Surface air temperature

• The average annual surface air temperature anomaly over land north of 60° N for October 2017-September 2018 was the second highest (after 2015-2016) in the observational record beginning in 1900. Arctic temperatures for the past five years (2014-2018) all exceed previous records. • Arctic air temperature continues to increase at double the rate of the global mean air temperature increase. • Autumn, winter and spring months all contributed positive anomalies to the annual average temperature. These conditions were supported by advection of heat and moisture from the subarctic by north-south wavy jet stream patterns. • During summer, neutral temperature anomalies occurred across the central Arctic Ocean with a low pressure pattern. Like summer 2016 and 2017, 2018 weather conditions did not support rapid summer sea ice and ice sheet loss

Surface air temperature [Arctic essays]

•The average annual surface air temperature anomaly over land north of 60° N for October 2015-September 2016 (+2.0° C, relative to a 1981-2010 baseline) was by far highest in the observational record beginning in 1900; this represents a 3.5° C increase since the beginning of the 20th Century. •Arctic temperatures continue to increase at double the rate of the global temperature increase. •Extreme Arctic-wide air warm temperatures in winter 2016 (Jan-Mar) greatly exceeding the previous record; several locations showed January anomalies exceeding +8° C. These conditions were primarily due to southerly winds moving warm air into the Arctic from mid-latitudes and the presences of sea ice free areas to the northeast of Novaya Zemlya. •Neutral to cold temperature anomalies occurred across the central Arctic Ocean in summer 2016; a condition which did not support rapid summer sea ice loss

Opportunities and challenges for GeoBIM in Europe: developing a building permits use-case to raise awareness and examine technical interoperability challenges

The integration of geoinformation with BIM (GeoBIM) is critical to underpin solutions to many city-related challenges. However, to achieve an effective integration it is necessary to consider not only data and technical options but also current practice and users’ needs. This paper describes work carried out within the EuroSDR-GeoBIM project to address this challenge. After investigating potential uses for GeoBIM and existing challenges, we address a planning permits for buildings use case, to help bridging the gap between theory and practice. The resultshighlights a high-level harmonised workflow envisaging the use of GeoBIM information for automating the planning permits process.Urban Data Scienc

How do intermittency and simultaneous processes obfuscate the Arctic influence on midlatitude winter extreme weather events?

Pronounced changes in the Arctic environment add a new potential driver of anomalous weather patterns in midlatitudes that affect billions of people. Recent studies of these Arctic/midlatitude weather linkages, however, state inconsistent conclusions. A source of uncertainty arises from the chaotic nature of the atmosphere. Thermodynamic forcing by a rapidly warming Arctic contributes to weather events through changing surface heat fluxes and large-scale temperature and pressure gradients. But internal shifts in atmospheric dynamics — the variability of the location, strength, and character of the jet stream, blocking, and stratospheric polar vortex (SPV) — obscure the direct causes and effects. It is important to understand these associated processes to differentiate Arctic-forced variability from natural variability. For example in early winter, reduced Barents/Kara Seas sea-ice coverage may reinforce existing atmospheric teleconnections between the North Atlantic/Arctic and central Asia, and affect downstream weather in East Asia. Reduced sea ice in the Chukchi Sea can amplify atmospheric ridging of high pressure near Alaska, influencing downstream weather across North America. In late winter southward displacement of the SPV, coupled to the troposphere, leads to weather extremes in Eurasia and North America. Combined tropical and sea ice conditions can modulate the variability of the SPV. Observational evidence for Arctic/midlatitude weather linkages continues to accumulate, along with understanding of connections with pre-existing climate states. Relative to natural atmospheric variability, sea-ice loss alone has played a secondary role in Arctic/midlatitude weather linkages; the full influence of Arctic amplification remains uncertain