Over the last few days, the 7-day forecast experiment upgrade has been working well. Our output from forecasts initialized on the 6th and 7th are largely in line with the forecast models that the National Hurricane Center (NHC) has been favoring in their forecast tracks. We have been utilizing additional resources provided by the High Performance Computing (HPC) center at NC State for our experimental 7-day simulations. However, the operational 3-day model simulations are our first priority to assess immediate hazards, so these experimental 7-day products take longer to develop.
As Irma moves closer to land and becomes a hazard to the mainland U.S. within our normal 72-hour forecast window, we will provide analysis on both products.
Over the last few weeks, we have been working to expand the current CNAPS forecast from 3 to 7 days. With the appearance of Hurricanes Harvey and Irma, and the peak of the hurricane season on September 10, we were graciously allocated additional computing power from the High Performance Computing (HPC) Center at North Carolina State University to perform some experimental simulations of a 7-day forecast. We now have a framework to run our CNAPS nowcast/forecast for 168 hours quasi-operationally.
This forecast, initialized at 00Z on September 5, shows Irma entering the CNAPS domain near the Leeward Islands in the Caribbean, moving along the northern coast of Cuba, abruptly making a turn to the north to bisect the state of Florida, then weakening over the southeast U.S. This is in line with several of the national forecast models run at the same time.
Our usual 72-hour CNAPS forecast will run as normal, and we will provide additional experimental analysis and products about Irma as it threatens the U.S. Stay tuned for more updates.
Dr. Roy He served on the PhD committee of Ann Kristin Sperrevik at the University of Bergen, in Norway, and attended her defense in June 2017. Her thesis title is “Modeling coastal circulation in Norway using a high-resolution 4D-Var ocean assimilation system.” Also serving on Ms. Sperrevik’s committee were Dr. Anthony T. Weaver of CERFACS, France, and Dr. Tor Eldevik of the University of Bergen. Dr. Sperrevik defended successfully and is now on staff at the Norwegian Meteorological Institute.
The Kenan Institute of Engineering, Technology, and Science (KIETS) at NC State University has funded OOMG’s research on Dynamical Model Downscaling of Climate Change and Its Impacts on Marine Environmental Conditions Off North Carolina. Support for this research into the slowdown on the Atlantic meridional overturning circulation (AMOC) will enable OOMG to refine fine-scale modeling of the Gulf Stream near North Carolina, and leverage other funding to enhance our programs. Together, KIETS and OOMG will provide important information to benefit coastal stakeholders and communities.
We thank KIETS for their support and look forward to a productive relationship.
OOMG director Dr. Roy He and grad student Laura McGee attended the Gordon Research Seminar and Conference at the University of New England from June 9 – 16, 2017. Dr. He served as the co-chair of the conference this year, along with Dr. Jack Barth. Vice-chair was Dr. Erica McPhee-Shaw. Laura McGee presented a poster titled “Physical Mechanisms Behind Asymmetric Cooling and Hurricane-Induced Phytoplankton Blooms,” developed from her master’s Thesis research. Congratulations to Laura for winning one of three Best Poster Awards!
Row 1: Antonio Baptista, Rachel Horwitz, Amy Waterhouse, Matthew Oliver, Jonathan Sharples, Maitane Olabarrieta, Ved Chirayath, Erika McPhee-Shaw, Jack Barth, Ruoying He, Alexander Barth, Hans Ngodock, Edward Zaron, Stefan Talke, Caroline Ummenhofer, Andrea Ogston, Joan Kleypas
Row 2: Emily Shroyer, Veronica Ruiz, Rebecca Jackson, Melissa Moulton, Melanie Fewings, Laura McGee, Hugo Bastos de Oliveira, Aboozar Tabatabai, Megan Williams, Christopher Edwards, Ivy Huang, Kurt Nelson, Lars Arneborg, Frode Vikebo, Eric Mayer, Ata Suanda, Michael Jacox, Courtney Harris
Row 3: Robert Hetland, Tracy Mandel, Julia Moriarty, Mary Lee King, Madeleine Harvey, Michelle DiBenedetto, Claudia Cenedese, Haixing Wang, Madeleine Hamann, Michelle Fogarty, Carol Ladd, Emily Lemagie, Frank Colberg, Weifeng (Gordon) Zhang, Gabriela Semolini Pilo, Ganesh Gopalakrishnan, Yan Jia, Qiang Sun, Sung Yong Kim, Xiaodong Wu
Row 4: Cristina Schultz, Anna Pfeiffer-Herbert, Kristen Thyng, Amala Mahadevan, Bob Chant, Michael Whitney, Lakshika Girihagama, Andre Paloczy, James Pringle, Jennifer Jardine, John Wilkin, George Voulgaris, Emma Reid, Juliane Wihsgott, Jennifer Thomas, Fernando Pareja, Jeff Coogan, Brian Dzwonkowski, Elise Olson, Hally Stone, Raul Flores Audibert
Row 5: Deepak Cherian, Praneeth Gurumurthy, Fei Da, Shih-Nan Chen, Charles McMahon, Yosuke Igeta, Ke Chen, Jacqueline McSweeney, Jacob Partida, Greg Sinnett, Neil Ganju, Steven Lentz, Kenneth Brink, James O’Donnell, Anthony Kirincich, Thomas Connolly, Alfredo Aretxabaleta, Sam Kastner, Kieran Newman, Lixin Qu, Suyash Bire
Row 6: Philip Orton, Dan Nowacki, Joe Adelson, Jordan Snyder, Gregory Gerbi, Geno Pawlak, Sally Warner, Angelica Rodriguez, Anna Lowe, Steven Schmidt, Justin Rogers, Kristen Davis, Albert Hermann, Bryan Flood, Till Hanebuth, Saeed Moghimi, Alexander Lopez, Tarandeep Kalra, Charles Stock, Andrew (Drew) Lucas, Kelly Cole, Claudia Hinrichs
Model coupling is the connection of several separate numerical models so that output from each model becomes input for the other models. Models exchange information at specified intervals, so that, for example, predictions about the weather affect and are affected by ocean surface temperature, sea surface roughness, heat flux, etc. This allows a more complete and realistic description of ocean conditions than that available from uncoupled, stand-alone models.
Some of the sub-models that can be coupled include models of ocean conditions, weather, sea ice, waves, plankton, and biogeochemistry.
Models of ocean conditions are numerical predictions of what the ocean is like at a given time, based on inputs and known physics. The inputs are observations from satellites, moorings, tidal gauges, high-frequency radar stations, and buoys, among other sources. This information is collected daily and fed into the model. The model takes this new data, along with model estimates from the previous calculation, and applies equations of fluid physics to calculate how the conditions at a site will change over a given time period. To describe the conditions of a body of water, the model fills that three-dimensional body with millions of points arrayed in a 3-D grid. It calculates the conditions at each point, based on the point’s previous conditions, observations near that point, and the amount of time from the last calculation. All these point calculations are the model output, and are often visualized in a 3-D map of the water body.
A research cruise in the Gulf of Mexico to support the project Three-Dimensional Gulf Circulation and Biogeochemical Processes Unveiled by State-of-the-Art Profiling Float Technology and Data Assimilative Ocean Models will take place May 1-10, 2017. University of Miami’s Rosenstiel School of Marine and Atmospheric Science (RSMAS) is leading the expedition, aboard the R/V F. G. Walton Smith. UMiami Principal Investigator (PI) Nick Shay, NC State University PI Roy He, Dalhousie University PI Katja Fennel, and Peter Furze of Teledyne Webb Research are collaborating on this project to build a rapid response capability that can be deployed in the event of an oil spill.
Jodi Brewster of RSMAS has posted a blog of cruise preparation, which will continue as a log book as the cruise gets underway. Follow along to learn about how scientists prepare for the intense 24-hour-a-day schedule of research activities onboard the ship.
NCSU’s College of Science set up tables of information and activities throughout Hunt Library on April 21. The Ocean Observing and Modeling Group was represented by Nabi Allahdadi, Shun Mao, Laura McGee, and Jennifer Warrillow. Hundreds of people toured the Library to learn about the science conducted at the university. Nabi, Shun, Laura, and Jennifer had the opportunity to explain ocean modeling in general and the CNAPS model specifically to people of all ages. Surfers, fishers, meteorologists, and others enjoyed learning about the features of ocean models.
Onboard the R/V Neil Armstrong, OOMG’s Joe Zambon and NCSU Marine Science undergrad Lauren Ball have been assisting with the NSF-funded Processes investigating Exchange Around Cape Hatteras (NSF-PEACH) project. A crucial component of the ongoing cruise is to utilize real-time in situ, satellite, and model data to assist Chief Scientist Magdalena Andres position the ship for crucial measurements while at sea. Joe designed a data pipeline to provide this imagery in a timely manner, with limited internet connection at sea. 24/7 operations means that the work never stops as Joe and Lauren has been working the overnight shift to sample and prepare important data for cruise planning meetings in the early morning. In addition, a concerning forecast for the next few days has extended this analysis to include weather and wave models. Over the next few hours, the crew will be deciding where to head next as a gale is expected to blow through the study region Monday night into Tuesday.
Valerie Winzenried, a retired gifted-education teacher and an education consultant for Eastman, boarded the R/V Neil Armstrong last week. During her time at sea, she has been participating in hands-on research and data analysis along with onboard scientists. In addition, she has been interviewing researchers in order to construct lesson plans in geosciences to educate the next generation of oceanographers. She sat down with OOMG’s Joe Zambon on Thursday night to discuss ocean models, remote observations, cruise planning, and the various methods that have been used to sample the ocean’s physical parameters. It was a great experience for both as their discussion covered a wide-range of possible topics for high school education and opened the door for future communication.
Last Saturday (22-April) marked the halfway point of the NSF-PEACH R/V Neil Armstrong cruise with OOMG’s Joe Zambon and NCSU Marine Science undergrad Lauren Ball. While underway at sea, both researchers have participated in research exploring the waters along the continental shelf from Cape Cod, MA to Cape Hatteras, NC. So far, the team has taken advantage of the prevailing calm seas and have deployed meteorological buoys, Acoustic Doppler Current Profilers (ADCPs), Pressure-Inverted Echo Sounders (PIES), eXpendible BathyThermographs (XBTs), Conductivity-Temperature-Depth (CTD) profilers, hydrophones, Argo floats, autonomous gliders, and have collected and filtered hundreds of liters of sea water from the surface to the sea floor for analysis.
Throughout the NSF-PEACH research cruise, OOMG’s Joe Zambon has been providing data to PIs and Chief Scientist Magdalena Andres for cruise planning. Several study sites were pre-determined months in advance, but this data has been instrumental in determining supplementary surveys of the Gulf Stream. In addition, short-duration features such as eddies have been sampled by determining their location while at sea. One significant challenge of this has been to balance data from satellites and models. While satellite data provides a high-resolution (~1 km) daily picture, there are gaps where they cannot see through clouds – a big problem in coastal environments. To fill the gaps, OOMG’s numerical models are employed with lower resolution (~7 km). The two products, working in tandem, allow research scientists to deploy instrumentation and direct transects with more confidence than any one product alone. Below is a short animation of the PEACH domain with Satellite and CNAPS model-resolved Sea Surface Temperature (SST).
One cruise objective for the April 2017 NSF-PEACH research cruise is to conduct a bathymetric survey of the shelf break approximately 20 nautical miles east-southeast of Cape Hatteras, NC. UNC’s Sara Haines explains that existing bathymetry in this area is of questionable quality possibly owing to the stitching of hand-drawn bathymetric maps in along the line of latitude at 35ºN. Over 2 evenings, R/V Neil Armstrong will drive several lines over the area while using shipboard multibeam sonar in order to survey the seafloor. This data will be extremely important for OOMG’s numerical models resolving the area in future studies of the Gulf Stream and shelf water exchange.
The cruise progresses, and the scientists have used calm weather days to work on instruments on moored buoys. Some deployed instruments are already returning data, showing the velocity of the Gulf Stream.
Read details of the instruments being used at the UNC Coastal Studies Institute’s site here.
Read the research project overview here.