Description and Analysis of the Ocean Component of NOAA’s Operational Hurricane Weather Research and Forecasting Model (HWRF)

2015 ◽  
Vol 32 (1) ◽  
pp. 144-163 ◽  
Author(s):  
Richard M. Yablonsky ◽  
Isaac Ginis ◽  
Biju Thomas ◽  
Vijay Tallapragada ◽  
Dmitry Sheinin ◽  
...  
Keyword(s):  
Tropical Cyclones ◽  
Three Dimensional ◽  
Storm Track ◽  
Temperature Response ◽  
Forecast Model ◽  
Ocean Model ◽  
Temperature Structure ◽  
Ocean Temperature ◽  
Princeton Ocean Model ◽  
Weather Research

AbstractThe Princeton Ocean Model for Tropical Cyclones (POM-TC), a version of the three-dimensional primitive equation numerical ocean model known as the Princeton Ocean Model, was the ocean component of NOAA’s operational Hurricane Weather Research and Forecast Model (HWRF) from 2007 to 2013. The coupled HWRF–POM-TC system facilitates accurate tropical cyclone intensity forecasts through proper simulation of the evolving SST field under simulated tropical cyclones. In this study, the 2013 operational version of HWRF is used to analyze the POM-TC ocean temperature response in retrospective HWRF–POM-TC forecasts of Atlantic Hurricanes Earl (2010), Igor (2010), Irene (2011), Isaac (2012), and Leslie (2012) against remotely sensed and in situ SST and subsurface ocean temperature observations. The model generally underestimates the hurricane-induced upper-ocean cooling, particularly far from the storm track, as well as the upwelling and downwelling oscillation in the cold wake, compared with observations. Nonetheless, the timing of the model SST cooling is generally accurate (after accounting for along-track timing errors), and the ocean model’s vertical temperature structure is generally in good agreement with observed temperature profiles from airborne expendable bathythermographs.

scholarly journals Assimilation of stratospheric and mesospheric temperatures from MLS and SABER into a global NWP model

2008 ◽  
Vol 8 (3) ◽  
pp. 8455-8490 ◽  
Author(s):  
K. W. Hoppel ◽  
N. L. Baker ◽  
L. Coy ◽  
S. D. Eckermann ◽  
J. P. McCormack ◽  
...  
Keyword(s):  
High Altitude ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Forecast Model ◽  
Temperature Structure ◽  
Deep Circulation ◽  
Zonal Winds ◽  
Mesospheric Temperature ◽  
Standard Deviations ◽  
Nwp Model

Abstract. The forecast model and three-dimensional variational data assimilation components of the Navy Operational Global Atmospheric Prediction System (NOGAPS) have each been extended into the upper stratosphere and mesosphere to form an Advanced Level Physics High Altitude (ALPHA) version of NOGAPS extending to ~100 km. This NOGAPS-ALPHA NWP prototype is used to assimilate stratospheric and mesospheric temperature data from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Radiometry (SABER) instruments. A 60-day analysis period in January and February, 2006, was chosen that includes a well documented stratospheric sudden warming. SABER temperatures indicate that the SSW caused the polar winter stratopause at ~40 km to disappear, then reform at ~80 km altitude and slowly descend during February. The NOGAPS-ALPHA analysis reproduces this observed stratospheric and mesospheric temperature structure, as well as realistic evolution of zonal winds, residual velocities, and Eliassen-Palm fluxes that aid interpretation of the vertically deep circulation and eddy flux anomalies that developed in response to this wave-breaking event. The observation minus forecast (O-F) standard deviations for MLS and SABER are ~2 K in the mid-stratosphere and increase monotonically to about 6 K in the upper mesosphere. Increasing O-F standard deviations in the mesosphere are expected due to increasing instrument error and increasing geophysical variance at small spatial scales in the forecast model. In the mid/high latitude winter regions, 10-day forecast skill is improved throughout the upper stratosphere and mesosphere when the model is initialized using the high-altitude analysis based on assimilation of both SABER and MLS data.

scholarly journals Comment on "Tropospheric temperature response to stratospheric ozone recovery in the 21st century" by Hu et al. (2011)

2012 ◽  
Vol 12 (5) ◽  
pp. 2533-2540 ◽  
Author(s):  
C. McLandress ◽  
J. Perlwitz ◽  
T. G. Shepherd
Keyword(s):  
Northern Hemisphere ◽  
Climate Models ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Temperature Response ◽  
Ocean Model ◽  
Tropospheric Temperature ◽  
Cmip3 Model ◽  
Incomplete Removal

Abstract. In a recent paper Hu et al. (2011) suggest that the recovery of stratospheric ozone during the first half of this century will significantly enhance free tropospheric and surface warming caused by the anthropogenic increase of greenhouse gases, with the effects being most pronounced in Northern Hemisphere middle and high latitudes. These surprising results are based on a multi-model analysis of CMIP3 model simulations with and without prescribed stratospheric ozone recovery. Hu et al. suggest that in order to properly quantify the tropospheric and surface temperature response to stratospheric ozone recovery, it is necessary to run coupled atmosphere-ocean climate models with stratospheric ozone chemistry. The results of such an experiment are presented here, using a state-of-the-art chemistry-climate model coupled to a three-dimensional ocean model. In contrast to Hu et al., we find a much smaller Northern Hemisphere tropospheric temperature response to ozone recovery, which is of opposite sign. We suggest that their result is an artifact of the incomplete removal of the large effect of greenhouse gas warming between the two different sets of models.

scholarly journals The Time-Scale-Dependent Response of the Wintertime North Atlantic to Increased Ocean Model Resolution in a Coupled Forecast Model

2020 ◽  
Vol 33 (9) ◽  
pp. 3663-3689 ◽  
Author(s):  
C. D. Roberts ◽  
F. Vitart ◽  
M. A. Balmaseda ◽  
F. Molteni
Keyword(s):  
North Atlantic ◽  
Time Scale ◽  
Storm Track ◽  
Forecast Model ◽  
Ocean Model ◽  
Surface Heating ◽  
Lead Times ◽  
Model Resolution ◽  
Seasonal Forecasts ◽  
The Impact

AbstractThis study uses initialized forecasts and climate integrations to evaluate the wintertime North Atlantic response to an increase of ocean model resolution from ~100 km [low-resolution ocean (LRO)] to ~25 km [high-resolution ocean (HRO)] in the European Centre for Medium-Range Weather Forecasts Integrated Forecasting System (ECMWF-IFS). Importantly, the simulated impacts are time-scale dependent such that impacts in subseasonal and seasonal forecasts cannot be extrapolated to climate time scales. In general, mean biases are reduced in HRO relative to LRO configurations and the impact is increased at longer lead times. At subseasonal to seasonal lead times, surface heating anomalies over the Gulf Stream are associated with local increases to the poleward heat flux associated with transient atmospheric eddies. In contrast, surface heating anomalies in climate experiments are balanced by changes to the time-mean surface winds that resemble the steady response under linear dynamics. Some aspects of air–sea interaction exhibit a clear improvement with increased resolution at all lead times. However, it is difficult to identify the impact of increased ocean eddy activity in the variability of the overlying atmosphere. In particular, atmospheric blocking and the intensity of the storm track respond more strongly to mean biases and thus have a larger response at longer lead times. Finally, increased ocean resolution drives improvements to subseasonal predictability over Europe. This increase in skill seems to be a result of improvements to the Madden–Julian oscillation and its associated teleconnections rather than changes to air–sea interaction in the North Atlantic region.

scholarly journals Comment on "Tropospheric temperature response to stratospheric ozone recovery in the 21st century" by Hu et al. (2011)

2011 ◽  
Vol 11 (12) ◽  
pp. 32993-33012 ◽  
Author(s):  
C. McLandress ◽  
J. Perlwitz ◽  
T. G. Shepherd
Keyword(s):  
Northern Hemisphere ◽  
Climate Models ◽  
Climate Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Temperature Response ◽  
Ocean Model ◽  
Tropospheric Temperature ◽  
Surface Warming ◽  
Incomplete Removal

Abstract. In a recent paper Hu et al. (2011) suggest that the recovery of stratospheric ozone during the first half of this century will significantly enhance free tropospheric and surface warming caused by the anthropogenic increase of greenhouse gases, with the effects being most pronounced in Northern Hemisphere middle and high latitudes. These surprising results are based on a multi-model analysis of IPCC AR4 model simulations with and without prescribed stratospheric ozone recovery. Hu et al. suggest that in order to properly quantify the tropospheric and surface temperature response to stratospheric ozone recovery, it is necessary to run coupled atmosphere-ocean climate models with stratospheric ozone chemistry. The results of such an experiment are presented here, using a state-of-the-art chemistry-climate model coupled to a three-dimensional ocean model. In contrast to Hu et al., we find a much smaller Northern Hemisphere tropospheric temperature response to ozone recovery, which is of opposite sign. We argue that their result is an artifact of the incomplete removal of the large effect of greenhouse gas warming between the two different sets of models.

scholarly journals Assimilation of stratospheric and mesospheric temperatures from MLS and SABER into a global NWP model

2008 ◽  
Vol 8 (20) ◽  
pp. 6103-6116 ◽  
Author(s):  
K. W. Hoppel ◽  
N. L. Baker ◽  
L. Coy ◽  
S. D. Eckermann ◽  
J. P. McCormack ◽  
...  
Keyword(s):  
High Altitude ◽  
Spatial Scales ◽  
Three Dimensional ◽  
Forecast Model ◽  
Temperature Structure ◽  
Deep Circulation ◽  
Broadband Emission ◽  
Mesospheric Temperature ◽  
Standard Deviations ◽  
Nwp Model

Abstract. The forecast model and three-dimensional variational data assimilation components of the Navy Operational Global Atmospheric Prediction System (NOGAPS) have each been extended into the upper stratosphere and mesosphere to form an Advanced Level Physics High Altitude (ALPHA) version of NOGAPS extending to ~100 km. This NOGAPS-ALPHA NWP prototype is used to assimilate stratospheric and mesospheric temperature data from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instruments. A 60-day analysis period in January and February 2006, was chosen that includes a well documented stratospheric sudden warming. SABER and MLS temperatures indicate that the SSW caused the polar winter stratopause at ~40 km to disappear, then reform at ~80 km altitude and slowly descend during February. The NOGAPS-ALPHA analysis reproduces this observed stratospheric and mesospheric temperature structure, as well as realistic evolution of zonal winds, residual velocities, and Eliassen-Palm fluxes that aid interpretation of the vertically deep circulation and eddy flux anomalies that developed in response to this wave-breaking event. The observation minus forecast (O-F) standard deviations for MLS and SABER are ~2 K in the mid-stratosphere and increase monotonically to about 6 K in the upper mesosphere. Increasing O-F standard deviations in the mesosphere are expected due to increasing instrument error and increasing geophysical variance at small spatial scales in the forecast model. In the mid/high latitude winter regions, 10-day forecast skill is improved throughout the upper stratosphere and mesosphere when the model is initialized using the high-altitude analysis based on assimilation of both SABER and MLS data.

Influence of Bathymetry on the Performance of Regional Scale Model

2017 ◽  
Vol 68 (1) ◽  
pp. 104
Author(s):  
P. Anand ◽  
P.V. Hareesh Kumar
Keyword(s):  
Ocean Circulation ◽  
Regional Scale ◽  
Three Dimensional ◽  
Coastal Region ◽  
Circulation Model ◽  
Ocean Model ◽  
Scale Model ◽  
Princeton Ocean Model ◽  
Nearshore Processes ◽  
Fine Resolution

<p class="p1"><span class="Apple-converted-space"> </span>A three dimensional ocean circulation model (Princeton Ocean Model) is utilised to study the thermohaline variability of the eastern Arabian Sea associated with changes in the three input bathymetry data sets, viz. ETOPO5 (E5), Modified ETOPO5 (ME5) and ME5 further modified based on actual fine resolution data collected using Multibeam echo-sounder (MEN5). The temperature and salinity measurements made onboard INS Sagardhwani for the period July 2000 is utilised to validate the model. Simulations of temperature using Princeton Ocean Model show good improvement in the coastal region with MEN5 bathymetry data (RMS error of 0.71 °C and correlation coefficient of 0.98). The study highlights the choice of fine resolution bathymetry data in the simulation of nearshore processes, where bathymetry is very complex.</p>

Evaluation of GFDL and Simple Statistical Model Rainfall Forecasts for U.S. Landfalling Tropical Storms

2007 ◽  
Vol 22 (1) ◽  
pp. 56-70 ◽  
Author(s):  
Robert E. Tuleya ◽  
Mark DeMaria ◽  
Robert J. Kuligowski
Keyword(s):  
Tropical Cyclones ◽  
Storm Track ◽  
Ground Truth ◽  
Forecast Model ◽  
Rain Gauge ◽  
Geophysical Fluid Dynamics Laboratory ◽  
Synoptic Conditions ◽  
Landfalling Tropical Cyclones ◽  
Model Versus ◽  
Gfdl Model

Abstract To date, little objective verification has been performed for rainfall predictions from numerical forecasts of landfalling tropical cyclones. Until 2001, digital output from the operational version of the Geophysical Fluid Dynamics Laboratory (GFDL) hurricane forecast model was available only on a 1° grid. The GFDL model was rerun or reanalyzed for 25 U.S. landfalling tropical cyclones from 1995 to 2002 to obtain higher resolution (1/3°) output. Several measures of forecast quality were used to evaluate the predicted rainfall from these runs, using daily rain gauge data as ground truth. The overall quality was measured by the mean error and bias averaged over all the gauge sites. An estimate of the quality of the forecasted pattern was obtained through the correlation coefficient of the model versus gauge values. In addition, more traditional precipitation verification scores were calculated including equitable threat and bias scores. To evaluate the skill of the rainfall forecasts, a simple rainfall climatology and persistence (R-CLIPER) model was developed, where a climatological rainfall rate is accumulated along either the forecasted or observed storm track. Results show that the R-CLIPER and GFDL forecasts had comparable mean absolute errors of ∼0.9 in. (23 mm) for the 25 cases. The GFDL model exhibited a higher pattern correlation with observations than R-CLIPER, but still only explained ∼30% of the spatial variance. The GFDL model also had higher equitable threat scores than R-CLIPER, partially because of a low bias of R-CLIPER for rainfall amounts larger than 0.5 in. (13 mm). A large case-to-case variability was found that was dependent on both synoptic conditions and track error.

Modeling and Assessment of the Produced Water Discharges from Offshore Petroleum Platforms

2007 ◽  
Vol 42 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Zhi Chen ◽  
Lin Zhao ◽  
Kenneth Lee ◽  
Charles Hannath
Keyword(s):  
Random Walk ◽  
Produced Water ◽  
Model Development ◽  
Three Dimensional ◽  
Monitoring Program ◽  
Ecological Monitoring ◽  
Numerical Approach ◽  
Ocean Model ◽  
Scale Model ◽  
Water Stream

Abstract There has been a growing interest in assessing the risks to the marine environment from produced water discharges. This study describes the development of a numerical approach, POM-RW, based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation of pollutant transport. Specifically, the POM is employed to simulate local ocean currents. It provides three-dimensional hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water stream on a regional spatial scale. Model development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results indicate that the POM-RW approach is useful to address environmental risks associated with the produced water discharges.

scholarly journals The effect of coastal upwelling on the sea-breeze circulation at Cabo Frio, Brazil: a numerical experiment

1998 ◽  
Vol 16 (7) ◽  
pp. 866-871 ◽  
Author(s):  
S. H. Franchito ◽  
V. B. Rao ◽  
J. L. Stech ◽  
J. A. Lorenzzetti
Keyword(s):  
Coastal Upwelling ◽  
Surface Wind ◽  
Three Dimensional ◽  
Sea Breeze ◽  
Atmospheric Model ◽  
Ocean Model ◽  
Breeze Circulation ◽  
Mesoscale Meteorology ◽  
Forcing Function ◽  
Cabo Frio

Abstract. The effect of coastal upwelling on sea-breeze circulation in Cabo Frio (Brazil) and the feedback of sea-breeze on the upwelling signal in this region are investigated. In order to study the effect of coastal upwelling on sea-breeze a non-linear, three-dimensional, primitive equation atmospheric model is employed. The model considers only dry air and employs boundary layer formulation. The surface temperature is determined by a forcing function applied to the Earth's surface. In order to investigate the seasonal variations of the circulation, numerical experiments considering three-month means are conducted: January-February-March (JFM), April-May-June (AMJ), July-August-September (JAS) and October-November-December (OND). The model results show that the sea-breeze is most intense near the coast at all the seasons. The sea-breeze is stronger in OND and JFM, when the upwelling occurs, and weaker in AMJ and JAS, when there is no upwelling. Numerical simulations also show that when the upwelling occurs the sea-breeze develops and attains maximum intensity earlier than when it does not occur. Observations show a similar behavior. In order to verify the effect of the sea-breeze surface wind on the upwelling, a two-layer finite element ocean model is also implemented. The results of simulations using this model, forced by the wind generated in the sea-breeze model, show that the sea-breeze effectively enhances the upwelling signal.Key words. Meteorology and atmospheric dynamics (mesoscale meteorology; ocean-atmosphere interactions) · Oceanography (numerical modeling)

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