1. On The Long-term Variations Of The Surface Hydrographic Anomalies In The Northern Hemisphere
Ibrahim A. Maiyza, Tarek M. El-Geziry,
Hussein I. Maiyza and Mohamed S. Kamel
National Institute of Oceanography & Fisheries (NIOF), Egypt
19-21 November 2015
SEE2015 Conference, Mie, Japan

2. SEE2015 Conference, Mie, Japan
Outlines
Research Question
To Reach An Answer
Data & Methods of Analysis
Results
Conclusions
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SEE2015 Conference, Mie, Japan

3. SEE2015 Conference, Mie, Japan
Research Question
Cyclic Behaviour and General Trends of Variations in Meteorological Conditions, Hydrographic Parameters and Fish Productivity have been examined both Worldwide and in the South-eastern Mediterranean Sea.
Research on long-term of variations in the examined parameters in the South-eastern Mediterranean Sea were carried out using linear and quadratic regressions in order to get the possible trends of variations in the investigated parameters.
19-21 November 2015
SEE2015 Conference, Mie, Japan

4. Research Question The Present Research Question is:
Does the Northern Hemisphere examine the same trends of variations in the Hydrographic Anomalies in its different water bodies?
19-21 November 2015
SEE2015 Conference, Mie, Japan

5. SEE2015 Conference, Mie, Japan
To Reach An Answer
19-21 November 2015
SEE2015 Conference, Mie, Japan

6. Data & Methods of Analysis
Surface hydrographic data (temperature and salinity) were collected for 61 years ( ) of surface temperature and for 63 years ( ) of surface salinity from the Ocean Data View (ODV) data bank and from the ARGO archive ( ).
The data have been selected, to cover the same period of the South-eastern Mediterranean file.
In the present work the surface layer is taken as the mean for the upper 20 m layer (Solviev and Lukas 2006; Maiyza et al. 2010; Güçlü 2013); in order to compensate the diurnal variation.
19-21 November 2015
SEE2015 Conference, Mie, Japan

7. Data & Methods of Analysis
Using the Linear and Quadratic regression approaches, the general long-term trends in the monthly surface hydrographic anomalies (MSTA & MSSA) within the North Atlantic and Pacific Oceans have been modelled.
The results are compared with those obtained by the same techniques and period at the same latitudes in the South-eastern Mediterranean Sea.
The Monthly Surface Temperature Anomaly (MSTA) is obtained by
where,
ΔT is the MSTA (°C), T is the mean monthly surface temperature (°C, mean for specific month every year) and Tm is the monthly mean surface temperature (°C, mean for specific month of all years)
19-21 November 2015
SEE2015 Conference, Mie, Japan

8. Data & Methods of Analysis
The Monthly Surface Salinity Anomaly (MSSA) is mathematically expressed as:
where,
ΔS is the MSSA (°C), S is the mean monthly surface salinity (mean for specific month every year) and Sm is the monthly mean surface salinity (mean for specific month of all years).
19-21 November 2015
SEE2015 Conference, Mie, Japan

9. SEE2015 Conference, Mie, Japan
Results
Trends of variations in the North Atlantic MSTA
y = x2 – x
y = x –
19-21 November 2015
SEE2015 Conference, Mie, Japan

10. SEE2015 Conference, Mie, Japan
Results
Trends of variations in the North Pacific MSTA
y = x2 – x
y = x –
19-21 November 2015
SEE2015 Conference, Mie, Japan

11. SEE2015 Conference, Mie, Japan
Results
Trends of variations in the North Atlantic MSSA
y = x2 – x
y = x –
19-21 November 2015
SEE2015 Conference, Mie, Japan

12. SEE2015 Conference, Mie, Japan
Results
Trends of variations in the North Pacific MSSA
y = -2E-07 x2 – x
y = x
19-21 November 2015
SEE2015 Conference, Mie, Japan

13. SEE2015 Conference, Mie, Japan
Conclusions
The linear trends of variations of MSTA in the two oceans reflect general increases over the period of investigation BUT with different rates: in the North Pacific is weak (0.004°C/month) and in the North Atlantic (0.011°C/month).
The two quadratic trends of MSTA in the two oceans reflect parabolic forms, i.e. cyclic variations.
The minimum occurrence of MSTA varied between the two water bodies being in 1966 for the North Atlantic and in 1982 for the North Pacific.
19-21 November 2015
SEE2015 Conference, Mie, Japan

14. SEE2015 Conference, Mie, Japan
Conclusions
The North Atlantic examined a general linear trend of increase in the MSSA with a rate of /month.
The North Pacific had a decreasing rate of /month.
This trend difference might refer to the inter-annual variability of ice melting, evaporation and rainfall process over the Pacific than on the Atlantic.
While the long-term quadratic MSSA variations in the North Atlantic reflect a parabolic form, the minimum of which occurred in 1980, that in the North Pacific did not show any cyclic trend.
This might reflect the absence of cyclic variations or a very large cycle of variations, a tiny part of it, appeared in the present research over the investigated period.
19-21 November 2015
SEE2015 Conference, Mie, Japan

15. Conclusions North Atlantic Ocean North Pacific Ocean SE-Med.
Basin (Maiyza and Kamel, 2009; 2010)
MSTA
0.011°C
0.004°C
-0.06°C
MSSA
0.0037
0.031
Year of minimum MSTA occurrence
1966
1982
1985
Year of minimum MSSA occurrence
1980
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19-21 November 2015
SEE2015 Conference, Mie, Japan

16. SEE2015 Conference, Mie, Japan
Conclusions
In conclusion, while the cyclic trends of sea surface temperature anomalies are clearly identified in the three areas: North Atlantic, North Pacific and South-eastern Mediterranean Sea, the trends of surface salinity anomalies are only determined in the North Atlantic and the South-eastern Mediterranean Sea.
Results of the authors' research, in total, spot the light on the basin morphometry and its impact on the variations of the general trends of surface hydrographic parameters.
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SEE2015 Conference, Mie, Japan

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