cw3e-web - Center for Western Weather and Water Extremes

FIRO-MAR Workshop Highlights Lessons Learned from Water Year 2023

August 10, 2023

The Flood-MAR Network hosted a FIRO-MAR virtual Workshop on Thursday, July 20th, 9:00 am – 12:00 pm PT.

Workshop Purpose: What are we learning from this past winter that can inform or improve reservoir operations in future wet years and advance FIRO-MAR?

The workshop was facilitated by Meagan Wylie (CSUS) and moderated by Duncan Axisa (CW3E). Opening remarks by Cary Talbot (USACE) focused on the research and development aspects of FIRO.

Presenters gave insight to what happened this water year with respect to atmospheric river activity, explored how FIRO made a difference in managing runoff in 2022/23, reviewed tools available for reservoir operators to make forecast-informed decisions, and discussed work being done throughout the state to identify FIRO-MAR opportunities and advance FIRO-MAR implementation.

The Workshop Recording is posted to the Flood-MAR Hub here.

FIRO-MAR Workshop Presenters:

ADAM HUTCHINSON, Orange County Water District (ahutchinson@ocwd.com)
CARY TALBOT, U.S. Army Engineer Research and Development Center, U.S. Army Corps of Engineers (Cary.A.Talbot@usace.army.mil)
CHAD HECHT, Center for Western Weather and Water Extremes (CW3E) , Scripps Institution of Oceanography (checht@ucsd.edu)
DAVID ARRATE, CA Department of Water Resources (David.Arrate@water.ca.gov)
DUNCAN AXISA, Center for Western Weather and Water Extremes (CW3E), Scripps Institution of Oceanography (daxisa@ucsd.edu)
PATRICK SING, U.S. Army Corps of Engineers, San Francisco District (Patrick.F.Sing@usace.army.mil)
WYATT ARNOLD, CA Department of Water Resources (Wyatt.Arnold@water.ca.gov)

Facilitated by:
Meagan Wylie (Sacramento State)

CW3E Welcomes Corrine DeCiampa

August 10, 2023

Corrine DeCiampa joined CW3E as an Atmospheric Data Scientist on August 1st, 2023. Prior to this position, Corrine received her B.S. in Meteorology from the University of North Carolina at Charlotte in 2018 and her M.S. in Meteorology and Atmospheric Science from the Pennsylvania State University in 2023. At Penn State, her thesis focused on modeling tropical cyclones in high-resolution unstructured global climate models, specifically using the Community Atmosphere Model and the Model for Prediction Across Scales (MPAS). Her research also included assisting in the development of tools to analyze the native output of these unstructured grids without interpolation to a structured grid. In between receiving her B.S. and M.S. degrees, Corrine worked at Pacific Northwest National Laboratory as a Post-Bachelors Research Associate, contributing to various projects ranging from GIS to machine learning. At CW3E, Corrine will be supporting the climate modeling and Near Real-Time forecasting efforts using West-WRF and MPAS.

CW3E Welcomes Jeri Wilcox

August 9, 2023

Jeri Wilcox joined CW3E as a field researcher on August 7th, 2023. This past June, Jeri graduated from the Master of Advanced Studies in Climate Science and Policy program at Scripps Institution of Oceanography. During her graduate career, she completed a capstone in collaboration with CW3E which looked at the impact that Atmospheric Rivers can have on Harmful Algal Blooms along the coast of California. Before that, Jeri completed her B.S. in Environmental Science with an Emphasis on the Biosphere and a Minor in Marine Science at the University of Arizona. At the U of A, Jeri conducted several research projects at Biosphere 2 and was involved in furthering campus sustainability through the student government. Jeri grew up just outside of Boulder, CO, where she gained a love for studying nature and understanding the complex systems around her. At CW3E, Jeri is going to conduct field research to collect meteorological data as well as conducting data management and analysis. Jeri is excited about getting to be part of such an exciting and hard-working team and to contribute her skills to furthering the many projects at CW3E!

CW3E Publication Notice: Forecast Evaluation of the North Pacific Jet Stream Using AR Recon Dropwindsondes

CW3E Publication Notice

Forecast Evaluation of the North Pacific Jet Stream Using AR Recon Dropwindsondes

August 9, 2023

A new paper titled Forecast Evaluation of the North Pacific Jet Stream Using AR Recon Dropwindsondes by David A. Lavers (ECMWF), Ryan D. Torn (University at Albany), Chris Davis (NCAR), David S. Richardson (ECMWF), F. Martin Ralph (Director, CW3E), and Florian Pappenberger (ECMWF) was recently accepted in the Quarterly Journal of the Royal Meteorological Society. This study evaluates the structure of the jet stream over the North Pacific within the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS) using dropwindsonde data collected between 2020–2022 during the CW3E-led Atmospheric River Reconnaissance field campaign (AR Recon). Results show that the IFS has a slow wind bias on the lead times assessed, with the strongest winds (≥ 50 ms-1) having a bias of up to -1.88 ms-1 on forecast day 4 (Figure 1). Also, the IFS cannot resolve the sharp potential vorticity (PV) gradient across the jet stream and tropopause, and this PV gradient weakens with forecast lead time. Cases with larger wind biases are characterized by higher PV biases and PV biases tend to be larger for cases with a higher horizontal PV gradient. These results suggest that further model-based experiments are needed to identify and address these biases, which could ultimately yield increased forecast accuracy.

The dropwindsonde data used in this study were collected during the CW3E-led AR Recon field campaign by the NOAA G-IV aircraft that provide targeted storm sampling over the North Pacific as part of the National Winter Season Operations Plan (NWSOP). AR Recon frequently targets the jet stream and its associated regions of PV, given their identification as “essential atmospheric structures” (defined within the NWSOP), which influence the development of the synoptic-scale storms that drive precipitation processes within atmospheric rivers along the US West Coast. These missions provide unique observations in the form of transects and vertical profiles of sparsely sampled regions of the upper-level jet and tropopause PV gradient, both atmospheric structures intrinsically linked to atmospheric rivers (Figure 2). The data collected during AR Recon are assimilated into global numerical weather prediction models and serve to improve the initial conditions in NWP models by providing observations in areas where atmospheric profiles are virtually non-existent. Additionally, the data are shared with various partner agencies and universities for analysis and evaluation, including those at the ECMWF, University at Albany, and NCAR who co-authored the present study. This study contributes to the goals of CW3E’s 2019–2024 Strategic Plan to support AR research and applications by highlighting the benefits that AR Recon provides to the global NWP models.

Figure 1: Fig. 3 from Lavers et al. 2023: Scatterplots of the observed versus model winds for (a) the long-window data assimilation [LWDA] analysis, (b) the LWDA background (3–15 hr) forecasts, (c) forecast day 2, and (d) forecast day 4, in the 20-hPa resolution atmospheric profiles. In each panel, the sample size (n), and the mean and standard deviation of the forecast-minus-observation departures are given for all winds and for those ≥50m⋅s−1. The 99% confidence interval of the mean bias is also provided in brackets. Red-shaded regions represent winds ≥50m⋅s−1 (i.e., jet stream winds) and the 1:1 and linear regression lines are shown in black and blue respectively. Quantile–quantile points are also plotted as black triangles.

Figure 2: Fig. 1 from Lavers et al. 2023: (a) The locations of the dropwindsondes deployed by the NOAA G-IV in 2020, 2021, and 2022. The NOAA G-IV was based in Portland, Oregon, in 2020, and in Honolulu, Hawaii, in 2021 and 2022. The number of dropwindsondes available in each year is given in the legend. (b) The 21 jet stream transects (grey lines) and the dropwindsondes along them (grey markers).

Lavers, D.A., Torn, R.D., Davis, C., Richardson, D.S., Ralph, F.M. and Pappenberger, F. (2023) Forecast Evaluation of the North Pacific Jet Stream Using AR Recon Dropwindsondes. Quarterly Journal of the Royal Meteorological Society 1–20. Available from: https://doi.org/10.1002/qj.4545

CW3E Welcomes Ricardo Vilela

August 8, 2023

Ricardo Vilela joined CW3E as a meteorology applications programmer on August 1st, 2023. Prior to this position, Ricardo worked for 6 years in a private company in Brazil as a meteorologist dedicated to remote sensing product development creating meteorological solutions for clients and stakeholders ranging from agricultural business to the energy market. He completed his B.S degree in Atmospheric Sciences at Federal University of Itajubá (Brazil) in 2014 and earned his M.S in Meteorology at University of São Paulo (Brazil) in 2017. At CW3E he will continue using his skills and experience in the development and implementation of forecast and observational tools to support CW3E and partnering agencies. His work will support the Research and Operations framework within CW3E to help meet the goals of AR Recon, the AR Program, FIRO, and AQPI.

CW3E Welcomes Paul Iñiguez

August 2, 2023

Paul Iñiguez joined CW3E as a Forecast Verification Analyst on August 1, 2023. Paul brings a wealth of operational forecasting experience to the center, gained through over 20 years with the NOAA National Weather Service (NWS). Paul is a native Minnesotan and earned his BS in Meteorology from St. Cloud State University. The early years of his NWS career took Paul to Weather Forecast Offices (WFOs) in Little Rock, AR and Phoenix, AZ, where he also earned an MA in Geography from Arizona State University (thesis: urban/anthropogenic effects on precipitation patterns across the Phoenix metropolitan area). Paul joined WFO Hanford, CA as the Science & Operations Officer (SOO) in 2012, which provided him with extensive experience with California’s unique climates (including the extreme drought of the early/mid 2010s). While there he managed the office’s science integration and training programs and led the operational forecast unit. In 2015, Paul returned to WFO Phoenix as the SOO, also leading that office’s science integration and training programs and being deeply involved in the day-to-day forecast operations. This included extreme precipitation events both from intense short duration rainfall from monsoonal thunderstorms and occasional deep, energetic winter storms with atmospheric rivers. Paul also spearheaded the office’s extensive extreme heat program and was an integral member of the team behind the development of the NWS HeatRisk prototype. Now at CW3E, Paul looks forward to leveraging his years of forecasting, coding, and leadership experience to contribute to the center’s forecast and verification efforts.

CW3E Publication Notice: Highlighting two new publications on the development of a regional coupled ocean–atmosphere model

CW3E Publication Notice

Highlighting two new publications on the development of a regional coupled ocean–atmosphere model

August 2, 2023

Two new papers on the development of the regional coupled ocean–atmosphere model were published in Geoscientific Model Development. This research contributes to CW3E’s 2019–2024 Strategic Plan to improve weather, hydrology, and coupled modeling capabilities that can be applied to the western United States. In our previous work, we have demonstrated that using coupled ocean–atmosphere model can improve the forecast of atmospheric rivers (ARs) associated with strong sea surface temperature changes. The new implements of the coupled model can allow us to investigate the sub-seasonal to seasonal predictability of ARs and study the physics of the ocean, wave, and sea-ice under AR conditions. Early research indicates ocean-atmosphere coupling can improve extended range (7-14 days) forecasts of atmospheric rivers. The work from the papers describes the new methods for coupling dynamics that can be applied to ARs to test how they might further improve AR forecasts.

The two new papers describe the implementations of waves and sea ice modules in the coupled model SKRIPS (Scripps–KAUST Regional Integrated Prediction System). The first paper, entitled “Waves in SKRIPS: WAVEWATCH III coupling implementation and a case study of Tropical Cyclone Mekunu”, by Rui Sun (SIO), Alison Cobb (SIO), Ana B Villas Bôas (Colorado School of Mines), Sabique Langodan (KAUST), Aneesh C. Subramanian (CU Boulder), Matthew R. Mazloff (SIO), Bruce D. Cornuelle (SIO), Arthur J. Miller (SIO), Raju Pathak (KAUST), Ibrahim Hoteit (KAUST). In this work, the wave model WAVEWATCH III model into the regional coupled model SKRIPS with flexibility options, meaning the coupled system can run with or without the wave component. The implementations also include the effect of Stokes drift, Langmuir turbulence, sea surface roughness, and wave-induced momentum fluxes. The skill of the newly implemented model is tested using a series of coupled and uncoupled simulations of tropical cyclone Mekunu, which occurred in the Arabian Sea in May 2018, using a series of 20-ensemble member experiments. Although the characteristics of the tropical cyclone are not significantly different due to the effect of surface waves when using different parameterizations, the coupled models better capture the minimum pressure and maximum wind speed. Moreover, in the region of the cold wake, the coupled model successfully captures the effect due to Langmuir turbulence that cools down the sea surface temperature by about 0.5 degrees and deepens the mixed layer by about 20 meters.

The second paper entitled “Conservation of heat and mass in P-SKRIPS version 1: the coupled atmosphere–ice–ocean model of the Ross Sea” by Alena Malyarenko (Victoria University of Wellington; NIWA), Alexandra Gossart (Victoria University of Wellington), Rui Sun (SIO), Mario Krapp (GNS Science). This paper addresses the conservation of heat and mass fluxes between coupled models when sea-ice exists, which is often overlooked due to computational difficulties. At the regional scale, the non-conservation of water and energy can lead to model drift over multi-year model simulations. A new version of the SKRIPS coupled model setup for the Ross Sea region is proposed (P-SKRIPS, version 1, a). The development includes full conservation of heat and mass fluxes transferred between the climate (PWRF) and sea ice–ocean (MITgcm) models. We examine open water, sea ice cover, and ice sheet interfaces. We show evidence of the flux conservation in the results of a 1-month-long summer and 1-month-long winter test experiment. P-SKRIPS v.1 shows the implications of conserving heat flux over the Terra Nova Bay and Ross Sea polynyas in August 2016, eliminating the mismatch between total flux calculation in PWRF and MITgcm up to 922 W /m^-2.

Figure 1: The schematic description of the SKRIPS regional coupled ocean–atmosphere model. The yellow block is the ESMF/NUOPC coupler; the white blocks are the ocean and atmosphere components; the red blocks are the implemented MITgcm–ESMF, WRF–ESMF, and WW3–ESMF interfaces.

Figure 2: The snapshots of the ensemble-averaged SST difference. Panels (a-c) show the SST difference between the simulations with Langmuir turbulence (CPL.LF17, CPL.VR12-MA, and CPL.LF17-ST) and without Langmuir turbulence (CPL.NoLT). The markers indicate the regions where the SST difference is significant (P < 0.05).

Figure 3: Exchanged flux pathways through snow and sea ice routines in PWRF (blue) and MITgcm (red), (A) and (C) represent the SKRIPS set up and (B) and (D) the P-SKRIPS. The i and o indices represent the variable over ice and ocean, respectively. LH, SH, SWNET and LWNET stand for latent heat, sensible heat, net shortwave radiation and net long wave radiation in W/m2. Prec stands for precipitation, QFX and EVAP for surface evaporation and RNFF for surface meltwater runoff (all in mm). SNOWH is the variable for the amount of snow on sea ice (in m). In panels (B) and (D) the overlapping blue and red lines indicate the fluxes are re-calculated by MITgcm and WRF.

Sun, R., Cobb, A., Villas Bôas, A.B., Langodan, S., Subramanian, A.C., Mazloff, M.R., Cornuelle, B.D., Miller, A.J., Pathak, R. and Hoteit, I., 2023. Waves in SKRIPS: WAVEWATCH III coupling implementation and a case study of Tropical Cyclone Mekunu. Geoscientific Model Development, 16(12), pp.3435-3458. https://doi.org/10.5194/gmd-16-3435-2023

Malyarenko, A., Gossart, A., Sun, R. and Krapp, M., 2023. Conservation of heat and mass in P-SKRIPS version 1: the coupled atmosphere–ice–ocean model of the Ross Sea. Geoscientific Model Development, 16(11), pp.3355-3373. https://doi.org/10.5194/gmd-16-3355-2023

CW3E Presents at UCSD’s Future Leaders Summer Program

July 25, 2023

CW3E hosted 32 international and domestic high school students attending the Future Leaders Summer Program for a session on Climate Crisis. The program is conducted by the 21st Century China Center and the Global Leadership Institute at the UC San Diego School of Global Policy and Strategy. The program is designed for high school students to develop problem-solving and diplomacy skills in global affairs, especially as they pertain to the roles of China, the U.S., Pacific and Indo-Pacific region countries including Mexico and India. The 2023 program focused on four critical issues: climate crisis, energy innovation (e.g., renewable energy, electric vehicles, etc.), artificial intelligence and global pandemics.

First, CW3E’s Douglas Alden and Ali Wolman led high school students from Global Leadership Institute in a weather balloon launch and a tour of the Ellen Browning Scripps Memorial Pier. The pier houses numerous environmental monitoring stations and enables small boat and scientific diving operations. During the group’s tour, students were able to see how busy a working research pier can get with cars, boats, golf carts, and people coming and going. Halfway down the pier, students gathered around CW3E’s weather station and Douglas introduced the sensors that observe variables including humidity, temperature, precipitation, and wind speed & direction. Students got an introduction to the technology used to set up and track the radiosonde sensor attached to the weather balloon. The group passed around example balloons and radiosondes, observed, and asked questions while Douglas and Ali prepared the weather balloon and radiosonde. Student volunteers from the Future Summer Leaders Program released the balloon on the group’s countdown.

Students continued their tour of Scripps Pier with a short talk from an Eastern Pacific Cloud Aerosol Precipitation Experience (EPCAPE) scientist about the work EPCAPE is doing studying aerosols in the atmosphere and their impact on cloud properties. Students continued to the end of the pier, where they saw the tide room. During the rainy season, CW3E keeps our radiosonde system set up there. In addition, students were able to see the saltwater intake that feeds saltwater tanks on campus including at the Birch Aquarium, the crane used to launch boats and lift them back onto the pier, and the staircase that lowers to the ocean surface to provide water access for researchers scuba diving around the pier.

After the pier tour, CW3E’s Deanna Nash was the guest speaker for the Interview with Experts in the Field: Climate Crisis and gave a presentation on some of the work the center is doing to improve the resiliency of different communities in the face of climate change. The presentation focused on several core areas of the center: precipitation extremes in the Western U.S., Forecast Informed Reservoir Operations (FIRO), Atmospheric River Reconnaissance, and climate science. Additionally, Deanna shared her experiences as a postdoctoral researcher at CW3E and summarized her current research on landslides, floods and avalanches triggered by precipitation in Southeast Alaska. Discussion with the students throughout the presentation dealt with many topics, including policy implications of scientific findings, building community resilience to extreme events due to climate change, and pathways to becoming a scientist. CW3E is grateful to have had the opportunity to interact with the intelligent and enthusiastic students.

CW3E Welcomes Sarah Burnett

July 19, 2023

Sarah Burnett joined CW3E as a field researcher on July 17, 2023. Earlier in the year, Sarah worked part-time with the Field Team, releasing weather balloons and measuring stream water flow to make observations of the atmospheric rivers hitting the west coast. Sarah earned a B.S. in physics in 2019 and an MA in physics education in 2020 from Stanford University. While at Stanford, she interned at SLAC National Accelerator Laboratory, testing an algorithm to model optical distortions of the Dark Energy Camera. After graduating, she taught introductory physics at Fremont High School in Sunnyvale, CA, and became a Knowles Teaching Fellow to advance her teaching practice. As a teacher, Sarah focused on Universal Design for Learning to make the curriculum accessible and useful to a diverse set of students. At CW3E, Sarah will continue assisting with observations of stream flow and precipitation, as well as data management and analysis. In her free time, Sarah can be found practicing piano, painting, and yoga.

CW3E Welcomes Matthew Steen

July 18, 2023

Matthew Steen join CW3E on July 1, 2023, as a Forecast Verification Analyst. Prior to this position, Matthew worked with CW3E part-time to assist with the most recent Atmospheric River Reconnaissance season as part of the forecast team where he helped create and deliver the daily forecast discussions. Matthew completed his B.S. in Meteorology at Millersville University in 2021 and earned his M.S. in Applied Meteorology at Plymouth State University in 2023. At Plymouth State, he compared dual-pol radar and MRMS QPE products for precipitation events in the Northern Plains and mid-Atlantic for completion of his M.S. thesis. In addition to his thesis research at Plymouth State, he also served as the REU Assistant for the Northeast Partnership for Atmospheric and Related Sciences (NEPARS) REU during the summer of 2022, where during this time he helped mentor research for three pairs of students while completing early work on his thesis. At CW3E will be assisting with research projects being completed at the center, primarily with forecasts and observations, as well as continuing to support the AR Recon forecasting team during the next AR season.