{"id":188332,"date":"2023-12-07T15:39:50","date_gmt":"2023-12-08T01:39:50","guid":{"rendered":"https:\/\/www.hawaii.edu\/news\/?p=188332"},"modified":"2023-12-07T15:39:50","modified_gmt":"2023-12-08T01:39:50","slug":"improved-accuracy-of-oahu-rainfall-data","status":"publish","type":"post","link":"https:\/\/www.hawaii.edu\/news\/2023\/12\/07\/improved-accuracy-of-oahu-rainfall-data\/","title":{"rendered":"More accurate O\u02bbahu rainfall data supports extreme weather preparedness"},"content":{"rendered":"Reading time: <\/span> 2<\/span> minutes<\/span><\/span>
\"rain
Mesonet<\/a> rain gauge at Lyon Arboretum, maintained by Tsang Stream Lab.<\/figcaption><\/figure>\n

Rainfall estimations on Oʻahu<\/span> can be more accurate by combining Â鶹´«Ã½<\/span>\u2019s two main types of rainfall observations, radar and rain gauge, according to a study by University of Â鶹´«Ã½<\/span> at M\u0101noa researchers. Current observations are based on one or the other, where specific weather stations are checked (rain gauge), or weather radars are observed to view patterns. The study is an effort to better understand Â鶹´«Ã½<\/span>\u2019s complex weather patterns and hydrological consequences.<\/p>\n

Like most of the world, Â鶹´«Ã½<\/span> is experiencing more extreme weather, yet often lacks adequate data. By bridging the gap between radar and gauge data, experts can now gain a better understanding of the complex rainfall patterns in mountainous tropical areas across the state, as well as the inherent uncertainties associated with various storm types and structures when simulating streamflow.<\/p>\n

The new dataset, which stemmed from combining radar and rain gauge data, also creates better synergy across disciplines. Meteorologists and hydrologists can deepen their understanding, leading to more accurate assessments of flash flood risks, urban planners can test their plans and products against rainfall data, and emergency responders can be more prepared for natural disasters.<\/p>\n

“The significance of this research is not only for its immediate benefit to resource managers, weather forecasters and emergency managers, but also for its potential to jumpstart new scientific advances in atmospheric and water sciences,” said Thomas Giambelluca, director of the UH<\/abbr> M\u0101noa Water Resources Research Center<\/a>.<\/p>\n

The study, “Deriving Gridded Hourly Rainfall on Oʻahu<\/span> by Combining Gauge and Radar Rainfall<\/a>,” was published in the Journal of Hydrometeorology<\/em>. It was conducted by Tsang Stream Lab<\/a> in the College of Tropical Agriculture and Human Resources<\/a>\u2019 Department of Natural Resources and Environmental Management<\/a> and the Nugent Research Group<\/a> in the Department of Atmospheric Sciences<\/a>.<\/p>\n

Better preparation, resilience<\/h2>\n

Radar rainfall observation provides rain rate over a large spatial area within a specific time frame (~every five minutes) but struggles with accuracy, while rain gauges provide “ground truth” values (information from direct observation and measurement), but only measures at limited point locations.<\/p>\n

Recognizing the need to combine these two observation types to collect more accurate data, the UH<\/abbr> M\u0101noa researchers built off of a previous effort that compiled hourly gauge and radar data throughout the state of Â鶹´«Ã½<\/span><\/a> (hourly rainfall data available here<\/a>), and merged the two main types of rainfall observations to create a detailed hourly gridded rainfall dataset for Oʻahu<\/span>. This incorporation of two data sources is also known as kriging with external drift (KED<\/abbr>), allowing the researchers to refine rainfall values estimated only by a single instrument.<\/p>\n

“With this developed and validated KED<\/abbr> method, we are advancing Â鶹´«Ã½<\/span>\u2019s capacity to better prepare and build resilience when facing climate extremes,” said Yinphan Tsang, co-author of the study and principal investigator of the Tsang Stream Lab.<\/p>\n

This research offers valuable insights into the performance of the KED<\/abbr> method across various storm types, such as tropical cyclones, cold fronts, upper-level troughs and Kona lows, to accurately estimate rainfall in these scenarios for flood forecasting and impact applications.<\/p>\n

“The validated KED<\/abbr> hourly rainfall dataset is an especially valuable tool for ongoing research on extreme weather impacts and water resources in Â鶹´«Ã½<\/span>,” said Giambelluca.<\/p>\n

\"graphic
Different rainfall estimates during Hurricane Lane.<\/figcaption><\/figure>\n","protected":false},"excerpt":{"rendered":"

By combining Â鶹´«Ã½<\/span>\u2019s two main types of rainfall observations, experts can now gain a better understanding of the complex rainfall patterns to boost preparedness in natural disasters.<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[745,212,1467,1363,544,158,9,347,704],"class_list":["post-188332","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","tag-atmospheric-sciences","tag-college-of-tropical-agriculture-and-human-resilience","tag-manoa-excellence-in-research","tag-manoa-research","tag-natural-resources-and-environmental-management","tag-publication","tag-uh-manoa","tag-water-resources-research-center","tag-weather","entry","has-media"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t