Author: AOML Communications

The HWRF Hurricane Ensemble Data Assimilation System (HEDAS) for High-Resolution Data: The Impact of Airborne Doppler Radar Observations in an OSSE

Aksoy, A., S. Lorsolo, T. Vukicevic, K.J. Sellwood, S.D. Aberson, and F. Zhang, 2012: The HWRF Hurricane Ensemble Data Assimilation System (HEDAS) for High-Resolution Data: The Impact of Airborne Doppler Radar Observations in an OSSE. Mon. Wea. Rev., 140, 1843–1862, https://doi.org/10.1175/MWR-D-11-00212.1

Abstract:

Within the National Oceanic and Atmospheric Administration, the Hurricane Research Division of the Atlantic Oceanographic and Meteorological Laboratory has developed the Hurricane Weather Research and Forecasting (HWRF) Ensemble Data Assimilation System (HEDAS) to assimilate hurricane inner-core observations for high-resolution vortex initialization. HEDAS is based on a serial implementation of the square root ensemble Kalman filter. HWRF is configured with a horizontal grid spacing of 9/3 km on the outer/inner domains. In this preliminary study, airborne Doppler radar radial wind observations are simulated from a higher-resolution (4.5/1.5 km) version of the same model with other modifications that resulted in appreciable model error. A 24-h nature run simulation of Hurricane Paloma was initialized at 1200 UTC 7 November 2008 and produced a realistic, category-2-strength hurricane vortex. The impact of assimilating Doppler wind observations is assessed in observation space as well as in model space. It is observed that while the assimilation of Doppler wind observations results in significant improvements in the overall vortex structure, a general bias in the average error statistics persists because of the underestimation of overall intensity. A general deficiency in ensemble spread is also evident. While covariance inflation/relaxation and observation thinning result in improved ensemble spread, these do not translate into improvements in overall error statistics. These results strongly suggest a need to include in the ensemble a representation of forecast error growth from other sources such as model error.

Download PDF

Read Full Article
Students engage with our scientists to learn about AOML's carbon labs

Join Us! NOAA Open House 2020

NOAA is turning 50!  The federal science agency that provides daily weather forecasts, severe storm warnings, fisheries management, and coastal restoration, is celebrating by opening its doors to the south Florida community with a free open house on April 25th, 2020 from 10:00 a.m to 3:00 p.m.  What better way to celebrate Earth Day than seeing science in action with friends and family!

Read Full Article

TACOS Program Hits 25,000th Profile Milestone!

TACOS has added 10 acoustic current meters to the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA) buoy, moored at 4N, 23W.  Profile measurements are taken every 1-10 minutes, depending on depth.  Prior to the addition of the TACOS upper ocean observations in March 6, 2017 velocity profiles were only collected at this location during shipboard surveys.  These measurements are important because ocean currents influence temperature, salinity, and air-sea fluxes in the tropical North Atlantic, which affect weather, climate, and fisheries of the surrounding continents.

Read Full Article
Muhling, B. A., S.-K. Lee, J. T. Lamkin and Y. Liu, 2011. Predicting the Effects of Climate Change on Bluefin Tuna (Thunnus thynnus) Spawning habitat in the Gulf of America. ICES Journal of Marine Science, doi:10.1093/icesjms/fsr008

Predicting the effects of climate change on bluefin tuna (Thunnus thynnus) spawning habitat in the Gulf of America

Muhling, B. A., S.-K. Lee, J. T. Lamkin and Y. Liu, 2011. Predicting the Effects of Climate Change on Bluefin Tuna (Thunnus thynnus) Spawning habitat in the Gulf of America. ICES Journal of Marine Science, doi:10.1093/icesjms/fsr008

Abstract:

Atlantic bluefin tuna (BFT) is a highly migratory species that feeds in cold waters in the North Atlantic, but migrates to tropical seas to spawn. Global climate-model simulations forced by future greenhouse warming project that upper-ocean temperatures in the main western Atlantic spawning ground, the Gulf of America (GOM), will increase substantially, potentially altering the temporal and spatial extent of BFT spawning activity. In this study, an ensemble of 20 climate model simulations used in the Intergovernmental Panel for Climate Change fourth Assessment Report (IPCC-AR4) predicted mean temperature changes…

Download PDF

Read Full Article

AOML Contributes Ocean Carbon Observations for the Global Carbon Budget 2019

Every year the Global Carbon Project publishes an authoritative observation based Global Carbon Budget detailing the annual release of fossil fuel carbon dioxide and the uptake by the terrestrial biosphere and oceans. In 2018 the global carbon emissions were still increasing, but their rate of increase had slowed. Global carbon emissions are set to grow more slowly in 2019, with a decline in coal burning offset by strong growth in natural gas use worldwide. 

Read Full Article
Diagram that shows the interactions, exchange, and circulation of carbon dioxide within the ocean, identifying where satellite-based Earth observations are likely to play a leading role in expanding understanding and capability: (1) atmospheric measurements at the ocean surface; (2) quantifying gas, momentum, and heat atmosphere–ocean exchange processes; (3) capturing near-surface gradients in the water; and (4) measuring internal circulation and surface transport. Image from Frontiers in Ecology and the Environment.

Study Calls for Greater Use of Satellites to Monitor Ocean Carbon

The ability to predict Earth’s future climate relies upon monitoring efforts to determine the fate of carbon dioxide emissions. For example, how much carbon stays in the atmosphere or becomes stored in the oceans or on land? The oceans in particular have helped to slow climate change as they absorb and then store carbon dioxide for thousands of years.

Read Full Article
AOML’s hurricane scientists and friends celebrated the last regularly scheduled tropical weather discussion of the year on October 18. While an AOML crew gathered data in Tropical Storm Nestor, those on the ground gathered for Aloha Friday. AOML hosted the daily discussions throughout hurricane season to review storm activity in the Atlantic and Pacific basins. This year’s discussions were presented by scientists and students from AOML, the National Hurricane Center, and an assortment of universities and cooperative institutes. Photo Credit: NOAA AOML.

AOML Flies Science Missions into Succession of Atlantic Storms

AOML’s hurricane scientists conducted multiple airborne missions into several tropical systems that formed in the Atlantic in September and October. The data gathered in Humberto, Jerry, pre-Karen, Lorenzo, and Nestor improved track and intensity forecasts, aiding NOAA’s efforts to prepare vulnerable communities for severe weather. The missions also supported research to better understand how tropical cyclones form, intensify, and dissipate, as well as supported efforts to validate satellite measurements of these storms.

Read Full Article
Ian Enochs presenting in experimental reef lab. Photo Credit: NOAA AOML.

AOML Hosts Three Day External Laboratory Review

November 19 – 21, 2019, AOML hosted a three day external review to evaluate the quality, performance, and relevance of our research portfolio. NOAA’s Office of Oceanic and Atmospheric Research conducts these reviews every five years to gauge the effectiveness of the research portfolios of all the labs, and also to forge new partnerships for research and collaborations across NOAA. Feedback received after the completion of the lab review will help set new priorities for AOML. The 2019 AOML review featured presentations from each science division, lightning talks from scientists, a poster session, lab tours, and an early career luncheon. We also had the pleasure of hosting Deputy NOAA Administrator Rear Admiral Tim Gallaudet at the opening of the review. 

Read Full Article

Braving the Eye of the Storm

The most dangerous part of the hurricane is the eyewall close to the ocean. It’s where the storm draws energy from heat in the water, which influences how strong – and how quickly – the storm will develop. It’s also where the strongest winds lurk.Direct and continuous observations of the lower eye-wall would help forecasters understand critical information about the storm’s development. NOAA P-3 “Hurricane Hunters” routinely fly through hurricane eyewalls to gather storm data, but avoid flying close to the ocean because conditions are too hazardous.

Read Full Article
Ian Enochs, pictured with his wife and son, awarded with the DOC Silver Medal Award.

AOML’s Ian Enochs Awarded DOC Silver Medal Award

AOML coral ecologist, Ian Enochs, was recently awarded with the Department of Commerce Silver Medal Award for his leadership in developing and implementing the Sub-Surface Automated Sampler (SAS).  The DOC Silver Medal is awarded to federal employees for exceptional performance characterized by noteworthy contributions which have a direct and lasting impact.

Read Full Article