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http://dx.doi.org/10.17576/jsm-2019-4811-04
Prediction Skill of
NCEP CFSv2 for Seasonal Precipitation and Surface Air Temperature Forecast over
Southeast Asia
(Kemahiran Peramalan NCEP CFSv2 untuk Kerpasan dan Suhu Udara
Permukaan Musiman
di Asia Tenggara)
SITI AMALIA, FREDOLIN TANGANG, SHEAU TIEH NGAI
& LIEW JUNENG*
Centre
for Earth Sciences and Environment, Faculty of Science and Technology, Universiti
Kebangsaan Malaysia, 43600 UKM Bangi,
Selangor Darul Ehsan, Malaysia
Diserahkan: 1
April 2019/Diterima: 15 Ogos 2019
ABSTRACT
Climate Forecast System
version 2 (CFSv2) is the ocean-atmosphere-land coupled model and the latest
version of seasonal climate forecast from National Centers for Environmental
Prediction (NCEP). This study presents the prediction skill of
seasonal precipitation and surface air temperature forecasting from CFSv2 over
Southeast Asia. The objective of the study was to verify the prediction
accuracy of CFSv2 by quantifying the deterministic quantities in term of
correlation coefficients with respect to different lead times and target
seasons based on a the 28-year ensemble means (1983/84 - 2010/11) for each
variables. Additionally, the prediction skill of 20 sub-regions over Southeast
Asia are verified with observation for regional assessment of the accuracy of
seasonal precipitation and surface air temperature forecasted by CFSv2. In
general, the result showed that the prediction skill of CFSv2 for seasonal
precipitation and surface air temperature forecasting is reasonable, especially
prediction skill after lead month-0 for all target seasons compared to other
lead months. The lowest prediction skill is after lead month-6. Overall, the
prediction skill of seasonal surface air temperature forecasting is better than
precipitation. Moreover, the result obtained in this study highlights the
advantages of using an ensemble technique for seasonal forecasting in Southeast
Asia.
Keywords: Ensemble
techniques; forecast skill assessment; NCEP CFS; seasonal forecasting;
Southeast Asia
ABSTRAK
Sistem Ramalan Iklim
versi kedua (CFSv2) merupakan sebuah model laut-atmosfera-darat berpasangan dan
versi terkini model peramalan iklim bermusim dari Pusat Kebangsaan untuk
Ramalan Sekitaran (NCEP). Kajian ini mengemukakan
kemahiran ramalan kerpasan dan suhu udara permukaan bermusim dari CFSv2 di Asia
Tenggara. Objektif kajian ini adalah untuk mengesahkan ketepatan ramalan CFSv2
dengan mengukur kuantiti deterministik dalam istilah pekali korelasi
berdasarkan analisis terhadap min kelompok 28 tahun (1983/84-2010/11) bagi
setiap pemboleh ubah pada masa bulan kedepan dan sasaran musim yang berbeza.
Tambahan pula, kemahiran ramalan 20 subkawasan di Asia Tenggara dikesahkan
dengan pemerhatian untuk melihat secara terperinci ramalan kerpasan dan suhu
udara permukaan bermusim yang telah diramalkan oleh CFSv2. Secara umumnya,
keputusan menunjukkan bahawa kemahiran ramalan CFSv2 bagi ramalan kerpasan dan
suhu udara permukaan bermusim adalah munasabah terutama sekali kemahiran
ramalan selepas 0-bulan kedepan untuk kesemua sasaran musim berbanding dengan
bulan kedepan yang lain. Kemahiran ramalan paling rendah adalah selepas 6-bulan
kedepan. Secara keseluruhannya, kemahiran ramalan bagi peramalan suhu udara
permukaan adalah lebih baik daripada kerpasan. Tambahan pula, kajian ini telah
menekankan kelebihan menggunakan teknik kelompok bagi peramalan bermusim di
Asia Tenggara.
Kata kunci: Asia
Tenggara; NCEP CFS; penilaian kemahiran ramalan;
peramalan bermusim; teknik berkelompok
RUJUKAN CPC Global Daily Temperature. 2018. https://www.esrl.noaa.
gov/psd/. Accessed on 26 September 2018.
Drbohlav, H.K.L. 2010. Spatial structure, forecast errors, and
predictability of the South Asian Monsoon in CFS monthly retrospective
forecasts. Journal of Climate 23: 4750-4769.
Jiang, J., Yang, S., Li, Y., Kumar, A., Liu, X., Zuo, Z. &
Jha, B. 2013. Seasonal-to-interannual prediction of the Asian summer monsoon in
the NCEP climate forecast system Version 2. Journal of Climate 26:
3708-3727.
Kim, H.M., Webster, P.J. & Curry, J.A. 2012. Asian summer
monsoon prediction in ECMWF System 4 and NCEP CFSv2 retrospective seasonal
forecasts. Climate Dynamics 39: 2975-2991.
Kim, H.M., Webster, P.J., Curry, J.A. & Toma, V.E. 2012. Seasonal
prediction skill of ECMWF system 4 and NCEP CFSv2 retrospective
forecast for the Northern Hemisphere winter. Climate Dynamics
39: 2957-2973. Ngai,
S.T., Tangang, F. & Juneng, L. 2017. Bias correction of global and regional
simulated daily precipitation and surface mean temperature over Southeast Asia
using quantile mapping method. Global and Planetary Change 149: 79-90.
Peng,
P., Barnston, A. & Kumar, A. 2013. A comparison of skill between two
versions of the NCEP Climate Forecast System (CFS) and CPC’s operational
short-lead seasonal outlooks. Weather Forecasting 28: 445-461.
Peng,
P., Kumar, A. & Wang, W. 2011. An analysis of seasonal predictability in
coupled model forecasts. Climate Dynamics 36: 419-430.
Peng,
P., Kumar, A., Barnston, A.G. & Goddard, L. 2000. Simulation skills of the
SST-forced global climate variability of the NCEP-MRF9 and the Scripps-MPI
ECHAM3 models. Journal of Climate 13: 3657-3679.
Pin,
K.F., Pereira, J.J. & Aziz, S. 2013. Platforms of climate change: An
evolutionary perspective and lessons for Malaysia. Sains Malaysiana 42(8):
1027-1040.
Rai,
S. & Krishnamurthy, V. 2011. Error growth in Climate Forecast System daily
retrospective forecasts of South Asian monsoon. Journal of Geophysical
Research 116(D3).
Saha,
S., Moorthi, S., Wu, X., Wang, J., Nadiga, S., Tripp, P., Behringer, D., Hou,
Y.T., Chuang, H.Y., Iredell, M., Ek, M., Meng, J., Yang, R., Mendez, M.P., van
den Dool, H., Zhang, Q., Wang, W., Chen, M. & Becker, E. 2014. The NCEP
climate forecast system version 2. Journal of Climate 27: 2185-2208.
Saha,
S., Moorthi, S., Pan, H.L., Wu, X., Wang, J., Nadiga, S., Tripp, P., Kistler,
R., Woollen, J., Behringer, D., Liu, H., Stokes, D., Grumbine, R., Gayno, G.,
Wang, J., Hou, Y.T., Chuang, H.Y., Juang, H.M.J., Sela, J., Iredell, M.,
Treadon, R., Kleist, D., Van Delst, P., Keyser, D., Derber, J., Ek, M., Meng,
J., Wei, H., Yang, R., Lord, S., van den Dool, H., Kumar, A., Wang, W., Long,
C., Chelliah, M., Xue, Y., Huang, B., Schemm, J.K., Ebisuzaki, W., Lin, R.,
Xie, P., Chen, M., Zhou, S., Higgins, W., Zou, C.Z., Liu, Q., Chen, Y., Han,
Y., Cucurull, L., Reynolds, R.W., Rutledge, G. & Goldberg, M. 2010. The
NCEP climate forecast system reanalysis. Bulletin of the American
Meteorological Society 91(8): 1015-1057.
Saha,
S., Nadiga, S., Thiaw, C., Wang, J., Wang, W., Zhang, Q., van den Dool, H.M.,
Pan, H.L., Moorthi, S., Behringer, D., Stokes, D., Pena, M., Lord, S., White,
G., Ebisuzaki, W., Peng, P. & Xie, P. 2006. The NCEP climate forecast
system reanalysis. Journal of Geophysical Research 19(15): 3483- 3517.
Schneider,
U., Finger, P., Meyer-Christoffer, A., Rustemeier, E., Ziese, M. & Becker,
A. 2017. Evaluating the hydrological cycle over land using the newly-corrected
precipitation climatology from the Global Precipitation Climatology Centre
(GPCC). Atmosphere 8(3): 52.
Tangang,
F. & Juneng, L. 2004. Mechanisms of Malaysian rainfall anomalies. Journal
of Climate 17: 3616-3622.
Tangang,
F., Juneng, L., Salimun, E., Sei, K.M., Le, L.J. & Muhamad, H. 2012.
Climate change and variability over Malaysia: Gaps in science and research
information. Sains Malaysiana 41(11): 1355-1366.
Weisheimer,
A., Doblas-Reyes, F.J., Palmer, T.N., Alessandri, A., Arribas, A.,
Déqué, M., Keenlyside, N., MacVean, M., Navarra, A.
& Rogel, P. 2009. ENSEMBLES: A new multi-model ensemble for
seasonal-to-annual prediction-Skill and progress beyond DEMETER
forecasting tropical Pacific SSTs. Geophysical Research Letters
36: L21711. Wang,
W., Chen, M. & Kumar, A. 2010. An assessment of the CFS real-time seasonal
forecasts. Weather Forecasting 25(3): 950-969.
Weigel,
A.P. 2012. Verification of ensemble forecasts. In Forecast Verification: A
Practitioner’s Guide in Atmospheric Science, 2nd ed., edited by Jolliffe,
I.T. & Stephenson, D.B. United Kingdom: John Wiley and Sons. pp. 141-166.
Wilks,
D.S. 2006. Statistical Methods in the Atmospheric Sciences. 2nd ed.
Massachusetts: Academic Press.
Xue,
Y., Chen, M., Kumar, A., Hu, Z. & Wang, W. 2013. Prediction skill and bias
of tropical pacific sea surface temperature in the NCEP Climate Forecast System
version 2. Journal of Climate 26: 5358-5378.
Yang,
S., Zhang, Z., Kousky, V.E., Higgins, R.W., Yoo, S.H., Liang, J. & Fan, Y.
2008. Simulations and seasonal prediction of the Asian summer monsoon in the
NCEP climate forecast system. Journal of Climate. 21: 3755-3775.
Yuan,
X., Wood, E.F., Luo, L. & Pan, M. 2011. A first look at Climate Forecast
System version 2 (CFSv2) for hydrological seasonal prediction. Geophysical
Research Letters 38: L13405.
*Pengarang untuk surat-menyurat;
email: juneng@ukm.edu.my
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