CW3E Publication Notice: West Coast Forecast Challenges and Development of Atmospheric River Reconnaissance

CW3E Publication Notice

West Coast Forecast Challenges and Development of Atmospheric River Reconnaissance

May 13, 2020

CW3E Director and Atmospheric River Reconnaissance (AR Recon) Principal Investigator F. Martin Ralph, alongside coauthors including CW3E’s Forest Cannon, Anna Wilson, Minghua Zheng, Chad Hecht, Brian Kawzenuk, and Luca Delle Monache; Scripps Institution of Oceanography researchers Jennifer Haase and Luca Centurioni; NOAA/NWS/NCEP AR Recon Co-PI Vijay Tallapragada; NCAR collaborator Chris Davis; Naval Research Laboratory collaborators Jim Doyle and Carolyn Reynolds; ECMWF collaborators Florian Pappenberger, David Lavers, and Bruce Ingleby; University of Colorado Boulder collaborator Aneesh Subramanian; NWS Western Region collaborator Jon Rutz; and Plymouth State University collaborator Jay Cordeira, published a paper in the Bulletin of the American Meteorological Society titled “West Coast Forecast Challenges and Development of Atmospheric River Reconnaissance” (Ralph et al. 2020). This work is a part of CW3E’s ongoing effort to understand and improve the predictions of ARs and their impacts on public safety and water management, supporting local water agencies, California Department of Water Resources, NOAA and the U.S. Army Corps of Engineers.

AR Recon is led by the Center for Western Weather and Water Extremes and NWS/NCEP. The effort’s core partners include the Navy, Air Force, NCAR, ECMWF and multiple academic institutions (see Figure 1 for a schematic of the organizational structure). It is part of the “National Winter Season Operations Plan” to support improved outcomes for emergency preparedness and water management in the West. AR Recon is now transitioning into an operational mode that enhances the deep linkage between research and operations and the collaborative culture that has been a pillar on which AR Recon has developed.

AR Recon was developed as a research and operations partnership to directly support critical water management and flood control objectives in the western United States (see Major Milestones in Table 1). It combines new observations, modeling, data assimilation and forecast verification methods to improve the science and predictions of landfalling ARs. ARs over the northeast Pacific are measured using dropsondes from up to three aircraft simultaneously. Additionally, innovative observations such as airborne radio occultation are being tested, and drifting buoys with pressure sensors are deployed each year. AR targeting and data collection methods have been developed, assimilation and forecast impact experiments are ongoing, and better understanding of AR dynamics is emerging.

Table 1. Table 4 from Ralph et al. (2020).

Figure 1. Fig. 6 from Ralph et al. (2020). Organizational chart showing participating individuals and their responsibilities during AR Recon 2018.

Ralph, F.M., F. Cannon, V. Tallapragada, C.A. Davis, J.D. Doyle, F. Pappenberger, A. Subramanian, A.M. Wilson, D.A. Lavers, C.A. Reynolds, J.S. Haase, L. Centurioni, B. Ingleby, J.J. Rutz, J.M. Cordeira, M. Zheng, C. Hecht, B. Kawzenuk, and L. Delle Monache, 2020: West Coast Forecast Challenges and Development of Atmospheric River Reconnaissance. Bull. Amer. Meteor. Soc., 0, https://doi.org/10.1175/BAMS-D-19-0183.1

Congratulations to Dr. Demirdjian – CW3E Graduate Student Successfully Defends Dissertation

Congratulations to Dr. Demirdjian – CW3E Graduate Student Successfully Defends Dissertation

May 12, 2020

The third CW3E PhD student (and second in one week!) has successfully defended his dissertation. Dr. Reuben Demirdjian’s defense was held on Friday, May 8, 2020. His dissertation title is “Mesoscale Dynamics of Atmospheric Rivers,” and includes two chapters published in peer-review journals (Demirdjian et al., 2020a,b). His third chapter has been submitted to the Journal of the Atmospheric Sciences. Reuben’s committee members were Marty Ralph and Joel Norris (Co-Chairs), Amato Evan, Jan Kleissl, Richard Rotunno, and Shang-Ping Xie. Funding for Reuben’s dissertation came from FIRO and the AR Program, both under PI Marty Ralph.

Reuben has been selected to be a Postdoctoral Scholar working with Jim Doyle and Carolyn Reynolds at the Naval Research Laboratory in Monterey, CA.

Due to the COVID-19 health crisis, Reuben defended his dissertation virtually. CW3E is incredibly proud of Reuben’s accomplishment, and looks forward to celebrating with him in-person as soon as the health precautions are no longer necessary.

Reuben Demirdjian beginning his dissertation defense via Zoom after an introduction by Committee Co-Chair Marty Ralph.

Reuben Demirdjian concluding his dissertation defense via Zoom.

Demirdjian, R., Doyle, J.D., Reynolds, C.A. Norris, J.A., Michaelis, A.C., Ralph, F.M., 2020a: A Case Study of the Physical Processes Associated with the Atmospheric River Initial Condition Sensitivity from an Adjoint Model. J. Atmos. Sci., 77, 691-709, https://doi.org/10.1175/JAS-D-19-0155.1

Demirdjian, R., J.R. Norris, A. Martin, and F.M. Ralph, 2020b: Dropsonde Observations of the Ageostrophy within the Pre-Cold-Frontal Low-Level Jet Associated with Atmospheric Rivers. Mon. Wea. Rev., 148, 1389-1406, https://doi.org/10.1175/MWR-D-19-0248.1

CW3E Surface Met Data Now Available on MesoWest and MADIS

CW3E Surface Met Data Now Available on MesoWest and MADIS

May 11, 2020

We are excited to announce that data from 11 CW3E surface met stations are now being disseminated to University of Utah’s MesoWest, a public data repository for real-time atmospheric data. The data is made available through a connection with Synoptic Data PBC, an entity formed out of MesoWest initiatives. These 11 stations monitor the Mendocino, Yuba, Feather, and Santa Ana watersheds in California as part of CW3E’s Forecast Informed Reservoir Operations (FIRO) program. FIRO is a management strategy that leverages watershed data for use in meteorological and hydrological forecasting to improve water supply management and flood risk reduction. Click on the station ID to view the real-time and historical weather station data.

Synoptic Data is also transmitting CW3E station data to MADIS (Meteorological Assimilation Data Ingest System) for use by the National Weather Service.

We are very grateful for MesoWest’s assistance and glad to now have our CW3E station data publicly available in this repository that is regularly accessed by tens of thousands of users in the government, industry, research, and education sectors.

Data remain available on the CW3E website and the NOAA Hydrometeorology Testbed data viewer. Historical data can be downloaded on CW3E’s ftp site. For any questions, please contact cw3e-fieldwork-g@ucsd.edu.

MesoWest Links:
Boyes Creek Canyon (C3BCC)
Downieville (C3DLA)
Deerwood (C3DRW)
Feather River College (C3FRC)
Hells Delight Canyon (C3HDC)
New Bullards Bar Dam (C3NBB)
North Cow Mountain (C3NCM)
Pottery Valley North (C3PVN)
Skyline Harvest (C3SKY)
Seven Oaks Dam (C3SOD)
Windy Gap (C3WDG)

National Weather Service Links:
C3BCC
C3DLA
C3DRW
C3FRC
C3HDC
C3NBB
C3NCM
C3PVN
C3SKY
C3SOD
C3WDG

Congratulations to Dr. Voss – CW3E Graduate Student Successfully Defends Dissertation

Congratulations to Dr. Voss – CW3E Graduate Student Successfully Defends Dissertation

May 7, 2020

The second CW3E PhD student has successfully defended her dissertation. Dr. Kara Voss’ defense was held on Tuesday, May 5, 2020. Her dissertation title is “What makes an Atmospheric River dusty? Spatio-temporal characteristics and drivers of dust in the vicinity of Atmospheric Rivers along the U.S. west coast,” and includes two chapters published in peer-review journals (Voss et al., 2020a,b). Her third chapter will be submitted to the Journal of Geophysics-Atmospheres. Kara’s committee members were Amato Evan (Chair), Jennifer Burney, Mark Jacobsen, Mark Merrifield, Marty Ralph, and Kate Ricke. Funding for Kara’s dissertation came from FIRO and the AR Program, both under PI Marty Ralph.

Kara has been selected to be a Postdoctoral Scholar working with Jennifer Burney at UC San Diego’s School of Global Policy and Strategy.

Due to the COVID-19 health crisis, Kara defended her dissertation virtually, which was a first for both CW3E and her advisor, Amato Evan. CW3E is incredibly proud of Kara’s accomplishment, and looks forward to honoring her with an in-person celebration as soon as the health precautions are no longer necessary!!

Kara Voss being introduced by her Committee Chair Amato Even before her dissertation defense via Zoom.

Dr. Voss’s conclusions for her dissertation. Her results help advance our physically-based understanding of the impact of dust on ARs.

Voss, K.K., and A.T. Evan, 2020: A new satellite-based global climatology of dust aerosol optical depth. J. Appl. Meteor. Climatol., 59, 83-102, https://doi.org/10.1175/JAMC-D-19-0194.1.

Voss, K. K., A.T. Evan, Prather, K.A., and F. Martin Ralph, 2020: Dusty Atmospheric Rivers: Characteristics and Origins. J. Clim., in press.

CW3E Welcomes Kerstin Paulsson

CW3E Welcomes Kerstin Paulsson

May 6, 2020

Kerstin Paulsson joined CW3E as a Field Researcher in February 2020. She earned her B.S. in Oceanography from University of Washington, Seattle (2012) and her M.S. in Physical Oceanography from University of Southampton, U.K. (2014), completing her thesis on the modulation of energy dissipation in small-scale turbulent mixing in the Southern Ocean. In 2015, Kerstin joined Scripps as part of the High Resolution eXendable BathyThermograph (HR-XBT) program, and later as part of the Coastal Observing Research and Development Center (CORDC), leading operations of the Miniature Wave Buoy Program. Her work at CORDC involved hands-on instrument building and design, and spectral analysis of surface wave data from Mini Wave Buoys drifting across all ocean basins.

As part of the field research team at CW3E, Kerstin will support observational efforts in Forecast Informed Reservoir Operations (FIRO) and the AR Program. She looks forward to bringing her observational and ocean-based experience to CW3E research efforts and expanding from her physical oceanographic background into the study of snow hydrology, meteorology, and climate on the West Coast.

CW3E Publication Notice: Recent Changes in United States Extreme 3-Day Precipitation Using the R-CAT Scale

CW3E Publication Notice

Recent Changes in United States Extreme 3-Day Precipitation Using the R-CAT Scale

May 6, 2020

CW3E recent PhD graduate Maryam Lamjiri, along with co-authors CW3E Director F. Martin Ralph and longtime CW3E collaborator Mike Dettinger (newly minted CW3E “visiting researcher”), published a paper in the Journal of Hydrometeorology titled “Recent Changes in United States Extreme 3-Day Precipitation Using the R-CAT Scale” (Lamjiri et al. 2020). This work is a part of CW3E’s ongoing effort to understand and improve the predictions of extreme precipitation and support emergency preparedness and resource management in the western United States. This effort includes monitoring and projections of climate variability and change, and the new study in particular strives to provide new insights from weather and climate observations to understand changes in the most extreme events, changes that may already be happening in the US.

Extraordinary precipitation events have impacted the United States (U.S.) in the past several years, with 3-day precipitation totals larger than any others reported in the U.S. during the past 70 years. The R-CAT scaling method is used to document extreme precipitation events and test for trends nationally. The R-CAT scale uses thresholds of 3-day precipitation totals in 100 mm increments (starting with 200 mm) that do not vary temporally or geographically, allowing for simple, intuitive, comparisons of extremes over space and time. The paper that introduced the scale (Ralph and Dettinger 2012) only required levels 1-4 to represent historical extremes, finding that R-CATs 3-4 strike the conterminous U.S. about as frequently as EF 4-5 tornadoes or Category 3-5 hurricanes. Remarkably, two recent hurricanes, Florence (2018) and Harvey (2017), require extending the scale to R-CAT 7 and 9, respectively (Table 1), and the largest 3-day total (Tropical Storm Imelda) in 2019 ranked as an R-CAT 6. This recent unprecedentedly unbroken string of new R-CAT levels prompted a new look at the scale, resulting in the new paper. The most extreme R-CAT event recorded on the west coast since 1950 reached level 5.

Trend analyses of annual maximum 3-day totals (1950-2019) identify significant increases in eastern U.S., along with overall declines in northern California and Oregon. Consistent with these results, R-CAT storms have been more frequent in the eastern and less frequent in the western U.S. during the past decade compared to 1950-2008. Tropical storms dominate R-CAT events along the southeast and east coasts with surprising contributions from atmospheric rivers (in up to 48% of the R-CAT-level events). Much less surprisingly, ARs completely dominate (more than 90%) along the west coast (Fig. 1). The new study, which is based solely on observations, could not demonstrate a statistically-significant shift in the distribution of R-CAT level storms in the past decade. However, a single decade is too small a sample to demonstrate irreversible changes. Nonetheless, the severity of the most recent storms may still turn out to be the first indication that ultra-extreme storms of the “future” are already here.

Table 1. Definition of R-CAT events and modifications to the original R-CAT scale.

Figure 1. (Fig. 6 from Lamjiri et al., 2020): (a) Center location of the R-CAT episodes, 1950-2015, colored based on their R-CAT levels with blue polygons showing coastal regions used in panels b-d. (b), (c), and (d) show number of R-CAT 1 and stronger, R-CAT 2 and stronger, and R-CAT 3 and stronger episodes, respectively, in each coastal region associated with pure-ARs (solid green and red bars), mixed ARs ( ARs mixed with hurricanes and tropical storms, hatched green and red bars), and non-ARs (tropical storms, tropical depressions, and subtropical storms (TS-TD-STS), hurricanes, and other processes, shown by blue, orange, and gray bars, respectively).

Lamjiri, M.A., F.M. Ralph, and M.D. Dettinger, 2020: Recent Changes in United States Extreme 3-Day Precipitation Using the R-CAT Scale. J. Hydrometeor, 0, https://doi.org/10.1175/JHM-D-19-0171.1

CW3E Welcomes Nina Oakley

CW3E Welcomes Nina Oakley

May 1, 2020

Dr. Nina Oakley joined CW3E in April 2020. Originally from Santa Barbara County, California, she earned a B.A. with a double major in Geography and Spanish from the University of California, Santa Barbara (2004). She then moved to Hawaii and received a teaching credential from the University of Hawaii, Manoa (2007) and taught middle and high school science in both Kona, Hawaii, and Santa Cruz, California. Nina went on to complete a M.S. degree (2013) in Atmospheric Science at the University of Nevada, Reno, during which she studied climatological characteristics of closed low pressure systems in the western United States. Nina began working collaboratively with the CW3E group in 2014 as a Ph.D. student at the University of Nevada, Reno. For her Ph.D. research, Nina studied characteristics of extreme precipitation in California and its applications to post-fire debris flows, shallow landslides, and water resources. She completed her Ph.D. in Atmospheric Science in 2018.

While completing her M.S. and Ph.D. degrees, Nina worked for nine years as a climatologist with the Western Regional Climate Center at the Desert Research Institute. In this position, she supported a wide range of climate data users in locating, accessing, and utilizing climate data. She was also involved building web-based climate tools and communicating climate information to a broad audience; she and colleagues recently completed a climate change assessment for Ventura County, California. Nina is also affiliated with the California Nevada Applications Program, part of the NOAA Regional Integrated Sciences and Assessments program.

At CW3E, Nina will serve as a Program Manager within the California Department of Water Resources Atmospheric River Program. Her work will focus on understanding and forecasting short-duration, high-intensity precipitation conducive to landslides and debris flows, such as the conditions that caused the destructive 9 January 2018 post-fire debris flow in Montecito, CA. She will also participate in the development of observational systems to monitor precipitation extremes, flooding, and water resources in California.

CW3E Delivers First Webinar in Scripps Innovation Series – Recording Now Available Online

CW3E Delivers First Webinar in Scripps Innovation Series – Recording Now Available Online

April 30, 2020

On January 30, CW3E’s Field Research Manager Anna Wilson gave the first webinar in the Scripps Innovation Webinar series. This quarterly seminar series covers topics under the Scripps priority research initiatives of risk and resilience to hazards and human health and the oceans. The goal of the series is to inform industry partners of Scripps Oceanography’s latest research and innovation, applied research tools, collaboration opportunities and ways to work with our community to achieve mutually beneficial goals.

Audience members learned how CW3E is working closely with partners and stakeholders to reach our goals, specifically on the theme of AR Research and Applications, identified in the recently released CW3E Strategic Plan. There was time for a great discussion after the webinar, which had over 100 registered attendees and 69 unique viewers, with expertise ranging from environmental engineering and consulting firms to water agencies to agriculture. CW3E is grateful to have had the opportunity to interact with this audience and be a part of this webinar series.

A recording of the webinar can be viewed here, with an opportunity to sign up for a mailing list to get updates on CW3E activities, or on Scripps Institution of Oceanography’s YouTube channel.

CW3E Student Helps Facilitate Virtual Conference on Sustainability and the Global Pandemic

CW3E Student Helps Facilitate Virtual Conference on Sustainability and the Global Pandemic

April 27, 2020

On Earth Day, nearly 100 researchers, students, and educators joined across time zones, career stages, and academic backgrounds for the inaugural E-Conference on Conservation, Sustainability, and the Global Pandemic.

This 100% virtual conference was organized to allow students, postdoctoral researchers, and early career professionals the chance to share their research on a global platform, and to offer insights and hopeful words from researchers and educators further in their careers. Participants joined the meeting on Blackboard Collaborate from Australia, Peru, the UK, the U.S., and other locations. They posed questions in the chat box and on Twitter using #CSGP2020.

The half-day event was organized and facilitated by Dr. Gillian Bowser and Sarah Whipple (Colorado State University), Dr. Brian Forist (Indiana University), Dr. Andrew Ramsey (University of Derby, UK), Dr. Susie Ho (Monash University, Australia), Dr. Javier Ñaupari (La Molina University, Peru), Dr. Sarah Green (Michigan Technological University), Dr. Pamela Templer (Boston University), CW3E student Tashiana Osborne, and others.

Following the opening keynote address by Dr. Richard Primack of Boston University, Osborne moderated an engaging 12-member panel focused on pandemic impacts on natural science fields, education, climate, policy, conservation and biodiversity efforts, global Sustainable Development Goals and negotiations (United Nations COP26).

Bowser, Green, Whipple, Ho, Ramsey, Primack, Templer, Ñaupari, Forist, and Osborne sharing insights and calls to action, as questions and comments stream in through the chat box and Twitter (Screenshots from Blackboard Collaborate)

After the plenary panel, participants were invited to virtual coffee breaks on various Slack channels before returning for poster sessions. Poster presentation topics ranged from COVID-19 impacts involving decreases in new greenhouse gas emissions since the start of the pandemic and increases in residential and hospital waste, to warming global temperatures contributing to decreases in Atlantic Cod populations along Norway’s coast, changes in land cover and use in micro-basins of Peru, and more. Osborne worked alongside Dr. Green to lead a session on atmospheric science and biogeochemistry topics.

Link to student presentations: https://derbyuni.padlet.org/a_ramsey2/padletofpadlets

Poster and pre-recorded video presentations on various natural science, sustainability, and conservation-related subjects involving mountain ecosystems, atmospheric matters, and more (Screenshot from Padlet)

In the end, this completely virtual, multidisciplinary, international conference proved to be both informative and uplifting. It served as a learning experience for all involved, especially during a time where physical distancing has been paramount and the future seems particularly uncertain.

CW3E Welcomes Peter Yao

CW3E Welcomes Peter Yao

April 27, 2020

Peter Yao joined CW3E as a Research Data Analyst in January 2020. Before joining Scripps he worked in several different fields, including robotics, software development, and automotives. He earned a B.S. in Biomedical Engineering from Johns Hopkins University in 2015, and an M.S. in Mechanical Engineering from the University of Michigan in 2017. At U-M, his Masters research involved developing a numerical model of the pressure distribution within an engine cylinder during stochastic pre-ignition. After graduating he worked as an engineer at General Motors, where he designed clutch control algorithms for automatic transmissions.

Peter made the leap to climate science when he joined the Great Lakes Integrated Sciences & Assessments Center (GLISA) as a Research Associate in 2019. He supported the group’s efforts to build climate resilience in the Great Lakes region by helping develop many of the observational and modeling datasets used in their work. At CW3E he will help the center maintain robust observational datasets and support numerical weather prediction model validation efforts. He is very excited for the opportunity to continue growing both his computing skills and climate science knowledge.