The effect of revised topography dataset on improvement of RegCM4 model results (Case study: northern of Iran)

Document Type : Original Article

Authors

1 M. Sc. Student of Water Resources Engineering, Department of Water Sciences and Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

2 Associate Professor of Water Sciences and Engineering Dep., Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

3 Lecturer of Water Sciences and Engineering Dep., Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

4 Assistant professor of Geography Dep., Faculty of Humanities, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

Lack of regional climatic data is great challenge for agroclimatic studies. In this research, the influence topography on RegCM4 model results was investigated. In order of determine the role of topography on improving the results of RegCM model, two topographic datasets (GTOPO, GMTED) were used for a specific period of time and similar conditions to run the model. The experiments were done with lateral boundary conditions obtained from The NCEP-DOE Reanalysis 2 (NNRP2) dataset at 2.5° × 2.5° latitude-longitude horizontal resolution. The sea surface temperature (SST) for the corresponding regional climate simulations were prescribed from the National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation SST (OISST) dataset with a weekly temporal resolution and 1° × 1° spatial resolution. The topographical output of the model showed an increase of elevation in the Caspian sea coast [max (GMTED-GTOPO) = 254 m], while in some areas of Alborz mountains a decrease in elevation [max (GMTED-GTOPO) = -400 m] was observed. Due to higher elevation of GTOPO in the Alborz Mountains, the derived speed of this simulation is relatively higher than GMTED, which could reach as high as 1.6 m/s during winter season. The highest precipitation difference occurred during spring season in the vicinity of the area where 400 m of decreased elevation was observed, with amounts as high as 16 mm/day (80% increase in precipitation). The temperature differences followed closely the topographical differences. In the seashore areas, where there was increased elevation, temperature decreased correspondingly (max. of -2.4°), whereas in mountainous areas with decrease in elevation, the temperature increase was observed (max. of 1.2°). The findings from this research identified, the modified data (GMTED) is improving the results of the model and should be replace the old data (GTOPO) in future research.

Keywords

References

Blumsack, S. L. 1971. On the effects of topography on planetary atmospheric circulation. Journal of the Atmospheric Sciences, 28(7): 1134-1143.
Danielson, J. J., Gesch, D. B. 2011. Global multi-resolution terrain elevation data 2010 (GMTED2010). US Geological Survey.
Dee, D., Uppala, S., Simmons, A., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U., Balmaseda, M., Balsamo, G., Bauer, P. 2011. The ERA‐Interim reanalysis: Configuration and performance of the data assimilation system. Quarterly Journal of the royal meteorological society, 137(656): 553-597.
Elguindi, N., Bi, X., Giorgi, F., Nagarajan, B., Pal, J., Solmon, F., Rauscher, S., Zakey, A., O’Brien, T., Nogherotto, R. 2014. Regional Climate Model RegCM Reference Manual Version 4.5.
Fan, Y., Van den Dool, H. 2008. A global monthly land surface air temperature analysis for 1948–present. Journal of Geophysical Research: Atmospheres, 113(D1), DOI: 10.1029/2007JD008470.
Flesch, T. K., Reuter, G. W. 2012. WRF model simulation of two Alberta flooding events and the impact of topography. Journal of Hydrometeorology, 13(2): 695-708.
Giorgi, F., 1990. Simulation of regional climate using a limited area model nested in a general circulation model. Journal of Climate, 3(9): 941-963.
Giorgi, F., Bates, G. T. 1989. The climatological skill of a regional model over complex terrain. Monthly Weather Review, 117(11): 2325-2347.
Grell, G. A. 1993. Prognostic evaluation of assumptions used by cumulus parameterizations. Monthly Weather Review, 121(3): 764-787.
Hahn, D. G., Manabe, S. 1975. The role of mountains in the south Asian monsoon circulation. Journal of the Atmospheric Sciences, 32(8): 1515-1541.
Joyce, R. J., Janowiak, J. E., Arkin, P. A., Xie, P. 2004. CMORPH: A method that produces global precipitation estimates from passive microwave and infrared data at high spatial and temporal resolution. Journal of Hydrometeorology, 5(3): 487-503.
Kanamitsu, M., Ebisuzaki, W., Woollen, J., Yang, S.-K., Hnilo, J., Fiorino, M., Potter, G. 2002. Ncep–doe amip-ii reanalysis (r-2). Bulletin of the American Meteorological Society, 83(11): 1631-1643.
Karimi, M., Azizi, G., Shamsipour A., Rezaee Mahdi, L. 2016. Dynamic simulation of the Alborz Mountain in spread and thickness of sea breeze on the southern coast of the Caspian Sea. Researches in Geographical Sciences, 16 (41):1 35-152. (In Farsi)
Konrad II, C. E. 1996. Relationships between precipitation event types and topography in the southern Blue Ridge mountains of the southeastern USA. International Journal of Climatology, 16(1): 49-62.
Manabe, S., Broccoli, A. 1990. Mountains and arid climates of middle latitudes. Science, 247(4939): 192-195.
McCauley, M., Sturman, A. 1999. A study of orographic blocking and barrier wind development upstream of the Southern Alps, New Zealand. Meteorology and Atmospheric Physics, 70(3): 121-131.
Mousavi Baygi, M. 2006. Calculation of rainfall increase in mountainous areas around Mashhad using a computer model. Agricultuaal Sciences and Technologhy, 6: 1029-4791. (In Farsi)
Ogwang, B. A., Chen, H., Li, X., Gao, C. 2014. The influence of topography on East African October to December climate: sensitivity experiments with RegCM4. Advances in Meteorology, 2014: 1-14.
Reynolds, R. W., Rayner, N. A., Smith, T. M., Stokes, D. C., Wang, W. 2002. An improved in situ and satellite SST analysis for climate. Journal of climate, 15(13): 1609-1625.
Shi, X., Wang, Y., Xu, X. 2008. Effect of mesoscale topography over the Tibetan Plateau on summer precipitation in China: A regional model study. Geophysical Research Letters, 35(19), DOI: 10.1029/2008GL034740.
Soltanzadeh, I., Ahmadi Givi, F., Irannejad, P. 2006. Investigation of three months Zagros mountains on the mesoscale streams of the eastern Zagros using the regional model RegCM. Journal of the Earth and Space Physics, 33(1): 31-50. (In Farsi)
Journal of Agricultural Meteorology
Volume 5, Issue 2 - Serial Number 10
Vol. 5, No. 2, Autumn &Winter 2017
March 2018
Pages 24-34

Files

Share

How to cite

Statistics