scholarly journals Analysis of climate indicator association with hotspots in Indonesia using heterogeneous correlation map

2021 ◽  
Vol 893 (1) ◽  
pp. 012041
Author(s):  
M Dafri ◽  
S Nurdiati ◽  
A Sopaheluwakan ◽  
P Septiawan
Keyword(s):  
Forest Fires ◽  
Cloud Formation ◽  
Wind Pattern ◽  
Australian Monsoon ◽  
Zonal Winds ◽  
East Wind ◽  
Monsoon Index ◽  
Java Sea ◽  
Climate Indicator ◽  
Local Cloud

Abstract In several regions, land and forest fires of Indonesia occurred almost annually during the drought season. The severity of Indonesia's drought season is mainly influenced by the Australian Monsoon, local cloud formation controlled by Sea Surface Temperature (SST) around Indonesia. Moreover, it affects the severity of land and forest fires itself indirectly. This research aims to examine the association of the Australian Monsoon and local SST with land and forest fires in Indonesia. This research uses the Australian Monsoon Index (AUSMI) as an indicator for the Australian Monsoon and SST in the Karimata Strait and the Java Sea as indicators of local SST. An indicator of land and forest fires that will be used is the number of hotspots. A heterogeneous Correlation Map (HCM) is used to describe hotspots associated with AUSMI and local SST. The analysis shows that the east wind pattern of AUSMI associated with hotspots in Indonesia, especially in years when zonal winds enter an upward phase more slowly. Karimata Strait’s SST is associate with hotspots in the coastal part of Riau. Meanwhile, Java Sea’s SST is associate with hotspots in Lampung, South Sumatra, Jambi, and Kalimantan.

scholarly journals High-resolution (375 m) cloud microstructure as seen from the NPP/VIIRS satellite imager

2014 ◽  
Vol 14 (5) ◽  
pp. 2479-2496 ◽  
Author(s):  
D. Rosenfeld ◽  
G. Liu ◽  
X. Yu ◽  
Y. Zhu ◽  
J. Dai ◽  
...  
Keyword(s):  
High Resolution ◽  
Forest Fires ◽  
Infrared Imaging ◽  
Cloud Formation ◽  
Cumulus Clouds ◽  
Marine Stratocumulus ◽  
Initial Stage ◽  
Microphysical Parameters ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. VIIRS (Visible Infrared Imaging Radiometer Suite), onboard the Suomi NPP (National Polar-orbiting Partnership) satellite, has an improved resolution of 750 m with respect to the 1000 m of the Moderate Resolution Imaging Spectroradiometer for the channels that allow retrieving cloud microphysical parameters such as cloud drop effective radius (re). VIIRS also has an imager with five channels of double resolution of 375 m, which was not designed for retrieving cloud products. A methodology for a high-resolution retrieval of re and microphysical presentation of the cloud field based on the VIIRS imager was developed and evaluated with respect to MODIS in this study. The tripled microphysical resolution with respect to MODIS allows obtaining new insights for cloud–aerosol interactions, especially at the smallest cloud scales, because the VIIRS imager can resolve the small convective elements that are sub-pixel for MODIS cloud products. Examples are given for new insights into ship tracks in marine stratocumulus, pollution tracks from point and diffused sources in stratocumulus and cumulus clouds over land, deep tropical convection in pristine air mass over ocean and land, tropical clouds that develop in smoke from forest fires and in heavy pollution haze over densely populated regions in southeastern Asia, and for pyro-cumulonimbus clouds. It is found that the VIIRS imager provides more robust physical interpretation and refined information for cloud and aerosol microphysics as compared to MODIS, especially in the initial stage of cloud formation. VIIRS is found to identify significantly more fully cloudy pixels when small boundary layer convective elements are present. This, in turn, allows for a better quantification of cloud–aerosol interactions and impacts on precipitation-forming processes.

scholarly journals Colorado air quality impacted by long-range-transported aerosol: a set of case studies during the 2015 Pacific Northwest fires

2016 ◽  
Vol 16 (18) ◽  
pp. 12329-12345 ◽  
Author(s):  
Jessie M. Creamean ◽  
Paul J. Neiman ◽  
Timothy Coleman ◽  
Christoph J. Senff ◽  
Guillaume Kirgis ◽  
...  
Keyword(s):  
Air Quality ◽  
Case Studies ◽  
Pacific Northwest ◽  
Long Range ◽  
Biomass Burning ◽  
Forest Fires ◽  
Surface Radiation ◽  
Cloud Formation ◽  
Synoptic Scale ◽  
Transport Pathways

Abstract. Biomass burning plumes containing aerosols from forest fires can be transported long distances, which can ultimately impact climate and air quality in regions far from the source. Interestingly, these fires can inject aerosols other than smoke into the atmosphere, which very few studies have evidenced. Here, we demonstrate a set of case studies of long-range transport of mineral dust aerosols in addition to smoke from numerous fires (including predominantly forest fires and a few grass/shrub fires) in the Pacific Northwest to Colorado, US. These aerosols were detected in Boulder, Colorado, along the Front Range using beta-ray attenuation and energy-dispersive X-ray fluorescence spectroscopy, and corroborated with satellite-borne lidar observations of smoke and dust. Further, we examined the transport pathways of these aerosols using air mass trajectory analysis and regional- and synoptic-scale meteorological dynamics. Three separate events with poor air quality and increased mass concentrations of metals from biomass burning (S and K) and minerals (Al, Si, Ca, Fe, and Ti) occurred due to the introduction of smoke and dust from regional- and synoptic-scale winds. Cleaner time periods with good air quality and lesser concentrations of biomass burning and mineral metals between the haze events were due to the advection of smoke and dust away from the region. Dust and smoke present in biomass burning haze can have diverse impacts on visibility, health, cloud formation, and surface radiation. Thus, it is important to understand how aerosol populations can be influenced by long-range-transported aerosols, particularly those emitted from large source contributors such as wildfires.

scholarly journals KAJIAN STATISTIK UKURAN BESAR BUTIR SEDIMEN DAN KAITANNYA DENGAN VARIABILITAS IKLIM MUSIMAN DAN TAHUNAN DI MUARA GEMBONG, TELUK JAKARTA

2019 ◽  
Vol 11 (3) ◽  
pp. 683-695 ◽  
Author(s):  
Taufik R. Syachputra ◽  
Ivonne M. Radjawane ◽  
Rina Zuraida
Keyword(s):  
El Niño ◽  
Southern Oscillation Index ◽  
El Nino ◽  
Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Dipole Mode ◽  
Australian Monsoon ◽  
Dipole Mode Index ◽  
Monsoon Index ◽  
Mode Index

Variabilitas iklim dapat mempengaruhi sifat sedimen yang terendapkan di dasar laut. Salah satu sifat sedimen yang dipengaruhi oleh iklim adalah besar butir. Penelitian ini bertujuan untuk menguji hubungan antara besar butir dengan variabilitas iklim menggunakan sampel core GM01-2010-TJ22 dari Muara Gembong, Teluk Jakarta, muara sungai Citarum. Sampel core diambil pada tahun 2010 dengan menggunakan Kapal Riset Geomarin I oleh Pusat Penelitian dan Pengembangan Geologi Kelautan (P3GL). Pengukuran besar butir dilakukan dengan menggunakan Mastersizer 2000. Hasil pengukuran ditampilkan dalam seri waktu dari tahun 2001 sampai 2010. Hasil analisis besar butir sampel sedimen dikorelasikan secara statistik dengan fenomena musiman (monsun), tahunan dan antar tahun (El Niño/La Niña dan Dipole Mode). Verifikasi data dilakukan dengan menggunakan data sekunder temperatur permukaan laut dari citra satelit di sekitar lokasi sampel dan data curah hujan di Bekasi. Hasil verifikasi menunjukkan bahwa peningkatan curah hujan di sekitar daerah hilir Sungai Citarum diikuti dengan penurunan temperatur permukaan laut dan peningkatan ukuran rata-rata besar butir. Hasil yang didapat dalam uji statistika menunjukkan bahwa perubahan ukuran besar butir sampel sedimen di Muara Gembong memiliki korelasi signifikan dengan Multivariate ENSO (El Niño Southern Oscillation) Index (MEI), Ocean Niño Index (ONI), Dipole Mode Index (DMI) dan Australian Monsoon Index (AUSMI). Hasil tersebut menunjukkan bahwa besar butir sedimen dasar laut potensial digunakan untuk mengetahui variabilitas iklim di sekitar Teluk Jakarta.

scholarly journals Ocean Forcing to Changes in Global Monsoon Precipitation over the Recent Half-Century

2008 ◽  
Vol 21 (15) ◽  
pp. 3833-3852 ◽  
Author(s):  
Tianjun Zhou ◽  
Rucong Yu ◽  
Hongmei Li ◽  
Bin Wang
Keyword(s):  
Tropical Indian Ocean ◽  
Warming Trend ◽  
Global Ocean ◽  
Monsoon Precipitation ◽  
Global Monsoon ◽  
Half Century ◽  
Australian Monsoon ◽  
Monsoon Index ◽  
Community Atmosphere Model ◽  
Global Land

Abstract Previous examination of changes in global monsoon precipitation over land reveals an overall weakening over the recent half-century (1950–2000). The present study suggests that this significant change in global land monsoon precipitation is deducible from the atmosphere’s response to the observed SST variations. When forced by historical sea surface temperatures covering the same period, the ensemble simulation with the NCAR Community Atmosphere Model, version 2 (CAM2) model successfully reproduced the weakening tendency of global land monsoon precipitation. This decreasing tendency was mainly caused by the warming trend over the central-eastern Pacific and the western tropical Indian Ocean. At the interannual time scale, the global land monsoon precipitation is closely correlated with ENSO. The simulated interannual variation of the global land monsoon index matches well with the observation, indicating that most monsoon precipitation variations arise from the ocean forcing. There are uncertainties between the GPCP and the CMAP data in describing the evolution of global ocean monsoon precipitation. There is very little correspondence between the simulated and the observed global monsoon index over the ocean area. Uncertainties in the satellite data and model deficiencies in describing the ocean monsoon domain are partly to blame. Among the components of global monsoon systems, the Asian–Australian monsoon system has the lowest reproducibility with prescribed SST forcing due to the neglect of air–sea feedback.

scholarly journals Seasonality of Tides in Southeast Asian Waters

2018 ◽  
Vol 48 (5) ◽  
pp. 1169-1190 ◽  
Author(s):  
Adam T. Devlin ◽  
Edward D. Zaron ◽  
David A. Jay ◽  
Stefan A. Talke ◽  
Jiayi Pan
Keyword(s):  
Seasonal Variability ◽  
Perturbation Approach ◽  
Gulf Of Thailand ◽  
Study Region ◽  
Geostrophic Currents ◽  
Monsoon Index ◽  
Astronomical Tide ◽  
Continental Shelves ◽  
Java Sea ◽  
Tidal Variability

AbstractAn analysis of water level time series from 20 tide gauges in Southeast Asia finds that diurnal and semidiurnal astronomical tides exhibit strong seasonal variability of both amplitude and phase, which is not caused by known modulations of the astronomical tide-generating forces. Instead, it is found that the tidal properties are coherent with the western North Pacific monsoon index (WNPMI), indicating that monsoonal mechanisms are the likely cause. The study domain includes the Malacca Strait, Gulf of Thailand, the southern South China Sea, and Java Sea. The character of the geography and the tidal variability is different in each of these subregions. A new barotropic regional tide model is developed that incorporates the coupling between geostrophic currents, wind-driven (Ekman) currents, and tidal currents in the bottom boundary layer in order to examine the influence of these factors on tides. The dynamics thus preserve the frictional nonlinearities while neglecting advective nonlinearities and baroclinic tides, approximations that should be valid on the wide and shallow continental shelves in the study region. The model perturbation approach uses the climatological seasonal variability of wind stress and geostrophic currents, which are prescribed singly and in combination in the model, to explain the observed tidal variability. Results are most successful in the southern Gulf of Thailand and near Singapore, where it is found that the combined effect of geostrophic and Ekman currents shows increased skill in reproducing the tidal variability than individual models. Ambiguous results at other locations suggest more localized processes such as river runoff.

scholarly journals Detection of dry season anomaly using radiosonde data during intensive observation period (IOP) in 2017

2018 ◽  
Vol 229 ◽  
pp. 02008
Author(s):  
Rini Mariana S. ◽  
Ibnu Athoillah ◽  
Rahmawati Syahdiza ◽  
Erwin Mulyana ◽  
Findy Renggono ◽  
...  
Keyword(s):  
Wind Profile ◽  
Meteorological Station ◽  
Radiosonde Data ◽  
Moisture Profile ◽  
Australian Monsoon ◽  
Monsoon Index ◽  
Monsoon Area ◽  
Sinusoidal Pattern ◽  
Intensive Observation ◽  
Observation Period

In the period between July - August 2017, Indonesia experiences drought which was caused by The Australian Monsoon wind. Radiosonde data obtained from launches conducted at the Palembang Meteorological Station during the IOP of 17 July - 16 August 2017 and those from cities that represents monsoon area (Pangkalpinang, Jakarta, and Surabaya) were also added to analyze the connection between Australian monsoon and precipitation in Indonesia. During IOP, the Australian Monsoon Index (AUSMI) is weaker than during normal conditions. Australian Monsoon index is normally around 6 m/s. Here, The Australian Monsoon Index chart shows a sinusoidal pattern in which during the peaks and troughs of the index there were drought anomalies in the aforementioned cities. In addition, medium to heavy rainfall also occurs during the Australian Monsoon index peaks and troughs. That conditions are affected by MJO and local influence. When MJO is a negative anomaly, AUSMI Index can be at peak or at the troughs. During the drought anomalies in all of the four cities, moisture profile at the surface to 6000-8000m is very wet (65-100%) with vertical wind profile dominated by the southeasterly-southerly direction.

scholarly journals High resolution (375 m) cloud microstructure as seen from the NPP/VIIRS Satellite imager

2013 ◽  
Vol 13 (11) ◽  
pp. 29845-29894 ◽  
Author(s):  
D. Rosenfeld ◽  
G. Liu ◽  
X. Yu ◽  
Y. Zhu ◽  
J. Dai ◽  
...  
Keyword(s):  
High Resolution ◽  
Forest Fires ◽  
Infrared Imaging ◽  
Cloud Formation ◽  
Cumulus Clouds ◽  
Marine Stratocumulus ◽  
Initial Stage ◽  
Microphysical Parameters ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. The VIIRS (Visible Infrared Imaging Radiometer Suite) onboard the Suomi NPP (National Polar-Orbiting Partnership) satellite has improved resolution of 750 m with respect to 1000 m of the MODerate-resolution Imaging Spectroradiometer, for the channels that allow retrieving cloud microphysical parameters such as cloud drop effective radius (re). The VIIRS has also an imager with 5 channels of double resolution of 375 m, which was not designed for retrieving cloud products. A methodology for a high resolution retrieval of re and microphysical presentation of the cloud field based on the VIIRS imager was developed and evaluated with respect to MODIS in this study. The tripled microphysical resolution with respect to MODIS allows obtaining new insights for cloud aerosol interactions, especially at the smallest cloud scales, because the VIIRS imager can resolve the small convective elements that are sub-pixel for MODIS cloud products. Examples are given for new insights on ship tracks in marine stratocumulus, pollution tracks from point and diffused sources in stratocumulus and cumulus clouds over land, deep tropical convection in pristine air mass over ocean and land, tropical clouds that develop in smoke from forest fires and in heavy pollution haze over densely populated regions in southeast Asia, and for pyro-cumulonimbus clouds. It is found that the VIIRS imager provides more robust physical interpretation and refined information for cloud and aerosol microphysics as compared to MODIS, especially in the initial stage of cloud formation. VIIRS is found to identify much more full-cloudy pixels when small boundary layer convective elements are present. This, in turn, allows a better quantification of cloud aerosol interactions and impacts on precipitation forming processes.

scholarly journals EVALUASI PERFORMA INDEKS MONSUN AUSMI DAN WNPMI DI WILAYAH INDONESIA

2021 ◽  
Vol 22 (2) ◽  
pp. 61-70
Author(s):  
Adi Mulsandi ◽  
Ardhasena Sopaheluwakan ◽  
Akhmad Faqih ◽  
Rahmat Hidayat ◽  
Yonny Koesmaryono
Keyword(s):  
Annual Cycle ◽  
Global Precipitation Climatology Project ◽  
Australian Monsoon ◽  
Monsoon Index ◽  
Monsoon System ◽  
Australian Summer Monsoon ◽  
Two Indices ◽  
Global Precipitation ◽  
Monsoon Indices ◽  
Australian Summer

Intisari Iklim di wilayah Indonesia sangat dipengaruhi oleh aktivitas monsun Asia-Australia. Variabilitas kedua sistem monsun tersebut dapat direpresentasikan dengan baik masing-masing oleh indeks monsun Australian Summer Monsoon Index (AUSMI) dan Western North Pacific Monsoon Index (WNPMI). Saat ini, BMKG secara operasional menggunakan indeks AUSMI dan WNPMI untuk memonitor aktivitas monsun di wilayah Indonesia sebagai bahan prakiraan musim. Meskipun banyak literatur menyatakan bahwa wilayah Indonesia merupakan bagian dari sistem monsun Asia-Australia, namun kondisi topografi lokal yang kompleks berpotensi memodifikasi sirkulasi monsun sehingga perlu dikaji performa kedua indeks tersebut sebelum digunakan secara operasional. Penelitian ini dilakukan untuk menguji performa indeks monsun AUSMI dan WNPMI dalam menggambarkan variasi antartahunan (interannual), variasi dalam musim (intraseasonal), dan siklus tahunan (annual cycle) hujan monsun Indonesia. Hasil penelitian mengungkapkan bahwa kedua indeks memiliki performa yang sangat baik hanya di wilayah dimana indeks tersebut didefinisikan namun kurang baik untuk wilayah Indonesia seperti yang ditunjukan oleh nilai koefisien korelasi yang tidak signifikan dari hasil uji statistik antara kedua indeks dengan curah hujan dari Global Precipitation Climatology Project (GPCP) pada periode 1981-2010. Selain itu, kedua indeks juga memperlihatkan karakteristik siklus tahunan yang berbeda dengan karakteristik siklus tahunan hujan wilayah Jawa sebagai wilayah kunci monsun Indonesia. Hasil ini mengindikasikan perlunya pendefinisian indeks sendiri untuk memonitor aktivitas monsun di wilayah Indonesia.    Abstract  The climate of Indonesia is strongly affected by the Asian-Australian monsoon system. The variability of the two monsoon systems can be well represented by the Western North Pacific Monsoon Index (WNPMI) and the Australian Summer Monsoon Index (AUSMI) respectively. For producing seasonal forecast, BMKG uses the WNPMI and AUSMI monsoon index to monitor monsoon activity in Indonesia. Although most literature states that the Indonesian region is part of the Asian-Australian monsoon system, the complex local topography may modify the monsoon circulation. Hence, it is necessary to assess the performance of the two indices before they are operationally used. This study was conducted to evaluate the performance of the AUSMI and WNPMI monsoon indices in describing the annual cycle, intraseasonal and interannual variability of the Indonesian monsoon rainfall. The results revealed that the two indices only performed very well in the areas where the index was defined but lack of skill for the Indonesian region because of insignificant linear correlation based on a statistical significance test between the two indices and the Global Precipitation Climatology Project (GPCP) rainfall in the 1981-2010 period. In addition, both monsoon indices and Java rainfall showed different characteristics of the annual cycle. These results indicate that it is necessary to define a specific index for monitoring monsoon activity in Indonesia.

scholarly journals Regression-based Gap-filling Methods Show Air Temperature Reductions and Wind Pattern Changes During the 2019 Total Eclipse in Chile

2021 ◽  
Author(s):  
Arno Christian Hammann ◽  
Shelley MacDonell
Keyword(s):  
Observational Data ◽  
Forest Fires ◽  
Temperature Drop ◽  
Volcanic Eruptions ◽  
Gap Filling ◽  
Near Surface ◽  
Wind Pattern ◽  
Regression Methods ◽  
Air Temperatures ◽  
Surface Station

Abstract Singular disruptive events like solar eclipses affect the measured values of meteorological variables at the earth’s surface. To quantify such an impact, it is necessary to estimate what value the parameter would have taken had the event not occurred. We design and compare several methods to perform such an estimate based on longer observational timeseries from individual meteorological surface stations. Our methods are based on regularized regressions (including a Bayesian variant) and provide both a point an associated error estimate of the disruptive event’s impact. With their help, we study the effect of the total solar eclipse of July 2 nd , 2019, in the Coquimbo Region of Chile, on near-surface air temperatures and winds. The observational data used have been collected by the meteorological surface station network of the Centro de Estudios Avanzados en Zonas Áridas (CEAZA). Most stations inside the eclipse’s umbra registered a temperature drop of 1-2 • C, while the most extreme estimated temperature drop surpassed 6 • C. The presence of an ‘eclipse cyclone’ can neither be proven nor refuted. Application of the regression methods to other, comparable problems, like volcanic eruptions, forest fires or simply gap filling of observational data, are conceivable.

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