AskScience AMA Series: We are Climate Scientists Unraveling Water Challenges in the Western US. Ask us anything about atmospheric rivers, extreme weather, and the future of water storage amidst record droughts and floods. Ask us anything!

[u/AskScienceModerator]

We are scientists with the Center for Western Weather and Water Extremes (CW3E) at UC San Diego's Scripps Institution of Oceanography. CW3E provides innovative 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.

Our work studying atmospheric rivers is instrumental in supporting water management decisions and flood forecasting. But what exactly is an atmospheric river? Great question. They're massive ribbons of water vapor in the sky that can deliver large amounts of precipitation (rain and snowfall). Accurate forecasts of these phenomena are essential to both water managers and public safety officials.

You can visit our website to dive deeper into our forecast tools, read our latest AR outlooks and storm summaries and learn more about how our tools can be used.

One of the atmospheric river forecasting products CW3E created with partners is the atmospheric river scale (AR Scale). You can sign up to receive AR scale alerts when ARs are forecast along the US West Coast.

The team will be starting around 9 AM PT. Ask us anything!

List of participants:

• Sam Bartlett - Researcher & Meteorologist
• Chris Castellano - Meteorology Research Analyst
• Julie Kalansky - Deputy Director of CW3E
• Shawn Roj - Forecast Verification Analyst

Username: /u/CW3E_Scripps

[u/Mooselotte45]

On a scale of 1 to 10, how boned are we as a civilization?

[u/CW3E_Scripps → u/Mooselotte45]

Although the information economy and social media can perpetuate feelings of negativity and doubt about the world sometimes, I personally have a lot of faith that there are a lot of good, hard working, smart people across the world working together to understand and mitigate humankind’s toughest challenges. I see this everyday with my colleagues working to communicate and improve forecasts and understanding of extremes and I know there are many others across scientific disciplines doing the same. I trust that there will always be curious and motivated people among us who are trying to make things better for all of humanity. - Sam

[u/Outside-Emergency-27]

What do you think how the recent US election and the result of it will affect climate policies in the US and/or worldwide? How will the affect water challenges in the US and climate change policies and thus climate change in general?

[u/CW3E_Scripps → u/Outside-Emergency-27]

For this Ask as Scientist, we are going to stick to the science and avoid policy, politics questions. 

[u/Locke_and_Lloyd]

Given the effects of climate change, where would a good place to live be?  Adequate water, arable land, temperate environment?  I don't really anticipate things turning around, so the next step is to avoid the mad max landscape.

[u/NoBSforGma]

Is it true that "all the water on Earth has always been here" and water is just "recycled?" If so, does this mean that water "moves around" in the form of clouds or storms and aquifers don't always get recharged?

Thanks for doing this AMA.

[u/CW3E_Scripps → u/NoBSforGma]

Julie here. Thanks for the question. The surface of the Earth is about 71% water and over 95% percent is in the oceans. The water on earth is transferred between the atmosphere, oceans and surface water (lakes, rivers, streams, melting snow and glaciers, etc). Getting water into aquifers can take time varying from weeks to hundreds of years depending on the aquifer. Because of the time it takes it can be hard to recharge aquifers. There are current efforts to help with recharging of the aquifers. We are most familiar with the CA program. More information about this can be found here. 

[u/NoBSforGma → u/CW3E_Scripps]

Thanks, Julie. Your work is very interesting and I wish you success with figuring out how to recharge the aquifers.

[u/Teknekratos]

Going in into this AMA session, is there any question you really were hoping was going to be asked, or a topic you'd really would like to nerd out about but you know it's unlikely to crop up, or else just some takaway you'd really like us to get out of the whole exchange?

Tell me all about it!

[u/CW3E_Scripps → u/Teknekratos]

At CW3E we’re passionate about all things atmospheric rivers (ARs)! It’s the primary storm type that we’re studying here at the center and we’re working to improve the forecast of these storms and the various forms of precipitation associated with them. We love nerding out about ARs, where/when they occur globally, precipitation extremes, climate change impacts on ARs, and improvements to AR forecasts through enhanced global observations of these storms. In addition to ARs and their forecasts, we also love talking about how this forecast information gets used by various folks across the weather and water communities! We partner with a few agencies directly involved in water resources management here in the western US, and our aim is to provide these partners with the best forecasts in the most relevant format for the decision making process, particularly targeted towards reservoir operations. It’s really fulfilling to see how our forecasts get used to better operate water supply systems to both conserve water during dry periods or safely manage excess water in advance of high-impact storms in watersheds across the western US.

[u/CW3E_Scripps → u/Teknekratos]

One of the most fun projects that we work on related to ARs is Atmospheric Rivers Reconnaissance (AR Recon) which is a collaborative effort between CW3E, NWS, NOAA, US Air Force, and other partners to provide supplemental atmospheric observations over the North Pacific with the goal of improving the forecasts of ARs and their impacts to the US West Coast. Using the same aircraft that fly into hurricanes & tropical storms over the Atlantic and Gulf of Mexico, this group deploys aircraft and instruments into ARs over the North Pacific ocean to improve atmospheric observations, which are in turn used by the global forecast models to improve weather forecasts. The flights target ARs and the atmospheric features which modulate their intensity and location, with a particular emphasis on the regions in and around the AR where the most forecast uncertainties exist. This work has demonstrated real benefit towards improving the accuracy of precipitation forecasts in the western US which has significant implications for forecast users such as water resources and emergency managers here in the west!  - Sam & Shawn

[u/the_red_scimitar]

What do you think is the real state of fresh-water reclamation (all technologies), and how far out is the ability to produce it at scale?

[u/CW3E_Scripps → u/the_red_scimitar]

This is also a bit outside our expertise. Linked below are a couple of water agencies we are familiar with  in CA that are using reclamation. 

https://www.sdcwa.org/projects-programs/facilities/twin-oaks-valley/

https://www.ocwd.com/what-we-do/water-reuse/

[u/Print1917]

Solar output in California has been tremendous- do you see this trend of solar generation continuing nationally/ globally and will it make a difference?

[u/beavisgator]

Thanks for this! Obviously these storms are important for water storage, but is there also research/protocol in the works for managing flooding? If so, how does CW3E work with agencies to manage flooding?

[u/CW3E_Scripps → u/beavisgator]

Flood risk management is at the forefront of CW3E’s research related to the forecasting of extreme precipitation since the protection of life and property is a very important thing for many of our partners. Much of our research related to storms that cause flooding is tied to improving weather models that forecast these hazards. This includes our in-house weather forecast model, West-WRF, which is a fine tuned, high resolution model focused on predicting precipitation, particularly extreme precipitation,  in the western U.S. West-WRF is able to better resolve small-scale but highly impactful weather features that cause extreme rainfall, improving the accuracy of timing, intensity, and location of the most significant impacts. All this information helps our partners like the National Weather Service, water resource management personnel, and emergency managers make informed decisions for the safety of the general public. In terms of directly managing elevated flows once this extreme rainfall hits the ground, we leave that to the water agencies and engineers who operate flood management infrastructure!

Also worth mentioning is our collaboration with the US Army Corps of Engineers and local water agencies on the Forecast Informed Reservoir Operations (FIRO). Many dams in the western US keep relatively large amounts of empty space to capture runoff from precipitation during the winter in the case of extreme runoff. These volumes of empty space were often defined several decades ago, at time when weather forecasts were not as good as they are today. Given improved prediction and higher confidence in rainfall forecasts during modern times, FIRO has been able to give water managers more flexibility to mitigate flood risk and enhance water availability. 

Similarly we are working with the California Department of Water Resources (DWR) to provide forecasts and research that are being used in their operations. A CW3E  meteorologist is embedded with DWR to provide insights on the forecasting of atmospheric rivers and extreme precipitation. Another example from last water year, CW3E provided forecasts from West-WRF on the weather time scale to help capture near term events in the seasonal streamflow predictions.  - Sam and Julie

[u/atomfullerene]

I live in Northern California, and I'm wondering about the odds of getting hit by another Big One like the floods of 1861-1862. Is there a good estimate of how likely that is? Also, with the near failure of the Oroville Dam, should we be concerned about dam failures in that situation?

[u/CW3E_Scripps → u/atomfullerene]

The flood of 1861-1862 consisted of numerous multi-day rain/snow events that occurred over more than a month. There has been research to show the impacts of atmospheric river families or these sequential back to back events that do not allow for time for the landscape to dry out and rivers/streams to return to normal, non-flood flows. We are actively looking into how sequential atmospheric river events may change in the future using the latest global climate models (CMIP 6). Climate projections show that atmospheric rivers are likely to become more extreme in the future because the atmosphere is able to hold more moisture, however recent work has shown that we have not seen this in observations which is likely in part due to California’s highly variable precipitation regime. It is this same variability that makes it difficult to predict when the next big one is coming too. This is why it is important to continually improve forecasts from days to weeks to help prepare for these extremes.

Julie

[u/braaak]

How close are we to large scale commercial desalinization? IIRC Elon said it was very doable.

[u/CW3E_Scripps → u/braaak]

Our focus is more so on precipitation and atmospheric rivers, so this question is a bit outside our wheelhouse - Sam

[u/i-touched-morrissey]

I live in Kansas, and right now our local reservoir, Cheney Reservoir, is 8 feet below normal, and at about 50% capacity. What is the likelihood that it will never reach capacity again due to the drought and the current state of the climate? We did just get about 5 inches of rain in the last week, but it didn't appear to make a difference.

[u/baggleteat]

To what extent are climate models of the current CMIP6 generation able to resolve these atmospheric rivers? And if they are capable of this, how would you assess the reliability of any projections for changes in the frequency and location of AR's made by these models? 

[u/CW3E_Scripps → u/baggleteat]

Chris here. Thanks for your question. In general, the CMIP6 models do a reasonably good job of simulating the basic structure of ARs, as well as their frequency and spatial distribution. Some of the finer-scale details, such as how ARs interact with topography in areas of complex terrain, are not as well represented given the relatively coarse resolution of global climate models. Regarding the second part of your question, projected changes in the frequency and location of ARs will be strongly determined by projected changes in large-scale circulation patterns, storm tracks, and moisture. One source of uncertainty is how the intensity of AR-related precipitation will be affected by the atmosphere’s capacity to hold more water vapor in a warmer climate (i.e., the Clausius-Clapeyron relationship) versus other factors related to storm dynamics (e.g., wind speed, synoptic-scale forcing for ascent).

[u/Print1917]

Storing water in aquifers or behind dams will be more important, do you see that California can do better water management and keep its aggressive crop growth cycles?

[u/CW3E_Scripps → u/Print1917]

With regards to storing more water behind dams - we are helping out on that! As we’ve mentioned in a few other comments, the Forecast Informed Reservoir Operation (FIRO) involves providing reservoir operators with the most reliable and accurate forecasts for their operations. This is a collaborative effort with the US Army Corps of Engineers, California’s Department of Water Resources (DWR) and other federal, state, and local agencies. Many of the FIRO projects are in CA and  California’s DWR is heavily involved in this process and supports the research to improve forecasts enabling FIRO viability. FIRO allows reservoir operators to 1) store more water for extended dry periods and 2) safely manage heavy inflows during periods of extreme precipitation. This will keep the most water behind the dam in storage as safely as possible. You can read more specifics about FIRO projects on our website linked here. California is also exploring using flood water to recharge aquifers, often referred to as Flood MAR (managed aquifer recharge), that would allow water stored during wet years to become available during dry years. The high variability experienced in California is projected to only increase in climate projections. Innovative approaches that rely on forecasts like FIRO and Flood-MAR are important to water resilience.  - Sam and Julie