Analysis of the Standardized Precipitation Evapotranspiration Index over Iraq and its relationship with the Arctic Oscillation Index

2020 ◽  
Author(s):  
Omar M. A. Mahmood Agha ◽  
Yousif H. Al-Aqeeli
Keyword(s):  
Arctic Oscillation ◽  
The Arctic ◽  
Standardized Precipitation Evapotranspiration Index ◽  
Arctic Oscillation Index ◽  
The Arctic Oscillation

scholarly journals Where can the Arctic oscillation be reconstructed? Towards a reconstruction of climate modes based on stable teleconnections

2005 ◽  
Vol 1 (1) ◽  
pp. 17-56 ◽  
Author(s):  
G. Lohmann ◽  
N. Rimbu ◽  
M. Dima
Keyword(s):  
Arctic Oscillation ◽  
Ice Core ◽  
The Arctic ◽  
Boreal Winter ◽  
Arctic Oscillation Index ◽  
Climate Modes ◽  
Teleconnection Patterns ◽  
Temperature And Precipitation ◽  
The Arctic Oscillation ◽  
Coral Tree

Abstract. Proxy data can bring observed climate variability of the last 100 years into a long-term context. We identify regions of the Northern Hemisphere where the teleconnection patterns of the Arctic Oscillation are stationary. Our method provides a systematic way to examine optimal sites for the reconstruction of climate modes based on paleoclimatic archives that sensitively record temperature and precipitation variations. We identify the regions for boreal winter and spring that can be used to reconstruct the Arctic Oscillation index in the pre-instrumental period. Finally, this technique is applied to high resolution coral, tree ring, ice core and mollusk shell data to understand proxy-climate teleconnections and their use for climate reconstructions.

scholarly journals Chaotic Properties of the Arctic Oscillation Index

SOLA ◽  
2011 ◽  
Vol 7 ◽  
pp. 33-36 ◽  
Author(s):  
Yoshito Hirata ◽  
Yuko Shimo ◽  
Hiroshi L. Tanaka ◽  
Kazuyuki Aihara
Keyword(s):  
Arctic Oscillation ◽  
The Arctic ◽  
Arctic Oscillation Index ◽  
The Arctic Oscillation

scholarly journals VARIABILITY OF THE ICE CONDITIONS IN THE CHUKCHI SEA AND THEIR LINKS WITH ARCTIC OSCILLATION

2020 ◽  
Vol 200 ◽  
pp. 155-167
Author(s):  
V. V. Plotnikov ◽  
N. M. Vakulskaya ◽  
L. I. Mezentseva ◽  
V. A. Dubina ◽  
V. I. Pustoshnova
Keyword(s):  
Arctic Oscillation ◽  
Chukchi Sea ◽  
The Arctic ◽  
Seasonal Development ◽  
Arctic Oscillation Index ◽  
Atmospheric Circulation Patterns ◽  
Ice Conditions ◽  
The Arctic Oscillation ◽  
Available Information ◽  
Sea Area

Variability of the ice conditions in the Chukchi Sea is considered in various scales on the basis of all available information for 1950–2017. Its dependence on the atmospheric circulation patterns measured with the Arctic Oscillation index is shown. Tendency to the ice reducing has intensified in the early 21st century in the Chukchi Sea that is accompanied with changes in its seasonal development, as shift of the ice destruction beginning from June to July, gradual increasing of the ice destruction rate till September, shift of the ice formation beginning from September to October, and delay of the ice spreading over entire sea area from November to December. Relationship of the ice conditions in the Chukchi Sea on summer phase of Arctic oscillation is detected: the maximum positive values of the index always correspond with heavy ice conditions, the minimum values of the index correspond with low-ice conditions only, and various ice conditions are observed in other years without neither positive nor negative extremities of Arctic oscillation. However, winter phase of Arctic oscillation does not affect on the ice conditions in the Chukchi Sea in June-November.

scholarly journals Self-Organizing Maps of Atmospheric Circulation and Interannual Variability of Hydrometeorological Fields in the Arctic

2020 ◽  
Author(s):  
E. E. Lemeshko ◽  
Keyword(s):  
Interannual Variability ◽  
Atmospheric Circulation ◽  
Atmospheric Pressure ◽  
Arctic Oscillation ◽  
Sea Surface ◽  
The Arctic ◽  
Self Organizing Maps ◽  
Arctic Oscillation Index ◽  
The Arctic Oscillation ◽  
Self Organizing

The article suggests the use of a nonlinear method of data analysis based on a neural network – an algorithm of Kohonen self-organizing maps for the task of typing the atmospheric surface circulation in the Arctic. Based on the construction of self-organizing surface pressure maps, the seasonal and interannual variability of atmospheric circulation in the Arctic for the period 1979–2018 is studied. Several modes were distinguished: cyclonic, two anticyclonic, and three mixed types. Indices of seasonal and annual repeatability of self-organizing atmospheric pressure maps are introduced, which allow us to study the temporal variability of atmospheric circulation modes and a composite method is proposed for calculating connected maps of other hydrometeorological parameters. The regimes of variability of the area of sea ice distribution and sea surface temperature depending on the type of atmospheric circulation are highlighted. Depending on the type of wind regime, there is a change in the area of sea ice distribution due to the variability of the flows of warm Atlantic waters into the Arctic Ocean. The characteristic types of sea surface temperature variability in the Barents Sea are identified, which are modulated by cyclonic / anticyclonic regimes of atmospheric circulation in the region and are an indicator of heat advection by the Atlantic waters. The interrelation is established of the repeatability index of self-organizing atmospheric pressure maps characterizing the types of atmospheric circulation with the variability of the Arctic Oscillation Index. The revealed regularities of the change in the types of cyclonic-anticyclonic atmospheric circulation are manifested in the interannual variability of the introduced repeatability index of selforganizing atmospheric pressure maps, which is a development of the Arctic Oscillation Index, improves understanding of the atmospheric climate circulation regimes in the Arctic.

scholarly journals Influence of the Arctic Oscillation on the Formation of Water Circulation Regimes in the Sector of the North, Norwegian and Barents Seas

2021 ◽  
Author(s):  
E. E. Lemeshko ◽  
E. М. Lemeshko ◽  
V. P. Novitskaya ◽  
◽  
◽  
...  
Keyword(s):  
Linear Regression ◽  
Sea Level ◽  
Arctic Oscillation ◽  
Regression Coefficients ◽  
The Arctic ◽  
Arctic Oscillation Index ◽  
Geostrophic Currents ◽  
The North ◽  
Ocean Level ◽  
The Arctic Oscillation

The article studies the influence of wind forcing associated with the Arctic Oscillation on the water circulation regimes in the sector of the World Ocean (65–81.5 N, 0–70 E), which consolidates the North, Norwegian and Barents Seas. The study aims at establishing quantitative patterns of variability of the ocean level and surface geostrophic current velocities depending on the value of the Arctic Oscillation index. In general, the response of the sea level averaged over the ocean sector under consideration is in an antiphase with this index. However, there are periods of mismatch between antiphase fluctuations of the sea level and the Arctic Oscillation index. After 2009, an increase in the amplitude and a decrease in the duration of the phases of the Arctic Oscillation index are noted. The difference between the areas of positive and negative values of sea level anomalies creates a pressure gradient that causes surface geostrophic currents carrying Atlantic waters along the shelf edge eastward in a cyclonic regime (the Arctic Oscillation index is greater than 0) and westward in an anticyclonic regime (the index is less than 0). The article provides estimates of the linear regression coefficients: for the sea level they are ~ 2 cm in the shelf zone and about minus 1 cm in the deep-water part of the sector. Thus, the level difference between the shelf and the deeper part of the considered water area is ~ 3 cm per 1 unit of the Arctic Oscillation index. Estimates of the linear regression coefficients for anomalies of the geostrophic currents velocity were ~ 0.5 cm/s per 1 unit of the index. Analysis of the longterm variability of the steric component of the ocean level showed a better relationship with the interannual variability of the Arctic Oscillation index as compared to the ocean level.

scholarly journals Volcanic activity sparks the Arctic Oscillation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weizheng Qu ◽  
Fei Huang ◽  
Jinping Zhao ◽  
Ling Du ◽  
Yong Cao
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruption ◽  
Arctic Oscillation ◽  
Polar Vortex ◽  
Volcanic Eruptions ◽  
The Arctic ◽  
Vortex System ◽  
Significant Fluctuation ◽  
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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