ANALYSIS OF STORM CATEGORY AND COALESCENCE ACTIVITY : RELATIONSHIP TO THE DAILY MEAN CATCHMENT RAINFALL (CASES CLOUD SEEDING OPERATIONAL IN LARONA AND CITARUM CATCHMENT AREA)

2012 ◽  
Vol 13 (1) ◽  
pp. 7
Author(s):  
Untung Haryanto ◽  
Dini Harsanti ◽  
R. Djoko Goenawan ◽  
Krisna Adithya
Keyword(s):  
Catchment Area ◽  
Inverse Correlation ◽  
Activity Relationship ◽  
Cloud Base ◽  
Cloud Seeding ◽  
The Mean ◽  
Cloud Base Height ◽  
Threshold Range

Cloud seeding operational has been conducted in Indonesia. In this study, the two cases operational were analysis, ie Larona (2005) and Citarum Catchment Area (2011). The coalescence activity during operational were analysed using archives of NOAAGFS model sounding and it also used to determined storm category and ICA. For this purpose, the number parameters for moderate threshold range on Raob-55 software were reduced and modified with more suitable range for Indonesia region. Result indicated that in Larona Catchment Area, the most of the storm having category weak to moderate with mean of storm category 67% and 21% respectively, the mean ICA value was -5.7. Relative larger weight of Weak and Medium category of storm were shown in Citarum ie 72% for weak and 18%, with the mean of ICA was -2.7%. As consequences, proportion of Medium together with Strong category for Larona is larger than Citarum,resulting larger amount mean catchment rainfall for Larona (17.1mm) compare to the Citarum (5.2 mm). The coalescence actifity in cloud during operation was effective for booth of two area, but varies due to the varies of cloud base height temperature and potential buoyancy (PB). The mean of CCL temperature in Larona was 20.30C since PB was 3.80C. This study also found that mean 500mb temperature (T) and mean rising parcel (TP) in Larona catchments was more warmer comparing to the Citarum is -4.00C and -0.150C for Larona , and -5.30C and -1.50C for Citarum. Base of the result it has been concluded that ICA has inverse correlation to the mean daily catchments rainfall, since together of Medium and Strong Storm Category has positive correlation.Modifikasi awan sudah operasional. Pada studi ini dilakukan analisis dua kasus operasional , yaitu operasional di DAS (Daerah Aliran Sungai) Larona (2005) dan DAS Citarum (2011). Aktifitas koalesensi selama operasional dianalisis menggunakan arsip data sounding NOAA-GFS yang digunakan untuk menentukan ICA (Index Coalescence Activity – indeks aktifitas koealesensi) dan Storm Category – kategori awan hujan). Bagi keperluan ini banyaknya parameter dan rentang kategori moderat pada perangkat lunak Raob -55 di dikurangi dan dimodifikasi dengan yang paling sesuai dengan kondisi daerah di Indonesia. Hasil analisis menunjukkan sebagian besar awan hujan yang ada memiliki kategori weak hingga moderat – yaitu 67% dan 21% di DAS Larona dengan rata-rata nilai ICA besarnya -5.7, sedangkan di DAS Citarum, nilai kategori ini lebih besar yaitu 72% dan 18% dengan nilai rata rata ICA adalah -2.7. Sebagai konsekuensinya adalah porsi awan hujan dengan kategori ini lebih banyak muncul di DAS Larona dibandingkan pada DAS Citarum dengan rata rata hujan masing masing 17.1mm di DAS Larona dan 5.2mm di DAS Citarum. Aktivitas koalesensi di kedua DAS ini sama-sama aktif, variasinya ditentukan oleh variasi ketinggian dasar awan konvektif (CCL) dan potensi daya apung awan (PB). Di DAS Larona CCL cukup hangat yaitu 20.30C , dengan nilai PB 3.80C. Pada sutudi ini juga di peroleh bahwa rata rata suhu dan suhu parsel paras 500mb pada DAS Larona lebih hangat (-4.00C dan -0.150C) dari pada di DAS Citarum (-5.30C dan -1.50C). Dari studi ini, disimpulkan bahwa ICA berkorelasi terbalik dengan curah hujan harian, dan berkorelasi positif dengan awan hujan berkategori “ sedang” dan “kuat” secara bersama-sama.

scholarly journals Exploring the Potential of Statistical Modeling to Retrieve the Cloud Base Height from Geostationary Satellites: Applications to the ABI Sensor on Board of the GOES-R Satellite Series

2021 ◽  
Vol 13 (3) ◽  
pp. 375
Author(s):  
Pedro A. Jiménez ◽  
Tyler McCandless
Keyword(s):  
Weather Prediction ◽  
Numerical Weather Prediction Model ◽  
Cloud Base ◽  
Random Forest Algorithm ◽  
Relevant Variable ◽  
Geostationary Satellites ◽  
The Mean ◽  
Infrared Radiances ◽  
State Of The Science ◽  
Cloud Base Height

Although cloud base height is a relevant variable for many applications, including aviation, it is not routinely monitored by current geostationary satellites. This is probably a consequence of the difficulty of providing reliable estimations of the cloud base height from visible and infrared radiances from current imagers. We hypothesize that existing algorithms suffer from the accumulation of errors from upstream retrievals necessary to estimate the cloud base height, and that this hampers higher predictability in the retrievals to be achieved. To test this hypothesis, we trained a statistical model based on the random forest algorithm to retrieve the cloud base height, using as predictors the radiances from Geostationary Operational Environmental Satellites (GOES-16) and variables from a numerical weather prediction model. The predictand data consisted of cloud base height observations recorded at meteorological aerodrome report (METAR) stations over an extended region covering the contiguous USA. Our results indicate the potential of the proposed methodology. In particular, the performance of the cloud base height retrievals appears to be superior to the state-of-the-science algorithms, which suffer from the accumulation of errors from upstream retrievals. We also find a direct relationship between the errors and the mean cloud base height predicted over the region, which allowed us to obtain estimations of both the cloud base height and its error.

A 42 year inference of cloud base height trends in the Luquillo Mountains of northeastern Puerto Rico

2018 ◽  
Vol 76 (1) ◽  
pp. 87-94 ◽  
Author(s):  
PW Miller ◽  
TL Mote ◽  
CA Ramseyer ◽  
AE Van Beusekom ◽  
M Scholl ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Cloud Base ◽  
Luquillo Mountains ◽  
Cloud Base Height

scholarly journals Forensic Investigation of Four Monitored Green Infrastructure Inlets

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1787
Author(s):  
Leena J. Shevade ◽  
Franco A. Montalto
Keyword(s):  
Measurement Uncertainty ◽  
Green Infrastructure ◽  
Stormwater Management ◽  
Catchment Area ◽  
Low Flow ◽  
Inflow Rate ◽  
Forensic Investigation ◽  
Flow Conditions ◽  
The Mean

Green infrastructure (GI) is viewed as a sustainable approach to stormwater management that is being rapidly implemented, outpacing the ability of researchers to compare the effectiveness of alternate design configurations. This paper investigated inflow data collected at four GI inlets. The performance of these four GI inlets, all of which were engineered with the same inlet lengths and shapes, was evaluated through field monitoring. A forensic interpretation of the observed inlet performance was conducted using conclusions regarding the role of inlet clogging and inflow rate as described in the previously published work. The mean inlet efficiency (meanPE), which represents the percentage of tributary area runoff that enters the inlet was 65% for the Nashville inlet, while at Happyland the NW inlet averaged 30%, the SW inlet 25%, and the SE inlet 10%, considering all recorded events during the monitoring periods. The analysis suggests that inlet clogging was the main reason for lower inlet efficiency at the SW and NW inlets, while for the SE inlet, performance was compromised by a reverse cross slope of the street. Spatial variability of rainfall, measurement uncertainty, uncertain tributary catchment area, and inlet depression characteristics are also correlated with inlet PE. The research suggests that placement of monitoring sensors should consider low flow conditions and a strategy to measure them. Additional research on the role of various maintenance protocols in inlet hydraulics is recommended.

scholarly journals Differences between Nonprecipitating Tropical and Trade Wind Marine Shallow Cumuli

2016 ◽  
Vol 144 (2) ◽  
pp. 681-701 ◽  
Author(s):  
Virendra P. Ghate ◽  
Mark A. Miller ◽  
Ping Zhu
Keyword(s):  
Surface Fluxes ◽  
Cloud Base ◽  
Trade Wind ◽  
Cumulus Clouds ◽  
Wind Speeds ◽  
Lower Cloud ◽  
Observational Site ◽  
Velocity Scale ◽  
Atmospheric Radiation Measurement ◽  
The Mean

Abstract Marine nonprecipitating cumulus topped boundary layers (CTBLs) observed in a tropical and in a trade wind region are contrasted based on their cloud macrophysical, dynamical, and radiative structures. Data from the Atmospheric Radiation Measurement (ARM) observational site previously operating at Manus Island, Papua New Guinea, and data collected during the deployment of ARM Mobile Facility at the island of Graciosa, in the Azores, were used in this study. The tropical marine CTBLs were deeper, had higher surface fluxes and boundary layer radiative cooling, but lower wind speeds compared to their trade wind counterparts. The radiative velocity scale was 50%–70% of the surface convective velocity scale at both locations, highlighting the prominent role played by radiation in maintaining turbulence in marine CTBLs. Despite greater thicknesses, the chord lengths of tropical cumuli were on average lower than those of trade wind cumuli, and as a result of lower cloud cover, the hourly averaged (cloudy and clear) liquid water paths of tropical cumuli were lower than the trade wind cumuli. At both locations ~70% of the cloudy profiles were updrafts, while the average amount of updrafts near cloud base stronger than 1 m s−1 was ~22% in tropical cumuli and ~12% in the trade wind cumuli. The mean in-cloud radar reflectivity within updrafts and mean updraft velocity was higher in tropical cumuli than the trade wind cumuli. Despite stronger vertical velocities and a higher number of strong updrafts, due to lower cloud fraction, the updraft mass flux was lower in the tropical cumuli compared to the trade wind cumuli. The observations suggest that the tropical and trade wind marine cumulus clouds differ significantly in their macrophysical and dynamical structures.

scholarly journals Large-Eddy Simulations of a Drizzling, Stratocumulus-Topped Marine Boundary Layer

2009 ◽  
Vol 137 (3) ◽  
pp. 1083-1110 ◽  
Author(s):  
Andrew S. Ackerman ◽  
Margreet C. vanZanten ◽  
Bjorn Stevens ◽  
Verica Savic-Jovcic ◽  
Christopher S. Bretherton ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Marine Boundary Layer ◽  
Cloud Water ◽  
Large Eddy Simulations ◽  
Cloud Base ◽  
Entrainment Rate ◽  
Liquid Water Path ◽  
Average Maximum ◽  
Large Eddy ◽  
The Mean

Abstract Cloud water sedimentation and drizzle in a stratocumulus-topped boundary layer are the focus of an intercomparison of large-eddy simulations. The context is an idealized case study of nocturnal stratocumulus under a dry inversion, with embedded pockets of heavily drizzling open cellular convection. Results from 11 groups are used. Two models resolve the size distributions of cloud particles, and the others parameterize cloud water sedimentation and drizzle. For the ensemble of simulations with drizzle and cloud water sedimentation, the mean liquid water path (LWP) is remarkably steady and consistent with the measurements, the mean entrainment rate is at the low end of the measured range, and the ensemble-average maximum vertical wind variance is roughly half that measured. On average, precipitation at the surface and at cloud base is smaller, and the rate of precipitation evaporation greater, than measured. Including drizzle in the simulations reduces convective intensity, increases boundary layer stratification, and decreases LWP for nearly all models. Including cloud water sedimentation substantially decreases entrainment, decreases convective intensity, and increases LWP for most models. In nearly all cases, LWP responds more strongly to cloud water sedimentation than to drizzle. The omission of cloud water sedimentation in simulations is strongly discouraged, regardless of whether or not precipitation is present below cloud base.

Estimating the intra- and inter-individual imprecision of manual pipetting

2017 ◽  
Vol 55 (7) ◽  
Author(s):  
Giuseppe Lippi ◽  
Gabriel Lima-Oliveira ◽  
Giorgio Brocco ◽  
Antonella Bassi ◽  
Gian Luca Salvagno
Keyword(s):  
Coefficient Of Variation ◽  
Biological Samples ◽  
Inverse Correlation ◽  
Distilled Water ◽  
Years Of Experience ◽  
Laboratory Practice ◽  
Scientific Publications ◽  
Plastic Container ◽  
Water Solutions ◽  
The Mean

AbstractBackground:Despite the importance of manual pipetting of fluids such as water, solutions, buffers, reagents, or biological samples in daily laboratory practice, the intra- and inter-individual imprecision of this activity has not been recently described in scientific publications.Methods:Twenty laboratory operators were randomly enrolled for this study. Imprecision of manual pipetting was estimated by asking each laboratory professional to dispense 1 mL, 100 μL or 10 μL of distilled water for 10 consecutive times with three certified pipettes into a 50-mL plastic container placed into a gravimetric balance. The weight of the water dispensed was systematically recorded for each of the 10 repeated attempts, and the inter- and intra-operator imprecision was finally calculated and expressed as coefficient of variation (CV%).Results:The mean intra-individual imprecision was 5.7% (range, 0%–11.8%) for pipetting 10 μL, 0.8% (range, 0.4%–1.9%) for pipetting 100 μL, and 0.2% (range, 0.1%–0.5%) for pipetting 1 mL. Overall, the mean inter-individual imprecision was 8.1% for pipetting 10 μL, 1.1% for pipetting 100 μL and 0.4% for pipetting 1 mL. A significantly inverse correlation was found between intra-individual pipetting imprecision and the amount of water dispensed (r = –0.80; p<0.001). No significant correlation was observed between individual pipetting performance and sex, age, qualification, and years of experience in the laboratory.Conclusions:The results of this study show that manual pipetting is plagued by a considerable intra- and inter-individual imprecision, which is inversely correlated with the amount of fluid dispensed.

Why sometimes its simply sunny (in the trades)

2021 ◽  
Author(s):  
Bjorn Stevens ◽  
Ilya Serikov ◽  
Anna Lea Albright ◽  
Sandrine Bony ◽  
Geet George ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
Marine Boundary Layer ◽  
Cloud Base ◽  
Lidar Signal ◽  
Cloud Base Height

&lt;p&gt;Cloud free skies are rare in the trades. &amp;#160;We analyze conditions in which cloud-free conditions prevail. &amp;#160;For this purpose Raman water vapor measurements from the Barbados Cloud Observatory, complemented by ship-based measurements during EUREC4A are used to explore water vapor variability in the marine boundary layer. &amp;#160; We explore the consistency of the inferred cloud base height with estimates of temperature and water vapor from the lidar signal, and examine the co-variability of these quantities. &amp;#160;After having established the properties of these measurements, we seek to use them as well as others, to explain in what ways periods of cloud-free conditions are maintained, investigating the hypothesis that only when the wind stills is it simply sunny.&lt;/p&gt;

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