Regional Climate Observation & Simulation of Extreme Temperature & Precipitation Trends By: M.K. Sammathuria & L.K. Ling Malaysian Meteorological Department Ministry of Science, Technology and Innovation -------------------------------------------------------------------------------------------------- The 14 th International Rainwater Catchment Systems Conference, PWTC, Kuala Lumpur, 3-63 6 August 2009
SCOPE Introduction Meteorological Observation Data Analysis Regional Climate Simulation Analysis Concluding Remarks
Introduction IPCC reports a 0.74ºC increase in global average temperature over the last 100 years (IPCC, 2007) Cold days and cold nights becoming less frequent Hot days and hot nights becoming more frequent Frequency of heavy precipitation events has increased over most land areas
Global Average Surface Temperature Anomaly Source: IPCC AR4 WG1 - Physical Science Basic
Observation Data Meteorological Stations observation data used: Alor Setar Ipoh Mersing Kuantan Kota Bharu, in Peninsular Malaysia Sandakan Kota Kinabalu Miri Kuching, in East Malaysia These stations are selected because they have > 40 years of meteorological records evenly distributed across the country The parameters investigated: mean daily minimum/maximum temperature annual rainfall amount the number of rain days per annum
PULAU ANGKAWI BAYAN LEPAS CHUPING ALOR SETAR BUTTERWORTH PRAI L. MERBAU KOTA BHARU KUALA KRAI KUALA TRENGGANU Observation Stations Location RANGKAIAN STESEN PENCERAPAN LABUAN KUDAT KOTA KINABALU SANDAKAN IPOH SITIAWAN CAMERON HIGHLAND BATU EMBUN MIRI TAWAU TEMERLOH SUBANG P. JAYA MUADZAM SHAH KUANTAN SIBU BINTULU (Doppler) KLIA MALACCA B. PAHAT KLUANG MERSING KUCHING SRI AMAN SENAI Omar
Annual Mean Daily Min/Max Temperature ANNUAL MEAN OF DAILY MAXIMUM TEMPERATURE (1966-2008) FOR IPOH, ALOR STAR, MERSING, KUANTAN AND KOTA BHARU ANNUAL MEAN OF DAILY MINIMUM TEMPERATURE (1966-2008) FOR IPOH, ALOR STAR, MERSING, KUANTAN AND KOTA BHARU Temperature ( C) 34.1 33.8 33.5 33.2 32.9 32.6 32.3 32.0 31.7 31.4 31.1 30.8 30.5 30.2 29.9 29.6 29.3 1966 1969 1972 1975 1978 1981 1984 1987 YEAR IPOH ALOR STAR MERSING KUANTAN KOTA BHARU Higher annual mean daily max surf T are observed for the west coast of Pen Malaysia but not the annual mean daily min surf T. Last 15 yrs, Kota Kinabalu recorded higher annual mean Temperature ( C) 32.7 32.4 32.1 31.8 31.5 31.2 30.9 30.6 30.3 30.0 ANNUAL MEAN OF DAILY MAXIMUM TEMPERATURE (1966-2008) FOR KOTA KINABALU, SANDAKAN, MIRI AND KUCHING 1966 1969 1972 1975 1978 1981 1984 1987 1990 1990 1993 1993 1996 daily max surf T in E Malaysia YEAR KOTA KINABALU SANDAKAN MIRI KUCHING 1996 1999 1999 2002 2002 2005 2005 2008 2008 Temp increase trend is more evident in the annual mean of the daily min T vs max T for E & W Malaysia (Sandakan) Most stns have new annual mean daily min & max surf T highs recorded in 1972, 1982, & 1997 (severe El Niño). Highest annual mean daily min surf T recorded during the extremely severe 1997 1998 El Niño event. Temperature ( C) Temperature ( C) 24.8 24.5 24.2 23.9 23.6 23.3 23.0 22.7 22.4 22.1 21.8 21.5 24.9 24.6 24.3 24.0 23.7 23.4 23.1 22.8 22.5 22.2 1966 1969 1972 1975 1978 1981 1984 1987 YEAR IPOH ALOR STAR MERSING KUANTAN KOTA BHARU Sandakan recorded higher annual mean daily min surf T since the 1980's. A sig. drop in annual mean daily max & daily min surf T are observed in all the stns during the 1983 1984 time period ANNUAL MEAN OF DAILY MINIMUM TEMPERATURE (1966-2008) FOR KOTA KINABALU, SANDAKAN, MIRI AND KUCHING 1966 1969 1972 1975 1978 1981 1984 1987 YEAR KOTA KINABALU SANDAKAN MIRI KUCHING 1990 1990 1993 1993 1996 1996 1999 1999 2002 2002 2005 2005 2008 2008
Annual Rainfall Amount Annual Rainfall (mm) 4500 4000 3500 3000 2500 2000 1500 1000 1951 Annual Precipitation (1951-2008) - IPOH, ALOR S TAR, MERS ING, KUANTAN AND KOTA BHARU 1954 1957 1960 1963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 2005 2008 Rainfall amount trend shown neither an increasing nor a decreasing trend. Kuching recorded the highest annual rainfall amount. Year IPO H ALOR STAR MERSING KUANTAN KO TA BHARU 6000 5500 5000 4500 4000 3500 3000 2500 2000 150 0 10 0 0 Annual Precipitation (1947-2008) - K. KINABALU, SANDAKAN, MIRI AND KUCHING Alor Setar & Kota Kinabalu are the stations with the min annual rainfall amount for Peninsular and East Malaysia respectively. Year KO TA KINABALU SANDAKAN MIRI KUCHING
Annual Number of Rain Days ANNUAL TOTAL RAIN DAYS (1951-2008) FOR IPOH, ALOR STAR, MERSING, KUANTAN AND KOTA BHARU ANNUAL TOTAL RAIN DAYS (1951-2008) FOR KOTA KINABALU, SANDAKAN, MIRI AND KUCHING 240 220 290 270 RAIN DAYS 200 180 160 140 RAIN DAYS 250 230 210 190 170 150 120 1951 1954 1957 1960 1963 1966 1969 1972 1975 1978 1981 1984 YEAR 1987 1990 1993 1996 1999 2002 2005 2008 130 1951 1954 1957 1960 1963 1966 1969 1972 1975 1978 1981 1984 YEAR 1987 1990 1993 1996 1999 2002 2005 2008 IPOH ALOR STAR MERSING KUANTAN KOTA BHARU KOTA KINABALU SANDAKAN MIRI KUCHING Number of rain days trend shown neither an increasing nor a decreasing trend. The stations with min number of annual rain days for Peninsular Malaysia and East Malaysia are Kota Bharu and Kota Kinabalu respectively Kuching recorded the highest annual number of rain days.
Standardized Annual Precipitation Anomaly for Peninsular Malaysia The relatively stronger El Niño events of 1972, 1982 & 1997 have resulted in relatively drier years for most of the stations During the years 1972, 1982 & 1997, the number of annual rain days and annual rainfall amount of most stations had shown distinct decrease However, in 1982, some stations in Peninsular Malaysia actually recorded an increase in annual rainfall amount. A moderate strength El Niño event is known to have influence on East Malaysia but may not have strong influence on Peninsular Malaysia
Regional Climate Simulation The Providing Regional Climates for Impacts Studies (PRECIS) regional climate model (RCM) developed by the Hadley Centre, UK is used to simulate future climate Lateral boundary conditions (LBC) obtained from the Hadley Centre HadCM3 atmospheric ocean coupled GCM (Global Circulation Model) with the SRES A1B scenario The HadCM3 regional simulations were done for 1960 to 2100 simulation results for 1961 to 1990 as the baseline 2001 to 2099 are used to generate future climate change scenarios Model resolutions for the GCM and RCM are 2.5º x 3.75º and 0.44º x 0.44º respectively
Regional Climate Simulation (cont.) The RCM baseline simulation was validated using temperature and rainfall observation data from the Climate Research Unit (CRU) of the University of East Anglia, UK The monthly variation trend of the temperature and monthly distribution of rainfall between the baseline simulation and the observed are consistent 5-year running means were used to display the trend patterns Temperature and rainfall anomalies were obtained by comparing future annual projections with the simulation for 1990 to 1999
PRECIS Simulation (2001 2099) Annual Temperature Anomaly driven by HadCM3 A1B MALAYSIA - TEMPERATURE ANOMALY TEMPERATURE ANOMALY ( C ) 3.9 3.6 3.3 3.0 2.7 2.4 2.1 1.8 1.5 1.2 0.9 0.6 0.3 0.0 2000 2007 2014 2021 2028 2035 2042 PENINS ULAR MALAYS IA SABAH S ARAWAK 2049 YEAR 2056 2063 2070 2077 2084 2091 2098 The annual temperature increasing trend shown is as expected with marked inter-decadal variability in the time-series. Significant annual mean temperature increase is simulated during the end of the third decade (2028) and middle of the century. Nevertheless the significant increase simulated during the end of the third decade is extremely severe compared to the other decades in the century
PRECIS Simulation (2001 2099) Annual Rainfall Anomaly driven by HadCM3 A1B MALAYSIA - PRECIPITATION ANOMALY PRECIPITATION ANOMALY ( % ) 19.0 16.0 13.0 10.0 7.0 4.0 1.0-2.0-5.0-8.0-11.0-14.0-17.0-20.0-23.0-26.0-29.0-32.0-35.0 2000 2007 2014 2021 2028 PENINSULAR MALAYSIA SABAH SARAWAK 2035 2042 2049 YEAR 2056 2063 All the 3 regions experience significant increase in rainfall during 2030 to 2031. This bears the signature of a strong La Niña like event. 2070 2077 2084 2091 2098 The negative annual rainfall trend is extremely evident for Sabah. All the 3 regions seem to experience increased rainfall towards the end of the century The highest rainfall reduction was simulated during the end of the third decade, corresponds to the period during which the highest temp increase was simulated. This significant reduction of rainfall together with significant increase in temp is generally exhibited during El Niño events.
Concluding Remarks From the analysis of meteorological observation data, it was found that the temperature increase trend is more evident in the annual mean of the daily minimum temperature as compared to that of the daily maximum temperature El Niño events are known to result in relatively drier years for most of the stations in both Peninsular and East Malaysia El Niño events have stronger influence over the climate of East Malaysia relative to Peninsular Malaysia
Concluding Remarks (cont.) PRECIS simulation projected a consistent increasing trend of annual average daily surface temperature for the Peninsular Malaysia, Sabah and Sarawak in the 21st century A deficit in annual rainfall is generally simulated in the same period for the Malaysia regions The PRECIS also can simulate the ENSO events