Naval Research Laboratory Multiscale Targeting Guidance for T-PARC and TCS-08

2010 ◽  
Vol 25 (2) ◽  
pp. 526-544 ◽  
Author(s):  
Carolyn A. Reynolds ◽  
James D. Doyle ◽  
Richard M. Hodur ◽  
Hao Jin
Keyword(s):  
Tropical Cyclone ◽  
Research Laboratory ◽  
Large Scale ◽  
Adjoint System ◽  
Horizontal Resolution ◽  
Naval Research Laboratory ◽  
Naval Research ◽  
Prediction System ◽  
Initial State ◽  
The North

Abstract As part of The Observing System Research and Predictability Experiment (THORPEX) Pacific Asian Regional Campaign (T-PARC) and the Office of Naval Research’s (ONR’s) Tropical Cyclone Structure-08 (TCS-08) experiments, a variety of real-time products were produced at the Naval Research Laboratory during the field campaign that took place from August through early October 2008. In support of the targeted observing objective, large-scale targeting guidance was produced twice daily using singular vectors (SVs) from the Navy Operational Global Atmospheric Prediction System (NOGAPS). These SVs were optimized for fixed regions centered over Guam, Taiwan, Japan, and two regions over the North Pacific east of Japan. During high-interest periods, flow-dependent SVs were also produced. In addition, global ensemble forecasts were produced and were useful for examining the potential downstream impacts of extratropical transitions. For mesoscale models, TC forecasts were produced using a new version of the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) developed specifically for tropical cyclone prediction (COAMPS-TC). In addition to the COAMPS-TC forecasts, mesoscale targeted observing products were produced using the COAMPS forecast and adjoint system twice daily, centered on storms of interest, at a 40-km horizontal resolution. These products were produced with 24-, 36-, and 48-h lead times. The nonhydrostatic adjoint system used during T-PARC/TCS-08 contains an exact adjoint to the explicit microphysics. An adaptive response function region was used to target favorable areas for tropical cyclone formation and development. Results indicate that forecasts of tropical cyclones in the western Pacific are very sensitive to the initial state.

scholarly journals Prediction and Diagnosis of Tropical Cyclone Formation in an NWP System. Part II: A Diagnosis of Tropical Cyclone Chris Formation

2006 ◽  
Vol 63 (12) ◽  
pp. 3091-3113 ◽  
Author(s):  
K. J. Tory ◽  
M. T. Montgomery ◽  
N. E. Davidson ◽  
J. D. Kepert
Keyword(s):  
Tropical Cyclone ◽  
Large Scale ◽  
Vertical Motion ◽  
Limited Area ◽  
Initial State ◽  
Absolute Vorticity ◽  
Vertical Advection ◽  
The North ◽  
Convective Bursts ◽  
Vortex Cascade

This is the second of a three-part investigation into tropical cyclone (TC) genesis in the Australian Bureau of Meteorology’s Tropical Cyclone Limited Area Prediction System (TC-LAPS). The primary TC-LAPS vortex enhancement mechanism (convergence/stretching and vertical advection of absolute vorticity in convective updraft regions) was presented in Part I. In this paper (Part II) results from a numerical simulation of TC Chris (western Australia, February 2002) are used to illustrate the primary and two secondary vortex enhancement mechanisms that led to TC genesis. In Part III a number of simulations are presented exploring the sensitivity and variability of genesis forecasts in TC-LAPS. During the first 18 h of the simulation, a mature vortex of TC intensity developed in a monsoon low from a relatively benign initial state. Deep upright vortex cores developed from convergence/stretching and vertical advection of absolute vorticity within the updrafts of intense bursts of cumulus convection. Individual convective bursts lasted for 6–12 h, with a new burst developing as the previous one weakened. The modeled bursts appear as single updrafts, and represent the mean vertical motion in convective regions because the 0.15° grid spacing imposes a minimum updraft scale of about 60 km. This relatively large scale may be unrealistic in the earlier genesis period when multiple smaller-scale, shorter-lived convective regions are often observed, but observational evidence suggests that such scales can be expected later in the process. The large scale may limit the convection to only one or two active bursts at a time, and may have contributed to a more rapid model intensification than that observed. The monsoon low was tilted to the northwest, with convection initiating about 100–200 km west of the low-level center. The convective bursts and associated upright potential vorticity (PV) anomalies were advected cyclonically around the low, weakening as they passed to the north of the circulation center, leaving remnant cyclonic PV anomalies. Strong convergence into the updrafts led to rapid ingestion of nearby cyclonic PV anomalies, including remnant PV cores from decaying convective bursts. Thus convective intensity, rather than the initial vortex size and intensity, determined dominance in vortex interactions. This scavenging of PV by the active convective region, termed diabatic upscale vortex cascade, ensured that PV cores grew successively and contributed to the construction of an upright central monolithic PV core. The system-scale intensification (SSI) process active on the broader scale (300–500-km radius) also contributed. Latent heating slightly dominated adiabatic cooling within the bursts, which enhanced the system-scale secondary circulation. Convergence of low- to midlevel tropospheric absolute vorticity by this enhanced circulation intensified the system-scale vortex. The diabatic upscale vortex cascade and SSI are secondary processes dependent on the locally enhanced vorticity and heat respectively, generated by the primary mechanism.

scholarly journals Seasonal Forecasts of Tropical Cyclone Activity in a High-Atmospheric-Resolution Coupled Prediction System*

2016 ◽  
Vol 29 (3) ◽  
pp. 1179-1200 ◽  
Author(s):  
Julia V. Manganello ◽  
Kevin I. Hodges ◽  
Benjamin A. Cash ◽  
James L. Kinter ◽  
Eric L. Altshuler ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
North Pacific ◽  
Large Scale ◽  
Coupled Model ◽  
Prediction System ◽  
Seasonal Forecasts ◽  
The North ◽  
Skill Scores ◽  
Activity Measures ◽  
The Tropical Pacific

Abstract Seasonal forecast skill of the basinwide and regional tropical cyclone (TC) activity in an experimental coupled prediction system based on the ECMWF System 4 is assessed. As part of a collaboration between the Center for Ocean–Land–Atmosphere Studies (COLA) and the ECMWF called Project Minerva, the system is integrated at the atmospheric horizontal spectral resolutions of T319, T639, and T1279. Seven-month hindcasts starting from 1 May for the years 1980–2011 are produced at all three resolutions with at least 15 ensemble members. The Minerva system demonstrates statistically significant skill for retrospective forecasts of TC frequency and accumulated cyclone energy (ACE) in the North Atlantic (NA), eastern North Pacific (EP), and western North Pacific. While the highest scores overall are achieved in the North Pacific, the skill in the NA appears to be limited by an overly strong influence of the tropical Pacific variability. Higher model resolution improves skill scores for the ACE and, to a lesser extent, the TC frequency, even though the influence of large-scale climate variations on these TC activity measures is largely independent of resolution changes. The biggest gain occurs in transition from T319 to T639. Significant skill in regional TC forecasts is achieved over broad areas of the Northern Hemisphere. The highest-resolution hindcasts exhibit additional locations with skill in the NA and EP, including land-adjacent areas. The feasibility of regional intensity forecasts is assessed. In the presence of the coupled model biases, the benefits of high resolution for seasonal TC forecasting may be underestimated.

The Naval Research Laboratory’s Coupled Ocean/Atmosphere Mesoscale Prediction System – Tropical Cyclone ensemble (COAMPS-TC ensemble)

2021 ◽  
Author(s):  
William A. Komaromi ◽  
Patrick A. Reinecke ◽  
James D. Doyle ◽  
Jonathan R. Moskaitis
Keyword(s):  
Tropical Cyclone ◽  
Boundary Conditions ◽  
Skill Score ◽  
Horizontal Resolution ◽  
Naval Research ◽  
Lead Times ◽  
Prediction System ◽  
Intensity Forecast ◽  
Probabilistic Forecasts ◽  
Ocean Atmosphere

AbstractThe 11-member Coupled Ocean/Atmosphere Mesoscale Prediction System for Tropical Cyclones (COAMPS-TC) ensemble has been developed by the Naval Research Laboratory (NRL) to produce probabilistic forecasts of tropical cyclone (TC) track, intensity and structure. All members run with a storm-following inner grid at convection-permitting 4-km horizontal resolution. The COAMPS-TC ensemble is constructed via a combination of perturbations to initial and boundary conditions, the initial vortex, and model physics to account for a variety of different sources of uncertainty that affect track and intensity forecasts. Unlike global model ensembles, which do a reasonable job capturing track uncertainty but not intensity, mesoscale ensembles such as the COAMPS-TC ensemble are necessary to provide a realistic intensity forecast spectrum.The initial and boundary condition perturbations are responsible for generating the majority of track spread at all lead times, as well as the intensity spread from 36-120 h. The vortex and physics perturbations are necessary to produce meaningful spread in the intensity prediction from 0-36 h. In a large sample of forecasts from 2014-2017, the ensemble-mean track and intensity forecast is superior to the unperturbed control forecast at all lead times, demonstrating a clear advantage to running an ensemble versus a deterministic forecast. The spread-skill relationship of the ensemble is also examined, and is found to be very well calibrated for track, but is under-dispersive for intensity. Using a mixture of lateral boundary conditions derived from different global models is found to improve upon the spread-skill score for intensity, but it is hypothesized that additional physics perturbations will be necessary to achieve realistic ensemble spread.

Progress in Laser Propagation in a Maritime Environment at the Naval Research Laboratory

2005 ◽  
Author(s):  
G. C. Gilbreath ◽  
W. S. Rabinovich ◽  
C. I. Moore ◽  
H. R. Burris ◽  
R. Mahon ◽  
...  
Keyword(s):  
Research Laboratory ◽  
Naval Research Laboratory ◽  
Naval Research ◽  
Laser Propagation ◽  
Maritime Environment

scholarly journals Tropical Cyclone Count Forecasting Using a Dynamical Seasonal Prediction System: Sensitivity to Improved Ocean Initialization

2011 ◽  
Vol 24 (12) ◽  
pp. 2963-2982 ◽  
Author(s):  
Andrea Alessandri ◽  
Andrea Borrelli ◽  
Silvio Gualdi ◽  
Enrico Scoccimarro ◽  
Simona Masina
Keyword(s):  
Tropical Cyclone ◽  
Indian Ocean ◽  
Wind Shear ◽  
Large Scale ◽  
Initial Conditions ◽  
North Pacific Ocean ◽  
Convective Available Potential Energy ◽  
Seasonal Prediction ◽  
Boreal Summer ◽  
Prediction System

Abstract This study investigates the predictability of tropical cyclone (TC) seasonal count anomalies using the Centro Euro-Mediterraneo per i Cambiamenti Climatici–Istituto Nazionale di Geofisica e Vulcanologia (CMCC-INGV) Seasonal Prediction System (SPS). To this aim, nine-member ensemble forecasts for the period 1992–2001 for two starting dates per year were performed. The skill in reproducing the observed TC counts has been evaluated after the application of a TC location and tracking detection method to the retrospective forecasts. The SPS displays good skill in predicting the observed TC count anomalies, particularly over the tropical Pacific and Atlantic Oceans. The simulated TC activity exhibits realistic geographical distribution and interannual variability, thus indicating that the model is able to reproduce the major basic mechanisms that link the TCs’ occurrence with the large-scale circulation. TC count anomalies prediction has been found to be sensitive to the subsurface assimilation in the ocean for initialization. Comparing the results with control simulations performed without assimilated initial conditions, the results indicate that the assimilation significantly improves the prediction of the TC count anomalies over the eastern North Pacific Ocean (ENP) and northern Indian Ocean (NI) during boreal summer. During the austral counterpart, significant progresses over the area surrounding Australia (AUS) and in terms of the probabilistic quality of the predictions also over the southern Indian Ocean (SI) were evidenced. The analysis shows that the improvement in the prediction of anomalous TC counts follows the enhancement in forecasting daily anomalies in sea surface temperature due to subsurface ocean initialization. Furthermore, the skill changes appear to be in part related to forecast differences in convective available potential energy (CAPE) over the ENP and the North Atlantic Ocean (ATL), in wind shear over the NI, and in both CAPE and wind shear over the SI.

scholarly journals A View of Tropical Cyclones from Above: The Tropical Cyclone Intensity Experiment

2017 ◽  
Vol 98 (10) ◽  
pp. 2113-2134 ◽  
Author(s):  
James D. Doyle ◽  
Jonathan R. Moskaitis ◽  
Joel W. Feldmeier ◽  
Ronald J. Ferek ◽  
Mark Beaubien ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Lower Stratosphere ◽  
Inner Core ◽  
Horizontal Resolution ◽  
Intensity Change ◽  
Naval Research ◽  
Atmospheric Conditions ◽  
Tropical Cyclone Intensity ◽  
High Definition ◽  
Cyclone Intensity

Abstract Tropical cyclone (TC) outflow and its relationship to TC intensity change and structure were investigated in the Office of Naval Research Tropical Cyclone Intensity (TCI) field program during 2015 using dropsondes deployed from the innovative new High-Definition Sounding System (HDSS) and remotely sensed observations from the Hurricane Imaging Radiometer (HIRAD), both on board the NASA WB-57 that flew in the lower stratosphere. Three noteworthy hurricanes were intensively observed with unprecedented horizontal resolution: Joaquin in the Atlantic and Marty and Patricia in the eastern North Pacific. Nearly 800 dropsondes were deployed from the WB-57 flight level of ∼60,000 ft (∼18 km), recording atmospheric conditions from the lower stratosphere to the surface, while HIRAD measured the surface winds in a 50-km-wide swath with a horizontal resolution of 2 km. Dropsonde transects with 4–10-km spacing through the inner cores of Hurricanes Patricia, Joaquin, and Marty depict the large horizontal and vertical gradients in winds and thermodynamic properties. An innovative technique utilizing GPS positions of the HDSS reveals the vortex tilt in detail not possible before. In four TCI flights over Joaquin, systematic measurements of a major hurricane’s outflow layer were made at high spatial resolution for the first time. Dropsondes deployed at 4-km intervals as the WB-57 flew over the center of Hurricane Patricia reveal in unprecedented detail the inner-core structure and upper-tropospheric outflow associated with this historic hurricane. Analyses and numerical modeling studies are in progress to understand and predict the complex factors that influenced Joaquin’s and Patricia’s unusual intensity changes.

Design of the naval research laboratory computer

1951 ◽  
Vol 70 (2) ◽  
pp. 111-111 ◽  
Author(s):  
D. H. Gridley ◽  
B. L. Sarahan
Keyword(s):  
Research Laboratory ◽  
Naval Research Laboratory ◽  
Naval Research ◽  
Laboratory Computer
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