Category: Scientific Papers (Abstract & PDF)

Study Finds Atlantic Meridional Overturning Circulation Increases Flood Risk Along the United States Southeastern Coast

Sea level rise is one of the most challenging consequences of global warming. A new collaborative study led by Dr. Denis Volkov from NOAA-AOML and the University of Miami’s Cooperative Institute of Marine and Atmospheric Studies found that Atlantic Meridional Overturning Circulation (AMOC) induced changes in basin-wide ocean heat content are influencing the frequency of floods along the United States southeastern coast. 

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Low Net Carbonate Accretion Characterizes Florida’s Coral Reef

John T. Morris, Ian C. Enochs, et al.

Coral reef habitat is created when calcium carbonate production by calcifiers exceeds removal by physical and biological erosion. Carbonate budget surveys provide a means of quantifying the framework-altering actions of diverse assemblages of marine species to determine net carbonate production, a single metric that encapsulates reef habitat persistence. In this study, carbonate budgets were calculated for 723 sites across the Florida Reef Tract (FRT) using benthic cover and parrot fish demographic data from NOAA’s National Coral Reef Monitoring Program, as well as high resolution LiDAR topobathymetry. Results highlight the erosional state of the majority of the study sites, with a trend towards more vulnerable habitat in the northern FRT, especially in the Southeast Florida region (− 0.51 kg CaCO3m−2 year−1), which is in close proximity to urban centers. Detailed comparison of reef types reveals that mid-channel reefs in the Florida Keys have the highest net carbonate production (0.84 kg CaCO3 m−2 year− 1) and indicates that these reefs may be hold-outs for reef development throughout the region. This study reports that Florida reefs, specifically their physical structure, are in a net erosional state. As these reefs lose structure, the ecosystem services they provide will be diminished, signifying the importance of increased protections and management efforts to offset these trends.

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New study establishes monitoring framework for evaluating reef persistence under climate change and ocean acidification

Webb, A.E., Enochs, I.C., van Hooidonk, R. et al. Restoration and coral adaptation delay, but do not prevent, climate-driven reef framework erosion of an inshore site in the Florida Keys. Sci Rep 13, 258 (2023).

For reef framework to persist, calcium carbonate production by corals and other calcifiers needs to outpace loss due to physical, chemical, and biological erosion. This balance is both delicate and dynamic and is currently threatened by the effects of ocean warming and acidification. Although the protection and recovery of ecosystem functions are at the center of most restoration and conservation programs, decision makers are limited by the lack of predictive tools to forecast habitat persistence under different emission scenarios. To address this, we developed a modelling approach, based on carbonate budgets, that ties species-specific responses to site-specific global change using the latest generation of climate models projections (CMIP6). We applied this model to Cheeca Rocks…

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Statistical Analysis of Convective Updrafts in Tropical Cyclone Rainbands Observed by Airborne Doppler Radar

Barron, N. R., Didlake Jr, A. C., & Reasor, P. D. (2022). Statistical Analysis of Convective Updrafts in Tropical Cyclone Rainbands Observed by Airborne Doppler Radar. Journal of Geophysical Research: Atmospheres127(6), e2021JD035718.4

Abstract: Ten years of airborne Doppler radar observations are used to study convective updrafts’ kinematic and reflectivity structures in tropical cyclone (TC) rainbands. An automated algorithm is developed to identify the strongest rainband updrafts across 12 hurricane-strength TCs. The selected updrafts are then collectively analyzed by their frequency, radius, azimuthal location (relative to the 200–850 hPa environmental wind shear), structural characteristics, and secondary circulation (radial/vertical) flow pattern. Rainband updrafts become deeper and stronger with increasing radius. A wavenumber-1 asymmetry arises, showing that in the downshear (upshear) quadrants of the TC, updrafts are more (less) frequent and deeper (shallower)…

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2019 Atlantic Hurricane Forecasts from the Global-Nested Hurricane Analysis and Forecast System: Composite Statistics and Key Events

Hazelton, A., Zhang, Z., Liu, B., Dong, J., Alaka, G., Wang, W., … & Marks, F. (2021). 2019 Atlantic hurricane forecasts from the global-nested hurricane analysis and forecast system: Composite statistics and key events. Weather and Forecasting36(2), 519-538.

Abstract: NOAA’s Hurricane Analysis and Forecast System (HAFS) is an evolving FV3-based hurricane modeling system that is expected to replace the operational hurricane models at the National Weather Service. Supported by the Hurricane Forecast Improvement Program (HFIP), global-nested and regional versions of HAFS were run in real time in 2019 to create the first baseline for the HAFS advancement. In this study, forecasts from the global-nested configuration of HAFS (HAFS-global nest) are evaluated and compared with other operational and experimental models. The forecasts by HAFS-global nest covered the period from July through October during the 2019 hurricane season. Tropical cyclone (TC) track, intensity, and structure forecast verifications are examined…

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Evaluating Satellite Sounders for Monitoring the Tropical Cyclone Environment in Operational Forecasting

Esmaili, R., Barnet, C., Dunion, J., Folmer, M., & Zawislak, J. (2022). Evaluating Satellite Sounders for Monitoring the Tropical Cyclone Environment in Operational Forecasting. Remote Sensing14(13), 3189.

Abstract: Tropical cyclones can form over open ocean where in situ observations are limited, so forecasters rely on satellite observations to monitor their development and track. We explore the utility of an operational satellite sounding product for tropical forecasting by characterizing the products retrieval skill during research flights. Scientists from both the NOAA-Unique Combined Atmospheric Processing System (NUCAPS) research team and tropical cyclone communities collaborated to target relevant tropical cyclones during the campaign. This effort produced 130 dropsondes that are welltimed with satellite sounder overpasses over three different tropical cyclones and one Saharan Air Layer outbreak…

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Performance of an Improved TKE-Based Eddy-Diffusivity Mass-Flux (EDMF) PBL Scheme in 2021 Hurricane Forecasts from the Hurricane Analysis and Forecast System

Chen, X., Hazelton, A., Marks, F. D., Alaka Jr, G. J., & Zhang, C. (2023). Performance of an Improved TKE-Based Eddy-Diffusivity Mass-Flux (EDMF) PBL Scheme in 2021 Hurricane Forecasts from the Hurricane Analysis and Forecast System. Weather and Forecasting38(2), 321-336.

Abstract: Continuous development and evaluation of planetary boundary layer (PBL) parameterizations in hurricane conditions are crucial for improving tropical cyclone (TC) forecasts. A turbulence kinetic energy (TKE)-based eddy-diffusivity mass-flux (EDMF-TKE) PBL scheme, implemented in NOAA’s Hurricane Analysis and Forecast System (HAFS), was recently improved in hurricane conditions using large-eddy simulations. This study evaluates the performance of HAFS TC forecasts with the original (experiment HAFA) and modified EDMF-TKE (experiment HAFY) based on a large sample of cases during the 2021 North Atlantic hurricane season…

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An Improved One-Dimensional Bending Angle Forward Operator for the Assimilation of Radio Occultation Profiles in the Lower Troposphere

Cucurull, L., & Purser, R. J. (2023). An improved one-dimensional bending angle forward operator for the assimilation of radio occultation profiles in the lower troposphere. Monthly Weather Review151(5), 1093-1108.

Abstract: Under very large vertical gradients of atmospheric refractivity, which are typical at the height of the planetary boundary layer, the assimilation of radio occultation (RO) observations into numerical weather prediction (NWP) models presents several serious challenges. In such conditions, the assimilation of RO bending angle profiles is an ill-posed problem, the uncertainty associated with the RO observations is higher, and the one-dimensional forward operator used to assimilate these observations has several theoretical deficiencies. As a result, a larger percentage of these RO observations are rejected at the NWP centers by existing quality control procedures, potentially limiting the benefits of this data type to improve weather forecasting in the lower troposphere…

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Observed Relationships Between Tropical Cyclone Vortex Height, Intensity, and Intensification Rate

DesRosiers, A. J., Bell, M. M., Klotzbach, P. J., Fischer, M. S., & Reasor, P. D. (2023). Observed relationships between tropical cyclone vortex height, intensity, and intensification rate. Geophysical Research Letters, 50(8), e2022GL101877.

Abstract: As a tropical cyclone (TC) intensifies, the tangential wind field expands vertically and increases in magnitude. Observations and modeling support vortex height as an important TC structural characteristic. The Tropical Cyclone Radar Archive of Doppler Analyses with Recentering data set provides kinematic analyses for calculation of the height of the vortex (HOV) in observed storms. Analyses are azimuthally-averaged with tangential wind values taken along the radius of maximum winds. A threshold-based technique is used to determine the HOV. A fixed threshold HOV strongly correlates with current intensity. A dynamic HOV metric quantifies vertical decay of tangential wind with reduced dependency on intensity. Statistically significant differences are present between dynamic HOV values in groups of steady-state, intensifying, and rapidly-intensifying cases categorized by subsequent changes in pressure.

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High-Definition Hurricanes: Improving Forecasts with Storm-Following Nests

Alaka Jr, G. J., Zhang, X., & Gopalakrishnan, S. G. (2022). High-definition hurricanes: improving forecasts with storm-following nests. Bulletin of the American Meteorological Society103(3), E680-E703.

Abstract: To forecast tropical cyclone (TC) intensity and structure changes with fidelity, numerical weather prediction models must be “high definition,” i.e., horizontal grid spacing ≤ 3 km, so that they permit clouds and convection and resolve sharp gradients of momentum and moisture in the eyewall and rainbands. Storm-following nests are computationally efficient at fine resolutions, providing a practical approach to improve TC intensity forecasts. Under the Hurricane Forecast Improvement Project, the operational Hurricane Weather Research and Forecasting (HWRF) system was developed to include telescopic, storm-following nests for a single TC per model integration.

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