Influence of circulation indices upon winter temperature variability in Egypt

El-Mallah, E. S.; Elsharkawy, S.G.

doi:10.1016/j.jastp.2010.10.013

Cited by 10 publications

(4 citation statements)

References 14 publications

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“…According to [4] From Table 3, both positive and negative correlations were observed in the correlation of rainfall with sunspot number and aa index. However, the correlations were not significant at 0.05 significant levels.…”

Section: Resultsmentioning

confidence: 98%

“…Many authors have observed positive, negative and even zero correlation between solar indices and climatic parameters (e.g. [4]), but the physical mechanism for this relationship has been the major challenge. Hence, spectral analysis was further used to investigate the relationship between rainfall and solar indices (sunspot number and aa index); since the impact of solar and geomagnetic activities on climatic parameters cannot be directly measured.…”

Section: Resultsmentioning

confidence: 99%

“…The impacts of climate change have been observed both locally and globally. The climate of any location can easily be understood in terms of annual or seasonal variations of temperature and precipitation, since they are used as climate change indicator [4], [5]. Hence, this work hopes to investigate the seasonal variability of rainfall and its decadal anomaly over Nigeria from 1950 -2012 and the possible role of solar and geomagnetic activities on climate change in Nigeria.…”

Section: Introductionmentioning

confidence: 99%

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Seasonal Variability of Rainfall and its Decadal Anomaly over Nigeria: Possible Role of Solar and Geomagnetic Activities

Owoicho¹,

Nneka²

2018

IJAERS

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This study investigates seasonal variations of rainfall and its decadal anomaly over Nigeria and the possible role of solar and geomagnetic activities. Sunspot number and geomagnetic aa index were used as solar indices. Monthly mean rainfall data from Nigeria Meteorological Agency was used in this study. Bivariate and power spectral density analyses were employed in analyzing the data. Rainfall anomaly was calculated using the mean of the base period, 1981 -2010. Seasonally, rainfall varies from the coastal areas to the hinterland from January to December during rainy and dry seasons. On the decadal rainfall anomaly, positive anomalies increases steadily towards the coastal regions; indicating an increase in rainfall characteristic, whereas negative anomalies increases towards the northern regions; depicting decrease in rainfall characteristic. This was confirmed from the Mann-Kendall trend test. These variations are evidence of climate change. Correlation analysis revealed that the correlation of rainfall with sunspot and aa index were statistically insignificant. The spectral analysis revealed signatures of solar and geomagnetic activities on the rainfall spectrum. We therefore infer that, in addition to anthropogenic activities, solar and geomagnetic activities might play important role in the observed climate change in Nigeria; since rainfall is used as climate change indicator.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Seasonal Variability of Rainfall and its Decadal Anomaly over Nigeria: Possible Role of Solar and Geomagnetic Activities

Owoicho¹,

Nneka²

2018

IJAERS

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“…The reasons for these changes, however, have always been subject of discussions and are still not well understood. The observed climate change is based on evidence from different sources, such as variations of climatic parameters, which are used as a climate change indicator [2][3][4]. It is worthy to note that the impacts of climate change are more pronounced now than ever before.…”

Section: Introductionmentioning

confidence: 99%

Investigation of possible connections between solar activity and climate change in Nigeria

Audu

Okeke

2019

SN Appl. Sci.

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Over the years, several attempts were made to establish the possible link by which solar activity influenced climate change. However, the physical mechanism for these relationships has been the major challenge. In this research, we investigate the relationship between solar/geomagnetic activity and cosmic rays, the connection between cosmic rays and cloud covers and finally, cloud covers and climatic parameters. This is the proposed physical mechanism used in this study to investigate how solar activity influenced climate change in Nigeria. Sunspot number, aa index, galactic cosmic rays (GCRs), rainfall and maximum temperature data were used in this study. The time period under investigation in this study spanned for 63 years (1950-2012). Spearman's rank correlation technique was employed in analyzing the data. Results reveal that sunspot number and aa index varied in the opposite direction with GCRs based on the 11-year solar cycle. This inverse relationship was confirmed from the correlation analysis. This depicts that solar and geomagnetic activities modulate cosmic rays penetrating into the Earth's atmosphere. Furthermore, the relationship between cosmic rays and cloud covers is yet to be fully ascertained in this study. This has limited the proposed physical mechanism that this study hoped to establish. However, the variations of cloud covers with rainfall and temperature show that changes in cloud covers are associated with changes in rainfall and temperature. This study has given useful information on the possible links by which solar activity could influence climate change.

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Inter-annual temperature and precipitation variations over the Litani Basin in response to atmospheric circulation patterns

Ramadan

Ramamurthy²,

Beighley

2011

Theor Appl Climatol

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This study examines the sensitivity of a mid-size basin's temperature and precipitation response to different global and regional climate circulation patterns. The implication of the North Atlantic Oscillation (NAO), El Niño Southern Oscillation (ENSO), Indian Monsoon and ten other teleconnection patterns of the Northern Hemisphere are investigated. A methodology to generate a basin-scale, longterm monthly surface temperature and precipitation time series has been established using different statistical tests. The Litani River Basin is the focus of this study. It is located in Lebanon, east of the Mediterranean Basin, which is known to have diverse geophysical and environmental characteristics. It was selected to explore the influence of the diverse physical and topographical features on its hydroclimatological response to global and regional climate patterns. We also examine the opportunity of conducting related studies in areas with limited long-term measured climate and/or hydrological data. Litani's monthly precipitation and temperature data have been collected and statistically extrapolated using remotely sensed data products from satellites and as well as in situ gauges. Correlations between 13 different teleconnection indices and the basin's precipitation and temperature series are investigated. The study shows that some of the annual and seasonal temperature and precipitation variance can be partially associated with many atmospheric circulation patterns. This would give the opportunity to relate the natural climate variability with the watershed's hydroclimatology performance and thus differentiate it from other anthropogenic induced climate change outcomes.

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Influence of circulation indices upon winter temperature variability in Egypt

Cited by 10 publications

References 14 publications

Seasonal Variability of Rainfall and its Decadal Anomaly over Nigeria: Possible Role of Solar and Geomagnetic Activities

Seasonal Variability of Rainfall and its Decadal Anomaly over Nigeria: Possible Role of Solar and Geomagnetic Activities

Investigation of possible connections between solar activity and climate change in Nigeria

Inter-annual temperature and precipitation variations over the Litani Basin in response to atmospheric circulation patterns

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