• Annamalai, H., Xie S. P. , McCreary J. P. , and Murtugudde R. , 2005: Impact of Indian Ocean sea surface temperature on developing El Niño. J. Climate, 18, 302319, doi:10.1175/JCLI-3268.1.

    • Search Google Scholar
    • Export Citation
  • Appelhans, T., and Nauss T. , 2016: Spatial patterns of sea surface temperature influences on East African precipitation as revealed by empirical orthogonal teleconnections. Front. Earth Sci., 4, 3, doi:10.3389/feart.2016.00003.

    • Search Google Scholar
    • Export Citation
  • Appelhans, T., Mwangomo E. , Otte I. , Detsch F. , Nauss T. , and Hemp A. , 2016: Eco-meteorological characteristics of the southern slopes of Kilimanjaro, Tanzania. Int. J. Climatol., 36, 32453258, doi:10.1002/joc.4552.

    • Search Google Scholar
    • Export Citation
  • Australian Bureau of Meteorology, 2014: Australian rainfall pattern during Indian Ocean dipole years. Accessed 22 July 2014. [Available online at http://www.bom.gov.au/climate/iod.]

  • Black, E., 2005: The relationship between Indian Ocean sea-surface temperature and East African rainfall. Philos. Trans. Roy. Soc. London, A363, 4347, doi:10.1098/rsta.2004.1474.

    • Search Google Scholar
    • Export Citation
  • Bracco, A., Kucharski F. , and Molteni F. , 2005: Internal and forced modes of variability in the Indian Ocean. Geophys. Res. Lett., 32, L12707, doi:10.1029/2005GL023154.

    • Search Google Scholar
    • Export Citation
  • Camberlin, P., and Philippon N. , 2002: The East African March–May rainy season: Associated atmospheric dynamics and predictability over the 1968–97 period. J. Climate, 15, 10021019, doi:10.1175/1520-0442(2002)015<1002:TEAMMR>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Camberlin, P., Moron V. , Okoola R. , Philippon N. , and Gitau W. , 2009: Components of rainy seasons variability in equatorial East Africa: Onset, cessation, rainfall frequency and intensity. Theor. Appl. Climatol., 98, 237249, doi:10.1007/s00704-009-0113-1.

    • Search Google Scholar
    • Export Citation
  • Chan, R. Y., Vuille M. , Hardy D. R. , and Bradley R. S. , 2008: Intraseasonal precipitation variability on Kilimanjaro and the East African region and its relationship to the large-scale circulation. Theor. Appl. Climatol., 93, 149165, doi:10.1007/s00704-007-0338-9.

    • Search Google Scholar
    • Export Citation
  • CPC, 2014: Cold and warm episodes by season: Historical El Niño/La Niña episodes (1950–present). NOAA/NWS, accessed 22 July 2014. [Available online at http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml.]

  • Duane, W. J., Pepin N. C. , Losleben M. L. , and Hardy D. R. , 2008: General characteristics of temperature and humidity variability on Kilimanjaro, Tanzania. Arct. Antarct. Alp. Res., 40, 323334, doi:10.1657/1523-0430(06-127)[DUANE]2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Fairman, J. G., Jr., Udaysankar S. N. , Christopher S. A. , and Mölg T. , 2011: Land use change impacts on regional climate over Kilimanjaro. J. Geophys. Res., 116, D03110, doi:10.1029/2010JD014712.

    • Search Google Scholar
    • Export Citation
  • Fischer, A. S., Terray P. , Guilyardi E. , Gualdi S. , and Delecluse P. , 2005: Two independent triggers for the Indian Ocean dipole/zonal mode in a coupled GCM. J. Climate, 18, 34283449, doi:10.1175/JCLI3478.1.

    • Search Google Scholar
    • Export Citation
  • Funk, C., Dettinger M. D. , Michaelsen J. C. , Verdin J. P. , Brown M. E. , Barlow M. , and Hoell A. , 2008: Warming of the Indian Ocean threatens eastern and southern African food security but could be mitigated by agricultural development. Proc. Natl. Acad. Sci. USA, 105, 11 08111 086, doi:10.1073/pnas.0708196105.

    • Search Google Scholar
    • Export Citation
  • Goddard, L., and Graham N. E. , 1999: Importance of the Indian Ocean for simulating anomalies over eastern and southern Africa. J. Geophys. Res., 104, 19 09919 116, doi:10.1029/1999JD900326.

    • Search Google Scholar
    • Export Citation
  • Grubbs, F., 1969: Procedures for detecting outlying observations in samples. Technometrics, 11, 121, doi:10.1080/00401706.1969.10490657.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., 2000: Zonal circulations over the equatorial Indian Ocean. J. Climate, 13, 27462756, doi:10.1175/1520-0442(2000)013<2746:ZCOTEI>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., 2001: Variations of East African climate during the past two centuries. Climatic Change, 50, 209217, doi:10.1023/A:1010678111442.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., 2010: Climate forcing of glacier thinning on the mountains of equatorial East Africa. Int. J. Climatol., 30, 146152, doi:10.1002/joc.1866.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., Nicklis A. , and Greischar L. , 1993: Atmospheric–hydrospheric mechanisms of climate anomalies in the western Indian Ocean. J. Geophys. Res., 98, 20 21920 235, doi:10.1029/93JC02330.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., Polzin D. , and Mutai C. , 2007: Diagnosing the droughts in equatorial East Africa. J. Climate, 20, 46284637, doi:10.1175/JCLI4238.1.

    • Search Google Scholar
    • Export Citation
  • Hastenrath, S., Polzin D. , and Mutai C. , 2010: Diagnosing the droughts and floods in equatorial East Africa during boreal autumn. J. Climate, 23, 813817, doi:10.1175/2009JCLI3094.1.

    • Search Google Scholar
    • Export Citation
  • Hemp, A., 2001: Ecology of the pteridophytes on the southern slopes of Mt. Kilimanjaro. Part II: Habitat selection. Plant Biol., 3, 493523, doi:10.1055/s-2001-17729.

    • Search Google Scholar
    • Export Citation
  • Hemp, A., 2005: Climate change–driven forest fires marginalize the impact of ice cap wasting on Kilimanjaro. Global Change Biol., 11, 10131023, doi:10.1111/j.1365-2486.2005.00968.x.

    • Search Google Scholar
    • Export Citation
  • Hemp, A., 2006: Vegetation of Kilimanjaro: Hidden endemics and missing bamboo. Afr. J. Ecol., 44, 305328, doi:10.1111/j.1365-2028.2006.00679.x.

    • Search Google Scholar
    • Export Citation
  • Hulme, M., 1992: Rainfall changes in Africa: 1931–1960 to 1961–1990. Int. J. Climatol., 12, 685699, doi:10.1002/joc.3370120703.

  • Indeje, M., Semazzi F. H. M. , and Ogallo L. J. , 2000: ENSO signals in East African rainfall seasons. Int. J. Climate, 20, 1946, doi:10.1002/(SICI)1097-0088(200001)20:1<19::AID-JOC449>3.0.CO;2-0.

    • Search Google Scholar
    • Export Citation
  • JAMSTEC, 2014: Dipole mode index (DMI): SST DMI dataset (monthly from 1958 to 2010) derived from HadISST dataset. Accessed 22 July 2014. [Available online at http://www.jamstec.go.jp/frcgc/research/d1/iod/DATA/dmi_HadISST.txt.]

  • Kijazi, A. L., and Reason C. J. C. , 2009a: Analysis of the 1998 to 2005 drought over the northeastern highlands of Tanzania. Climate Res., 38, 209223, doi:10.3354/cr00784.

    • Search Google Scholar
    • Export Citation
  • Kijazi, A. L., and Reason C. J. C. , 2009b: Analysis of the 2006 floods over northern Tanzania. Int. J. Climatol., 29, 955970, doi:10.1002/joc.1846.

    • Search Google Scholar
    • Export Citation
  • Latif, M., Dommenget D. , Dima M. , and Grötzner A. , 1999: The role of Indian Ocean sea surface temperature in forcing East African rainfall anomalies during December–January 1997/98. J. Climate, 12, 34973504, doi:10.1175/1520-0442(1999)012<3497:TROIOS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Lobell, D. B., Bänzinger M. , Magorokosho C. , and Vivek B. , 2011: Nonlinear heat effects on African maize as evidenced by historical yield trials. Nat. Climate Change, 1, 4245, doi:10.1038/nclimate1043.

    • Search Google Scholar
    • Export Citation
  • Lumley, T., Diehr P. , Emerson S. , and Chen L. , 2002: The importance of the normality assumption in large public health data sets. Annu. Rev. Public Health, 23, 151169, doi:10.1146/annurev.publhealth.23.100901.140546.

    • Search Google Scholar
    • Export Citation
  • Lyon, B., and DeWitt D. G. , 2012: A recent and abrupt decline in the East African long rains. Geophys. Res. Lett., 39, L02702, doi:10.1029/2011GL050337.

    • Search Google Scholar
    • Export Citation
  • McHugh, M. J., 2006: Impact of South Pacific circulation variability on East African rainfall. Int. J. Climatol., 26, 505521, doi:10.1002/joc.1257.

    • Search Google Scholar
    • Export Citation
  • Mölg, T., and Kaser G. , 2011: A new approach to resolving climate–cryosphere relations: Downscaling climate dynamics to glacier-scale mass and energy balance without statistical scale linking. J. Geophys. Res., 116, D16101, doi:10.1029/2011JD015669.

    • Search Google Scholar
    • Export Citation
  • Mölg, T., Renold M. , Vuille M. , Cullen N. J. , Stocker T. F. , and Kaser G. , 2006: Indian Ocean zonal mode activity in a multicentury integration of a coupled AOGCM consistent with climate proxy data. Geophys. Res. Lett., 33, L18710, doi:10.1029/2006GL026384.

    • Search Google Scholar
    • Export Citation
  • Mölg, T., Hardy D. R. , Cullen N. J. , and Kaser G. , 2008: Tropical glaciers, climate change, and society: Focus on Kilimanjaro (East Africa). Darkening Peaks: Glacier Retreat, Science, and Society, B. Orlove, E. Wiegandt, and B. Luckman, Eds., University of California Press, 168–182.

  • Mölg, T., Chiang J. C. H. , and Cullen N. J. , 2009a: Temporal precipitation variability versus altitude on a tropical high mountain: Observations and mesoscale atmospheric modelling. Quart. J. Roy. Meteor. Soc., 135, 14391455, doi:10.1002/qj.461.

    • Search Google Scholar
    • Export Citation
  • Mölg, T., Cullen N. J. , Hardy D. R. , Winkler M. , and Kaser G. , 2009b: Quantifying climate change in the tropical midtroposphere over East Africa from glacier shrinkage on Kilimanjaro. J. Climate, 22, 41624181, doi:10.1175/2009JCLI2954.1.

    • Search Google Scholar
    • Export Citation
  • Mölg, T., Großhauser M. , Hemp A. , Hofer M. , and Marzeion B. , 2012: Limited forcing of glacier loss through land-cover change on Kilimanjaro. Nat. Climate Change, 2, 254258, doi:10.1038/nclimate1390.

    • Search Google Scholar
    • Export Citation
  • Mutai, C. C., and Ward M. N. , 2000: East African rainfall and the tropical circulation/convection on intraseasonal to interannual timescales. J. Climate, 13, 39153939, doi:10.1175/1520-0442(2000)013<3915:EARATT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Mutai, C. C., Ward M. N. , and Colman W. , 1998: Towards the prediction of the East Africa short rains based on sea surface temperature atmosphere coupling. Int. J. Climatol., 18, 975997, doi:10.1002/(SICI)1097-0088(199807)18:9<975::AID-JOC259>3.0.CO;2-U.

    • Search Google Scholar
    • Export Citation
  • Myers, N., Mittermeier R. A. , Mittermeier C. G. , da Fonseca G. A. B. , and Kent J. , 2000: Biodiversity hotspots for conservation priorities. Nature, 403, 853858, doi:10.1038/35002501.

    • Search Google Scholar
    • Export Citation
  • NCDC, 2014: Global Summary of the Day (GSOD). NOAA/NCDC, accessed 22 July 2014. [Available online at http://gis.ncdc.noaa.gov/all-records/catalog/search/resource/details.page?id=gov.noaa.ncdc:C00516.]

  • Nicholson, S. E., 1996: A review of climate dynamics and climate variability in Eastern Africa. The Limnology, Climatology and Paleoclimatology of the East African Lakes, T. C. Johnson and E. Odada, Eds., Gordon and Breach, 25–56.

  • Nicholson, S. E., and Kim J. , 1997: The relationship of the El Niño–Southern Oscillation to African rainfall. Int. J. Climatol., 17, 117135, doi:10.1002/(SICI)1097-0088(199702)17:2<117::AID-JOC84>3.0.CO;2-O.

    • Search Google Scholar
    • Export Citation
  • Nicholson, S. E., and Selato J. C. , 2000: The influence of La Niña on African rainfall. Int. J. Climatol., 20, 17611776, doi:10.1002/1097-0088(20001130)20:14<1761::AID-JOC580>3.0.CO;2-W.

    • Search Google Scholar
    • Export Citation
  • Null, J., 2014: El Niño and La Niña years and intensities: Based on Oceanic Niño Index (ONI). Accessed 22 July 2014. [Available online at http://ggweather.com/enso/oni.htm.]

  • Ogallo, L. J., 1989: The spatial and temporal patterns of the East African seasonal rainfall derived from principal component analysis. Int. J. Climatol., 9, 145167, doi:10.1002/joc.3370090204.

    • Search Google Scholar
    • Export Citation
  • Plisnier, P. D., Serneels S. , and Lambin E. F. , 2000: Impact of ENSO on East African ecosystems: A multivariate analysis based on climate and remote sensing data. Global Ecol. Biogeogr., 9, 481497, doi:10.1046/j.1365-2699.2000.00208.x.

    • Search Google Scholar
    • Export Citation
  • Pohl, B., and Camberlin P. , 2011: Intraseasonal and interannual zonal circulations over the equatorial Indian Ocean. Theor. Appl. Climatol., 104, 175191, doi:10.1007/s00704-010-0336-1.

    • Search Google Scholar
    • Export Citation
  • Rodhe, H., and Virji H. , 1976: Trends and periodicities in East African rainfall data. Mon. Wea. Rev., 104, 307315, doi:10.1175/1520-0493(1976)104<0307:TAPIEA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Røhr, P. C., and Killingtveit Å. , 2003: Rainfall distribution on the slopes of Mt. Kilimanjaro. Hydrol. Sci. J., 48, 6577, doi:10.1623/hysj.48.1.65.43483.

    • Search Google Scholar
    • Export Citation
  • Ropelewski, C. F., and Halpert M. S. , 1987: Global and regional scale precipitation patterns associated with the El Niño/Southern Oscillation. Mon. Wea. Rev., 115, 16061626, doi:10.1175/1520-0493(1987)115<1606:GARSPP>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Saji, N. H., Goswami B. N. , Vinayachandran P. N. , and Yamagata T. , 1999: A dipole mode in the tropical Indian Ocean. Nature, 401, 360363.

    • Search Google Scholar
    • Export Citation
  • Schreck, C. J., and Semazzi H. M. , 2004: Variability of the recent climate of eastern Africa. Int. J. Climatol., 24, 681701, doi:10.1002/joc.1019.

    • Search Google Scholar
    • Export Citation
  • Shongwe, M. E., van Oldenborgh G. J. , van den Hurk B. , and van Aalst M. , 2011: Projected changes in mean and extreme precipitation in Africa under global warming. Part II: East Africa. J. Climate, 24, 37183733, doi:10.1175/2010JCLI2883.1.

    • Search Google Scholar
    • Export Citation
  • Smith, T. M., Reynolds R. W. , Peterson T. C. , and Lawrimore J. , 2008: Improvements to NOAA’s historical merged land–ocean surface temperature analysis (1880–2006). J. Climate, 21, 22832296, doi:10.1175/2007JCLI2100.1.

    • Search Google Scholar
    • Export Citation
  • Webster, P. J., Moore A. M. , Loschnigg J. P. , and Leben R. R. , 1999: Coupled ocean–atmosphere dynamics in the Indian Ocean during 1997–98. Nature, 401, 356360, doi:10.1038/43848.

    • Search Google Scholar
    • Export Citation
  • Wolff, C., Haug G. H. , Timmermann A. , Sinninghe Damasté J. S. , Brauer A. , Sigman D. M , Cane M. A. , and Verschuren D. , 2011: Reduced interannual rainfall variability in East Africa during the last ice age. Science, 33, 743747, doi:10.1126/science.1203724.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 373 207 0
PDF Downloads 286 153 0

Multidecadal Trends and Interannual Variability of Rainfall as Observed from Five Lowland Stations at Mt. Kilimanjaro, Tanzania

View More View Less
  • 1 Environmental Informatics, Faculty of Geography, Philipps University of Marburg, Marburg, Germany
  • | 2 Environmental Informatics, Faculty of Geography, Philipps University of Marburg, Marburg, Germany, and Tanzania National Parks, Arusha, Tanzania
  • | 3 Department of Plant Systematics, University of Bayreuth, Bayreuth, Germany
  • | 4 Environmental Informatics, Faculty of Geography, Philipps University of Marburg, Marburg, Germany
Restricted access

Abstract

Future rainfall dynamics in the Kilimanjaro region will mainly be influenced by both global climate and local land-cover change. An increase in rainfall is expected, but rising temperatures are also predicted for the ecosystem. In situ rainfall of five stations is analyzed to determine seasonal variability and multidecadal trends in the lowlands and lower elevations of the Kilimanjaro region. Monthly rainfall totals are obtained from the Tanzanian Meteorological Agency, from two mission stations, and from a sugar cane plantation. The datasets of the two mission stations cover time spans of 64 and 62 years, starting in 1940 and 1942, while rainfall data obtained from the Tanzanian Meteorological Agency and from the sugar cane plantation start in 1973 and 1974 and thus cover 40–41 years. In one out of five stations, a significant weak negative linear long-term trend in rainfall is observable, which is also evident in the other locations but is not significant. However, humid and dry decades are evident and seasonality has changed, especially during the long rains between March and May. El Niño–Southern Oscillation (ENSO) in combination with positive Indian Ocean dipole (IOD) leads to enhanced rainfall during the year of ENSO onset and the following year. During La Niña years, rainfall increases in the following year, while during the onset year rainfall patterns are more diverse. Positive IOD leads to enhanced rainfall amounts.

Denotes Open Access content.

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/JHM-D-16-0062.s1.

Corresponding author e-mail: Insa Otte, ottein@staff.uni-marburg.de

Abstract

Future rainfall dynamics in the Kilimanjaro region will mainly be influenced by both global climate and local land-cover change. An increase in rainfall is expected, but rising temperatures are also predicted for the ecosystem. In situ rainfall of five stations is analyzed to determine seasonal variability and multidecadal trends in the lowlands and lower elevations of the Kilimanjaro region. Monthly rainfall totals are obtained from the Tanzanian Meteorological Agency, from two mission stations, and from a sugar cane plantation. The datasets of the two mission stations cover time spans of 64 and 62 years, starting in 1940 and 1942, while rainfall data obtained from the Tanzanian Meteorological Agency and from the sugar cane plantation start in 1973 and 1974 and thus cover 40–41 years. In one out of five stations, a significant weak negative linear long-term trend in rainfall is observable, which is also evident in the other locations but is not significant. However, humid and dry decades are evident and seasonality has changed, especially during the long rains between March and May. El Niño–Southern Oscillation (ENSO) in combination with positive Indian Ocean dipole (IOD) leads to enhanced rainfall during the year of ENSO onset and the following year. During La Niña years, rainfall increases in the following year, while during the onset year rainfall patterns are more diverse. Positive IOD leads to enhanced rainfall amounts.

Denotes Open Access content.

Supplemental information related to this paper is available at the Journals Online website: http://dx.doi.org/10.1175/JHM-D-16-0062.s1.

Corresponding author e-mail: Insa Otte, ottein@staff.uni-marburg.de

Supplementary Materials

    • Supplemental Materials (RAR 4.27 MB)
Save