RAIN MICROSTRUCTURE IS AN IMPORTANT ASPECT TO UNDERSTAND THE DYNAMICS AND MICROPHYSICS CHARACTER OF THE CLOUDS. RAIN MICROSTRUCTURE IS CHARACTERIZED BY THE DISTRIBUTION OF SIZE, SHAPE AND FALL VELOCITY OF RAINDROP. RAINDROP SIZE DISTRIBUTION (DSD) EXPLAIN THE DETAIL OF MICROPHYSICAL PROCESS BECAUSE IT REPRESENTS PROCESS OF RAIN TO THE SURFACE. ONE OF THE PHENOMENA THAT INFLUENCES THE RAIN PATTERNS IN INDONESIA IS MADDEN JULIAN OSCILLATION (MJO). THEREFORE, OBSERVING RAIN MICROSTRUCTURE WITH ITS RELATION TO MJO CAN DETERMINE THE DIFFERENCES OF RAINFALL CHARACTERISTIC AND MICROPHYSICAL PROCESSES DURING ACTIVE AND INACTIVE MJO PERIOD. THE DATA USED IN THIS STUDY ARE MICRO RAIN RADAR (MRR), DISDROMETER AND REAL-TIME MULTIVARIATE (RMM) INDEX DATA. THE PERIOD/DATE SELECTION OF ACTIVE MJO EVENT PERFORMED USING RMM INDEX METHOD THAT IS MORE THAN 1 IN PHASES 4 AND 5 AND OTHERWISE FOR INACTIVE MJO. TYPES OF THE RAIN ARE DIVIDED INTO CONVECTIVE AND STRATIFORM RAIN BASED ON DISDROMETER DATA. RAIN MICROSTRUCTURE IN THIS STUDY FOCUSES ON DSD FROM MICRO RAIN RADAR AND DISDROMETER DATA ANALYSED WITH LIQUID WATER CONTENT PROFIL, FALL VELOCITY, REFLECTIVITY AND RAIN RATE FROM MMR. IN ADDITION, THERE ARE PARAMETERS OF DSD WHICH IS MASS-WEIGHTED DIAMETER (DM) AND TOTAL CONCENTRATION (NW) CALCULATED USING THE MOMENT AND GAMMA DISTRIBUTION METHOD. THE RESULT SHOW THAT DSD AND OTHER PARAMETERS ARE GREATER DURING INACTIVE MJO PERIOD. THIS MEANS THAT PROCESS OF COLLISION-COALESCENCE, EVAPORATION AND UPDRAFT
IS DOMINANT DURING INACTIVE MJO PERIOD.

 

KEY WORDS : MICRO RAIN RADAR, DISDROMETER, MICROSTRUCTURE, MICROPHYSICS, MJO

BASED ON PREVIOUS RESEARCH THAT HAS BEEN DONE, ABOUT THE IMPACT OF FOREST FIRE ON AIR QUALITY AND VISIBILITY IN PALANGKA RAYA, KALIMANTAN, THE RESULT ARE OBTAINED THAT DURING FOREST FIRES IN PALANGKA RAYA AIR QUALITY HAS DECREASED UNTIL DANGEROUS LEVELS AND REDUCES VISIBILITY TO 0.1 KM FROM THE NORMAL CONDITION AROUND 7.7 KM – 6.4 KM. THIS CONDITION WAS VERY DANGEROUS TO BOTH HUMAN HEALTH AND THE ENVIRONMENT, BECAUSE VISIBILITY CAN BE SIGNIFICANTLY ASSOCIATED WITH AIR QUALITY, AND CAN BE TAKEN AS A HIGHLY RELEVANT VISUAL INDICATOR OF AIR POLLUTION LEVEL. THIS RESEARCH WAS CARRIED OUT AS A CONTINUATION OF PREVIOUS RESEARCH BY FOCUSING ON CORRELATION BETWEEN PM10 AND VISIBILITY, BY ANALYZING SEASONAL AND ANNUAL, CORRELATION DURING FOREST FIRES IN PALANGKA RAYA FROM 2000 - 2014. THE CORRELATION WILL LATER BE USED TO PREDICT PM10 CONCENTRATION IN PALANGKA RAYA. THE RESULT SHOWED  THE CORRELATION BETWEEN PM10 AND VISIBILITY IN PALANGKA RAYA TENDS TO FORM A LOGARITHMIC FUNCTION WITH THE COEFFICIENT CORRELATION R = 0.90. THE SEASONAL PATTERN SHOWED THAT THE BEST CORRELATION BETWEEN PM10 AND VISIBILITY OCCOURS IN DRY SEASON (JJA AND SON), WITH THE COEFFICIENT CORRELATION R = 0.88 (JJA) AND R = 0.96 (SON). CORRELATION DURING THE FOREST FIRE USING CONCENTRATION VALUE ABOVE THE VALUE WHEN THERE IS NO FOREST FIRES (NORMAL CONDITION), WHICH IS 23.36 ΜG/M³. THE RESULT SHOWED CORRELATION COEFFICIENT R = 0.88. THE PREDICTION OF PM10 CONCENTRATION USING THE EQUATION FROM CORRELATION PM10 AND VISIBILITY DURING THE FOREST FIRES NOT GIVE A GOOD RESULTS BECAUSE THE ERROR VALUE IS STILL QUITE LARGE, BUT THE CORRELATION BETWEEN PM10 AND PM10 PREDICTION GIVE A GOOD CORRELATION COEFFICIENT R = 0.88. 

KEYWORDS: CORRELATION, PM10, VISIBILITY, CONCENTRATION

 

THE USE OF THE OCEANIC NINO INDEX (ONI) HAS OFTEN BEEN USED TO PREDICT INDONESIA'S MONTHLY RAINFALL CHARACTERISTIC (MRC).  HOWEVER, THE CORRELATION FOR EAST JAVA'S MRC IS CONSIDERED UNSATISFACTORY, SO ANOTHER ALTERNATIVE REGION IS NEEDED. WE USED THE MEDIAN OF THE MRC CATEGORY FROM THE INTERPOLATED RASTER OF THE MONTHLY RAINFALL FOR THE PERIOD JANUARY 1991 TO JANUARY 2020.  THE MEDIAN WAS ANALYZED USING MULTI LAG SPATIAL CORRELATION (1 TO 6) WITH REYN_SMITHOIV2 SEA SURFACE TEMPERATURE (SST) ANOMALY DATA.  NON-CATEGORICAL MEDIAN PLOTS ALONG WITH ONI WERE USED TO IDENTIFY PATTERNS.  WE PROPOSE THE NEAR MARITIME CONTINENT (NMC) REGION AS AN ALTERNATIVE.  PLOT ANALYSIS OF MONTE CARLO SIMULATION RESULTS (1000 TIMES RESAMPLING) OF THE MEAN STANDARDIZED SPATIAL CORRELATION SHOWS THAT THE NMC HAS A SIGNIFICANTLY GREATER CORRELATION FOR LAG 1-4. AS FOR LAG 5-6, THE NINO 3.4 REGION HAS A HIGHER CORRELATION. THIS SHOWS THAT THE NMC HAS MORE INFLUENCE FOR EAST JAVA'S MRC PREDICTION FOR 1-4 MONTHS.  IN ADDITION, THE NON-CATEGORICAL MEDIAN PLOT MRC WITH ONI SHOWS AN IDENTICAL PATTERN WHEN ONI IS POSITIONED THREE STEPS LATE. THIS INDICATES THAT THE MEDIAN OF EAST JAVA'S MRC HAS POTENTIAL TO PREDICT ONI.

 

KEYWORDS : MRC PREDICTION, SST ANOMALY, ONI, NMC

CLIMATE CHANGE HAS BECOME A TOPIC OF INTEREST IN THE LAST DECADE. CHANGES THAT OCCUR GLOBALLY DO NOT NECESSARILY HAVE AN EQUAL IMPACT ON ALL REGIONS. RAINFALL IS A VITAL ELEMENT IN OBSERVING CLIMATE CHANGE. ANALYSIS OF RAINFALL TRENDS IS USEFUL IN STUDYING THE IMPACTS OF CLIMATE CHANGE ON WATER AVAILABILITY AND AGRICULTURE. THIS STUDY EXAMINES VARIATIONS AND CHANGES IN RAINFALL ON WEST KALIMANTAN WITH FOCUSED AREA ON MEMPAWAH AND KUBU RAYA DISTRICTS IN 2000-2019. THE MANN-KENDALL (MK) TEST AND SEN'S SLOPE ESTIMATOR TEST THAT CAN DISTINGUISH BETWEEN RAINFALL VARIABILITY AND LONG-TERM MONOTONIC TRENDS WERE USED IN THE ANALYSIS AT 12 RAIN STATIONS. THE RESULTS OF THE ANALYSIS SHOW THAT THE TREND IS SEEN IN ALL RAIN STATIONS. MEMPAWAH REGION TENDS TO EXPERIENCE A DOWNWARD TREND IN ANNUAL RAINFALL, WHILE KUBU RAYA HAS AN INCREASING TREND IN ANNUAL RAINFALL. HOWEVER, THE TREND OF ANNUAL RAINFALL SHOWS A SIGNIFICANT CHANGE AT THE 95% CONFIDENCE LEVEL DETECTED ONLY AT ONE RAIN STATION(SUNGAI KUNYIT). WHILE MONTHLY RAINFALL TRENDS AT THE 95% CONFIDENCE LEVEL WERE DETECTED AT SEVEN LOCATIONS. FOUR LOCATIONS EXPERIENCED INCREASING TREND OF MONTHLY RAINFALL IN KUBU RAYA. DECREASING MONTHLY RAINFALL TRENDS OCCURRED IN TWO LOCATIONS IN MEMPAWAH AND ONE LOCATION IN KUBU RAYA.

NORTH SULAWESI, AS A PART OF THE AREA IN THE MARITIME CONTINENT, COULD BE A VULNERABLE REGION OF LIGHTNING ACTIVITY COMPARED TO NON-TROPICAL AREAS. THEREFORE, IT IS IMPORTANT TO STUDY LIGHTNING ACTIVITY IN ONE AREA TO IDENTIFY ITS SPATIAL AND TEMPORAL DISTRIBUTION. LIGHTNING ACTIVITY OVER NORTH SULAWESI HAS BEEN INVESTIGATED USING LIGHTNING DATA FROM WINANGUN GEOPHYSICAL STATION DURING 2019-2020. THE LIGHTNING FLASHES ARE THEN COMPARED WITH RAINFALL DATA WHICH IS OBTAINED FROM GSMAP SATELLITE AND ALSO SYNOPTIC CONDITIONS WHICH ARE OBTAINED FROM NCEP/NCAR REANALYSIS DATASET. THE RESULT SHOWS THAT THE MAXIMUM FLASH DENSITY DOES NOT OCCUR DURING THE RAINY SEASON (DECEMBER-JANUARY-FEBRUARY), BUT IT OCCURS DURING SEPTEMBER-OCTOBER-NOVEMBER WHICH ALSO HAS THE MAXIMUM SURFACE TEMPERATURE OVER THIS REGION. FROM THE 850 MB WIND DATA, IT IS ALSO KNOWN THAT MONSOONAL WIND CONTRIBUTES STRONGLY TO FORM CONVECTIVE CLOUDS WHICH TRIGGER THE LIGHTNING OCCURRENCE. IN THE LAND AREA OF NORTH SULAWESI, LIGHTNING OCCURS MORE FREQUENTLY IN TONDANO AND NORTH MINAHASA REGIONS. BUT OVERALL, LIGHTNING OCCURS MORE OVER SEA AREA COMPARED TO LAND AREA IN NORTH SULAWESI. 

 

KEYWORDS: LIGHTNING ACTIVITY, RAINFALL, SYNOPTIC CONDITIONS, NORTH SULAWESI.

 

EAST NUSA TENGGARA IS ONE OF PROVINCES IN INDONESIA THAT HAS BIG FOREST FIRE FOLLOWING SOME PROVINCES IN KALIMANTAN DAN SUMATRA. HOWEVER, FOREST FIRES IN EAST NUSA TENGGARA HAVE GOT LESS ATTENTION IN THE DISCUSSION OF FOREST FIRES IN INDONESIA. THIS PAPER STUDIES HOW THE FOREST FIRE IN EAST NUSA TENGGARA AND ITS SMOKE IMPACT ON THE ATMOSPHERIC ENVIRONMENT FROM 2015 TO 2019. THIS STUDY USED HOTSPOT, FOREST FIRE AREA, VISIBILITY, AND AEROSOL OPTICAL DEPTH (AOD) DATA, AND A STATISTICAL COMPARISON METHOD OF THESE DATA IN NTT AND IN KALIMANTAN AND SUMATRA.THE RESULT SHOWS THAT IT IS FOUND HOTSPOT FOR A SAME OF FOREST FIRE AREA IN EAST NUSA TENGGARA LESS THAN IN KALIMANTAN AND SUMATRA. THE FOREST FIRES IN EAST NUSA TENGGARA DO NOT HAVE AN ADVERSE IMPACT ON THE ATMOSPHERIC ENVIRONMENT SIGNIFICANTLY. FOREST BIOMASS BURNING IN EAST NUSA TENGGARA WHERE THERE ARE SAVANNA AREAS AND NO PEATLAND DOES NOT PRODUCE MUCH SMOKE. THE FOREST FIRE IN EAST NUSA TENGGARA HAS NOT AN IMPACT OF DECREASING OF VISIBILITY AND INCREASING OF AEROSOL OPTICAL DEPTH, WHILE IN SUMATRA AND KALIMANTAN VISIBILITY DECREASES DOWN TO 2 KM AND AOD INCREASES UP TO 2 DURING FIRE PEAK SEASON.