Sistem Peringatan Dini Menghadapi Iklim Ekstrem

Abstrak. Dengan letaknya diantara dua benua dan dua samudera serta berada di garis khatulistiwa, maka benua maritim Indonesia merupakan salah satu pusat konveksi utama dunia. Dengan kenyataan demikian maka Indonesia menghadapi risiko yang besar dari tingginya variabilitas iklim dan ekstremitas iklim. Guna menghadapi dampak dari iklim ekstrem maka diperlukan strategi yang mumpuni untuk membuat suatu peringatan dini secara nasional. Dengan desakan jumlah populasi dan kecanggihan teknologi informasi maka kedepan diperlukan sistem peringatan dini yang dapat menjangkau secara luas dan cepat menghadapi perubahan yang terjadi. Sebuah sistem peringatan dini yang juga harus dapat mengantisipasi dampak dan risiko. Sistem peringatan dini yang dibangun merupakan mata rantai dari pengamatan di lapangan, pengolahan data dan analisa serta sistem diseminasi yang memadai. Tulisan ini mengulas sistem peringatan dini iklim untuk sektor pertanian dengan evolusi sistem berbagi data, informasi, sistem informasi dan sistem informasi terkostumisasi. Tujuan akhir yang diupayakan adalah sebuah sistem online yang tanggap terhadap perubahan yang terjadi guna pemanfaatan yang maksimal di sektor pertanian.Abstract. Located between two continents, two oceans, and on the equator, the Indonesian maritime continent is one of the world's major deep convection. With such a reality, Indonesia experiences a substantial risk of high climate variability and climate extremes. In order to deal with the impact of extreme climate, there is a need for a strategy to establish a nationwide early warning. With stressors of demographic tension and technology sophistication, the future early warning system should be broad reaching as well as quickly responsive to face dynamical changes. That early warning system should also be able to anticipate probable impacts and risks. The established system is a chain of observations in the field, data processing and analysis as well as adequate dissemination system. This paper reviews the early warning system that can be done by observation agencies with the user agencies in the agricultural sector through sharing of data, information, information system and customized information system. The ultimate goal being pursued is an online system that is responsive to changes that occur to maximum utilization in the agricultural sector

Long Term Rainfall Trend of The Brantas Catchment Area, East Java

ABSTRACT Spatial and temporal rainfall analyses of the Brantas Catchment Area from 1955 to 2002 based on 40 daily rainfall stations has been performed. To identify the climate pattern for the last five decades, we used the Empirical Orthogonal Function (EOF) followed by the Fast Fourier Transform. By using EOF, we found the monsoonal pattern as the most dominant, which explains about 72% of all variances. The interannual pattern shows a negative trend of the monsoonal strength. From the monthly isohyets for each decade, the rainfall amount appears to decrease significantly during the last five decades, indicated by wider low rainfall amount areas and the orographic effect is detected, indicated by always greater amount in highlands. From rainfall data in mountain and coastal areas, dry periods had been increasing, mainly in lowlands. Thus, the continued imbalance of the dry and wet period is one cause of the monsoonal strength decrease during the last five decades. Key words: spatial rainfall trend, Brantas, EOF, climate chang

Ocean-atmosphere analysis of Super Typhoon Songda 2011 over Western North Pacific Ocean

The purpose of the research is to understand the influences of ocean and atmosphere to the formation of Super Typhoon Songda 2011. Daily SST from NOAA AVHRR with spatial resolution of 0.5° in latitude and longitude was used to study upper oceanic response to the formation of Typhoon Songda. Meanwhile, 3-hourly meteorological data from ARP model with spatial coverage of 0.5° Latitude x 0.5° Longitude cover 201 x 101 points from 25° N - 20° S and 70.0° E – 170.0° E as well as 13 levels of atmospheric columns was also used in the study. The study was also supported by  MT-SAT satellite images. The result showed that from early disturbances until reaching mature stage of Typhoon Songda, SST over WNP reached averages temperature of 30˚C. Warm ocean waters continuously produce heat and moisture to the air that are necessary to fuel the genesis, development, formation and intensification of Typhoon Songda. The study also proved that light vertical wind shear (850 – 200 hPa) at about 0 – 5 knot was observed in the early development of Songda at 1800 UTC on May 19th. For the time being, weak vertical wind shear extended to the northwestern of Pacific Ocean. Thus, it made the system to moved toward northwest and reached category Super Typhoon few days later on May 26th. The study also showed the present of Monsoon trough. Monsoon trough occurred where easterly wind met the reversal southerly wind. The region was stretched from southeast to northwest part of WNP Ocean and designated by an extended low pressure area at the surface as well as extended bands of thunderstorms as observed by satellite imagery. On the other hand, potential vorticity shown in the present paper is useful to obtain an understanding of atmospheric motions and development of the upper-level disturbance. Potential vorticity maximum characterize strong vorticity and upward motion. Conversely, weak vorticity with downward motion is demonstrated by mininum potential vorticity

Variasi Spasial Dan Temporal Hujan Konvektif Di Pulau Jawa Berdasarkan Citra Satelit(spatial and Temporal Variation of Convective Rain in Java Island Based on Citra Images)

Convective rain is one of precipitation types that usually occur in Indonesia, result by convective process. This convective rain brings heavy rainfall in short period and could reach a higher intensity than common monsoon rain. Convective process may have a variation with time and location. This research have determined spatial and temporal variation of convective rain in Java island by using the black body temperature (TBB) gradient method based on the GMS-6 (MTSAT-1R) images. As a result, the seasonal convective rain generally occurred in similar period i.e. in the morning from 07.00 to 11.00 LT (local time) and in the evening from 18.00 LT until 05.00 LT. The maximum event occurred from 18.00 LT until mid night. There were different locations between the seasonal convective event. In the seasonal convective rain, there were two spatial patterns. In wet season (DJF) and transitional season from wet to dry (MAM) convective rain spread from east to west Java. While in dry season (JJA) and transitional season from dry to wet (SON), convective rain mostly occurred only in west Java

SPATIOTEMPORALCHARACTERISTICSOF EXTREMERAINFALL EVENTS OVER.TAVA ISLAND, INDONESIA

The patterns and trends of extreme daily rainfall within period o.f 1981 - 2010 have been analyzed for Java Island, Indonesia particularly East Java Province. A set of extreme indices recommended by WMO were calculated using high quality data fi-om 84 rain stations to express the frequency and intensity of those events. The spatial patterns was identified by mapping climatological mean of indices while temporal trends was assessed using the nonparametric Mann-Kendal test. The study found that the spatial pattern of extreme rainfall events over East Java Province is generally characterized by low frequency and intensity in the coastal area, and high frequency and intensity in the mountainous area: The dominant finding from trend assessment is not-significant trend. However, the consistently significant trend was observed in some districts. Rain stations in District of Ponorogo, Ngawi, Bojonegoro, Gresik and Sumenep showed significant negative trend for almost all indices whereas significant positive trend was found in District of Surabaya and Pasuruan. Key words: spatia-temporal characteristics, extreme rainfall events, Java Islan

VARIASI SPASIAL DAN TEMPORAL HUJAN KONVEKTIF DI PULAU JAWA BERDASARKAN CITRA SATELIT(SPATIAL AND TEMPORAL VARIATION OF CONVECTIVE RAIN IN JAVA ISLAND BASED ON CITRA IMAGES)

Convective rain is one of precipitation types that usually occur in Indonesia, result by convective process. This convective rain brings heavy rainfall in short period and could reach a higher intensity than common monsoon rain. Convective process may have a variation with time and location. This research have determined spatial and temporal variation of convective rain in Java island by using the black body temperature (TBB) gradient method based on the GMS-6 (MTSAT-1R) images. As a result, the seasonal convective rain generally occurred in similar period i.e. in the morning from 07.00 to 11.00 LT (local time) and in the evening from 18.00 LT until 05.00 LT. The maximum event occurred from 18.00 LT until mid night. There were different locations between the seasonal convective event. In the seasonal convective rain, there were two spatial patterns. In wet season (DJF) and transitional season from wet to dry (MAM) convective rain spread from east to west Java. While in dry season (JJA) and transitional season from dry to wet (SON), convective rain mostly occurred only in west Java

Comparison of Total Suspended Particulate (TSP) Measurement in Urban and Suburban Areas of Bali during Nyepi Day 2015

Nyepi or the Balinese Day of Silence (DOS) is a day when people celebrate every New Year according to the Balinese calendar (Saka). On that day, all resident activities were very restricted, with no outdoor activities. This event, which only lasted for 24 hours, is a unique period to conduct air quality measurements such as Total Suspended Particulate (TSP) for assessing the influence of human activities. This study only focuses on TSP monitoring before, during and after the DOS and its comparison with the meteorological data. TSP concentration measurements were conducted in 2 urban areas (Badung and Ubung) and a sub-urban area (Singaraja) from March 17 to March 25, 2015. The results show that TSP concentrations are negatively correlated with temperature and wind speed at each location. Hourly TSP concentrations during DOS are lower than the averaged TSP concentrations before and after DOS. During DOS, TSP concentrations decreased significantly in urban areas by 73-78% relative to regular days, which is likely due to drastically decreasing of human activities. In suburban areas, the decrease of TSP concentration was about 59%. These results show that human activities highly influence the air quality

ANALISIS POLA DISPERSI PARTIKULAT DAN SULFURDIOKSIDA MENGGUNAKAN MODEL WRFCHEM DI SEKITAR WILAYAH INDUSTRI TANGERANG DAN JAKARTA (Analysis of Particulate and Sulfurdioxide Pattern Dispersion using WRFChem Model over Industrial Area In Tangerang)

ABSTRAKPeningkatan aktivitas industri dan transportasi menjadi pemicu timbulnya potensi pencemaran udara yang berdampak pada kesehatan masyarakat, terutama di sekitar wilayah industri dan kota-kota besar. Pengenalan daerah yang rawan terhadap pemaparan konsentrasi pencemar udara maksimum perlu dilakukan untuk mengantisipasi dampak terhadap kesehatan masyarakat dan lingkungan. Studi ini bertujuan untuk menganalisis sebaran pencemar udara di sekitar wilayah industri dan menentukan lokasi yang berpotensi terpapar pencemar udara dengan konsentrasi maksimum, khususnya partikulat (dalam hal ini PM10) dan sulfurdioksida (SO2). Lokasi studi adalah wilayah Jakarta dan Tangerang, yang merupakan daerah padat transportasi juga industri. Analisis dispersi menggunakan model Weather Research Forecasting / Chemistry (WRFChem) dengan ukuran grid 4 x 4 km, selama periode 5 hari (120 jam) masing-masing pada bulan Agustus dan Desember. Hasil analisis model menunjukkan lokasi yang rawan terpapar pencemar PM10 maupun SO2 dengan konsentrasi maksimum adalah Jakarta Pusat dan Jakarta Utara, secara umum terjadi pada tengah malam hingga pagi hari. Pada siang hari konsentrasi maksimum cenderung terjadi di sekitar Jakarta Selatan, Tangerang Selatan, serta Kabupaten Tangerang. Secara temporal terjadi fluktuasi konsentrasi pencemar udara, konsentrasi siang hari rendah dan meningkat menjelang malam hari hingga dini hari. Faktor meteorologi terutama pola angin sangat mempengaruhi pola sebaran pencemar di wilayah studi, dan keberadaan garis pantai juga mempengaruhi terakumulasinya pencemar di sekitar wilayah Jakarta.ABSTRACTIncreasing industrial and transportation activity were associated with air pollution, especially in urban and industrial area. The air pollution is associated with significant adverse health effects. Understanding the potential implications of the air pollution to human health, developing strategies to mitigate the pollution should be seen as a serious attention. The purpose of this study was to analyze air pollutant dispersion within industrial area and to determine the locations that potentially exposed to maximum pollutant concentrations, especially PM10 and SO2.The evaluation was conducted within Jakarta and Tangerang using a well known modelling tool ‘WRFChem’. The WRFChem was simulated for the period of 5 days (120 hours) in August and December using the grid size of 4 km x 4 km. The model shows that the maximum concentrations of PM10 and SO2 occurred within Central Jakarta and the North Jakarta, frequently found from the midnight to morning. While during the day time, the maximum concentration tend to occur within the region of South Jakarta, South Tangerang, and Tangerang Regency. Diurnal fluctuation shows the pollutant concentrations are increased at night and decreased after sunrise. Meteorological factors, mainly wind direction, affects the pollutants dispersion in the area of study, and the existence of the shoreline also affects pollutants accumulation around Central Jakarta

Development Model Using Multi Predictors for Predicting the Onset of Rainy Season (Case Study in Northern Coastal West Java Province Indonesia)

The prediction of the onset of rainy season is very important for many sectors especially for agricultural sector in order to make the best planning for planting calendar to get optimum paddy yield. Monsoon onset is characterized by the change of significant atmospheric circulation such as changes of wind direction; inter tropical convergence zone location, etc. This research used 16 predictors which have been selected using spatial correlation test at and above 95% significant level. Northern coastal west Java is the main rice production center in West Java province and contribute about 30% of total production of West Java Province. The selected predictors in the next process become indicators for the variability of rainy season onset and becoming predictors for climate statistical model. Through the many techniques, 3 models are resulted which are multiple linier regression, stepwise regression and principal component regression. These models produce the better performance to predict the onset of rainy season over northern coastal area of West Java Province including some extreme years during strong El Nino or La Nina events