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J. Jaagus  - - - 
Top co-authors See all
Ülo Suursaar

49 shared publications

University of Tartu, Institute, of Ecology and Earth Sciences, Tartu, Estonia

Toomas Tamm

41 shared publications

Tallinn University of Technology

H. Tõnisson

18 shared publications

Institute of Ecology, Tallinna University, Tallinn, Estonia

Kiira Mõisja

6 shared publications

Reimo Rivis

4 shared publications

Institute of Ecology, Tallinn University

Publication Record
Distribution of Articles published per year 
(2000 - 2017)
Publications See all
Article 2 Reads 0 Citations Trends and regime shifts in climatic conditions and river runoff in Estonia during 1951–2015 Jaak Jaagus, Mait Sepp, Toomas Tamm, Arvo Järvet, Kiira Mõis... Published: 03 November 2017
Earth System Dynamics, doi: 10.5194/esd-8-963-2017
DOI See at publisher website
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Time series of monthly, seasonal and annual mean air temperature, precipitation, snow cover duration and specific runoff of rivers in Estonia are analysed for detecting of trends and regime shifts during 1951–2015. Trend analysis is realised using the Mann–Kendall test and regime shifts are detected with the Rodionov test (sequential t-test analysis of regime shifts). The results from Estonia are related to trends and regime shifts in time series of indices of large-scale atmospheric circulation. Annual mean air temperature has significantly increased at all 12 stations by 0.3–0.4Kdecade−1. The warming trend was detected in all seasons but with the higher magnitude in spring and winter. Snow cover duration has decreased in Estonia by 3–4 daysdecade−1. Changes in precipitation are not clear and uniform due to their very high spatial and temporal variability. The most significant increase in precipitation was observed during the cold half-year, from November to March and also in June. A time series of specific runoff measured at 21 stations had significant seasonal changes during the study period. Winter values have increased by 0.4–0.9Ls−1km−2decade−1, while stronger changes are typical for western Estonia and weaker changes for eastern Estonia. At the same time, specific runoff in April and May have notably decreased indicating the shift of the runoff maximum to the earlier time, i.e. from April to March. Air temperature, precipitation, snow cover duration and specific runoff of rivers are highly correlated in winter determined by the large-scale atmospheric circulation. Correlation coefficients between the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices reflecting the intensity of westerlies, and the studied variables were 0.5–0.8. The main result of the analysis of regime shifts was the detection of coherent shifts for air temperature, snow cover duration and specific runoff in the late 1980s, mostly since the winter of 1988/1989, which are, in turn, synchronous with the shifts in winter circulation. For example, runoff abruptly increased in January, February and March but decreased in April. Regime shifts in annual specific runoff correspond to the alternation of wet and dry periods. A dry period started in 1964 or 1963, a wet period in 1978 and the next dry period at the beginning of the 21st century.
Article 2 Reads 5 Citations How to quantify long-term changes in coastal sea storminess? Ülo Suursaar, J. Jaagus, H. Tõnisson Published: 01 April 2015
Estuarine, Coastal and Shelf Science, doi: 10.1016/j.ecss.2014.08.001
DOI See at publisher website
Article 2 Reads 8 Citations Low-level jet characteristics over the Arctic Ocean in spring and summer L. Jakobson, T. Vihma, E. Jakobson, T. Palo, Aarne Männik, J... Published: 14 November 2013
Atmospheric Chemistry and Physics, doi: 10.5194/acp-13-11089-2013
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Low-level jets (LLJ) are important for turbulence in the stably stratified atmospheric boundary layer, but their occurrence, properties, and generation mechanisms in the Arctic are not well known. We analysed LLJs over the central Arctic Ocean in spring and summer 2007 on the basis of data collected in the drifting ice station Tara. Instead of traditional radiosonde soundings, data from tethersonde soundings with a high vertical resolution were used. The Tara results showed a lower occurrence of LLJs (46 ± 8%) than many previous studies over polar sea ice. Strong jet core winds contributed to growth of the turbulent layer. Complex relationships between the jet core height and the temperature inversion top height were detected: substantial correlation (r = 0.72; p < 0.01) occurred when the jet core was above the turbulent layer, but when inside the turbulent layer there was no correlation. The most important forcing mechanism for LLJs was baroclinicity, which was responsible for the generation of strong and warm LLJs, which on average occurred at lower altitudes than other jets. Baroclinic jets were mostly associated with transient cyclones instead of the climatological air temperature gradients. Besides baroclinicity, cases related to inertial oscillations and gusts were detected. As many as 49% of the LLJs observed were associated with a frontal passage, which provides favourable conditions for baroclinicity, inertial oscillations, and gusts. Further research needs on LLJs in the Arctic include investigation of low-level jet streams and their effects on the sea ice drift and atmospheric moisture transport.
Article 2 Reads 0 Citations Low-level jet characteristics over the Arctic Ocean in spring and summer L. Jakobson, T. Vihma, E. Jakobson, T. Palo, A. Männik, J. J... Published: 01 January 2013
Atmospheric Chemistry and Physics Discussions, doi: 10.5194/acpd-13-2125-2013
DOI See at publisher website
Conference 3 Reads 2 Citations Estimation of sea level rise and storm surge risks along the coast of Estonia, Baltic Sea – a tool for coastal managemen... Ü. Suursaar, J. Jaagus, T. Kullas, H. Tõnisson Published: 09 May 2011
Littoral 2010 – Adapting to Global Change at the Coast: Leadership, Innovation, and Investment, doi: 10.1051/litt/201112005
DOI See at publisher website
BOOK-CHAPTER 3 Reads 4 Citations Natural Development and Human Activities on Saaremaa Island (Estonia) in the Context of Climate Change and Integrated Co... Are Kont, Jaak Jaagus, Kaarel Orviku, Valdeko Palginõmm, Urv... Published: 01 January 2011
Coastal World Heritage Sites, doi: 10.1007/978-94-007-0400-8_8
DOI See at publisher website