Browsing Bergen Open Research Archive by Author "Boljka, Lina"
Now showing items 1-6 of 6
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Coupled stratosphere-troposphere-Atlantic multidecadal oscillation and its importance for near-future climate projection
Omrani, Nour-Eddine; Keenlyside, Noel Sebastian; Matthes, Katja; Boljka, Lina; Zanchettin, Davide; Jungclaus, Johann H.; Lubis, Sandro W. (Journal article; Peer reviewed, 2022)Northern Hemisphere (NH) climate has experienced various coherent wintertime multidecadal climate trends in stratosphere, troposphere, ocean, and cryosphere. However, the overall mechanistic framework linking these trends ... -
Identifying quasi-periodic variability using multivariate empirical mode decomposition: a case of the tropical Pacific
Boljka, Lina; Omrani, Nour-Eddine; Keenlyside, Noel Sebastian (Journal article; Peer reviewed, 2023)A variety of statistical tools have been used in climate science to gain a better understanding of the climate system's variability on various temporal and spatial scales. However, these tools are mostly linear, stationary, ... -
Metrics of the Hadley circulation strength and associated circulation trends
Pikovnik, Matic; Zaplotnik, Žiga; Boljka, Lina; Žagar, Nedjeljka (Journal article; Peer reviewed, 2022)This study compares trends in the Hadley cell (HC) strength using different metrics applied to the ECMWF ERA5 and ERA-Interim reanalyses for the period 1979–2018. The HC strength is commonly evaluated by metrics derived ... -
Potential impact of tropopause sharpness on the structure and strength of the general circulation
Boljka, Lina; Birner, Thomas (Journal article; Peer reviewed, 2022)The wintertime extratropical general circulation may be viewed as being primarily governed by interactions between Rossby waves and the background flow. These Rossby waves propagate vertically and meridionally away from ... -
Recent Hadley circulation strengthening: a trend or multidecadal variability?
Zaplotnik, Žiga; Pikovnik, Matic; Boljka, Lina (Journal article; Peer reviewed, 2022)This study explores the possible drivers of the recent Hadley circulation strengthening in the modern reanalyses. Predominantly, two recent generations of reanalyses provided by the European Centre for Medium-Range Weather ... -
Upstream influence of midlatitude jet stream biases in boreal summer
Boljka, Lina; Bethke, Ingo; Tao, Dandan; Li, Camille (Journal article; Peer reviewed, 2024)Climate models exhibit biases in the mean state and in variability across different regions of the Earth. For example, atmosphere-only models have a poleward bias in summertime jet streams across the Northern Hemisphere ...