CW3E Releases New Interactive Geospatial Observation and Forecast Maps
Spetember 18, 2017
CW3E has released a new interactive mapping tool that takes advantage of “web mapping services”, GIS-based coding/thinking, and interactive technologies in order to provide dynamic weather analysis graphics in support of the CW3E mission. These interactive maps allow the user to display and interact with numerous variables from a synoptic to a watershed scale with the goal of providing insight into potential impacts of landfalling atmospheric rivers over California.
This interactive tool was developed as a means to geospatially visualize meteorological and hydrologic observations on a new platform and from a new perspective. This first set of maps/webpages illustrate the utility of the tool in displaying atmospheric river related forecast products and CW3E will continue to build upon the tool. As we continue to experiment in improving and expanding the tool, we encourage any feedback or suggestions. Please contact the website creator or the CW3E Webmaster with any questions or feedback you may have.
The development of the tool and maps/webpage is supported by the California Department of Water Resources. The page was created and developed by CW3E collaborator Dr. Jason Cordeira and CW3E Director Dr. F. Martin Ralph with input from CW3E researchers Brian Kawzenuk, Chad Hecht, and Dr. Julie Kalansky.
CW3E Publication Notice
Dropsonde Observations of Total Integrated Water Vapor Transport within North Pacific Atmospheric Rivers
Spetember 14, 2017
F. Martin Ralph, director of CW3E, along with collaborators, recently published a paper in the American Meteorological Society’s Journal of Hydrometeorology: Ralph, F. M., S. Iacobellis, P. Neiman, J. Cordeira, J. Spackman, D. Waliser, G. Wick, A. White, and C. Fairall, 2017: Dropsonde Observations of Total Integrated Water Vapor Transport within North Pacific Atmospheric Rivers. J. Hydrometeor., 18, 2577-2596, https://doi.org/10.1175/JHM-D-17-0036.1
This study uses vertical profiles of water vapor, wind, and pressure obtained from 304 aircraft dropsondes across 21 ARs, in the midlatitudes as well as the subtropics, which were deployed during various experiments since the winter of 1998, including CALJET (Ralph et al. 2004), Ghostnets (Ralph et al. 2011), WISPAR (Neiman et al. 2014), CalWater-2014, CalWater-2015 (Ralph et al. 2016), and AR Recon-2016. Dropsondes provide the best measurements to date of horizontal water vapor transport in atmospheric rivers (ARs) and can document AR structure. Different methods of defining AR edges, using either integrated vapor transport (IVT) or integrated water vapor (IWV), were compared.
The study found that total water vapor transport (TIVT) in an AR averaged nearly 5×108 kg s-1, which is 2.6 times larger than the average discharge of liquid water from the Amazon River. The mean AR width was 890 ± 270 km. Subtropical ARs contained larger IWV but weaker winds than midlatitude ARs, although average TIVTs were nearly the same. Mean TIVTs calculated with an IVT-threshold versus an IWV- threshold produced results that differed by only 4% on average, although they did vary more between midlatitudes and subtropical regions. In general, important AR characteristics such as width and TIVT are less dependent on latitude when the IVT-threshold is used, and the IWV threshold often was not crossed on the warm side of subtropical ARs, so IVT represents a more robust threshold across a wider range of conditions than IWV.
Results were summarized in a schematic to illustrate the AR structure in 3 dimensions (see below). This schematic was used in the AR definition that was recently published in the American Meteorological Society’s Glossary of Meteorology.
Figure 1: Schematic summary of the structure and strength of an atmospheric river based on dropsonde measurements analyzed in this study, and on corresponding reanalyses that provide the plan-view context. (a) Plan view including parent low pressure system, and associated cold, warm, stationary and warm-occluded surface fronts. IVT is shown by color fill (magnitude, kg m-1 s-1) and direction in the core (white arrow). Vertically integrated water vapor (IWV, cm) is contoured. A representative length scale is shown. The position of the cross-section shown in panel (b) is denoted by the dashed line A-A’. (b) Vertical cross-section perspective, including the core of the water vapor transport in the atmospheric river (orange contours and color fill) and the pre-cold-frontal low-level jet (LLJ), in the context of the jet-front system and tropopause. Water vapor mixing ratio (green dotted lines, g kg-1) and cross-section-normal isotachs (blue contours, m s-1) are shown. Magnitudes of variables represent an average mid-latitude atmospheric river with lateral boundaries defined using the IVT threshold of 250 kg m-1 s-1. Depth corresponds to the altitude below which 75% of IVT occurs. Adapted primarily from Ralph et al. 2004 and Cordeira et al. 2013.
CW3E Publication Notice
The Chiricahua Gap and the Role of Easterly Water Vapor Transport in Southeastern Arizona Monsoon Precipitation
Spetember 13, 2017
This study is a collaborative effort between CW3E and University of Arizona that identifies a terrain feature along the Arizona-New Mexico border just north of Mexico that is potentially important to the weather and climate of the southeast Arizona summer monsoon. The terrain feature is a “gap” that is approximately 250 km across and 1 km deep and represents the lowest terrain elevation along the 3000-km length the Continental Divide from 16-45°N. The name “Chiricahua Gap” is introduced to identify this key terrain feature, which reflects the name of a nearby mountain range in southeast Arizona and the region’s Native American history. The importance of the Chiricahua Gap is that it represents the primary pathway in which low altitude atmospheric water vapor is transported across the Continental Divide.
Motivated by identification of the Chiricahua Gap, upper-air observations from a wind profiling radar in Tucson, model reanalyses (Climate Forecast System Reanalysis), and gridded daily precipitation data (NCEP Stage-IV) are used to construct a case study and 15-year climatology to link summer monsoon rainfall events in southeast Arizona to low-altitude water vapor transport within the Chiricahua Gap. The results show that 76% of the wettest summer monsoon days in southeast Arizona during 2002-2016 occurred in conditions of low-altitude easterly water vapor transport in the Chiricahua Gap on the previous day. This result highlights how low-altitude water vapor associated with the wettest summer monsoon days in southeast Arizona originates from the east side of the Continental Divide, which differs from previous studies published since the 1970s. Much of the recent scientific literature points to southwesterly surges of low-altitude water vapor from over the Gulf of California as the primary driver of rainfall over southern Arizona during the summer monsoon. The current study by F. M. Ralph and T. J. Galarneau shows that the source region of low-altitude water vapor in southeast Arizona during the summer monsoon is potentially more complex, and is significantly influenced by source regions east of the Divide.
The paper is an example of CW3E expanding its research to examine the dynamics of the North American monsoon. Because monsoon is an important source or water for the US southwest and can cause flooding events, particularly flash floods, better understanding and improving forecasts of the North American monsoon is and important component of CW3E achieving its goal of revolutionizing the physical understanding, observations, weather predictions, of extreme events in Western North America and their impacts on floods, droughts, hydropower, ecosystems and the economy.
Figure 1: Terrain height (shaded in m) over Arizona, New Mexico, western Texas, and northern Mexico. Key terrain features are labeled in black. The location of Tucson, Arizona, is labeled by the black-filled circle. Low-altitude easterly water vapor transport through the Chiricahua Gap is shown by the blue arrows. This figure is modified from Fig. 1b in Ralph and Galarneau (2017).
CW3E Publication Notice
Characterizing the Influence of Atmospheric River Orientation and Intensity on Precipitation Distributions over North-Coastal California
Spetember 12, 2017
Chad Hecht, a CW3E staff researcher, and Jason Cordeira, a CW3E affiliate and professor at Plymouth State University, recently published an article in AGU Geophysical Research Letters: Hecht, C. W., and J. M. Cordeira, 2017: Characterizing the Influence of Atmospheric River Orientation and Intensity on Precipitation Distribution over North-Coastal California. Geophys. Res. Lett., 44, doi:10.1002/2017GL074179. click here for personal use pdf file.
The key result of the study found that south-southwesterly oriented atmospheric rivers (ARs) produce significantly more Russian River watershed areal-average precipitation compared to westerly ARs (median areal-precipitation of 13 mm vs. .5 mm). This difference in precipitation accumulations is attributed to both the orientation of water vapor flux relative to the watershed topography and large-scale forcing that results in ascent.
The study uses clustering to objectively identify different orientations and intensities of ARs that make landfall over the California Russian River watershed (Fig. 1). Daily averaged IVT was calculated using 11-years of National Centers for Environmental Prediction (NCEP)–Climate Forecast System Reanalysis (CFSR) data spanning from 1 January 2004 to 31 December 2014. The paper analyzed the synoptic-scale flow configurations and resulting precipitation accumulations and distributions of westerly and south-southwesterly oriented ARs (Orange and Blue clusters in Fig. 1b).
Figure 1. (a) Domain averaged daily IVT direction (angular coordinate) and magnitude (kg m/s ; radial coordinate) for all days from 1 January 2004 to 31 December 2014 that data were available. Markers are color-coded based on 24-h accumulated precipitation (mm). The colored lines illustrate the average IVT for days with precipitation >10 (black), >25 (blue) and >50 mm (red). The 200 kg/m/s threshold that was applied in this study is shown by the black circle. (b) As in (a) except for days with daily average IVT ≥200 kg/m/s and color-coded based on K-means cluster.
Composite analyses illustrate the vastly different synoptic-scale characteristics associated with westerly and south/southwesterly ARs (Cluster 2 and Cluster 3). These different synoptic-scale flow configurations result in differences in synoptic scale forcing co-located over the composite AR and the Russian River watershed (Fig. 2).
Figure 2. (a, b) Composite mean IVT (kg/m/s ; plotted according to the reference vector in the upper right), SLP (hPa; contoured), and IWV (mm; color-coded according to scale), (c, d) composite mean 250-hPa geopotential height (dam; contoured), wind speed (m s–1 ; colorcoded according to scale), and IWV (mm; dashed blue contour), and (e, f) composite mean 700-hPa geopotential height (dam; solid contours), Q-vectors (1011 K/m/s ; plotted according to the reference vector in the bottom right), Q-vector divergence (1016 K/m/s ; color-coded according to scale) and potential temperature (K; dashed red contours) at t–12 h during (a,c,e) westerly and (b,d,f) south–southwesterly ARs.
The large difference in Russian River watershed area-averaged precipitation between westerly and south-southwesterly ARs (Fig. 3a) is not likely explained by statistically similar cluster IVT magnitudes (i.e., AR intensity; Fig. 3b) and IWV values (Fig. 3e) but likely a combination of a more favorable southwesterly IVT direction (i.e., AR orientation) relative to the orientation of the local topography and favorable synoptic-scale forcing for ascent (Fig. 2) illustrated by Q-vector convergence (Fig. 3d). While both AR types exhibit significantly statistically similar mean IVT, south-southwesterly ARs are associated with statistically significantly higher mean low-level IVT (1000–850 hPa; Fig. 3c).
Results from this study suggest that extreme precipitation produced by ARs is the result of both upslope moisture flux and quasi-geostrophic forcing for ascent.
Figure 3. Box and whisker plots of Russian River Watershed (a) area-average 24-h precipitation (mm), (b) domain average IVT (kg/m/s ), (c) domain average lower tropospheric (1000–850 hPa) IVT (kg/m/s ), (d) domain average Q-vector divergence (1016 K/m/s ), and (e) domain average IWV (mm) for westerly (orange) and south–southwesterly (blue) ARs. The boxes represent the interquartile range of the data and the whiskers represent upper and lower quartile of the data. The horizontal line within the boxes is the median value. The colored dots represent outliers and the asterisks represent extreme outliers. The box in the upper-left corner of each panel indicates the result of the independent samples t-test with 95% confidence (white indicates significantly statistically similar means and black indicates significantly statistically different).
Support for this project was provided by the State of California-Department of Water Resources and the U.S. Army Corps of Engineers, both as part of broader projects led by CW3E. A majority of this work was conducted while Chad was a graduate student at Plymouth State University. Dr. Cordeira and his graduate students at Plymouth State University actively collaborate with CW3E on topics related to atmospheric rivers, such as analyzing, understanding, and forecasting their impacts along the U.S. West Coast.
CW3E Accepted as a National Oceanic and Atmospheric Administration Weather-Ready Nation Ambassador
September 7, 2017
CW3E recently became a NOAA Weather-Ready Nation (WRN) Ambassador. The Weather-Ready Nation Ambassador Initiative is a collaborative entity that brings numerous organizations, businesses, and people together in order to strengthen national resilience against extreme weather and water events.
CW3E is being recognized as a WRN Ambassador because it promotes the Weather-Ready Nation messages and themes to their stakeholders and engages with NOAA personnel on potential collaboration opportunities. CW3E is doing this through scientific research to improve forecasts of extreme precipitation and flooding on the west coast, as well as communicating about extreme events through the hydrometeorological outlooks and post-event summaries on the CW3E website and Twitter. CW3E in collaboration with NOAA, will assist in improving the nation’s readiness, responsiveness, and overall resilience against extreme weather.
Becoming a WRN Ambassador advances CW3E one step further in executing our mission to provide 21st Century water cycle science, technology and outreach to support effective policies and practices that address the impacts of extreme weather and water events on the environment, people and the economy of Western North America.
Visit NOAA’s WRN website to learn more about the initiative, its goals, and its participants.
CW3E Field Team Beats the Heat, Installs Meteorology and Hydrology Instruments in Russian River Watershed
September 6, 2017
A group of CW3E graduate students, postdocs, and staff worked to install soil moisture, meteorology, and streamflow instruments in the Lake Mendocino watershed August 28 – September 1. Taking extra precautions and shifting work schedules due to California’s triple-digit heat wave, the team installed three soil moisture and surface meteorology arrays and a stream gauge on ranchlands representative of the hilly topography draining into Lake Mendocino. CW3E thanks the landowners who have volunteered to have instruments installed on their properties, as well as Steve Turnbull of the U.S. Army Corps of Engineers for participating in the installations. Two more soil moisture and meteorology arrays and three more stream gauges are planned to be installed in the watershed prior to the 2017-18 AR season for a total of six soil moisture and meteorology arrays and six stream gauges. The data from these sites will be used to better understand AR meteorological and hydrologic impacts in this region and improve streamflow forecasts on the Russian River.
CW3E Field Trip to Experience the North American Monsoon in Southern Arizona
August 14, 2017
Several members of CW3E spent a recent weekend observing the North American monsoon in the Tucson, Arizona area, including Nogales and Sonoita. It provided an opportunity to experience an iconic type of “extreme event” that occurs in the Western U.S.
Activities included early-morning hiking in Ventana Canyon (Fig. 1), touring southern Arizona from Tucson to Nogales, Patagonia and Sonoita, learning about Sonoran Desert and nearby grassland landscapes and climate (Fig. 2), observing long-lived monsoon convection and its impacts, and discussing active topics of research related to the North American monsoon, including a recent paper on the role of the Chiricahua Gap (Ralph and Galerneau 2017 – http://journals.ametsoc.org/doi/abs/10.1175/JHM-D-17-0031.1).
Fig.1. The CW3E group with a saguaro during the Ventana Canyon hike. From left Marty Ralph, Brian Henn, Anna Wilson, and Maryam Asgari-Lamjiri.
Fig.2. Example of landscape 30 miles southeast of Tucson, near Sonoita, AZ on 29July 2017 at about 5000 ft MSL.
A highlight was observing flood water in normally dry washes, such as Tanque Verde Wash in northeast Tucson (Fig. 3).
Fig.3. The Tanque Verde River looking east from the bridge on Kolb Road after monsoon storms in the Tucson area. The Rincon Mountains, including their high point at 8664 ft MSL, are in the background. Photograph taken at 6:45 pm local time on 29 July 2017.
Precipitation totals in Tucson were significantly above normal. Fig. 4 shows the July 2017 climate summary from NWS. In fact, the CW3E team experienced the heavy downpour near the Tucson airport on Saturday, 29 July 2017 that broke the all-time record for July monthly precipitation (now 6.8 inches; previously 6.24 inches in July 1921).
Fig.4. National Weather Service July 2017 climate summary with dates of the CW3E field trip highlighted.
CW3E’s goal is to revolutionize the physical understanding, observations, weather predictions and climate projections of extreme events in Western North America (http://cw3e.ucsd.edu/overview/), including the North American summer monsoon.
Points of contact: Anna Wilson, Marty Ralph.
Post-Doctoral Positions Available at the Center for Western Weather and Water Extremes
August 3, 2017
Location: La Jolla, California
Deadline: Positions are available immediately. Applications will be considered until positions are filled. Preference will be given to applications received by 1 September 2017.
Number of new positions available: 4
The Center for Western Weather and Water Extremes (CW3E), is a research and applications center established in 2013 at Scripps Institution of Oceanography by its Director, Dr. F. Martin Ralph. CW3E focuses on the physical understanding, observations, weather predictions, seasonal outlooks and climate projections of extreme weather and water events to support effective policies and practices to improve resilience in the Western U.S. Funding for this set of Postdoctoral positions is in place from several federal, state and local agencies, with a major emphasis on the unique science and applications needs associated with water supply and flood risk in the Western United States. CW3E carries out its goals with a diverse network of research and operational partners at more than ten other institutions across the U.S. Individuals will be joining a group of several existing Postdoctoral scholars and graduate students, and a number of experienced faculty, researchers and staff at Scripps who are involved with CW3E.
Per normal Postdoctoral appointment policies, all positions are envisioned as being initially for 1-year, with extension possible contingent upon performance and availability of funding. The University of California, San Diego is an AA/EOE.
Interested individuals are encouraged to submit their resumes and a 1-page statement of relevant personal interests, goals, range of potential start dates and at minimum two references. These should be sent to the person listed below as the “position coordinator” for the position you are interested in.
Applicants should have 0-2 years of Postdoctoral experience, or be nearing completion of their Ph.D. (estimated within 3 months), and be self-motivated and hard-working. Good written and verbal communication skills, including the ability to produce scientific publications and presentations and meet project milestones are required. Strong analytical backgrounds with a Ph.D. in atmospheric science, meteorology, atmospheric chemistry, climate science, hydrology or environmental engineering is preferred. Programming experience working in a Unix environment with experience in scripting languages such as Python, Perl, R and Matlab along with true programming language experience in C and Fortran is highly desired. Experience with using high performance computing is also desired. Successful applicants should be comfortable independently working with large code libraries and producing novel visualizations.
Position 1: Hydrometeorological Advancements for Management Decision Support
CW3E position coordinator – Dr. Brian Henn; email@example.com
CW3E seeks a Postdoctoral researcher to design and contribute to efforts that lead toward improved operational application of distributed hydrologic and hydrometeorological sciences. The position would work on research that improves hydrologic model performance associated with extreme events. Anticipated methodologies include data assimilation (DA) techniques that leverage in-situ soil moisture observations and remotely sensed observations, improving hydrologic model parameterization and determining the most appropriate unbiased atmospheric forcing’s for hydrologic model applications from NWP output. Additionally the candidate would develop guidelines for parsimonious application of hydrologic models in time and space and evaluation processes and metrics for hydrologic model simulations and forecasts that isolate areas of potential improvement. The research would support the development, by the candidate, of a prototype decision support system that combines a variety of observed and forecast information to aid in operational decision making. Through the research the candidate would continually develop and support a connection between CW3E and California-Nevada River Forecast Center operational forecasts systems. The candidate should have experience with hydrological model development, calibration, application, and verification. Additional experience in developing observed datasets for forcing hydrologic models and operating hydrologic and hydraulic models in a forecasting mode using NWPs or other sources is also desired.
Position 2: Aerosols Influence on Winter Precipitation
CW3E position coordinator – Dr. Amato Evan; firstname.lastname@example.org
CW3E seeks a Postdoctoral researcher to investigate the manner by which aerosols influence wintertime precipitation in the western US, with a focus on ice nuclei from marine and terrestrial sources, using high-resolution numerical modeling. The goal of this work is to improve basic understanding of aerosol-cloud interactions and their affect upon precipitation from atmospheric rivers to improve forecasts of precipitation from such events. In order to address the scientific needs of the project the postdoctoral scholar will be expected to design, implement and validate aerosol emission, transport, removal, cloud condensation and ice nuclei activation models within West-WRF, which is a version of the Weather Research and Forecast Model (WRF) that has been developed at CW3E to improve the accuracy of forecasting extreme precipitation events and as a testbed for understanding the physical processes that drive extremes in weather. These activities will be conducted in collaboration with a team of students, faculty and scientists at CW3E. The successful candidate will have the opportunity to present at conferences and will be expected to publish major results in peer-reviewed journals as first author.
Position 3: Terrestrial Water Storage
CW3E position coordinator – Dr. Julie Kalansky; email@example.com
We seek a postdoctoral researcher to investigate variability in regional terrestrial water storage, including groundwater and snowpack, as revealed by a growing archive of GPS crustal displacements collected throughout California and across the United States. The GPS-inferred water storage contains variability over a range of time scales, much of which is driven by extreme events from synoptic scale storm activity to interannual wet and dry spells. Regionally, the high density of the GPS network may afford resolution at 10’s of km scales and thus provide new insight into catchment water balances. This investigation will require synthesis and comparison with other observational data, along with model-simulated hydrological variability. The postdoc will use the GPS data for information about snowpack and groundwater and relate these to weather and climate events. As part of the project, the postdoc may develop online tools for tracking this information for decision support. Support for this position will come from CW3E, in partnering with CNAP (cnap.ucsd.edu) and the Institute of Geophysics and Planetary Physics (igpp.ucsd.edu). The post-doc should be familiar with climate and hydrological phenomena in western North America.
Position 4: Mesoscale Dynamics and Predictability of Atmospheric Rivers
CW3E position coordinator – Dr. Jason Cordeira; firstname.lastname@example.org
The position will explore the mesoscale dynamics and predictability of ARs affecting the western U.S. coast. The research will use a variety of observational and modeling-based tools and analysis techniques to diagnose the multiscale processes associated with persistent AR conditions culminating in extreme precipitation. The candidate should have experience forecasting extreme events from an operational or modeling perspective, and the ability to conduct in depth case studies and verification analyses. The position will involve participation in an atmospheric river airborne reconnaissance project “AR Recon” effort that is aimed at improving the 1-to-3-day skill of AR landfall forecasts. For example, the incumbent will develop methods to utilize targeting observations in order to improve prediction of mesoscale frontal waves that are key to determining position and duration errors associated with landfalling ARs. The project involves active collaboration with NCEP (GFS) and the Navy (COAMPS) to identify, analyze, and diagnose dynamical processes associated with skillful AR landfall and precipitation characteristics. The candidate should have strong knowledge of mesoscale and synoptic-scale atmospheric dynamics and forecasting techniques, including but not limited to frontal circulations, jet streaks, cyclone kinematics, multiscale precipitation processes, data assimilation, and mesoscale modeling.
Sonoma County Water Agency Board of Directors Chairwoman, Zane, testifies on FIRO before Senate Committee
August 2, 2017
CW3E works closely with Sonoma County Water Agency (SCWA) on the application of atmospheric river science to inform water management practices in the Russian River. SCWA and CW3E are leaders on the Forecast Informed Reservoir Operations (FIRO) project. FIRO is a proposed management strategy that uses data from watershed monitoring and modern weather and water forecasting to help water managers selectively retain or release water from reservoirs in a manner that reflects current and forecasted conditions. FIRO is being developed and tested as a collaborative effort focused on Lake Mendocino that engages experts in civil engineering, hydrology, meteorology, biology, economics and climate from several federal, state and local agencies, universities and others.
Shirlee Zane, SCWA Board of Directors Chairwoman, today testified before the Senate Committee on Energy and Natural Resources’ Subcommittee on Water and Power to discuss the many innovative water supply and drought resilience initiatives the Water Agency is currently implementing, including FIRO. The purpose of the hearing was to examine increasing water security and drought preparedness through infrastructure, management and innovation.
“I was honored to testify and share with the committee the innovative water supply management tools the Sonoma County Water Agency is developing and implementing,” said Sonoma County Water Agency Chairwoman Shirlee Zane. “Securing our water future means thinking outside of the box and not being afraid to lead by example. That is exactly what the Water Agency continues to do as we develop first-class initiatives with our partners. Our investment in water innovation can be replicated across the nation. I am excited to share our experiences to help build innovation in the water industry.” Zane highlighted FIRO, amongst the many innovative water management programs the Water Agency is currently implementing.
For more information on FIRO: Click here
For video of the briefing click here.
American Geophysical Union Publishes Collection of Atmospheric River Publications in Geophysical Research Letters
July 27, 2017
The American Geophysical Union recently published a special hand selected collection of papers on atmospheric rivers that have been published in Geophysical Research Letters.
Atmospheric rivers are a relatively new phenomena in atmospheric science that have become a popular subject of meteorological, hydrological, and climatological research due to their influence on global moisture transport, extreme precipitation, flooding, drought mitigation, and water supply. The collection in GRL highlights the research that has been published over the past three decades beginning with Newell et al’s seminal paper, which introduced the term “tropospheric river.”
Papers from numerous CW3E researchers and collaborators are featured in the collection which discuss topics ranging from extreme precipitation to the influence of climate change on atmospheric river characteristics. The collection of papers can be found here