CAREER: The Upstream Impacts of Mountains on Frontal Precipitation Using Olympic Mountain Experiment (OLYMPEX) Observations

该奖项支持研究山区降水发展的研究。当天气系统被迫越过或靠近山区时，降雨量和降雪量往往会增加，这严重影响了华盛顿州奥林匹克山脉等地区的水资源供应，但也增加了洪水、雪崩和泥石流等灾害的风险。在某些条件下，这种强化降水的位置和强度可能会发生变化，这种由地形引起的增强发生在山脉本身上游的远处。量化这种上游降水增加的方式和地点，以及它在快速变化的条件下如何演变，对于完整了解这些天气系统如何向一个地区提供降水，以及更准确地量化系统与地形相互作用带来的与天气有关的不断演变的灾害至关重要。通过全面的现场观测和高分辨率数值模拟，该项目将量化上游增强发生的条件，并确定在快速演变的大气流动中导致这种增强的机制。该项目将与开发一个全面的指导和研究体验计划相一致，以支持两年制大学项目的学生转学。通过全面的导师模式，该项目将发展跨机构关系，同时还提供全年研究、沟通技能建设和专业发展机会，以支持学生进入地球科学的道路。该项目使用对NASA-NSF OLYMPEX野外活动期间收集的高分辨率雷达数据和探测数据的分析，来自美国国家气象局WSR-88D雷达和华盛顿州探空站的业务数据，以及免费的高分辨率数值模拟，以量化华盛顿州奥林匹克山脉迎风的锋面降水过程是如何独特地改变的。主要任务将是通过对业务雷达数据的统计分析，确定山区上游地形降水增强的优先区域，通过高分辨率多普勒分析和数值模拟，量化上游水流分流的变化和演变，并通过对地面和卫星雷达的详细个案研究，确定低空风和大气稳定性的变化如何扩大地形增强的范围，以及这如何影响锋面环流和降水。这项研究将有助于对锋面和其他高度可变的大气流动与孤立山脉的相互作用做出新的理解，这对于了解山区岛屿周围地形增强降水的分布和演变具有重要意义。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award supports research to study the development of precipitation over mountainous terrain. Increased rainfall and snowfall often occur when weather systems are forced to go over or around mountainous terrain, significantly impacting the availability of water for regions such as the Olympic Mountains of Washington State, but also increasing the risk of hazards such as flooding, avalanches and mudslides. Under some conditions, the location and intensity of this intensified precipitation can change, with this terrain-induced enhancement occurring at distances upstream of the mountains themselves. Quantifying how, and where, this upstream precipitation enhancement occurs and how it evolves in rapidly changing conditions is crucial to completing the full picture of how these weather systems provide precipitation to a region, as well as more accurately quantifying the evolving weather-related hazards that come with the system interacting with terrain. Through comprehensive field observations and high-resolution numerical simulations, this project will quantify the conditions where this upstream enhancement occurs and identify the mechanisms that lead to this enhancement in rapidly evolving atmospheric flows. This project will coincide with the development of a holistic mentoring and research experience program to support the transfer of students from two-year college programs. Through a comprehensive mentorship model, this program will develop cross institutional relationships while also providing year-round research, communication skill building, and professional development opportunities to support students’ path into geosciences.This project use analysis of high-resolution radar data and soundings collected during NASA-NSF OLYMPEX field campaign, operational data from the National Weather Service WSR-88D radars and NWS Quillayute, WA sounding station, and complimentary high-resolution numerical simulations to quantify how frontal precipitation processes are uniquely altered upwind of the Olympic Mountains of Washington State. The main tasks will be to identify the preferred regions of orographic precipitation enhancement upstream of the mountains through statistical analysis of operational radar data, to quantify the variability and evolution of upstream flow diversion through high-resolution Doppler analysis and numerical simulations, and to determine how variations in low-level winds and atmospheric stability extend the reach of the orographic enhancement and how this affects frontal circulations and precipitation through detailed case study analysis of ground-based and satellite-based radars. This research will contribute new understanding about the interaction of fronts and other highly variable atmospheric flows with isolated mountain ranges, which has significant implications for understanding the distribution and evolution of orographically-enhanced precipitation around mountainous islands.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.