Coupling of the Quasi-Biweekly Oscillation of the Tibetan Plateau Summer Monsoon With the Arctic Oscillation

AbstractThe parasol effect of volcanic dust and aerosol caused by volcanic eruption results in the deepening and strengthening of the Arctic vortex system, thus stimulating or strengthening the Arctic Oscillation (AO). Three of the strongest AOs in more than a century have been linked to volcanic eruptions. Every significant fluctuation of the AO index (AOI = ΔH_middle latitudes − ΔH_Arctic) for many years has been associated with a volcanic eruption. Volcanic activity occurring at different locations in the Arctic vortex circulation will exert different effects on the polar vortex.

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Assessment of the Arctic Oscillation influence on the formation of the Arctic Ocean circulation regimes for the last decades

10.1117/12.2603394 ◽

2021 ◽

Author(s):

Egor E. Lemeshko

Keyword(s):

Arctic Ocean ◽

Ocean Circulation ◽

Arctic Oscillation ◽

The Arctic ◽

The Arctic Ocean ◽

The Arctic Oscillation ◽

Arctic Ocean Circulation

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Numerical study of surface energy partitioning on the Tibetan Plateau: comparative analysis of two biosphere models

Biogeosciences Discussions ◽

10.5194/bgd-6-10849-2009 ◽

2009 ◽

Vol 6 (6) ◽

pp. 10849-10881

Author(s):

J. Hong ◽

J. Kim

Keyword(s):

Comparative Analysis ◽

Tibetan Plateau ◽

Surface Energy ◽

Summer Monsoon ◽

Numerical Study ◽

Asian Summer Monsoon ◽

Energy Partitioning ◽

In Situ Observation ◽

Observation Data ◽

The Tibetan Plateau

Abstract. The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1) the parameterization for soil evaporation; 2) the way to deal with roughness lengths of momentum and scalars; and 3) the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.

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Climate Extremes of the 2019/2020 Winter in Northern Eurasia: Contributions by the Climate Trend and Interannual Variability Related to the Arctic Oscillation

Meteorologiya i Gidrologiya ◽

10.52002/0130-2906-2021-2-5-16 ◽

2021 ◽

pp. 5-16

Author(s):

V. N. Kryjov ◽

Keyword(s):

Interannual Variability ◽

Arctic Oscillation ◽

Global Climate ◽

Linear Trend ◽

Climate Extremes ◽

The Arctic ◽

Northern Eurasia ◽

Climate Trend ◽

Temperature And Precipitation ◽

The Arctic Oscillation

The 2019/2020 wintertime (December–March) anomalies of sea level pressure, temperature, and precipitation are analyzed. The contribution of the 40-year linear trend in these parameters associated with global climate change and of the interannual variability associated with the Arctic Oscillation (AO) is assessed. In the 2019/2020 winter, extreme zonal circulation was observed. The mean wintertime AO index was 2.20, which ranked two for the whole observation period (started in the early 20th century) and was outperformed only by the wintertime index of 1988/1989. It is shown that the main contribution to the 2019/2020 wintertime anomalies was provided by the AO. A noticeable contribution of the trend was observed only in the Arctic. Extreme anomalies over Northern Eurasia were mainly associated with the AO rather than the trend. However, the AO-related anomalies, particularly air temperature anomalies, were developing against the background of the trend-induced increased mean level.

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