The Indonesian seas located in the tropical country between the Pacific and the Indian Oceans, comprise shelf and deep sea countries with their spacial features. Furthermore, it lies between Asia and Australia continent and it compasses the equator part in Southeast Asia. This part is besides known as the ‘Maritime Continent ‘ ( Ramage 1968 ; Qu et.al. 2005 ) . Furthermore, Ffield and Gordon ( 1996 ) describe that the parts are non a inactive channel associating the two oceans ( Pacific and Indian Ocean ) that within the seas the thermal and salt stratification and the sea surface temperature ( SST ) are significantly modified by tidal and wind-induced commixture and by sea-air fluxes.
The part experiences some of the most variable clime status. The specific geographical place of Indonesia influences the features of clime and ocean kineticss. The inter-tropical convergence zone ( ITCZ ) shifts from northern hemisphere in July to the southern hemisphere in January traversing the equatorial line. Therefore, the difference of air force per unit area between Asia and Australia continents that ‘s alterations every 6 months causes the monsoonal air currents over Indonesia and drives non merely the sea surface current ( SSC ) forms but besides the influences of sea surface temperature ( SST ) and sea surface salt ( SSS ) . During the boreal summer, Indonesia indicates a dry season and during the boreal winter indicates a rainy season. The difference of the sea surface degree between the Pacific and the Indian Oceans causes the currents to flux from the Pacific to the Indian Ocean through Indonesian Waterss, which is known as the Indonesian Throughflow ( ITF ) ( Gordon 2005, Susanto 2006, Susanto et.al, 2001 ; Meyers et.al. , 1999 ; Potemra 1999 ) .
In the ensuing survey, the ocean has a map to brace the surface temperature of the Earth due to its ability to organize latent heat and to execute as the dominant beginning of atmospheric wet ( Duxbury et.al. , 2002 ; Tomczak and Godfrey 2003 ) . In add-on, Tomczak and Godfrey ( 2003 ) explain that the magnitude and the spacial distribution of the wet flux to the ambiance are controlled mostly by the SST. Hence, the SST is the chief pelagic parametric quantity for the ambiance. A proper apprehension of how the SST variableness in Indonesian part during monsoon period is of import particularly in the Makassar Strait as the chief tract of ITF.
1.2 Outline of Thesis Proposal
This thesis proposal is divided into three chapters. Chapter 1 summarises the background and relevant literature reappraisal of sea surface temperature in Indonesian Seas from old surveies. The research objectives of this survey are listed at the terminal of this subdivision. Chapter 2 explains the information set that will be utilised in this survey. Chapter 3 explains the methods will be used to accomplish these aims.
1.3. The Indonesian clime
The clime of Indonesian seas is influenced dominantly by the monsoon, and by high rainfall ( Tomczak and Godfrey 2001 ) . Furthermore, the part is located at the action Centres of north-south ( meridional ) circulation, known as Hadley Circulation, and the west-east ( zonary ) circulation, known as the Walker Circulation. Hence, the undermentioned subdivision will depict the clime factors in Indonesian part.
The term monsoon itself is traced back to an Arabic root intending ‘season ‘ ( Das, 1968 ) . The monsoon refers to a seasonally change by reversaling circulation with a period of one twelvemonth. The chief drive force for the monsoon circulation is the contrast in thermic belongingss of land and sea. The Earth ‘s surface has different response to the solar radiation from the Sun. Since land has smaller heat conductivity than the sea, the soaking up of solar radiation increases the surface temperature over land much more quickly than over the sea. The monsoon alterations way twice a twelvemonth and the air currents are practically reversed at the clip of their strongest development, and affects the pelagic circulation ( Wyrtki 1961 ; Das 1968 ; Duxbury et.al. 2002 ) . Furthermore, Roy ( 1996 ) explains that monsoon air current system is a tropical phenomenon that resulted by the interaction between a high atmospheric force per unit area cell centred over the continent in the winter hemisphere as a low atmospheric force per unit area cell that develops in the summer hemisphere over the continent.
The monsoon is a macro-scale phenomenon in character and its exciting characteristics of the clime fascinate scientist. Furthermore, there is tremendously importance for being able to calculate the monsoon due to its great impact on socio-economical and regional ( Webster et.al. , 1998 ; Webster and Yang 1992 ) . Furthermore, harmonizing to Webster and Yang ( 1992 ) , the variableness of the Asiatic monsoon is related with the El-Nino Southern Oscillation ( ENSO ) . Weak monsoon period is linked with El-Nino and strong monsoon period is associated with La-Nina. Meanwhile, during normal period, the warm pool ( SST & A ; gt ; 27 oC ) expands from eastern Indian Ocean toward western Pacific Ocean and is linked with a wide precipitation upper limit. In Indonesia, the monsoonal activity is chiefly related to the meridional motion of the ITCZ.
Ramage ( 1971 ) in Hastenrath ( 1985 ) proposes four standard to sketch the monsoon parts:
1. the prevailing air current waies displacements by at least 120 grades in January and July.
2. the mean frequence of predominating air current waies in January and July exceeds 40 % .
3. the mean end point air current in at least one of the months exceeds 3 m/s.
4. fewer than one cyclone-anticyclone alternation occurs every two old ages in either month in a 5 degree latitude-longitude rectangle.
Figure 1. Description of the universe ‘s monsoon part ( from Ramage 1971 in Hastenrath 1985 ) . Hatched countries meet at the same time the air current standard ( 1 ) to ( 3 ) , meanwhile heavy lines mark the northern bound of the part within the Northern hemisphere where the cyclone/anticyclone standard ( 4 ) is satisfied. Rectangle encloses the monsoon part. Indonesia is in the monsoon part with standards ( 1 ) to ( 3 ) .
During normal status ( December – March ) , the air force per unit area in Asia is higher than Australia. The northeasterly air current blows north of the equator ; it is known as nor’-east monsoon and turns sou’-east in the South of equator. Therefore, in Indonesia this monsoon is known as the northwest monsoon ( NWM ) from December to March, or boreal winter. Normally, during the NWM known as a rainy season and the extremum occurs in January. The air current blows sou’-east and due east near the equator. Meanwhile, in the southern hemisphere from 10 oS the air current blows to the North and so turns to the E ( Wyrtki, 1961 ) . In add-on, Wyrtki ( 1961 ) described that the equatorial trough lies over the Indian Ocean around 10 oS, in the southern portion of which the sou’-east trades are found.
The passage period occurs from April to May. In May, the system of the nor’-east air current over the South China Sea and the Philippines lessenings and the south monsoon predominates over the Indonesian part. In the South of the equator, the sou’-east air current blows and enters to the Indian Ocean as the sou’-east trades. At the equator, south air current prevails, whereas in the North of the equator southwest air current dominates. Meanwhile, during southeast monsoon ( SEM ) or boreal summer ( June-September ) , the air current blows from Australia, which has a higher air force per unit area than Asia continent. In July to August, the SEM reaches its extremum ( to the full developed ) . October and November is the passage period from SEM to NWM ( Wyrtki, 1961 ) .
The rainfall clime of the maritime continent is really alone as it is situated in the most active convective country of the universe ( Aldrian, 2003 ) . Maximum rainfall over most location in this part occurs during the boreal winter ( Chang et al. , 2005 ) . This moisture season is frequently related to the Australian summer monsoon due to the closeness of the two parts ( McBride, 1987 ; Chang et al. , 2005 ) .
In order to give a wide description about the clime of the part based on the rainfall variableness, Aldrian and Susanto ( 2003 ) found the three clime parts by utilizing dual correlativity method ( DCM ) . The consequence is three parts as shown in Figure 2. Region A ( solid line ) covers south and cardinal Indonesia from south Sumatra to Timor Island, parts of Kalimantan, parts of Sulawesi and parts of Papua Island. Region B ( short dashed line ) is located in northwest Indonesia ( near to the Asian continent ) and Region C in Maluku and parts of Sulawesi ( near to the western Pacific part ) .
Region A, which covers the largest country, is the dominant form over Indonesia. This part experiences strong influence of two monsoons ; there are the northwest monsoon from November to March ( NDJFM ) with the wettest in December and the southeast monsoon from May to September ( MJJAS ) with the driest in JAS. The minimal rainfall reaches a average below 3.3 mm/day and the upper limit is about 10.7 mm/day. On the other manus, part B has rainfall maximal about 10.3 mm/day in October-November ( ON ) and in March to May ( MAM ) . The part C has maximum rainfall about 10 mm/day in June-July and reaches minimal in November-February ( Aldrian and Susanto 2003 ) .
Figure 2. the three parts harmonizing to the average one-year forms utilizing the DCM method. Indonesia is divided into part A in solid line, part B in short dotted line and part C in long dotted line ( Aldrian and Sutanto 2003 ) .
1.4. El-Nino Southern Oscillation ( ENSO )
The air-sea interaction and the ocean kineticss in the Pacific and the Indian Ocean influence the conditions in the Indonesian seas. Harmonizing to Tomczak and Godfrey ( 1994 ) , ENSO is irregular clime phenomenon which relates to fluctuation of rainfall, air currents, ocean currents and SST of the tropical oceans and Pacific Ocean. In add-on, Suppiah ( 2004 ) defined ENSO as El-Nino phenomena and the southern oscillation together comprises a manner of clime fluctuations ( Suppiah 2004 ) .
The southern oscillation index ( SOI ) is a step of the variableness in ENSO. Troup ( 1965 ) defines the SOI with the differences in surface atmospheric force per unit area between Tahiti and Darwin. In add-on, the SOI is observed as a planetal graduated table phenomenon which involves fluctuations in the atmospheric force per unit area difference at the surface between the Indonesian-Austalian part and the sou’-east Pacific ( Drosdowsky and Williams 1991 ) .
The monsoon, ENSO and the complex plumbing interplay affect the air-exchange and the inter-ocean throughflow within Indonesian Seas ( Potemra 1999 ; Webster et.al. , 1998 ) . During SEM, the south-easterly air current from Australia generates upwelling along the Java-Sumatra South seashore. The upwelling is chiefly forced both locally by alongshore air currents associated with the SEM and remotely by atmosphere-ocean circulation related with ENSO ( Susanto et.al.,2001 )
Hamada et.al ( 2002 ) attributed ENSO-Indonesian rainfall relationship to the different monsoon oncoming day of the months during ENSO. They reported that the oncomings are earlier in La Nina old ages and subsequently in El Nino old ages. During the wet season of northern winter, the negative correlativity between Indonesian rainfall and eastern equatorial Pacific sea surface temperature is the lowest in the one-year rhythm. The correlativity is low even though in northern winter the anomalous Walker circulation associated with ENSO events exhibits large-scale high-level convergence over the Maritime Continent during warm events and divergency during cold events.
In order to understand the weakening of the Indonesian rainfall – ENSO relationship from dry season to the moisture season, Hendon ( 2003 ) examined the relationships between Indonesian rainfall, SSTs and atmospheric circulation over the full tropical Indian Ocean and Pacific Ocean. He suggested that the weakening of the relationship consequences from seasonally changing feedback of ENSO on the local SST environing Indonesia.
Across the eastern equatorial Pacific, El-Nino events are characterised by anomalously high SST and weaker trade air currents. The latter have a inclination to change by reversal way in utmost El-Nino events ( Suppiah 2004 ) . Warm Waterss in the eastern Pacific lead the part to take down atmospheric force per unit area at that place, while in the western Pacific, force per unit area additions as a consequence of decreased conveyance of warm Waterss under the influence of the southeast trade air currents.
The rainfall in the maritime continent part has considerable interannual fluctuation ( e.g. Webster et.al. 1998 ; McBride 1998 ) . Many research workers ( McBride and Nicholls 1983 ; Nichols 1985 ; Nichols 1981 ) noted the important relationship between rainfall in the Indonesia-northern Australia country and the ENSO. This relationship is sometimes manifested in the rampant wood fires and the ensuing haze in Indonesia during El-Nino status ( Nichol 1998 ) . However, the ENSO-Indonesian rainfall relationship is strongest during the northern summer and autumn, which are the dry and transitional seasons severally ( Aldrian et.al. , 2003 )
Chang et.al ( 2004 ) suggested that the low correlativity between all-Indonesian rainfall during the moisture monsoon season and ENSO reported by old surveies may be in portion due to the averaging of rainfall across the eastern ( E of 112oE ) and western ( west of 112oE ) parts that have opposite features. In add-on, Indonesia part has a strong seasonal reversal of air currents that is frequently coupled with one-year fluctuation of rainfall, peculiarly near the equator where the prevailing air current is westerly during the wet season of boreal winter, which reach the maximal rainfall and easterly during the dry season of boreal summer ( McBride 1998 ; Hamada et.al. 2002, Ramage 1971 in Chang et.al. 2004 ) .
1.5. Indonesian Sea Surface Temperature
The greatest variableness of SST in the eastern Indonesian seas occurs in the eastern Banda and the Arafura Sea. The SST averaged over the Banda Sea from 1982 to 2000 shows an one-year rhythm from 29 oC – 30 oC from late November to May period to 26.5 oC in August. Furthermore, the SST variableness is related to thermocline deepness alterations, which vary with the monsoon and with the ENSO ( Gordon and Susanto, 2001 ) .
A mechanism commanding the spacial and temporal graduated tables of SST in this part has been studied by Susanto et.al ( 2006 ) , which follows the Wyrtki ‘s ( 1961 ) function utilizing the Ekman theory. They found that the monsoon rhythm has affected to the climatological monthly SST. Colder temperatures are found in the boreal winter months ( December to March ) in the South China Sea due to the northwest monsoon and in June to August in the South of the equator due to the sou’-east monsoon. Meanwhile, during the extremums of sou’-east monsoon, from June-September, colder temperatures are observed in the Arafuru Sea, Banda Sea and off the southern portion of the Jawa-Nusa Tenggara Island concatenation. Strong south easterly winds induce divergency along the seashores of the Jawa-Nusa Tenggara Island concatenation and within the Banda Sea, and generate upwelling, cut downing the SST. In add-on, strong air currents enhance perpendicular commixture, besides cut downing the SST.
Furthermore, Susanto et Al. ( 2006 ) investigated the forms of ocean colour variableness and how physical procedures affect those forms in the Indonesian seas by utilizing 6 old ages ( 1998-2003 ) of satellite-derived ocean colour ( SeaWiFS ) and 7 old ages of sea surface temperature ( AVHRR ) and sea surface air current ( ERS1/2, NSCAT, and QuikSCAT ) . During the southeast monsoon, easterly winds bend and go southwesterly to the North of the equator. Similarly, during the northwest monsoon, winds to the North of the equator are northeasterly and go northwesterly in the southern hemisphere.
For short term planetary clime anticipation, the SST anomalousnesss associated with ENSO are recognised as the most dominant forcing factor ( Trenberth 1998 ; Annamalai and Liu 2005 ) . However, Godfrey ( 1996 ) explained the correlativity of Indonesian SST with ENSO is non principle. Nicholls ( 1989 ) found a form of SST anomalousness that was extraneous to the Southern Oscillation Index, which correlated closely with anomalousnesss of southern Australian rainfall. This form had a dipole form, with one pole in the center of the Indian Ocean and the other in Indonesian seas. Godfrey ( 1996 ) suggested that climatically this form provides extra empirical indicant that the little Indonesian SST anomalousnesss are rather important. Godfrey ( 1996 ) based on Allan and Haylock ( 1993 ) probe explains that SST alterations in Indian Ocean were affected by Indonesian Throughflow ( ITF ) .
1.6. The Makassar Strait
Many research workers observed the Makassar Strait since it is the chief waterway of H2O through the Indonesian Seas that known as ITF ( Ffield and Gordon 1992 ; Illahude and Gordon 1996 ; Gordon and Susanto 1999 ; Waworuntu et al. , 1999 ) . Bathymetrically, the Makassar Strait is shallow in the West but over 2000 thousand deep in the E where it is connected straight to the Sulawesi Sea in the North. Still, the Makassar Strait is a passage between eastern part and western part, which has a sill at about 550 m in the southern terminal the sound ( Tomczak and Godfrey, 2003 ; Gordon et.al 1994 ; Wyrtki 1961 ) .
Refering SST and its relation to monsoon, Illahude and Gordon ( 1996 ) describe that during SEM the SST in the Makassar Strait is largely between 28,2 oC and 28,7 oC, which indicates as a portion of warm pool of the tropical Pacific Ocean. Meanwhile during NWM the SST making values around 29,4 oC. Furthermore, the SST in the northern Makassar Strait is higher than the South for both monsoon periods. Meanwhile, vertically the chief Makassar Strait thermocline bed is discovered between 60 and 300 dbar with the temperature worsening from 27 oC to 10 oC and a gradient of 0,7 oC/m.
The Makassar Strait surface currents tend to southward and its velocity is slow during the NWM period ; nevertheless, the air current is northern air current. Gordon et.al. ( 2003 ) suggested that the decrease of the current velocity is perchance caused by the strong Java Sea eastward current that inhibits the due south Makassar Strait during the NWM. Furthermore, the due south Makassar Strait current velocity is faster during the SEM. The strong due south Makassar Strait current push back the low salt and low temperature of surface H2O back to the Java Sea.
Other oceanographic parametric quantities are H2O mass, tides and intraseasonal variableness that are investigated by research worker. Water mass analysis confirms that the Makassar Strait is the major way for the ITF from the equatorial Pacific path to the assorted export transitions of the Nusa Tenggara Islands discharge ( Lombok, Ombai and Timor ) to the eastern Indian Ocean ( Gordon and Fine 1996 ; Susanto and Gordon 2005 ) . On the other manus, Susanto et.al ( 2000 and 2001 ) investigated intraseasonal variableness and tides along the Makassar Strait utilizing spectral and clip frequence analysis. They found that intraseasonal variableness likely is a response to remotely Kelvin moving ridges from Indian Ocean through Lombok Strait and to Rossby moving ridges from the Sulawesi Sea. Furthermore, semidiurnal and diurnal tides are dominant characteristics, with higher semidiurnal and lower diurnal in the north compared to the South.
1.7. Aims and Purposes:
Although the monsoon has such a strong consequence on the sea, non many surveies on the monsoonal belongingss and its consequence to the SST of Indonesian Waterss in comparing to other atmospheric surveies. This survey besides developed from the cognition that clime variableness is related to the kineticss of the ocean and the ambiance, both regionally and globally. Knowledge of the influence that these procedures have is of import for the endurance of agricultural viability, population and economic system. Hence the purpose of this survey is to:
Improve understanding the ocean-atmosphere procedures within Indonesian Seas, particularly within the Makassar Strait.
Analyze the dynamical and statistical significance of SST variableness during monsoon periods ( NEM and SEM ) .
Supply links between the large-scale manners of SST variableness and clime events over Indonesia.
Chapter 2 Datas
In order to back up the research, the undermentioned information sets will be used.
2.1. Sea Surface Temperature
The SST informations will be obtained from the International Comprehensive Ocean-Atmosphere Data Set ( ICOADS ) . The ICOADS information is provided by National Oceanic and Atmospheric Administration ( NOAA ) Earth System Research Laboratory/Physical Sciecne Division ( ICOADS, 2007 ) . The SST information is a reconstructed monthly mean SST informations set from the aggregation of surface Marine informations for the universe ocean with a declaration of 1o latitude x 1o longitude ( ICOADS 2007 ) . Furthermore, the monthly mean SST information set will cross the period 1960 to 2002. The SST will be averaged in 10 degree latitude-longitude boxes ( e.g. 5oS – 5oN, 110oE – 120oE ) . Meanwhile, the in situ informations will be acquired from International Nusantara Stratification and Transport ( INSTANT ) undertaking in peculiar location, which provides moorage and CTD informations in the Makassar Strait.
Figure 3. Indonesia map and analyze country in this research ( bluish box ) .
To place the advection of wet across the part during monsoon periods, seasonal complexs of air current anomalousnesss at the 850hPa degree are bring forthing for the relevant periods. The air current informations will be achieved from 40 twelvemonth European Centre for Medium scope Weather Forecast ( ECMWF ) reanalysis ( ERA-40 ) informations sets ( ECMWF 2007 ) . ERA-40 is a reanalysis of meteoric observations in period of clip 1957 to 2002 produced by the ECMWF and other establishment, which is 45-year 2nd coevals re-analysis informations set. The chief end of this information set is bring forthing the best possible set of analyses, given the altering observing system and the available computational resources. The ERA-40 850hPa air currents come as separate meridional ( V ) and zonary ( u ) constituents on a 2.5o latitude x 2.5o longitude grid ( Uppala et.al, 2005 ) .
2.3. Precipitation and Rainfall
The precipitation and rainfall informations will be derived from Indonesia Meteorology and Geophysics Agency ( BMG ) . This information set contains Indonesian monthly sum rainfall.
Furthermore, to back up this local information set we use the information set that provided by Global Historical Climate Network ( GHCN ) ver.2. ( Peterson and Vose 1997 ) . Another information set is the 1950-1997 Indonesian rainfall studies, which was made available by J. McBride of the Australian Bureau of Meteorology Research Centre. The studies more accurately stand for the rainfall at each local station than the GHCN informations within Indonesia part.
2.2. Calculated indices
A monthly value of the Dipole Mode Index ( DMI ) is computed by taking the difference between the climatological mean and monthly mean SST averaged over the spacial extent of the part.
Chapter 3 Methodology
The undermentioned research methods will be used to look into the variableness of SST during monsoon period in the Makassar Strait.
3.1. Chief Component Analysis ( PCA )
Chief constituent analysis is a tool and a technique for compacting the variableness in the clip series informations of physical field ( Preisendorfer, 1988 ; Emery and Thomson 1997 ) . In climatology field, which has spacial complexness and reading trouble, PCA represents these complex fluctuations such that reading is made easier ( Preisendorfer 1988 ) . In add-on, PCA gives the most efficient description of the ascertained variableness by cut downing big informations sets to a few dominant manners. This is multivariate statistical analysis method in conditions anticipation that introduced by Lorenz ( 1956 ) and became popular in the atmospheric analysis so by term Empirical Orthogonal Function ( EOF ) . This method has wide application non merely in oceanology but besides in weather forecasting ( Wilks 2006 ; Emery and Thomson 1997 ) .
This method is chosen due to its ability to supply a compact description of the spacial and temporal variableness of informations series. Harmonizing to Emery and Thomson ( 1997 ) , there are two primary methods for calculating the PCAs/EOFs for a grid of clip series of observations. First, the spread matrix method that uses a ‘brute force ‘ that is decomposed into characteristic root of a square matrixs and eigenvectors utilizing standard computing machine algorithms ( Preisendorfer, 1988 ) . Second, the computationally efficient remarkable value decomposition ( SVD ) method which derives all the constituents of the EOF analysis ( eigenvectors, characteristic root of a square matrixs and time-varying amplitudes ) without calculation of the covariance matrix ( Kelly 1988 in Emery and Thomson 1997 ) .
In this present research we are traveling to take the 2nd method since it required computational velocity and stableness through SVD attack.
Given a information vector ten, that contains observation of a variable at a figure of different locations, PCA finds
Survey on ocean clime variableness ( 1960-2002 ) in the Makassar Strait during monsoon periods.
The Maritime Continent consists of 17.508 islands ( Indonesian Hydro-Oceanographic Office 2003 ) , with five chief islands with an country bigger than 132.000 km2. These chief islands are Kalimantan, Sumatra, Sulawesi, Irian Jaya and Java. Furthermore, the population in this state is about 206 million ( population nose count 2000 ) .
Aldrian and Susanto ( 2003 ) have introduced a regionalisation method, ‘double
correlativity method ( DCM ) ‘ , based on the one-year rainfall rhythm or the one-year mean
variableness. The consequence of the DCM is three clime parts as shown in Figure 1-3a.
The average one-year rainfall rhythms of each part and their interannual criterion
divergences are described in Figure 1-3b. Region A ( solid line ) covers south Indonesia
from Sumatra to Timor Island, parts of Kalimantan, parts of Sulawesi, parts of Irian
Jaya. Region B ( short dashed line ) is located in northwest Indonesia ( near to the
Asiatic continent ) and Region C in Maluku and parts of Sulawesi ( near to the western
Pacific part ) .
The part ‘maritime continent ‘ was defined by Ramage ( 1968 ) to dwell of Malaysia, Indonesia and the surrounding land and pelagic countries of the equatorial western Pacific between 10oS – 10oN.
Review of old research workers:
Gordon ( 2006 ) suggested that the surface current within the Java sea, the Makassar sound, the Flores sea and the Banda sea are modulated by the monsoonal air current.
Although the monsoon has such a strong consequence on the sea every bit good, surveies on the monsoonal belongingss of Indonesian Waterss have been really rare in comparing to similar atmospheric surveies.
This explains that the SST is the chief pelagic parametric quantity for the ambiance that provides the nexus between two constituents of a tightly coupled system ( Tomczak and Godfrey, 2003 ) .
In order to give wide description about the clime of the part based on the rainfall variableness, Aldrian and Susanto ( 2003 ) found the three clime parts harmonizing to the average one-year precipitation forms utilizing the dual correlativity method ( DCM ) . This method based on the one-year rainfall rhythm or the one-year mean variableness. The consequence of DCM is three parts as shown in Figure 1.1. Region A ( solid line ) covers south and cardinal Indonesia from south Sumatra to Timor Island, parts of Kalimantan, parts of Sulawesi and parts of Papua Island. Region B ( short dashed line ) is located in northwest Indonesia ( near to the Asian continent ) and Region C in Maluku and parts of Sulawesi ( near to the western Pacific part ) .
Region A, which covers the largest country, is the dominant form over Indonesia. This part has one extremum and one lower limit and experiences strong influences of two monsoons. Those are the wet northwest monsoon from November to March ( NDJFM ) and the dry sou’-east monsoon from May to September ( MJJAS ) . Region B has two extremums, in October-November ( ON ) and in March to May ( MAM ) . Those two extremums are associated with the due south and northbound motion of the Inter Tropical Convergence Zone ( ITCZ ) . There is no clear ground why the extremum in ON is much higher than that of MAM. There is a possible influence of a cool surface current from the north out of the South China Sea during January-March ( JFM ) that suppresses the rainfall sum. Otherwise the one-year rhythm of Region B would be similar to that of Region A ( Aldrian and Susanto 2003 ) .
Furthermore, Aldrian and Susanto 2003 explained that the part C has one extremum in June to July one lower limit ( NDJF ) . The JJ extremum in Region C is about 10 mm/day, while the extremums in Region A and B are 10.7 and 10.3 mm/day severally. The lower limit in part A is the lowest and reaches a average below 3.3 mm/day. Thus, part A is the driest part during the dry season in JAS and the wettest part in December. Region C, in com-parison to the other two, has a alone one-year rhythm. The other two parts have its extremums near in the terminal of the twelvemonth, while the Region C ‘s extremum is in the center. There is a strong grounds of the possibility of ocean influence in Region C. Region C, or Maluku, is along the eastern path of the Indonesian Throughflow ( ITF ; a H2O transition from the Pacific to the Indian Ocean via Indonesian Seas ) .
The ITF flows chiefly through the Makassar Strait with a little portion fluxing through the Maluku Sea ( Gordon et al. , 1999 ) . The ITF in Maluku brings sea surface current from the warm pool country, which is located nor’-east of Irian Jaya Island ( New Guinea ) .
Rainfall variableness in this part is really complex and is considered as the ‘chaotic portion ‘ of the monsoon variableness ( Ferranti 1997 ) .
In add-on, the interannual variableness of monsoon rainfall over India and the Indonesian-Australian part shows the two-year variableness.
The monsoon government creates such a strong seasonality of the features of the environment that the alternation of the North and south air currents wholly reorganises the surface circulation this can be expected to hold a strong ecological impact interannual variableness issues ( Webster et.al, 1998 ) .
at each latitudes, the one-year temperature alterations are controlled by alterations in available solar radiation and heat loss that merged with the heat capacity of the surface stuff ( Duxbury et.al 2002 ) .
Where vaporization at the sea surface is high, at tropic and bomber tropic latitudes, there is a high rate of remotion of heat energy and big measures of H2O vapor enter the ambiance. Furthermore, the oceans play a important function in bracing the surface temperature of the Earth. They can hive away and let go of big measures of heat without big alterations in temperature centrists surface temperature both seasonally and over the twenty-four hours and dark rhythms ( Duxbury et.al 2002 ) .
characterised by monsoonal air currents and high rainfall. Winds blow from the South, swerving across the equator with a westbound constituent in the South and an eastbound constituent in the North, during May to September and in about precisely the opposite way during November to March ( Tomczak and Godfrey 2001 ) . During the southeast monsoon from May to September, the easterly and southward air current blows in the Java Sea and the Makassar Strait, severally. Furthermore, during the northwest monsoon from November to March, the Java Sea and the Makassar Strait wind waies are changed from easterly and southward to westerly and northwards, severally.
Annual rainfall in surplus of 1000 millimeter occurs in many of the Indonesia countries and one-year minimal temperatures are normally more than 20 & A ; deg ; C other than in the Highlandss. Rainfall in the part is highest on the highland countries, notably of cardinal Kalimantan ( Borneo ) , cardinal Sumatra, Java and Papua. Some topographic points receive more than 3000 millimeter of rain yearly. By contrast, parts of the Lowlandss, coastal countries and other countries in rain-shadows receive far less rain ( less than 1000 mm/year ) , and may see terrible H2O deficits and drouths.
Harmonizing to Lau et.al, ( 1997 ) , the rainfall sum is additions with SST although the addition is non additive below 29 oC. Meanwhile, they showed that the above 29.6 oC the addition of local SST causes a lessening in the maximal rainfall sum.
The local SSTA during ENSO tend to be of opposite mark to those in eastern Pacific and western Indian Oceans during the dry season but of the same mark during the moisture season ( Rasmusson and Carpenter 1982 ) .
There is sweetening of the equatorial Pacific SST gradient and Walker circulation from the dry season to the passage season and a rapid decrease in the correlativity between SSTs and rainfall during the moisture season and decrease in spacial coherency of rainfall across Indonesia in traveling from dry season to the moisture season ( Chang, et.al. 2004 )
Meanwhile, during normal conditions, go uping air creates lower surface force per unit area and high rainfall over the western Pacific originating from the Walker Circulation and the development of El-Nino conditions ( Colls and Whitaker 2001 ) .
The maritime continent is frequently considered to be a portion of the Asiatic monsoon government because maximal rainfall over most of the part occurs during boreal winter ( Ramage 1971 in Chang et.al. 2004 )
In add-on, Susanto et.al ( 2006 ) shows that the lowest overall air current velocities or weave stress appear in April, which clearly represents the month of passage between the northwest and southeast monsoons. The southeast monsoon Begins in May, with air currents in the Arafuru Sea and the eastern Indian Ocean indicating foremost. The zone of maximal air current moves north-west in the Indian Ocean along the Nusa Tenggara Island concatenation from Jawa to Sumatra. Easterly winds spread and escalate through June making their upper limit in July and August, and so they begin to lessen. A set of really low air current velocity brackets a zone somewhat north of the equator. Meanwhile, during the northwest monsoon ( showery season ) , the precipitation is higher than the vaporization, so that the sea surface salt and sea surface temperature go lower. On the other manus, during southeast monsoon ( dry season ) , the vaporization is higher than the precipitation. Hence, sea surface salt and sea surface temperature are increased ( Sutanto et al. , 2006 ) .
However, harmonizing to Roy ( 1996 ) , sea surface temperature variableness in the western Indonesian part does n’t to be closely associated with ENSO events.
On the other manus, Godfrey ( 1996 ) believed that SST alteration by tidal commixture in the Indonesian seas likely rather indispensable constituent of the ENSO unsteadiness system.
Wyrtki ( 1961 ) gives detail description of the part ‘s complex plumbing. The Indonesian seas can be sub-divided into the following two major parts ; the shoal ( & A ; lt ; 75 m ) western part over the Sunda shelf, chiefly the Java sea and the South China sea, and the eastern part consisting of a series of deep ( & A ; gt ; 1000 m ) basins connected by shallower Sillss.
In the ensuing survey, the ocean has a map to brace the surface temperature of the Earth due to its ability to maintain and dispatch heat without big alterations in mean temperature ( Duxbury et.al. , 2002 ) . The ocean, furthermore, is the dominant beginning of atmospheric wet and the latent heat released when this wet condenses into rain or snow in the primary drive force for the atmospheric circulation. The air currents in bend affect the SST in several different ways and the SST mostly controls the magnitude and the spacial distribution of the wet flux to the ambiance. This explains that the SST is the chief pelagic parametric quantity for the ambiance ( Tomczak and Godfrey, 2003 ) . Therefore a treatment of the ocean and the universe ‘s clime has to get down with a elaborate apprehension of the SST distribution and Indonesian part is one of the of import places that need to be investigated.
Susanto et.al ( 2000 and 2001 ) investigated intraseasonal variableness and tides along the Makassar Strait utilizing spectral and clip frequence analysis. and Atmospheric Dataset ) during 1950-1990 periods. He found the minimal temperature ( 27.5 & A ; deg ; C ) observed in January and February in the Natuna sea High sea surface temperature ( & A ; gt ; 25 oC ) and little seasonal amplitude ( & A ; lt ; 3 oC ) are the dominant features of Southeast Asiatic Waterss ; furthermore, their spacial distribution is rather unvarying, with little gradient over the full part.
The Java Sea lies on the Sunda Shelf with an mean deepness of about 40 m and is a semi-closed sea located between Sumatra in the West, Kalimantan in the North, and Java in the South ( Figure 1-6 ) .
On the other manus, H2O mass analysis confirms that the Makassar Strait is the major way for the ITF from the equatorial Pacific path to the assorted export transitions of the Nusa Tenggara Islands discharge ( Lombok, Ombai and Timor ) to the eastern Indian Ocean ( Gordon and Fine 1996 ; Susanto and Gordon 2005 ) .
A portion of this H2O besides exits to the Indian Ocean through the Lombok Strait ( Murray and Arief 1988 ) . Prior to come ining the Banda Sea, H2O which takes the eastern path ( east of Sulawesi Island ) is largely from the South Pacific ( Van Aken et.al. , 1988 ; Gordon 1995 ; Ilahude and Gordon, 1996 ; Gordon and Fine 1996 ; Hautala et.al, 1996 ) . It flows via the Halmahera and the Seram Sea to the Banda Sea and the Timor Sea. Most surveies abandon the ITF from the western Pacific through the South Cina Sea, the Karimata Strait and the Java Sea due to the superficiality of the shelf ( average deepness of Java Sea is about 40 m ) ( Waworuntu et.al 2000 ; Putri 2005 ) .
Eastern Indonesian Seas
Oceanographic surveies ;
In this part, there are many oceanographic surveies, most of them are the Indonesian Throughflow ( ITF ) issue. The ITF transportation warm, low salt Waterss from the western Pacific into the Indian Ocean ( Gordon and Fine 1996 ; Sprintal et Al 2004 ) . There are two chief ITF tracts in the Indonesian Seas ; the western path and eastern path. The H2O that flows through the western path is largely from the North Pacific. It flows through the Makassar Strait, the Flores Sea and the Banda Sea before go outing to the Indian Ocean via the Timor Sea and the Ombai Strait ( Fine, 1985 ; Ffield and Gordon 1992 ; Fieux et.al, 1994, 1996 ; Gordon et.al. , 1994 ; Bingham and Lukas 1995 ; Ilahude and Gordon 1996 ; Gordon and Fine 1996 ) .
1.6.1. Oceanographic status
1.6.2. Meteorology status
Manners of clime variableness
Sea Level fluctuations and Indonesian throughflow during ENSO old ages
El Nino Southern Oscillation ( ENSO ) is the most celebrated interannual clime variableness in the universe clime. It is good known that ENSO is associated with lay waste toing dhroughts over western tropical Pacific, torrential inundations around the eastern tropical Pacific and unusual conditions form over the universe ( Nkendirim 2000 ) . El-Nino events occur irregularly at intervals of 2 to 7 old ages, although the norm is about one time every 3 to 4 old ages ( McPhaden 1993 ) . Throughout the strong 1997 to 1998 ENSO old ages peculiarly during the northwest monsoon, Indonesian part had terrible drouth ( Kumar et.al. 1999 ) .
The chief job of the ENSO is the development of near-equator sea surface temperature ( Harrison 1990 ) .
In the western Pacific warm pool is migrated eastward with the autumn down of the trade air currents ( McPhaden 1999 ) . Based on the higher correlativity between SST and sea degree and between SOI and sea degree, Nerem and Mitchum ( 2001 ) developed fake long-run series of planetary average sea degree fluctuations. A big addition in planetary mean SST was observed since 1982 and the largest changing occurred during the ENSO event from 1997 to 1998 ; moreover, SST has changed about 0,35 oC ( Nerem 1999 ; Nerem and Mitchum 2001 ) .
The feature of Indonesian throughflow was affected by ENSO. Ffield et.al. ( 2000 ) found the high correlativity between the thermocline and the due south Makassar conveyance ; moreover, Ffield ( 2000 ) besides found that SOI has extremely correlated with thermocline. From these relationships, during the El Nino period the sum of the due south conveyance ( 0 m – 200 m ) is high during the El-Nino period and low during the La Nina ( Sofian et.al. , 2006 ) . On the other manus, Waworuntu et.al ( 2000 ) explains that the support of the force per unit area gradient in the lower thermocline between the Pacific Ocean and the Indonesian Seas during the La-nina period could increase the flow in the deeper thermocline from the Banda Sea to the Makassar Strait. In the eastern Indian Ocean, the important interannual variableness of the upwelling along the southern seashore of Java and Sumatra Island is linked to the ENSO by manner of the Indonesian throughflow and by irregular easterly air current ( Susanto et al 2001 ) .
Southward conveyance within the Makassar Strait shows high correlativity with the thermocline. During high ( low ) temperature, the volume conveyance is besides high ( low ) ( Ffield et al. 2000 ) . Gordon et.al ( 2003 ) shows that the consequence from the measuring utilizing MAK-1 and MAK-2 moorages that the largest volume conveyance was occurred during the La-Nina period and acquiring smaller during the El-nino period. The direct measurings from MAK-1 and MAK-2 moorages were 12,5 Sv during the La-nina months of December 1996 through February 1997, and 5,1 Sv during El Nino months of December 1997 through February 1998 ( Gordon et.al, 1999 )
1.2.4. Indian Ocean Dipole
1.3. Oceanography of the Indonesian seas
We will reexamine the oceanographic researches conducted in the internal Indonesian seas. Figure 1-5 illustrates the distribution of reviewed documents collected from many beginnings. Deducing from those documents, there are two chief parts that intensively have been studied, foremost, western Indonesian seas ( western of 112oE ) and 2nd, eastern Indonesian seas ( Eastern 112o Tocopherol ) ( Chang et.al. 2004 ) . The western Indonesian seas part covers the Java Sea which is the largest sea in this part, Karimata Strait, Natuna Sea, Sunda Strait, and Malaka Strait. Meanwhile, the eastern Indonesian Seas covers the Banda Sea, Flores Sea, Maluku Sea, Seram Sea, Halmahera Sea, Savu Sea, and Arafura Sea. Correspondingly, the reappraisals on oceanographic status and fisheries/marine biodiversity for western and eastern Indonesian Seas are given in the following twosome sub-chapters.
Western Indonesian seas
I. Oceanographic Condition
In this part, Gordon ( 2005 ) explains that the monsoonal air currents shift the lowest surface salt into the Java Sea and the southern Makassar Strait from January to March, and into the South China Sea from July to September.
Refering the largest sea in this country, which is the Java Sea, Putri ( 2005 ) explains that the exchange of H2O mass to/from the sea is through the Karimata Strait that is the transition in the western portion. Meanwhile, in the eastern portion of the Java Sea, there is a transition between the Java Sea and the eastern portion of the Indonesian Seas. In add-on, Sunda Strait is a transition between the Java Sea and the Indian Ocean in the southern portion of the Java Sea.
Hydrographically, the perpendicular temperature in the Java Sea, which has an mean deepness of about 40 m, is good assorted as typical for shallow Waterss.
With a population of about 206 million, Indonesia chiefly depends on rain-fed agribusiness for nutrient grains. Seventy per centum of the one-year rainfall over Indonesia comes from the monsoon rain.
when this wet condenses into rain or snow in the primary drive force for the atmospheric circulation. The air currents in bend affect the SST in several different ways and the SST mostly controls the magnitude and the spacial distribution of the wet flux to the ambiance. This explains that the SST is the chief pelagic parametric quantity for the ambiance ( Tomczak and Godfrey, 2003 ) . Therefore a treatment of the ocean and the universe ‘s clime has to get down with a elaborate apprehension of the SST distribution and Indonesian part is one of the of import places that need to be investigated.
Chief constituent analysis is a tool and a technique for compacting the variableness in the types of clip series informations the analysis of the spacial or temporal variableness of physical field ( Preisendorfer, 1988 ) . In climatology field, which has spacial complexness and reading trouble, PCA can stand for these complex fluctuations such that reading is made easier ( Preisendorfer 1988 ) . In add-on, PCA gives the most efficient description of the ascertained variableness by cut downing big informations sets to a few dominant manners. This is multivariate statistical analysis method in conditions anticipation that introduced by Lorenz ( 1956 ) and became popular in the atmospheric analysis so by term Empirical Orthogonal Function ( EOF ) ( Wilks 2006 ; Emery and Thomson 1997 ) .
With an improved apprehension of the ocean processes within the Indonesian seas and of the variableness of the SST, we can expect enhanced apprehension of the importance of the ocean ‘s function in this part in regulating ENSO and the Asiatic Monsoon.
MJO forces surface current that thrust SST fluctuations at the eastern border of the warm pool ( Kessler et.al 1995 )