MJO Modulation of Station Rainfall in the Semiarid Seridó, Northeast Brazil

Cati E. A. Valadão^1,2*, Paulo S. Lucio¹, Rosane R. Chaves¹, Leila M. V. Carvalho²

¹Programa de Pós-Graduação em Ciências Climáticas, Universidade Federal do Rio Grande do Norte, Natal, Brazil.
²Earth Research Institute and Department of Geography, University of California, Santa Barbara, USA.

DOI: 10.4236/acs.2015.54032                

Abstract

The influence of the Madden Julian Oscillation (MJO) on station rainfall over the Seridó region of Rio Grande do Norte state, Northeast Brazil is examined based on 17 raingauge daily data over 30-year period (1 January-31 December, 1981-2010). The Seridó is one of the driest regions in Northeast Brazil and is recognized as particularly vulnerable to desertification by the United Nations Convention to Combat Desertification. Firstly, daily anomalies were calculated by removing the 30-year daily climatology. Then, to distinguish the MJO signal from other patterns of climate variability, the daily anomalies were band pass filtered in the frequency domain (20 - 90 days) by applying Fast Fourier Transform (FFT). Composites of rainfall anomalies were computed for each of the eight phases of the MJO during February-May (FMAM) rainy season, based on the Jones-Carvalho MJO index. Only days classified as MJO events were considered in the composites. For each phase composite, statistical significance tests were computed independently at each individual station by applying a two-tailed Student’s t-test at 5% significance level. Preliminary results showed that the rainfall anomalies have a spatial coherence throughout the MJO cycle. Extreme positive (negative) anomalies occurred in phase 2 (phase 5), where 13 (12) out of the 17 stations showed statistically significant anomalies in the range of 0.9 - 1.9 mm/day (0.8 - 1.7 mm/day). The typical difference between the wet MJO phase 2 and dry phase 5 represented at least 50% modulation of the daily mean rainfall.

Keywords

Madden-Julian Oscillation, Intraseasonal, Raingauge

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	MMA (2004) National Action Program to Combat Desertification and Mitigate the Effects of Drought: Pan-Brazil. Environment Ministry, Water Resources Secretariat, Tech. Rep. http://www.unccd.int/ActionProgrammes/brazil-eng2004.pdf
[2]	Madden, R.A. and Julian, P.R. (1971) Detection of a 40-50 Day Oscillation in the Zonal Wind in the Tropical Pacific. Journal of the Atmospheric Sciences, 28, 702-708. http://dx.doi.org/10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2
[3]	Madden, R.A. and Julian, P.R. (1972) Description of Global-Scale Circulation Cells in the Tropics with a 40-50 Day Period. Journal of the Atmospheric Sciences, 29, 1109-1123. http://dx.doi.org/10.1175/1520-0469(1972)029<1109:DOGSCC>2.0.CO;2
[4]	Madden, R.A. and Julian, P.R. (1994) Observations of the 40-50-Day Tropical Oscillation: A Review. Monthly Weather Review, 122, 814-837.
[5]	Zhang, C. (2005) Madden-Julian Oscillation. Reviews of Geophysics, 43, n/a. http://dx.doi.org/10.1029/2004rg000158
[6]	Carvalho, L.M.V., Jones, C. and Liebmann, B. (2002) Extreme Precipitation Events in Southeastern South America and Large-Scale Convective Patterns in the South Atlantic Convergence Zone. Journal of Climate, 15, 2377-2394. http://dx.doi.org/10.1175/1520-0442(2002)015<2377:EPEISS>2.0.CO;2
[7]	(2004) The South Atlantic Convergence Zone: Intensity, Form, Persistence, and Relationships with Intraseasonal to Interannual Activity and Extreme Rainfall. Journal of Climate, 17, 88-108. http://dx.doi.org/10.1175/1520-0442(2004)017<0088:TSACZI>2.0.CO;2
[8]	Liebmann, B., Vera, C.S., Carvalho, L.M.V., Camilloni, I.A., Hoerling, M.P., Allured, D., Barros, V.R., Bez, J. and Bidegain, M. (2004) An Observed Trend in Central South American Precipitation. Journal of Climate, 17, 4357-4367. http://dx.doi.org/10.1175/3205.1
[9]	Muza, M.N., Carvalho, L.M.V., Jones, C. and Liebmann, B. (2009) Intraseasonal and Interannual Variability of Extreme Dry and Wet Events over Southeastern South America and the Subtropical Atlantic during Austral Summer. Journal of Climate, 22, 1682-1699. http://dx.doi.org/10.1175/2008JCLI2257.1
[10]	Nogus-Paegle, J.N., Byerle, L.A. and Mo, K.C. (2000) Intraseasonal Modulation of South American Summer Precipitation. Monthly Weather Review, 128, 837-850. http://dx.doi.org/10.1175/1520-0493(2000)128<0837:IMOSAS>2.0.CO;2
[11]	Souza, E.B. and Ambrizzi, T. (2006) Modulation of the Intraseasonal Rainfall over Tropical Brazil by the Madden-Julian Oscillation. International Journal of Climatology, 26, 1759-1776. http://dx.doi.org/10.1002/joc.1331
[12]	Pohl, B. and Camberlin, P. (2006) Influence of the Madden-Julian Oscillation on East African Rainfall. I: Intraseasonal Variability and Regional Dependency. Quarterly Journal of the Royal Meteorological Society, 132, 2521-2539. http://dx.doi.org/10.1256/qj.05.104
[13]	Pohl, B. and Camberlin, P. (2006) Influence of the Madden-Julian Oscillation on East African rainfall: II. March-May Season Extremes and Interannual Variability. Quarterly Journal of the Royal Meteorological Society, 132, 2541-2558. http://dx.doi.org/10.1256/qj.05.223
[14]	Mo, K.C. and Higgins, R.W. (1998) Tropical Convection and Precipitation Regimes in the Western United States. Journal of Climate, 11, 2404-2423. http://dx.doi.org/10.1175/1520-0442(1998)011<2404:TCAPRI>2.0.CO;2
[15]	Jones, C. (2000) Occurrence of Extreme Precipitation Events in California and Relationships with the Madden-Julian Oscillation. Journal of Climate, 13, 3576-3587. http://dx.doi.org/10.1175/1520-0442(2000)013<3576:OOEPEI>2.0.CO;2
[16]	Jones, C. and Carvalho, L.M.V. (2012) Spatial-Intensity Variations in Extreme Precipitation in the Contiguous United States and the Madden-Julian Oscillation. Journal of Climate, 25, 4898-4913. http://dx.doi.org/10.1175/JCLI-D-11-00278.1
[17]	Mo, K.C. and Higgins, R.W. (1998) Tropical Influences on California Precipitation. Journal of Climate, 11, 412-430. http://dx.doi.org/10.1175/1520-0442(1998)011<0412:TIOCP>2.0.CO;2
[18]	Zhou, S., Heureux, M.L., Weaver, S. and Kumar, A. (2011) A Composite Study of the MJO Influence on the Surface Air Temperature and Precipitation over the Continental United States. Climate Dynamics, 38, 1459-1471. http://dx.doi.org/10.1007/s00382-011-1001-9
[19]	Lin, H., Brunet, G. and Mo, R. (2010) Impact of the Madden-Julian Oscillation on Wintertime Precipitation in Canada. Monthly Weather Review, 138, 3822-3839. http://dx.doi.org/10.1175/2010MWR3363.1
[20]	Wheeler, M.C., Hendon, H.H., Cleland, S., Meinke, H. and Donald, A. (2009) Impacts of the Madden-Julian Oscillation on Australian Rainfall and Circulation. Journal of Climate, 22, 1482-1498. http://dx.doi.org/10.1175/2008JCLI2595.1
[21]	Kanamori, H., Yasunari, T. and Kuraji, K. (2013) Modulation of the Diurnal Cycle of Rainfall Associated with the MJO Observed by a Dense Hourly Rain Gauge Network at Sarawak, Borneo. Journal of Climate, 26, 4858-4875. http://dx.doi.org/10.1175/JCLI-D-12-00158.1
[22]	Peatman, S.C., Matthews, A.J. and Stevens, D.P. (2013) Propagation of the Madden-Julian Oscillation through the Maritime Continent and Scale Interaction with the Diurnal Cycle of Precipitation. Quarterly Journal of the Royal Meteorological Society, 140, 814-825. http://dx.doi.org/10.1002/qj.2161
[23]	Jia, X., Chen, L., Ren, F. and Li, C. (2011) Impacts of the MJO on Winter Rainfall and Circulation in China. Advances in Atmospheric Sciences, 28, 521-533. http://dx.doi.org/10.1007/s00376-010-9118-z
[24]	Zhang, L., Wang, B. and Zeng, Q. (2009) Impact of the Madden-Julian Oscillation on Summer Rainfall in Southeast China. Journal of Climate, 22, 201-216. http://dx.doi.org/10.1175/2008JCLI1959.1
[25]	Hartmann, D.L. and Michelsen, M.L. (1989) Intraseasonal Periodicities in Indian Rainfall. Journal of the Atmospheric Sciences, 46, 2838-2862. http://dx.doi.org/10.1175/1520-0469(1989)046<2838:IPIIR>2.0.CO;2
[26]	Hendon, H.H. and Liebmann, B. (1990) A Composite Study of Onset of the Australian Summer Monsoon. Journal of the Atmospheric Sciences, 47, 2227-2240. http://dx.doi.org/10.1175/1520-0469(1990)047<2227:ACSOOO>2.0.CO;2
[27]	Jones, C. and Carvalho, L.M.V. (2002) Active and Break Phases in the South American Monsoon System. Journal of Climate, 15, 905-914. http://dx.doi.org/10.1175/1520-0442(2002)015<0905:AABPIT>2.0.CO;2
[28]	Matthews, A.J. (2004) Atmospheric Response to Observed Intraseasonal Tropical Sea Surface Temperature Anomalies. Geophysical Research Letters, 31. http://dx.doi.org/10.1029/2004gl020474
[29]	Pai, D., Bhate, J., Sreejith, O. and Hatwar, H. (2009) Impact of MJO on the Intraseasonal Variation of Summer Monsoon Rainfall over India. Climate Dynamics, 36, 41-55. http://dx.doi.org/10.1007/s00382-009-0634-4
[30]	Pohl, B., Richard, Y. and Fauchereau, N. (2007) Influence of the Madden-Julian Oscillation on Southern African Summer Rainfall. Journal of Climate, 20, 4227-4242. http://dx.doi.org/10.1175/JCLI4231.1
[31]	Souza, E.B., Kayano, M.T. and Ambrizzi, T. (2005) Intraseasonal and Submonthly Variability over the Eastern Amazon and Northeast Brazil during the Autumn Rainy Season. Theoretical and Applied Climatology, 81, 177-191. http://dx.doi.org/10.1007/s00704-004-0081-4
[32]	Mo, K.C., Jones, C. and Nogues-Paegle, J. (2012) Pan America. In: Lau, K.M. and Waliser, D.E., Eds., Intraseasonal Variability in the Atmosphere-Ocean Climate System, 2nd Edition, Springer-Verlag, Berlin, 613.
[33]	Jones, C. (2009) A Homogeneous Stochastic Model of the Madden-Julian Oscillation. Journal of Climate, 22, 3270-3288. http://dx.doi.org/10.1175/2008JCLI2609.1
[34]	Jones, C. and Carvalho, L.M.V. (2011) Will Global Warming Modify the Activity of the Madden-Julian Oscillation? Quarterly Journal of the Royal Meteorological Society, 137, 544-552. http://dx.doi.org/10.1002/qj.765
[35]	Jones, C. and Carvalho, L.M. (2011) Stochastic Simulations of the Madden-Julian Oscillation Activity. Climate Dynamics, 36, 229-246. http://dx.doi.org/10.1007/s00382-009-0660-2
[36]	Matthews, A.J. (2000) Propagation Mechanisms for the Madden-Julian Oscillation. Quarterly Journal of the Royal Meteorological Society, 126, 2637-2651. http://dx.doi.org/10.1002/qj.49712656902
[37]	Matthews, A.J. (2008) Primary and Successive Events in the Madden-Julian Oscillation. Quarterly Journal of the Royal Meteorological Society, 134, 439-453. http://dx.doi.org/10.1002/qj.224