CLIMATE INDICES IN WEST SUMATERA

Sugeng NugrohoGlobal Atmosphere Watch (GAW) Bukit Kototabang Station

Jln. Raya Bukittinggi-Medan Km.17, Palupuh, Kab. Agam, Prop. Sumatera BaratTelp.: 0752-7446089, Fax.: 0752-7446449

e-mail: sugeng.nugroho@bmkg.go.id

International Workshop on The Digitization of Historical Climate Data, The New SACA&D Database and Climate Analysis in The Asean Region

02-05 April 2012, Citeko, Bogor, Indonesia

OUTLINE

• INTRODUCTION• Background• Aim of study

• METHODOLOGY• Site of study• Data• Data analysis• Climate extreme indices

• RESULTS

• SUMMARY

INTRODUCTION

One of the most significant consequences of global warming due to increase in greenhouse gases would be an increase in magnitude and frequency of climate extreme events (temperature & precipitation).

BackgroundMonitoring CO2 concentration in Bukit Kototabang GAW Station

CO2 annual average concentration in Bukit Kototabang GAW Station has been increasing from 373.1 ppm in 2004 to 381.9 ppm in 2009

The main aim of this study is to determine the annual air temperature variations and extreme rainfall event in West Sumatra by using ETCCDMI extreme indices.

Aim of study

METHODOLOGY

Study was carried out in Teluk Bayur, Padang and Sicincin as representation of lowland areas, Padang Panjang and Bukit Kototabang for highland areas .

Site of study

Mentawai Strait

METHODOLOGY

This study using daily observation data for the last 20 years at BMKG West Sumatera Stations

Data

METHODOLOGY

Data were analyzed by using RClimDex 1.0 and nonparametric statistic method (Mann-Kendal test) to analyze the trend variation

Data Analysis

METHODOLOGY

Using 18 extreme indices from ETCCDMI (Expert Team for Climate Change Detection Monitoring and Indices).

Climate Extreme Indices

9 indices for extreme air temperature (TXx, TNx, TXn, TNn, TN10p, TX10p, TN90p, TX90p and DTR)

9 indices were used for extreme rainfall event (RX1D, RX5D, SDII, R125,CDD, CWD, R95p, R99p and PrcpTOT)

Extreme Temperature Indices

RESULTS

All site show negative trend for TX10p (cool days) indexAll site show positive trend for TX90p (warm days) index

RESULTS

Extreme Rainfall Event Indices

All site show positive trend for RX1D (max 1-day prec amount)

All site show positive trend for RX5D (max 5-day prec amount)

All site show positive trend for R99p (extremely wet days)

All site show positive trend for SDII (simple daily intensity index)

1. Result showed that generally the observed areas indicated positive trends for extreme rainfall event indices

SUMMARY

2. Extreme air temperature index, positive trends were mostly observed on TXx, TNx, TXn, TNn, TN90p and TX90p indices, whereas negative trends were found on TN10p and TX10p indices

3. Statistical analysis showed not all of trend variations were significant at 95% of convidence level

4. Result suggested that there is no difference between lowlands and highlands in terms of extreme climate condition in West Sumatra.

TerimTerimaakasih kasih