Dr Anjuli S. Bamzai, NSF Division Director for Atmospheric and Geospatial Sciences and Ms Elizabeth Zelenski, Staff Member, NSF Deputy Director’s Office for Geosciences, explain research on extreme water events that have profound implications for society
Hurricanes, droughts, floods and hailstorms. These disastrous natural events are the flip side of our most precious natural resource: water. Water makes life on Earth possible and is found in three distinct phases (gas, liquid and solid). While the water cycle is often taught as evaporation, condensation, and precipitation, the movement of water through our planet is actually much more complex.
The water molecule connects the components of the Earth system by its incessant movements in the atmosphere, clouds, oceans, lakes, vegetation, snowpack, glaciers, rivers and underground storage. In a âGoldilocks worldâ, water would be neither too scarce nor too abundant and of good quality. However, in the real world, interactions and feedbacks between water (âthe hydrosphereâ) and other parts of the earth system can result in natural hazards that endanger human life. For example, extreme precipitation events pose risks to life, society and the economy in sectors such as water resources management, energy, infrastructure, transport, health and safety and the ‘Agriculture.
Researchers supported by the National Science Foundation (NSF) in the United States are working to find ways to minimize the damaging effects of hurricanes, droughts, floods and hailstorms. Atmospheric scientists are harnessing the power of advanced technology in observations, computer modeling and data science to study natural hazards. Their e ï¬ orts provide information that can be used by communities in the United States and around the world to increase resilience and protect economies.
Below, we outline some of the knowledge gained through research funded by NSF’s Division of Atmospheric and Geospatial Sciences that can improve society’s resilience to natural hazards, resulting in tangible benefits for society as a whole.
For three consecutive hurricane seasons, storms with record precipitation have caused catastrophic flooding in the southern United States: Harvey in 2017, Florence in 2018, and Imelda in 2019. Recent research results indicate that modern storms have failed. not only an increase in water vapor holding capacity, but also become stronger and contribute to higher rainfall rates, causing more damage and danger to affected communities.
When a hurricane hits a coast, the wind near the ground depends on what is there. The e ï¬ ects can vary from neighborhood to neighborhood in a city, or even from side to side of a building. Scientists use cutting-edge modeling techniques to improve our ability to predict how buildings disrupt and alter the wind in hurricanes that strike land, from just above ground to the tops of buildings. Such analyzes will promote better ways of designing and locating buildings and other coastal infrastructure in order to protect lives and property in the face of impending storms, and to develop better ways of responding immediately thereafter.
Despite considerable progress, significant uncertainty in projections of future hurricane risk remains. The climatic factors of changes in hurricane activity are not well understood and there is a short instrumental record of hurricane occurrence. Using indirect recordings such as sediment, scientists are currently working to reconstruct hurricane activity in the western North Atlantic, thereby extending our knowledge of hurricane frequency and intensity across centuries. By creating an extensive archive of the past, scientists can examine how natural processes such as changes in ocean circulation and response to volcanic eruptions affect hurricane activity and can better understand hurricane patterns in the future.
Drought conditions affect irrigation systems, crop yields, fish habitats and spawning, industrial use of water resources for cooling processes, and drinking water supply for humans and animals . Droughts can be long lasting and very harmful to society and the economy. Scientists are studying links between atmospheric circulation and regional drought, for example, the cause of persistent drought in California, a region that relies on a relatively small amount of heavy rainfall to make up most of its annual total. Current understanding suggests that a persistent atmospheric circulation pattern of extremely high atmospheric pressure over the Northeast Pacific may cause winter storms to deflect northward and prevent them from reaching California, resulting in prolonged drought.
In another part of our country, scientists are exploring the links between snowpack, soil moisture and drought, and have suggested that the “flash drought” that unexpectedly hit the Southern Rockies and the Midwest United States in the summer of 2012 could have been predicted months in advance. using observations of soil moisture and snowpack. This advanced knowledge could be used to reduce the impact of future droughts and enable natural resource management agencies and the agricultural industry to be better prepared.
In addition, El NiÃ±o Southern Oscillation (ENSO) phenomena in the Pacific are influencing weather patterns globally on interannual timescales, with far-reaching consequences including changes in crop yields, fire risk and energy demands for heating and cooling needs of homes. , workplaces and other buildings. The drought over southwestern North America is linked to the La NiÃ±a phase of ENSO. NSF-funded researchers are gaining a better understanding of the interconnected natural processes that cause droughts – information essential to our farming practices and water management e ï¬ orts.
Floods are the most common natural hazard, causing billions of dollars in damage each year. Researchers are working to understand the natural processes that cause flooding, from storm surges near our coasts to heavy rains that can overflow rivers and sewers. A multi-stakeholder approach is needed to tackle flood risks, with increased collaboration between researchers and water resource managers and emergency managers. Co-production of knowledge prompts science to focus on the urgent needs that are most important to decision makers, thereby improving the ability to predict what is meaningful to end users.
Scientists are working on a better scienti ï¬ c understanding of extreme precipitation events on a sub-seasonal to seasonal timescale with the aim of improving their predictions and increasing communication between research and stakeholder communities regarding such events. . The following questions are addressed: What are the associated synoptic patterns and characteristics of extreme precipitation events at sub-seasonal to seasonal timescales in the contiguous United States? Do large-scale modes of climate variability modulate these events? If so, how?
Hailstorms are another area of ââinterest for research on natural hazards. NSF-funded researchers are working to identify the types of environments that produce high-impact hail episodes and how the physical processes that produce hail are affected by environmental processes. With a better understanding of the environments that can produce different hail threats, such as giant hail, or large amounts of small or different sized hail, scientists can provide information to local practitioners about the type of weather event. expected, such as giant hail or a lot of small hail (or “blizzard”), so that weather, safety and traffic authorities can make informed decisions.
Natural disasters: mitigating the risks
In partnership with academic researchers and government agencies, NSF works to mitigate the risks associated with natural disasters. Rapid advances in new observation, modeling and simulation technologies provide unprecedented insight into processes and phenomena and their associated predictability. The ability to deliver deadlines and develop early warning systems has proven to have enormous benefits for society.