بررسی تغییرات دما و شوری سطح دریای عربی از سال 2010 تا 2017

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری فیزیک دریا، دانشکده علوم و فنون دریایی، دانشگاه هرمزگان

2 استادیار دانشکده علوم و فنون دریایی، دانشگاه هرمزگان

3 استاد دانشکده فیزیک، دانشگاه اصفهان

4 پژوهشیار دانشگاه صنعتی مالک اشتر

چکیده

روند گرمایشی در اقیانوس هند سهم عمده ای در روند کلی میانگین گرمایش سطح اقیانوس های جهانی دارد که در این میان سهم دریای عربی بنابر شرایط خاص حاکم بر آن به لحاظ جغرافیایی و بادهای مونسون قابل توجه است. در این پژوهش تغییرات درون و بین سالیانة دما و شوری سطح دریای عربی از سال 2010 تا 2017 با استفاده از مدل MITgcm، با دقیق‌ترین اطلاعات عمق سنجی با دقت مکانی 033/0 درجه بررسی شده است. به این منظور داده های دما، شوری، نرخ تبخیر منهای بارندگی، باد، شار گرمای خالص با دقت زمانی یک ماهه و دقت مکانی یک درجه به عنوان داده های اولیه، نخست به دقت مدل درآمده و سپس به مدل معرفی گردید. در این مدل معادله های ناویر-استوکس در حالت غیر خطی، تراکم ناپذیر و غیرهیدروستاتیکی با گسسته سازی حجم محدود مکانی بر روی یک شبکة محاسباتی مکعبی حل می‌گردد. نتایج تحلیل زمانی در دورة مذکور و در منطقة مورد مطالعه نشان می‌دهد که میانگین دمای سطح دریا 36/0 درجة سانتیگراد و میانگین شوری سطح دریا نیز PSU 04/0 افزایش داشته است. این در حالیست که بیشترین مقدار دما و شوری سطحی در طول دورة مطالعه مربوط به ژوئن سال 2016 است که مقادیر این متغیرها به ترتیب 30 درجة سانتیگراد و PSU51/36 است. علت این تغییرات می‌تواند عواملی نظیر تبخیر بیش از بارندگی در دریای عربی، تنش بادهای مونسون، وارونگی‌های جریانی و شار گرمای خالص باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Investigation of Sea Surface Temperature (SST) and Sea Surface Salinity (SSS) variations in the Arabian Sea from 2010 to 2017

نویسندگان [English]

  • S Mollaesmaeilpour 1
  • M Mohammad Mahdizadeh 2
  • S Hassanzadeh 3
  • M. R Khalilabadi 4
1 PHD Student of Physical Oceanography
2 Faculty member, Hormozgan University, Bandarabbas, Iran
3 Faculty member, University of Isfahan, Isfahan,81746, Iran
4 Faculty member, Malek-Ashtar university of technology, Shiraz, Iran
چکیده [English]

The warming process in the Indian Ocean is a major contributor to the overall global warming trend of the global oceans and the contribution of the Arabian Sea is remarkable due to the special conditions governing it, geographically and monsoon winds. In this study, inter-and intra-annual variations of SST, SSS were studied from 2010 to 2017 using the MITgcm model in the Arabian Sea with the most accurate bathymetric data and the spatial resolution of 0.033deg and monthly temporal resolution. For this purpose, temperature, salinity, evaporation minus precipitation rate, wind, net heat flux with a spatial resolution of 1 degree and monthly temporal resolution as the initial data were first introduced to the model. In this model, Navier-Stokes equations in nonlinear, incompressible and non-hydrostatic states are solved by finite volume spatial discretization over a cubic computational grid. The results of time analysis in the mentioned period indicate that the mean sea surface temperature increased about 0.36 °C and also the mean sea surface salinity by 0.04 PSU. This is despite the fact that the highest value of temperature and surface salinity during the study period is in June 2016, the values of these variables are 30°C and 36.51 PSU respectively. The reasons can be attributed to factors such as he excess of evaporation over precipitation in the Arabian Sea, Monsoon wind stress, current inversions, net surface heat flux.

کلیدواژه‌ها [English]

  • Arabian sea
  • monsoon
  • Sea Surface Temperature (SST)
  • Sea Surface Salinity (SSS)
  • MITgcm Model
[1]    McCreary J P, Kohler K E, Hood R R, Smith S, Kindle J, Fischer A S and Weller R A (2001), Influences of diurnal and intraseasonal forcing on mixed-layer and biological variability in the central Arabian Sea; J. Geophys. Res.1067139–7155.

[2]    S. Prasanna Kumar, Jayu Narvekar, Ajoy Kumar, C. Shaji, P.Anand, P.Sabu, G. Rijomon, J. Josia, K. A. Jayaraj, A. Radhika, and K. K. C. Nair (2004), Intrusion of the Bay of Bengal water into the Arabian Sea during winter monsoon and associated chemical and biological response, Geophysical Research Letters,Vol.31, L15304, doi:10.1029/2004GL020247.

[3]    Grunseich, G., B. Subrahmanyam, V. S. N. Murty, and B. S. Giese (2011), Sea surface salinity variability during the Indian Ocean Dipole and ENSO events in the tropical Indian Ocean, J. Geophys. Res., 116, C11013, doi:10.1029/2011JC007456.

[4]    Alok Kumar Mishra, Suneet Dwivedi, Atul Shrivastava (2015), High resolution simulation of the salinity variability in the Bay of Bengal and Arabian Sea during the years 1998-2014 using an ocean circulation model. Discovery, 2015, 39(180), 173-179.

[5]    S. S. C Shenoi, N Nasnodkar , G Rajesh, K Jossia Joseph, Suresh and A M Almeida (2009), On the diurnal ranges of Sea Surface Temperature (SST) in the north Indian Ocean, J. Earth Syst. Sci. 118, No. 5, October 2009, pp. 483–496.

[6]    Chaitanya, A. V. S., Durand, F., Mathew, S., Gopalakrishna, VV., Papa, F., Lengaigne, M., & Venkatesan, R. (2015). Observed year-to-year sea surface salinity variability in the Bay of Bengal during the 2009–2014 period. Ocean Dynamics, 65(2), 173-186.

[7]    Moum, J., “Air–Sea Intraction from Westerly Wind Bursts during the November 2011 MJO in the Indian Ocean”, American Meteorological Society. 2014.

[8]    Ebenezer S. Nyadjro, Bulusu Subrahmanyam , V. S. N. Murty , Jay F. Shriver (2012), The role of salinity on the dynamics of the Arabian Sea mini warm pool, Ebenezer S. Nyadjro, Bulusu Subrahmanyam, V. S. N. Murty, Jay F. Shriver ,doi.org/10.1029/ 2012JC007978, 01 September 2012.

[9]    WMO Statement on the State of the Global Climate in 2017, Chairperson Publications Board, No. 1212. WMO, 2018.

[10]            Levitus, S.,J . Antonov, and T. Boyer (2005), Warming of the world ocean, 1955–2003. Geophys. Res. Lett., 32, L02604, doi:10.1029/2004GL021592.

[11]            Clark CO, Cole JE, Webster PJ (2000), Indian Ocean SST and Indian summer rainfall: predictive relationships and their decadal variability. J Clim 13:2503–2519. doi:10.1175/1520-0442(2000) 013 < 2503: IOSAIS>2.0.CO;2.

[12]            Vecchi, G. A. and D. E. Harrison, (2004), Interannual Indian rainfall variability and Indian Ocean Sea Surface temperature anomalies. Earth’s Climate; The Ocean-Atmosphere Interactions, eds Wang, C., S. P. Xie and J. A. Carton, Geophysical Monograph Series 147, 247-259.

[13]            Jochum, M., & Murtugudde, R. (2005), Internal variability of Indian ocean SST.Journal of climate, 18(18), 3726-3738.

[14]            Rajendran, K., Nanjundiah, R. S., Gadgil, S., & Srinivasan, J. (2012). How good are the simulations of tropical SST–rainfall relationship by IPCC AR4 atmospheric and coupled models?. Journal of earth system science, 121(3), 595-610.

[15]            Suryachandra A. Rao, Subodh Kumar Saha, Samir Pokhrel, RRV Suresh (2010), Modulation of SST, SSS over northern Bay of Bengal on ISO time scale. Journal of Geophysical Research Atmospheres, DOI: 10.1029/2010JC006804.

[16]            K. Jaswal, Virendra Singh and S. R. Bhambak (2012), Relationship between sea surface temperature and surface air temperature over Arabian Sea, Bay of Bengal and Indian Ocean. J. Ind. Geophys. Union April (2012 ) Vol.16, No.2, pp. 41-53.

[17]            P. N. Vinayachandran, C. P. Neema, Simi Mathew, and R. Remya (2012), Mechanisms of summer intraseasonal sea surface temperature oscillations in the Bay Bay of Bengal, JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, C01005, doi:10.1029/2011JC007433.

[18]            Kawai Y and Wada A (2007), Diurnal sea surface temperature variation and its impact on the atmosphere and ocean: A review; J. Oceanogr. 63 721–744.

[19]            Clayson C A and Chen A (2002), Sensitivity of a coupled single-column model in the Tropics to treatment of the interfacial parameterizations; J. Clim. 151805–1831.

[20]            Bernie D J, Guilyardi E, Madec G, Slingo J M and Woolnough S J (2007), Impact of resolving the diurnal cycle in an ocean-atmosphere GCM. Part 1: a diurnally forced OGCM; Clim. Dyn. 29 575–590.

[21]            Bijoy Thompson, C. Gnanaseelan, P.S. Salvekar (2006), Variability in the Indian Ocean circulation and salinity and its impact on SST anomalies during dipole events, Journal of Marine Research, 64, 853–880.

[22]            Anjaneyulu, T. S. S., (1980), A study of the air and sea surface temperatures over the Indian Ocean, Mausam, 31, 4, 551-560.

[23]            Duncan, B., and W. Han (2009), Indian Ocean intraseasonal sea surface temperature variability during boreal summer: Madden-Julian Oscillation versus submonthly forcing and processes, J. Geophys. Res., 114, C05002, doi:10.1029/2008JC004958.

[24]            P. N. Vinayachandran, C. P. Neema, Simi Mathew, and R. Remya (2012), Mechanisms of summer intraseasonal sea surface temperature oscillations in the Bay of Bengal, JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, C01005, doi:10.1029/2011JC007433.

[25]            P. N. Vinayachandran, S Jahfer and R S Nanjundiah (2015), Impact of river runoff into the ocean on Indian summer monsoon, Environ. Res. Lett. 10 (2015), doi:10.1088/1748-9326/10/5/054008.

[26]            Weiqing Han, Julian P. McCreary Jr (2001). Modeling salinity  distributions  in  the Indian  Ocean, Journal of Geophysical Research,  VOL. 106 NO. C1, Pages 859-877, January  15.

[27]            M.C.Gregg (1985), Structures and fluxes in a deep convecting  mixed  layer, Applied Physics   Laboratory    and  School of Oceanography,   College   of  Ocean    and Fishery     Sciences , University of Washington,   Seattle, Washington    98105.

[28]            Wyrtki, K., (1971), Oceanographic Atlas of the International Indian Ocean Expedition. U.S. Government Printing Office, 531 pp.

[29]            Naresh      Krishna     Vissa   A.   N.    V. Satyanarayana   and      B.        Prasad Kumar (2013),   Comparison  of  mixed  layer depth and barrier  layer thickness  for  the   Indian Ocean using two different climatologies, Int. J. Climatol. 33: 2855–2870.

[30]            Defant, A., (1961), Physical Oceanography, Vol 1, 729 pp., Pergamon, New York.

[31]            Adrian Gill, Atmosphere-Ocean Dynamics, Academic Press, 1982, Appendix2 (properties of seawater),  page 599.

[32]            Atul Srivastava, Suneet Dwivedi, Alokkumar Mishra, (2015), High resolution numerical modeling of the Indian Ocean surface Hydrography and circulation, Discovery, 2015, 40(181): 34-40

[33]            Cheng, X., & Qi, Y. (2007). Trends of sea level variations in the South China Sea from merged altimetry data. Global and Planetary Change, 57(3-4), 371-382.

[34]            Marshall J, Hill C, Perelman L, Adcroft A. (1997), Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling, Journal of Geophysical Research: Oceans. 1997 Mar 15; 102(C3):5733-52.

[35]            Adcroft, A, Campin, J.M, Dutkiewicz, S, Evangelinos, C, Ferreira, D, Forget, G, Fox-Kemper, B, Heimbach, P, Hill, C, Hill, F, Hill, H, Jahn, O, Losch, M, Marshall, J, Maze, G, Menemenlis, D, Molod, A. (2018), MITgcm user manual. mitgcm.org/ public/r2_manual/ final/online_documents/ manual.html. 415P.

[36]            Kara, A.B., Wallcraft, A.J., Metzer E.J., Gunduz,M., (2010). Imapact of freshwater on the seasonal variations of surface salinity and circulation in the Caspian Sea, Continental Shelf Research, Vol. 30, p.1211-1225.

[37]            Arshad Ali, Naeem  Ahmed  Syed, Labeed I. Kazi, Mohsin Tabrez  and  Shahid   Amjad (1995), Seasonal  variation  of   mixed  layer depth  in  the  north  Arabian    sea,   Pakistan Journal  of  Marine  Sciences, Vol.4(1),  1-4.

[38]            Dong, L. and M.J. McPhaden, (2018), Unusually warm Indian Ocean sea surface temperatures help to arrest development of El Nino in 2014. Science Reports, 8, 2249, doi:10.1038/s41598-018-20294-4.