Preliminary study of wave energy resource assessment and its seasonal variation along the southern coasts of Java, Bali, and Nusa Tenggara waters

: The Navy Operational Global Atmospheric Prediction System (NOGAPS) has recently (13 March 2013 12Z) been replaced by the NAVy Global Environmental Model (NAVGEM) as the U.S. Navy s operational atmospheric forecast system. NOGAPS will be decommissioned on 31 August 2013 but before that date both the Global Ocean Forecast System 3.01 and Arctic Cap Nowcast/Forecast System must switch from using NOGAPS to NAVGEM atmospheric forcing. Calibrations to the wind velocities and net heat flux are performed. Wind velocities are calibrated against satellite scatterometer data whereas heat flux is calibrated using 5-day forecast SST error. The sequence of hindcasts and forecast simulations are described with the net impact of reducing 5-day forecast SST error and ice concentration error in the NAVGEM 1.1-forced system, compared to the NOGAPS-forced system. Overall, the methodology is shown to be effective in minimizing upper ocean discontinuities when switching from one atmospheric product to another.

: The long-term goal of this ONR project is to prepare the technical framework for the associated ONR DRI on Unified physical parameterization for seasonal prediction which aims to develop generalized physical parameterizations that will enable a global prediction system useful for forecasts out to seasonal time scales. Targeted specifically at improving/extending the forecast capability of the Navy Operational Global Atmospheric Prediction System (NOGAPS) and the Navy Global Environmental Model (NAVGEM; a successor to NOGAPS with new dynamical core and advanced physics) from weather prediction to seasonal prediction, potential PIs of the DRI will be able to work collaboratively and efficiently on model physics development using the technical framework developed by this project. The objective of this project is to offer support (e.g., consultation, code updates and version control, data transfer, user feedback collection and implementation, etc.) for users of NOGAPS/NAVGEM who obtain the system through the release of the code as determined by release guidelines. One of the primary objectives of this proposal is to establish a more comprehensive technical support capability for the NOGAPS/NAVGEM users, particularly those who have projects supported by ONR. The distribution of NOGAPS/NAVGEM to the scientific community will be accomplished by Naval Research Laboratory (NRL)-Monterey whose functions include, but are not limited to, making incremental improvements to the website, updating versions of the code as necessary, updating the NOGAPS/NAVGEM documentation, providing user feedback to NOGAPS/NAVGEM developers, and providing atmospheric and surface initial and boundary condition data for forecast model simulations.

Indonesia is passed by an atmospheric phenomenon, called the Madden-Julian Oscillation (MJO), which has an impact on the wave height in the Indonesian Seas. The significant wave height is simulated using WAVEWATCH-III (WW3) numerical model in Indonesian region (90 °E-150 °E, 20 °N-20 °S) forced by surface winds from Cross-Calibrated Multi-Platform (CCMP), Navy Global Environmental Model (NAVGEM), and Navy Operational Global Atmospheric Prediction System (NOGAPS). This simulation is concentrated on MJO phase 3, 4, and 5 which passed through Indonesia and its adjacent waters that occurred in particular time between 1990-2015. In this study, the impact of MJO was analyzed during every monsoon season. In addition, wind speed analysis was carried out to further enrich the analysis of the MJO impact. The simulation result shows that MJO exerts the highest impact during phase 5 and DJF, which contributes to the increase of wind speed (WS) and significant wave height (SWH) in Indonesian inner seas by 6 m/s and 30 cm, respectively, and in southern Lesser Sunda Island by 8 m/s and 1.2 m, respectively. MJO can also contribute to decreasing of the WS and SWH, when it occurred during DJF and MAM phase 3, and JJA phase 4. There is no noticabe change of WS and SWH during SON.

At the Fleet Numerical Oceanography Center, two computer models, the Navy Operational Global Atmospheric Prediction System, NOGAPS, and the Navy Operational Regional Atmospheric Prediction System, NORAPS, generate a twice-daily suite of atmospheric analyses and forecasts. NOGAPS is the driving force behind many of the center's products and has become a complex, highly structured system designed to run automatically. The execution of NOGAPS and NORAPS within the operational schedule is described. The systems consist of 1) automated data processing and quality control, 2) a multivariate optimum interpolation analysis, 3) initialization and forecast, and 4) output. The data-processing step is shared between the two systems.

The seas along the Southern Coast of Java, which are parts of the Indian Ocean, are exposed to climate variability conditions that influence the dynamic of oceanographic parameters in these areas. In terms of interannual climate variability, previous studies showed that Indian Ocean Dipole (IOD) variability is more influential than El Niño Southern Oscillation on the upwelling variability along the Southern Coast of Java. This study aimed to determine the effect of strong positive IOD in 2019 on the upwelling along the Southern coast of Java and investigate the possible mechanisms. This study used sea surface temperature data from OISST, wind speed data from the ASCAT satellite, chlorophyll-a data from the Aqua-MODIS, and sea level anomaly data obtained from altimetry satellites. All data were processed using the composite method. The results show enhanced southeast monsoon upwelling during the 2019 strong positive IOD along the Southern Coast of Java as denoted by higher positive (negative) anomaly of chlorophyll-a (SST) from the climatology. Interestingly, the easterly wind speed is lower than the climatology. Since the IOD influences upwelling along the Southern Coast of Java through the propagation of Kelvin wave, our results indicate the enhancing (weakening) upwelling (downwelling) Kelvin wave during the strong positive IOD in 2019 with the propagation speed of about 1.16 m/s. This Kelvin Wave propagation may amplify the coastal upwelling along the Southern Coast of Java.

Upwelling events analysis in southern coast of Java and Banda sea were conducted. The events were identified by using satellite data i.e. wind surface, Sea Surface Temperature (SST) and ocean color during period of 14 years (2002-2016) which calculated by Ekman pumping and Ekman transport. It’s found that Ekman pumping velocity in Banda Sea reached a maximum in June-July-August (JJA) by approximately 3,65x10 -6 . Comparing with Ekman transport, Ekman pumping makes an even greater contribution to the local upwelling in Banda Sea. Ekman pumping velocity in southern coast of Java reached a maximum in June-July-August (JJA) by approximately 4,9x10 -1 ms . Ekman pumping and Ekman transport makes an equal contribution to coastal upwelling in southern coast of Java. That’s related to highest clorophyll-a concentration apperars in JJA periode. Partial correlation analysis then was applied to identify a correlation between chlorophyll-a concentration and interannual climate variabilities such as ENSO and IOD. Partial Correlation between chlorophyll-a and Nino 3.4 and DMI-Dipole Mode Index (controlled) in Banda Sea is 0.18, and 0.05 in southercoast of Java. It’s represent ENSO (Elnino Southern Oscilation) has higher influences to Banda Sea than southern coast of Java. Partial correlation between chlorophyll-a and DMI and Nino 3.4 (controlled) is 0.55 in southern coast of Java, and 0.25 in Banda Sea. Its represent IOD (Indian Ocean Dipole) has higher influences to southern coast of Java than Banda Sea. Upwelling in Banda sea and along southern coast of Java dominantly occurs in southeast monsoon as a responds to regional wind driven motion associated with the monsoon climate. Various condition of chlorophyll-a booming also occured according to combination of ENSO and IOD events. -6 -1 msKeywords: upwelling, Banda sea, southern coast of Java, Ekman transport, Ekman pumping, IOD, ENSO

The convective parameterization of Emanuel has been employed in the forecast model of the Navy Operational Global Atmospheric Prediction System (NOGAPS) since 2000, when it replaced a version of the relaxed Arakawa–Schubert scheme. Although in long-period data assimilation forecast tests the Emanuel scheme has been found to perform quite well in NOGAPS, particularly for tropical cyclones, some weaknesses have also become apparent. These weaknesses include underprediction of heavy-precipitation events, too much light precipitation, and unrealistic heating at upper levels. Recent research efforts have resulted in modifications of the scheme that are designed to reduce such problems. One change described here involves the partitioning of the cloud-base mass flux into mixing cloud mass flux at individual levels. The new treatment significantly reduces a heating anomaly near the tropopause that is associated with a large amount of mixing cloud mass flux ascribed to that region in the original Emanuel ...

Seventy-two-hour forecasts of sea level cyclones from the Navy Operational Global Atmospheric Prediction System are examined. Cyclones that formed over the North Pacific region of maximum cyclogenesis frequency are included for study. The analysis is oriented to assist the forecaster in evaluating the numerical model guidance by emphasizing verification of operationally oriented factors (i.e., cyclogenesis, explosive deepening). Initially, systematic errors in forecast intensities and positions are identified. Maximum underforecasting errors (forecast central pressure higher than actual central pressure) occur over the central North Pacific region of climatological maximum cyclone deepening. Maximum overforecasting errors (forecast central pressure lower than the actual central pressure) occur over the region of climatological cyclone dissipation. Maximum position errors also occur over the central North Pacific region of climatological maximum deepening. These systematic error distributions indi...

A high-order accurate radiative transfer (RT) model developed by Fu and Liou has been implemented into the Navy Operational Global Atmospheric Prediction System (NOGAPS) to improve the energy budget and forecast skill. The Fu–Liou RT model is a four-stream algorithm (with a two-stream option) integrating over 6 shortwave bands and 12 longwave bands. The experimental 10-day forecasts and analyses from data assimilation cycles are compared with the operational output, which uses a two-stream RT model of three shortwave and five longwave bands, for both winter and summer periods. The verifications against observations of radiosonde and surface data show that the new RT model increases temperature accuracy in both forecasts and analyses by reducing mean bias and root-mean-square errors globally. In addition, the forecast errors also grow more slowly in time than those of the operational NOGAPS because of accumulated effects of more accurate cloud–radiation interactions. The impact of parameterized cloud effective radius in estimating liquid and ice water optical properties is also investigated through a sensitivity test by comparing with the cases using constant cloud effective radius to examine the temperature changes in response to cloud scattering and absorption. The parameterization approach is demonstrated to outperform that of constant radius by showing smaller errors and better matches to observations. This suggests the superiority of the new RT model relative to its operational counterpart, which does not use cloud effective radius. An effort has also been made to improve the computational efficiency of the new RT model for operational applications.

The Navy Operational Global Atmospheric Prediction System (NOGAPS) has proven itself to be competitive with any of the large forecast models run by the large operational forecast centers around the world. The navy depends on NOGAPS for an astonishingly wide range of applications, from ballistic winds in the stratosphere to air-sea fluxes to drive ocean general circulation models. Users of these applications will benefit from a better understanding of how a system such as NOGAPS is developed, what physical assumptions and compromises have been made, and what they can reasonably expect in the future as the system continues to evolve. The discussions will be equally relevant for users of products from other large forecast centers, e.g., National Meteorological Center, European Centre for Medium-Range Weather Forecasts. There is little difference in the scientific basis of the models and the development methodologies used for their development. However, the operational priorities of each center and t...

In June 1990, the assimilation of synthetic tropical cyclone observations into the Navy Operational Global Atmospheric Prediction System (NOGAPS) was initiated at Fleet Numerical Oceanography Center (FNOC). These observations are derived directly from the information contained in the tropical cyclone warnings issued by the Joint Typhoon Warning Center (JTWC) and the National Hurricane Center. This paper describes these synthetic observations, the evolution of their use at FNOC, and the details of their assimilation into NOGAPS. The results of a comprehensive evaluation of the 1991 NOGAPS tropical cyclone forecast performance in the western North Pacific are presented. NOGAPS analysis and forecast position errors were determined for all tropical circulations of tropical storm strength or greater. It was found that, after the assimilation of synthetic observations, the NOGAPS spectral forecast model consistently maintained the tropical circulations as evidenced by detection percentages of 96%, 90% ...

The tropical cyclone (TC) track forecasts of the Navy Operational Global Atmospheric Prediction System (NOGAPS) were evaluated for a number of data assimilation experiments conducted using observational data from two periods: 4 July–31 October 2005 and 1 August–30 September 2006. The experiments were designed to illustrate the impact of different types of satellite observations on the NOGAPS TC track forecasts. The satellite observations assimilated in these experiments consisted of feature-track winds from geostationary and polar-orbiting satellites, Special Sensor Microwave Imager (SSM/I) total column precipitable water and wind speeds, Advanced Microwave Sounding Unit-A (AMSU-A) radiances, and Quick Scatterometer (QuikSCAT) and European Remote Sensing Satellite-2 (ERS-2) scatterometer winds. There were some differences between the results from basin to basin and from year to year, but the combined results for the 2005 and 2006 test periods for the North Pacific and Atlantic Ocean basins indicated that the assimilation of the feature-track winds from the geostationary satellites had the most impact, ranging from 7% to 24% improvement in NOGAPS TC track forecasts. This impact was statistically significant at all forecast lengths. The impact of the assimilation of SSM/I precipitable water was consistently positive and statistically significant at all forecast lengths. The improvements resulting from the assimilation of AMSU-A radiances were also consistently positive and significant at most forecast lengths. There were no significant improvements/degradations from the assimilation of the other satellite observation types [e.g., Moderate Resolution Imaging Spectroradiometer (MODIS) winds, SSM/I wind speeds, and scatterometer winds]. The assimilation of all satellite observations resulted in a gain in skill of roughly 12 h for the NOGAPS 48- and 72-h TC track forecasts and a gain in skill of roughly 24 h for the 96- and 120-h forecasts. The percent improvement in these forecasts ranged from almost 20% at 24 h to over 40% at 120 h.

The paper evaluates the meteorological quality and operational utility of the Navy Operational Global Atmospheric Prediction System (NOGAPS) in forecasting tropical cyclones. It is shown that the model can provide useful predictions of motion and formation on a real-time basis in the western North Pacific. The meterological characteristics of the NOGAPS tropical cyclone predictions are evaluated by examining the formation of low-level cyclone systems in the tropics and vortex structure in the NOGAPS analysis and verifying 72-h forecasts. The adjusted NOGAPS track forecasts showed equitable skill to the baseline aid and the dynamical model. NOGAPS successfully predicted unusual equatorward turns for several straight-running cyclones.

We present a description of the development of the spectral forecast components of the Navy Operational Global Atmospheric Prediction System (NOGAPS). The original system, called 3.0, was introduced in January 1988. New versions were introduced in March 1989 (3.1) and August 1989 (3.2). A brief description of each version of the forecast model is given. Each physical parameterization is also described. We discuss the large changes in 3.1 and the motivation behind the changes. Statistical results from forecast comparison tests are discussed. Figures showing the total monthly forecast performance in the Northern Hemisphere and the Southern Hemisphere are also given. A brief discussion is presented of computational details, running times, and memory requirements of the forecast model.

A set of criteria is developed to identify tropical cyclone (TC) formations in the Navy Operational Global Atmospheric Prediction System (NOGAPS) analyses and forecast fields. Then the NOGAPS forecasts of TC formations from 1997 to 1999 are verified relative to a formation time defined to be the first warning issued by the Joint Typhoon Warning Center. During these three years, the spatial distributions of TC formations were strongly affected by an El Nino–Southern Oscillation event. The successful NOGAPS predictions of formation within a maximum separation threshold of 4° latitude are about 70%–80% for 24-h forecasts, and drop to about 20%–30% for 120-h forecasts. The success rate is higher for formations in the South China Sea and between 160°E and 180° but is generally lower between 120° and 160°E. The composite 850-hPa large-scale flow for the formations between 120° and 160°E is similar to a monsoon confluence region with marked cross-equatorial flow. Therefore, it is concluded that the skil...