NASA’s Hurricane and Severe Storm Sentinel (HS3) Investigation

Abstract The National Aeronautics and Space Administration’s (NASA) Hurricane and Severe Storm Sentinel (HS3) investigation was a multiyear field campaign designed to improve understanding of the physical processes that control hurricane formation and intensity change, specifically the relative roles of environmental and inner-core processes. Funded as part of NASA’s Earth Venture program, HS3 conducted 5-week campaigns during the hurricane seasons of 2012–14 using the NASA Global Hawk aircraft, along with a second Global Hawk in 2013 and a WB-57f aircraft in 2014. Flying from a base at Wallops Island, Virginia, the Global Hawk could be on station over storms for up to 18 h off the East Coast of the United States and up to about 6 h off the western coast of Africa. Over the 3 years, HS3 flew 21 missions over nine named storms, along with flights over two nondeveloping systems and several Saharan air layer (SAL) outbreaks. This article summarizes the HS3 experiment, the missions flown, and some preliminary findings related to the rapid intensification and outflow structure of Hurricane Edouard (2014) and the interaction of Hurricane Nadine (2012) with the SAL.

Download Full-text

The Impact of Outer-Core Surface Heat Fluxes on the Convective Activities and Rapid Intensification of Tropical Cyclones

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-19-0348.1 ◽

2020 ◽

Vol 77 (11) ◽

pp. 3907-3927

Author(s):

Chin-Hsuan Peng ◽

Chun-Chieh Wu

Keyword(s):

Inner Core ◽

Surface Wind ◽

Outer Core ◽

Surface Heat ◽

Heat Fluxes ◽

Intensity Change ◽

Rapid Intensification ◽

Core Surface ◽

Surface Heat Fluxes ◽

The Impact

AbstractThe rapid intensification (RI) of Typhoon Soudelor (2015) is simulated using a full-physics model. To investigate how the outer-core surface heat fluxes affect tropical cyclone (TC) structure and RI processes, a series of numerical experiments are performed by suppressing surface heat fluxes between various radii. It is found that a TC would become quite weaker when the surface heat fluxes are suppressed outside the radius of 60 or 90 km [the radius of maximum surface wind in the control experiment (CTRL) at the onset of RI is roughly 60 km]. However, interestingly, the TC would experience stronger RI when the surface heat fluxes are suppressed outside the radius of 150 km. For those sensitivity experiments with capped surface heat fluxes, the members with greater intensification rate show stronger inner-core mid- to upper-level updrafts and higher heating efficiency prior to the RI periods. Although the outer-core surface heat fluxes in these members are suppressed, the inner-core winds become stronger, extracting more ocean energy from the inner core. Greater outer-core low-level stability in these members results in aggregation of deep convection and subsequent generation and concentration of potential vorticity inside the inner core, thus confining the strongest winds therein. The abovementioned findings are also supported by partial-correlation analyses, which reveal the positive correlation between the inner-core convection and subsequent 6-h intensity change, and the competition between the inner-core and outer-core convections (i.e., eyewall and outer rainbands).

Download Full-text

Reassessing the Use of Inner-Core Hot Towers to Predict Tropical Cyclone Rapid Intensification*

Weather and Forecasting ◽

10.1175/waf-d-15-0024.1 ◽

2015 ◽

Vol 30 (5) ◽

pp. 1265-1279 ◽

Cited By ~ 6

Author(s):

Xiao-Yong Zhuge ◽

Jie Ming ◽

Yuan Wang

Keyword(s):

Tropical Cyclone ◽

Inner Core ◽

Prediction Method ◽

Vertical Shear ◽

Intensity Change ◽

False Alarms ◽

Rapid Intensification ◽

Central Pacific ◽

Prediction Scheme ◽

Skill Scores

Abstract The hot tower (HT) in the inner core plays an important role in tropical cyclone (TC) rapid intensification (RI). With the help of Tropical Rainfall Measurement Mission (TRMM) data and the Statistical Hurricane Intensity Prediction Scheme dataset, the potential of HTs in operational RI prediction is reassessed in this study. The stand-alone HT-based RI prediction scheme showed little skill in the northern Atlantic (NA) and eastern and central Pacific (ECP), but yielded skill scores of >0.3 in the southern Indian Ocean (SI) and western North Pacific (WNP) basins. The inaccurate predictions are due to four scenarios: 1) RI events may have already begun prior to the TRMM overpass. 2) RI events are driven by non-HT factors. 3) The HT has already dissipated or has not occurred at the TRMM overpass time. 4) Large false alarms result from the unfavorable environment. When the HT was used in conjunction with the TC’s previous 12-h intensity change, the potential intensity, the percentage area from 50 to 200 km of cloud-top brightness temperatures lower than −10°C, and the 850–200-hPa vertical shear magnitude with the vortex removed, the predictive skill score in the SI was 0.56. This score was comparable to that of the RI index scheme, which is considered the most advanced RI prediction method. When the HT information was combined with the aforementioned four environmental factors in the NA, ECP, South Pacific, and WNP, the skill scores were 0.23, 0.32, 0.42, and 0.42, respectively.

Download Full-text

Impact of Parameterized Boundary Layer Structure on Tropical Cyclone Rapid Intensification Forecasts in HWRF

Monthly Weather Review ◽

10.1175/mwr-d-16-0129.1 ◽

2017 ◽

Vol 145 (4) ◽

pp. 1413-1426 ◽

Cited By ~ 24

Author(s):

Jun A. Zhang ◽

Robert F. Rogers ◽

Vijay Tallapragada

Keyword(s):

Boundary Layer ◽

Tropical Cyclone ◽

Inner Core ◽

Layer Structure ◽

Intensity Change ◽

Rapid Intensification ◽

Near Surface ◽

Boundary Layer Structure ◽

Tangential Wind ◽

The Impact

Abstract This study evaluates the impact of the modification of the vertical eddy diffusivity (Km) in the boundary layer parameterization of the Hurricane Weather Research and Forecasting (HWRF) Model on forecasts of tropical cyclone (TC) rapid intensification (RI). Composites of HWRF forecasts of Hurricanes Earl (2010) and Karl (2010) were compared for two versions of the planetary boundary layer (PBL) scheme in HWRF. The results show that using a smaller value of Km, in better agreement with observations, improves RI forecasts. The composite-mean, inner-core structures for the two sets of runs at the time of RI onset are compared with observational, theoretical, and modeling studies of RI to determine why the runs with reduced Km are more likely to undergo RI. It is found that the forecasts with reduced Km at the RI onset have a shallower boundary layer with stronger inflow, more unstable near-surface air outside the eyewall, stronger and deeper updrafts in regions farther inward from the radius of maximum wind (RMW), and stronger boundary layer convergence closer to the storm center, although the mean storm intensity (as measured by the 10-m winds) is similar for the two groups. Finally, it is found that the departure of the maximum tangential wind from the gradient wind at the eyewall, and the inward advection of angular momentum outside the eyewall, is much larger in the forecasts with reduced Km. This study emphasizes the important role of the boundary layer structure and dynamics in TC intensity change, supporting recent studies emphasizing boundary layer spinup mechanism, and recommends further improvement to the HWRF PBL physics.

Download Full-text

INTERLOCKING PRECAST CONCRETE BLOCK SEAWALL

Coastal Engineering Proceedings ◽

10.9753/icce.v9.32 ◽

1964 ◽

Vol 1 (9) ◽

pp. 32

Author(s):

Robert A. Jachowski

Keyword(s):

United States ◽

East Coast ◽

Precast Concrete ◽

Concrete Block ◽

The United States ◽

Shore Protection ◽

Severe Storm ◽

Run Up

As a result of a survey of damage caused by the severe storm of March 1962 which affected the entire east coast of the United States, a new and specially-shaped interlocking concrete block was developed for use in shore protection. This block is designed to be used in a revetment-type seawall that will be both durable and economical as well as reduce wave run-up and overtopping, and scour at its base or toe. A description of model investigations conducted on the interlocking precast concrete block seawall and results there from are presented. It is shown that effective shore protection can be designed utilizing these units.

Download Full-text

Necessary Conditions for Tropical Cyclone Rapid Intensification as Derived from 11 Years of TRMM Data

Journal of Climate ◽

10.1175/jcli-d-12-00432.1 ◽

2013 ◽

Vol 26 (17) ◽

pp. 6459-6470 ◽

Cited By ~ 46

Author(s):

Haiyan Jiang ◽

Ellen M. Ramirez

Keyword(s):

Brightness Temperature ◽

Tropical Cyclones ◽

Inner Core ◽

Necessary Conditions ◽

Tropical Rainfall Measuring Mission ◽

Intensity Change ◽

Rapid Intensification ◽

Minimum Threshold ◽

Near Surface ◽

Total Lightning

Abstract Rainfall and convective properties of tropical cyclones (TCs) are statistically quantified for different TC intensity change categories by using Tropical Rainfall Measuring Mission (TRMM) data from December 1997 to December 2008. Four 24-h future intensity change categories are defined: rapidly intensifying (RI), slowly intensifying, neutral, and weakening. It is found that RI storms always have a larger raining area and total volumetric rain in the inner core. The maximum convective intensity in the inner core is not necessarily more intense prior to undergoing an RI episode than a slowly intensifying, neutral, or weakening episode. Instead, a minimum threshold of raining area, total volumetric rain, and convective intensity in the inner core is determined from the RI cases examined in this study. The following necessary conditions for RI are found in the inner core: total raining area > 3000 km2, total volumetric rain > 5000 mm h−1 km2, maximum near-surface radar reflectivity > 40 dBZ, maximum 20-dBZ (40 dBZ) echo height > 8 (4) km, minimum 85-GHz polarization–corrected brightness temperature (PCT) < 235 K, and minimum 10.8-μm brightness temperature < 220 K. To the extent that these thresholds represent all RI cases, they should be of value to forecasters for ruling out RI. This study finds that total lightning activities in the inner core (outer rainband) have a negative (positive) relationship with storm intensification.

Download Full-text

A Revised Tropical Cyclone Rapid Intensification Index for the Atlantic and Eastern North Pacific Basins

Weather and Forecasting ◽

10.1175/2009waf2222280.1 ◽

2010 ◽

Vol 25 (1) ◽

pp. 220-241 ◽

Cited By ~ 257

Author(s):

John Kaplan ◽

Mark DeMaria ◽

John A. Knaff

Keyword(s):

North Pacific ◽

Large Scale ◽

Inner Core ◽

Probability Of Detection ◽

Vertical Shear ◽

Intensity Change ◽

Rapid Intensification ◽

Atlantic Basin ◽

Linear Discriminant ◽

Intensity Index

Abstract A revised rapid intensity index (RII) is developed for the Atlantic and eastern North Pacific basins. The RII uses large-scale predictors from the Statistical Hurricane Intensity Prediction Scheme (SHIPS) to estimate the probability of rapid intensification (RI) over the succeeding 24 h utilizing linear discriminant analysis. Separate versions of the RII are developed for the 25-, 30-, and 35-kt RI thresholds, which represent the 90th (88th), 94th (92nd), and 97th (94th) percentiles of 24-h overwater intensity changes of tropical and subtropical cyclones in the Atlantic (eastern North Pacific) basins from 1989 to 2006, respectively. The revised RII became operational at the NHC prior to the 2008 hurricane season. The relative importance of the individual RI predictors is shown to differ between the two basins. Specifically, the previous 12-h intensity change, upper-level divergence, and vertical shear have the highest weights for the Atlantic basin, while the previous 12-h intensity change, symmetry of inner-core convection, and the difference in a system’s current and maximum potential intensity are weighted highest in the eastern North Pacific basin. A verification of independent forecasts from the 2006 and 2007 hurricane seasons shows that the probabilistic RII forecasts are generally skillful in both basins when compared to climatology. Moreover, when employed in a deterministic manner, the RII forecasts were superior to all other available operational intensity guidance in terms of the probability of detection (POD) and false alarm ratio (FAR). Specifically, the POD for the RII ranged from 15% to 59% (53% to 73%) while the FAR ranged from 71% to 85% (53% to 79%) in the Atlantic (eastern North Pacific) basins, respectively, for the three RI thresholds studied. Nevertheless, the modest POD and relatively high FAR of the RII and other intensity guidance demonstrate the difficulty of predicting RI, particularly in the Atlantic basin.

Download Full-text

Aeromagnetic survey of the east coast of the United States, Georges Bank area 38-66

Open-File Report ◽

10.3133/ofr791357 ◽

1979 ◽

Author(s):

John Charles Behrendt ◽

Kim D. Klitgord

Keyword(s):

United States ◽

East Coast ◽

The United States ◽

Georges Bank ◽

Aeromagnetic Survey

Download Full-text

Aeromagnetic survey of the east coast of the United States, Georges Bank area 38-70

Open-File Report ◽

10.3133/ofr791359 ◽

1979 ◽

Author(s):

John Charles Behrendt ◽

Kim D. Klitgord

Keyword(s):

United States ◽

East Coast ◽

The United States ◽

Georges Bank ◽

Aeromagnetic Survey

Download Full-text

Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change

Nature Communications ◽

10.1038/s41467-021-22838-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Benjamin H. Strauss ◽

Philip M. Orton ◽

Klaus Bittermann ◽

Maya K. Buchanan ◽

Daniel M. Gilford ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

East Coast ◽

The United States ◽

Hurricane Sandy ◽

Water Levels ◽

Anthropogenic Climate Change ◽

Economic Damage ◽

Sea Levels

AbstractIn 2012, Hurricane Sandy hit the East Coast of the United States, creating widespread coastal flooding and over $60 billion in reported economic damage. The potential influence of climate change on the storm itself has been debated, but sea level rise driven by anthropogenic climate change more clearly contributed to damages. To quantify this effect, here we simulate water levels and damage both as they occurred and as they would have occurred across a range of lower sea levels corresponding to different estimates of attributable sea level rise. We find that approximately $8.1B ($4.7B–$14.0B, 5th–95th percentiles) of Sandy’s damages are attributable to climate-mediated anthropogenic sea level rise, as is extension of the flood area to affect 71 (40–131) thousand additional people. The same general approach demonstrated here may be applied to impact assessments for other past and future coastal storms.

Download Full-text