Quantifying snowfall from orographic cloud seeding

Friedrich, Katja; Ikeda, Kyoko; Tessendorf, Sarah A.; French, Jeffrey R.; Rauber, Robert M.; Geerts, Bart; Xue, Lulin; Rasmussen, Roy; Blestrud, D.; Kunkel, M. L.; Dawson, Nicholas; Parkinson, Shaun

doi:10.1073/pnas.1917204117

Cited by 39 publications

(45 citation statements)

References 14 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Comparison to tower and sounding data have indicated that differences in temperatures are below 1.58C (Friedrich et al 2012;Bianco et al 2017). The vertical resolution of the retrieved profiles ranged from 50 m between the surface and 0.5 km AGL; 100 m between 0.5 and 2 km AGL; and 250 m between 2 and 10 km AGL.…”

Section: B Defining Thermodynamics and Dynamics Through Radiometer And Rawinsondesmentioning

confidence: 97%

“…The authors acknowledge that the maximum Z e value between the surface and 4 km MSL does not necessarily represent the snow hitting the surface, and that snow may continue to grow or sublimate in the atmosphere below and is a source of uncertainty in our analysis. Additionally, conversion of Z e to snowfall rates (S) depends on the snow characteristics and a large variety of Z e -S relationships and strategies to derive radar-based snowfall rates exist (e.g., Puhakka 1975;Wolfe and Snider 2012;Friedrich et al 2020). Instead of using S, we used Z e as a relative metric to compare snowfall in each pathway as if the same Z e -S relationship was applied to all cases.…”

Section: Precipitation Observing Systemmentioning

confidence: 99%

See 1 more Smart Citation

The Role of Moisture Pathways on Snowfall Amount and Distribution in the Payette Mountains of Idaho

Cann

Friedrich

2020

Monthly Weather Review

View full text Add to dashboard Cite

The pathways air travels from the Pacific Ocean to the Intermountain West of the United States are important for understanding how air characteristics change and how this translates to the amount and distribution of snowfall. Recent studies have identified the most common moisture pathways in the Intermountain West, especially for heavy precipitation events. However, the role of moisture pathways on snowfall amount and distribution in specific regions remains unclear. Here, we investigate 24 precipitation events in the Payette Mountains of Idaho during January–March 2017 to understand how local atmospheric conditions are tied to three moisture pathways and how it impacts snowfall amount and distribution. During one pathway, southwesterly, moist, tropical air is directed into the Central Valley of California where the air is blocked by the Sierra Nevada, redirected northward and over lower terrain north of Lake Tahoe into the Snake River Plain of Idaho. Other pathways consist of unblocked flows that approach the coast of California from the southwest and then override the northern Sierra Nevada and southern Cascades, and zonal flows approaching the coast of Oregon overriding the Oregon Cascades. Air masses in the Payette Mountains of Idaho associated with Sierra-blocked flow were observed to be warmer, moister, and windier compared to the other moisture pathways. During Sierra-blocked flow, higher snowfall rates, in terms of mean reflectivity, were observed more uniformly distributed throughout the region compared to the other flows, which observed lower snowfall rates that were predominantly collocated with areas of higher terrain. Of the total estimated snowfall captured in this study, 67% was observed during Sierra-blocked flow.

show abstract

Section: B Defining Thermodynamics and Dynamics Through Radiometer And Rawinsondesmentioning

confidence: 97%

Section: Precipitation Observing Systemmentioning

confidence: 99%

The Role of Moisture Pathways on Snowfall Amount and Distribution in the Payette Mountains of Idaho

Cann

Friedrich

2020

Monthly Weather Review

View full text Add to dashboard Cite

show abstract

“…The cloud could respond to seeding very differently if the AgI particles are released from an aircraft. The recently completed Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) field campaign collected a wealth of in situ and remote sensing measurements and observed clear seeding signals in clouds treated by aircraft seeding (French et al 2018;Tessendorf et al 2019;Friedrich et al 2020), which provides great opportunities to validate and improve our model in the near future. The possible indication of seedability level by the novel h-LWP parameter will be tested in the SNOWIE cases.…”

Section: Diffusional Growth Of Liquidmentioning

confidence: 99%

Evaluation of Orographic Cloud Seeding Using a Bin Microphysics Scheme: Three-Dimensional Simulation of Real Cases

Geresdi

Xue

Sarkadi

et al. 2020

Journal of Applied Meteorology and Climatology

Self Cite

View full text Add to dashboard Cite

The University of Pecs and NCAR Bin (UPNB) microphysical scheme was implemented into the Weather Research and Forecast (WRF) mesoscale model which was used to study the impact of AgI seeding on the precipitation formation in the winter orographic clouds. Four different experimental units were chosen from the Wyoming Weather Modification Pilot Project to simulate the seeding effect. The results of the numerical experiments show that: (i) Comparisons with the soundings, snow gauges and micro-wave radiometer (MWR) data indicate that the three dimensional simulations with detailed microphysics reasonably represent both the dynamics and the microphysics of the real clouds. (ii) The dispersion of the AgI particles from the simulated ground-based seeding was effective due to the turbulent mixing. (iii) In the investigated cases (surface temperature is less than 0°C) the surface precipitation and the precipitation efficiency show low susceptibility to the concentrations of Cloud Condensation Nuclei (CCN) and natural Ice Nucleating Particles (INP). (iv) If the available liquid water content promotes the enhancement of the amount of snowflakes by diffusional growth, the surface precipitation can be increased by more than 5%. A novel parameter relevant to orographic clouds, the horizontally integrated liquid water path, was evaluated to find the relation between the seeding efficiency and the liquid water content. The impact of seeding is negligible if the horizontal LWP is less than 0.1 mm, while it is apparent if the horizontal LWP is larger than 1 mm based on the cases investigated in this study.

show abstract

“…When seeding materials are injected into the cloud top, the simplest and easiest‐to‐observe cloud‐seeding feature is the glaciation and collapse of the cloud top (Langmuir, 1961), which indicates that the cloud‐seeding materials have altered the microphysical characteristics and structure of the cloud. Radar is a common tool to identify microphysical changes in cloud properties resulting from cloud seeding (French et al., 2018; Friedrich et al., 2020; Geerts et al., 2010; Hobbs et al., 1981; Pokharel, Geerts, Jing, Friedrich, Aikins, et al., 2014). Based on measurements from ground‐based X‐band radars, an airborne W‐band cloud radar and in situ physical cloud probes, French et al.…”

Section: Introductionmentioning

confidence: 99%

“…Friedrich et al. (2020) identified areas of orographic precipitation that were unambiguously generated by cloud seeding through the identification of seeding tracks with enhanced radar reflectivity, which could then be connected to enhanced surface snowfall.…”

Section: Introductionmentioning

confidence: 99%

The Evolution of an AgI Cloud‐Seeding Track in Central China as Seen by a Combination of Radar, Satellite, and Disdrometer Observations

et al. 2021

View full text Add to dashboard Cite

Operational cloud seeding has been implemented to alleviate local precipitation shortages in China for over half a century. Here, we present quantitative evidence for the effect of AgI seeding on supercooled layer clouds with a top cloud temperature of −15°C in China, as documented for the first time by a combination of radar, satellite, and disdrometer observations. A radar signature appeared 18 min after seeding, shortly followed by a visible glaciated seeding track. The seeding signature expanded horizontally at a rate of ∼1.4 and ∼0.3 m s−1 before and after 04:25 UTC. The radar signature descended to the surface 40 min after seeding. A disdrometer captured the precipitation of the first seeded raindrops that reached maximum diameter of 2.75 mm compared to the maximum diameter of 1 mm of the light background rain. The enhanced surface rainfall was observed within the subsequent 100 min. A conceptual model for the formation and expansion of the seeding track is presented. Although the precipitation was light, it is a promising step toward the goal of quantifying the impact of cloud seeding in China.

show abstract

Quantifying snowfall from orographic cloud seeding

Cited by 39 publications

References 14 publications

The Role of Moisture Pathways on Snowfall Amount and Distribution in the Payette Mountains of Idaho

The Role of Moisture Pathways on Snowfall Amount and Distribution in the Payette Mountains of Idaho

Evaluation of Orographic Cloud Seeding Using a Bin Microphysics Scheme: Three-Dimensional Simulation of Real Cases

The Evolution of an AgI Cloud‐Seeding Track in Central China as Seen by a Combination of Radar, Satellite, and Disdrometer Observations

Contact Info

Product

Resources

About