Within Wind Data
Can a model trace the UFO's drift?
Trajectory runs can test whether a plausible balloon release point and altitude match a reported path, while still showing uncertainty.
On this page
- What a trajectory model can and cannot prove
- Start point, time and altitude choices
- Why ensemble paths matter for uncertainty
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Introduction
Trajectory modelling is one of the most useful ways to test whether a reported UFO could have been a balloon, lantern or other wind-driven object. Rather than asking only whether winds were present, investigators can use meteorological data to estimate where a drifting object would have travelled if released from a particular location, at a particular time and altitude. When the predicted path resembles the reported movement, a balloon explanation becomes more plausible. When repeated model runs fail to reproduce the sighting, the balloon hypothesis becomes weaker.
The key point is that trajectory models are tests of consistency, not proof. A successful match shows that known winds could have carried an object along a path similar to the reported one. It does not demonstrate that a balloon was actually present. Likewise, a poor match may reflect uncertainty in the starting assumptions rather than a definitive rejection of the balloon explanation. Modern trajectory tools therefore work best when used as probability assessments rather than simple yes-or-no verdicts. [ready.noaa.gov]ready.noaa.govNOAA HYSPLIT Trajectory ModelEach member of the trajectory ensemble is calculated by offsetting the meteorological data by a fixed grid f…
Can a model trace the UFO’s drift?
Trajectory models calculate how an object would move through the atmosphere when carried by changing winds. The most widely used systems, such as NOAA’s Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT), were developed for atmospheric transport studies but are equally useful for reconstructing potential balloon paths. These models combine weather observations and forecast data with assumptions about an object’s location and altitude to generate a projected track. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported… [American Meteorological Society Journals]journals.ametsoc.orgAmerican Meteorological Society JournalsNOAA's HYSPLIT Atmospheric Transport and Dispersion…by AF Stein · 2015 · Cited by 6803 — HYSPL…
In a suspected balloon sighting, investigators typically compare two tracks:
- The reported path reconstructed from witness observations, photographs or video.
- The modelled path generated from weather data. [aoml.noaa.gov]aoml.noaa.govupper air observationsAir Observations: How Weather Balloons Improve…1 Sept 2017 — Weather balloons, also known as radiosondes, provide detailed and reliabl…
If the directions, speeds and timing broadly agree, the result supports the possibility that the object drifted with the wind. This approach is particularly valuable when witnesses report slow movement, gradual course changes or long-duration visibility, all of which are characteristic of drifting objects rather than powered aircraft. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…
A practical example comes from weather-balloon and radiosonde tracking. Thousands of balloon flights are routinely predicted and reconstructed using trajectory software because wind fields largely determine their movement. Balloon-recovery communities and meteorological agencies use these methods to estimate landing zones and flight paths with reasonable success. [Stratoflights]stratoflights.comStratoflightsPredicting the Weather Balloon flight pathThis tool will help you to predict the estimated flight path of your high altitude… [SondeHub]sondehub.orgSondeHubSondeHub TrackerLive tracking of radiosonde flights. Data via SondeHub v2. Includes weather overlay, predictions, and access to h…
What a trajectory model can and cannot prove
A trajectory model can demonstrate that a reported movement is physically compatible with known atmospheric conditions. It can also identify whether a claimed route would require winds that did not exist at plausible altitudes. [PMC]pmc.ncbi.nlm.nih.govPMCby H Hou · 2023 · Cited by 8 — HYSPLIT calculates forward and backward trajectories of particles based on wind speed, wind direction…
However, the model cannot establish:
- The object’s identity.
- Its exact altitude unless independent evidence exists.
- Whether the witness accurately perceived distance and direction.
- Whether the object changed altitude during the sighting.
A close match between modelled and observed tracks should therefore be treated as supporting evidence rather than conclusive identification. Conversely, a mismatch is not necessarily fatal to the balloon hypothesis if the starting assumptions remain uncertain. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…
Start point, time and altitude choices
The most difficult part of trajectory testing is often selecting the starting conditions. Small changes in launch time or altitude can produce substantially different paths because atmospheric winds vary with height and evolve over time. [NASA Open Data Portal]data.nasa.govNASA Open Data PortalWind Profile Data: Radiosonde (FIFE) - Dataset1 Apr 2025 — The wind profile data described in this document were der…
For suspected balloon sightings, investigators commonly explore multiple possibilities:
- Several potential release locations.
- Different launch times before the sighting.
- Multiple altitude bands.
- Different ascent rates if the object may have been climbing.
This matters because a drifting object may pass through several wind layers during a single observation. A balloon released near the ground might initially travel east, then curve north after rising into a different air current. Witnesses sometimes interpret such changes as controlled manoeuvres even when they are consistent with atmospheric transport. [Reddit]reddit.comHow is the spy balloon steerable?r/askscienceFebruary 11, 2023 — Balloons are “steerable” by changing altitude to find winds in a different direction. Altitude change is…
Altitude assumptions are especially important. NOAA’s trajectory tools include options to test paths from multiple starting heights because atmospheric transport can differ dramatically between layers separated by only a few hundred metres. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…
A strong analysis therefore avoids selecting a single preferred altitude and instead examines a range of realistic heights that fit the reported object.
Why ensemble paths matter for uncertainty
One of the most common mistakes in UFO investigations is treating a single trajectory line as if it were an exact reconstruction. Atmospheric scientists generally avoid this approach because every trajectory contains uncertainty. Weather observations are incomplete, models have finite resolution and the object’s true starting conditions may be unknown. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…
For that reason, many trajectory systems provide ensemble calculations. Instead of producing one path, they generate multiple trajectories by slightly altering the starting position, altitude or meteorological inputs. NOAA’s HYSPLIT ensemble option, for example, automatically computes numerous nearby trajectories to show how sensitive the result is to small changes in assumptions. [ready.noaa.gov]ready.noaa.govREAD YBalloon Flight Forecasting ToolsMay 12, 2025 — HYSPLIT Trajectory Optimization. This program developed at ARL (Draxler, 1996) can be used…
The difference between a single trajectory and an ensemble can be crucial:
- A narrow cluster suggests relatively stable atmospheric transport.
- A wide spread indicates substantial uncertainty.
- Diverging paths may show that the available data cannot distinguish between several plausible routes.
For UFO analysis, the most persuasive result is often not a perfect overlap but a situation where the reported path falls within a realistic envelope of ensemble solutions. That demonstrates compatibility with known winds while honestly acknowledging uncertainty. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…
When trajectory matches become meaningful
A trajectory result becomes more informative when independent evidence points in the same direction. Examples include:
- Reports of balloon launches, festivals or lantern releases near the estimated source area.
- Radiosonde launch records from nearby weather stations.
- Photographs showing behaviour consistent with drifting rather than powered flight.
- Multiple witnesses observing the same general direction and movement.
Trajectory modelling is strongest when it forms part of a larger evidential picture rather than standing alone. A model that places a potential balloon directly along the reported route at the correct time is far more persuasive when supported by known launch activity or documented atmospheric balloon operations. [SondeHub]sondehub.orgSondeHubSondeHub TrackerLive tracking of radiosonde flights. Data via SondeHub v2. Includes weather overlay, predictions, and access to h… [2SQ6KXY Radiosonde Tracker]radiosondy.infoSQ6KXY Radiosonde Tracker DatabaseGet Data. Radiosondes of last 48 hours: Show Table. Show Map. Last Status Changes: Number. Type. Launch…
The practical value of trajectory testing
Within investigations of UFO reports, trajectory modelling provides a way to move beyond intuition. Witnesses often estimate motion against a background of unknown distance, uncertain altitude and changing perspective. Wind-based modelling introduces an objective test: could a free-floating object have followed a similar route under the atmospheric conditions that actually existed?
The answer is rarely absolute. Yet when multiple trajectory runs, realistic altitude assumptions and ensemble analyses all point toward the same drifting path, the balloon explanation becomes substantially stronger than a simple visual guess. Equally important, when plausible trajectories repeatedly fail to match the reported movement, investigators gain a clearer understanding of where the balloon hypothesis may fall short. [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported… [Air Resources Laboratory]arl.noaa.govAir Resources Laboratory HYSPLITAir Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported…
Amazon book picks
Further Reading
Books and field guides related to Can a model trace the UFO's drift?. Use these as the next step if you want deeper reading beyond the article.
The Signal and the Noise
Useful for understanding modelling uncertainty, probability and limits of inference.
The UFO Experience
Connects model-based drift testing to the broader process of UFO case evaluation.
How to Lie with Statistics
Reinforces caution about overclaiming from uncertain model outputs.
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Example marketplace items related to this page. Use the search link to explore similar finds on eBay.
Endnotes
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Source: ready.noaa.gov
Link: https://www.ready.noaa.gov/hypub-bin/trajtype.plSource snippet
NOAA HYSPLIT Trajectory ModelEach member of the trajectory ensemble is calculated by offsetting the meteorological data by a fixed grid f...
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Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT
Link: https://www.arl.noaa.gov/hysplit/Source snippet
Air Resources LaboratoryHYSPLIT - Air Resources LaboratoryHYSPLIT models simulate the dispersion and trajectory of substances transported...
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Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT User’s Guide
Link: https://www.arl.noaa.gov/documents/reports/hysplit_user_guide.pdfSource snippet
Air Resources LaboratoryHYSPLIT User's Guide - Air Resources Laboratoryby R Draxler · Cited by 931 — The HYsplit (HYbrid Single-Particle...
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Source: arl.noaa.gov
Link: https://www.arl.noaa.gov/research/atmospheric-transport-and-dispersion/atd-programs-ready/Source snippet
Air Resources LaboratoryAtmospheric Transport: HYSPLIT & READYHYSPLIT is a complete system for computing simple air parcel trajectories a...
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Source: arl.noaa.gov
Title: balloon flight forecasting tools
Link: https://www.arl.noaa.gov/hysplit/getrun-hysplit/balloon-flight-forecasting-tools/Source snippet
Air Resources LaboratoryHYSPLIT Balloon Flight Forecasting ToolThis program developed at ARL (Draxler, 1996) can be used to visualize all...
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Source: stratoflights.com
Link: https://www.stratoflights.com/en/tutorial/weather-balloon-tools/predicting-the-flight-path/Source snippet
StratoflightsPredicting the Weather Balloon flight pathThis tool will help you to predict the estimated flight path of your high altitude...
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Source: sondehub.org
Link: https://sondehub.org/Source snippet
SondeHubSondeHub TrackerLive tracking of radiosonde flights. Data via SondeHub v2. Includes weather overlay, predictions, and access to h...
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Source: data.nasa.gov
Link: https://data.nasa.gov/dataset/wind-profile-data-radiosonde-fife-bca10Source snippet
NASA Open Data PortalWind Profile Data: Radiosonde (FIFE) - Dataset1 Apr 2025 — The wind profile data described in this document were der...
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Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT
Link: https://www.arl.noaa.gov/documents/workshop/NAQC2007/HTML_Docs/trajerro.htmlSource snippet
Air Resources LaboratoryHYSPLIT - Trajectory ErrorThe total error is composed of four error components: physical error due to the inadequ...
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Source: arl.noaa.gov
Title: Air Resources Laboratory HYSPLIT
Link: https://www.arl.noaa.gov/documents/workshop/NAQC2007/HTML_Docs/trajmult.htmlSource snippet
Multiple TrajectoriesOne way to reduce those uncertainties would be to compute multiple trajectories, in height, time, and space. HYSPLIT...
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Source: reddit.com
Title: How is the spy balloon steerable?
Link: https://www.reddit.com/r/askscience/comments/10zoxa0/how_is_the_spy_balloon_steerable/Source snippet
r/askscienceFebruary 11, 2023 — Balloons are “steerable” by changing altitude to find winds in a different direction. Altitude change is...
Published: February 11, 2023
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Source: aoml.noaa.gov
Title: upper air observations
Link: https://www.aoml.noaa.gov/upper-air-observations/Source snippet
Air Observations: How [Weather Balloons]({{ 'balloons/' | relative_url }}) Improve...1 Sept 2017 — Weather balloons, also known as radiosondes, provide detailed and reliabl...
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Source: ready.noaa.gov
Title: READ Y
Link: https://www.ready.noaa.gov/READY_balloon.phpSource snippet
Balloon Flight Forecasting ToolsMay 12, 2025 — HYSPLIT Trajectory Optimization. This program developed at ARL (Draxler, 1996) can be used...
Published: May 12, 2025
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Source: noaa.gov
Link: https://www.noaa.gov/jetstream/upperair/radiosondesSource snippet
National Oceanic and Atmospheric...16 Sept 2025 — The radiosonde is a small instrument package that is suspended below balloon filled wi...
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Source: noaa.gov
Link: https://www.noaa.gov/ -
Source: ready.noaa.gov
Title: Cheat Sheet 2020
Link: https://www.ready.noaa.gov/documents/ppts/Cheat_Sheet_2020.pdfSource snippet
Cheat Sheet8 Sept 2020 — The HYSPLIT model is a system for computing simple air parcel trajectories, dispersion simulations. includes thi...
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Source: ready.noaa.gov
Title: HYSPLIT traj
Link: https://www.ready.noaa.gov/HYSPLIT_traj.phpSource snippet
ectory Model - READY - - NOAA12 May 2025 — Trajectory optimization for balloon flights. Users are limited to 500 trajectories per day. HY...
Published: May 2025
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Source: ready.noaa.gov
Link: https://www.ready.noaa.gov/hypub-bin/trajsrc.pl?trjtype=4Source snippet
HYSPLIT Trajectory ModelSelect the forecast meteorological data set from the drop-down list. Currently, the NAM, GFS, and HRRR data are a...
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Source: www-n-bbs.arl.noaa.gov
Link: https://www-n-bbs.arl.noaa.gov/viewtopic.php?t=2704Source snippet
In this case, is it better to increase the initial height to be 250 m...Read more...
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Source: ready.noaa.gov
Link: https://www.ready.noaa.gov/HYSPLIT.phpSource snippet
Resources Laboratory - HYSPLIT12 May 2025 — The HYSPLIT model can be run interactively on the READY web site or installed on a PC (Mac) o...
Published: May 2025
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Source: weather.gov
Link: https://www.weather.gov/ -
Source: weather.gov
Link: https://www.weather.gov/gjt/education_corner_balloonSource snippet
Education Corner weather balloonThe weather balloon remains the best platform for observing temperature, wind, relative humidity, and pre...
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Source: weather.gov
Link: https://www.weather.gov/upperair/factsheetSource snippet
Radiosonde ObservationThe radiosonde is a small, expendable instrument package (weighs 60 to 80 grams) that is suspended below a large ba...
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Source: reddit.com
Link: https://www.reddit.com/r/TheMotte/comments/n5c0r1/a_theory_that_matches_observations_and_recent/Source snippet
ons via tractor beams would work, as well as the reports from people...Read more...
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Source: journals.ametsoc.org
Link: https://journals.ametsoc.org/view/journals/bams/96/12/bams-d-14-00110.1.xmlSource snippet
American Meteorological Society JournalsNOAA's HYSPLIT Atmospheric Transport and Dispersion...by AF Stein · 2015 · Cited by 6803 — HYSPL...
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Source: radiosondy.info
Link: https://radiosondy.info/Source snippet
SQ6KXY Radiosonde Tracker DatabaseGet Data. Radiosondes of last 48 hours: Show Table. Show Map. Last Status Changes: Number. Type. Launch...
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Source: balloonwiki.org
Link: https://www.balloonwiki.org/en/doku.php/hysplit/startSource snippet
HYSPLIT [BalloonWiki]8 Feb 2021 — Here you have to select the weather model and the location where the trajectories start. In the example...
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Source: Wikipedia
Title: Weather balloon
Link: https://en.wikipedia.org/wiki/Weather_balloonSource snippet
Weather balloonA weather balloon, also known as a sounding balloon, is a high-altitude balloon (HAB) that carries instruments into the...
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Source: Wikipedia
Link: https://en.wikipedia.org/wiki/HYSPLITSource snippet
HYSPLITThe Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) is a computer model that is used to compute air par...
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Source: mce2.org
Link: https://mce2.org/wmogurme/images/workshops/ASEAN/day1/saide/HYSPLIT.pdfSource snippet
Introduction to the HYSPLIT Trajectory ModelData is available globally and regionally over North America. PC HYSPLIT downloads data direc...
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Source: www2.atmos.umd.edu
Link: https://www2.atmos.umd.edu/~tcanty/hysplit/today/index.htmSource snippet
Trajectories - UMD - University of MarylandThe figures on this webpage illustrate air parcel trajectories found using the publicly access...
Additional References
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Source: hurricanescience.org
Link: https://hurricanescience.org/science/observation/landbased/radiosonde/index.htmlSource snippet
Upper-Air Observations: The RadiosondeAs the radiosonde rises at about 300 m/min (about 1,000 ft/min), its sensors make in-situ measureme...
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Source: researchgate.net
Link: https://www.researchgate.net/publication/275223272_Investigation_of_the_Effects_of_Considering_Balloon_Drift_Information_on_Radiosonde_Data_Assimilation_Using_the_Four-Dimensional_Variational_MethodSource snippet
Investigation of the Effects of Considering Balloon Drift...13 Dec 2025 — Effects of balloon drift information (i.e., position and elaps...
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Source: researchgate.net
Link: https://www.researchgate.net/publication/356315630_Moisture_trajectories_during_heavy_rainfall_events_using_Hybrid_Single-Particle_Lagrangian_Integrated_Trajectory_HYSPLIT_modelSource snippet
Moisture trajectories during heavy rainfall events using...Journal of Physics: Conference Series 2070 (2021) 012066; HYSPLIT model is o...
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Source: news.fsu.edu
Link: https://news.fsu.edu/news/expert-pitches/2023/02/15/weather-ballons-and-ufos-fsu-professor-offers-historical-perspective-on-aerial-surveillance/Source snippet
balloons and UFOs: FSU professor offers...15 Feb 2023 — The recent incursion of a Chinese spy balloon and other flying objects into Amer...
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Source: wired.com
Link: https://www.wired.com/story/radiosonde-huntersSource snippet
These devices, released by meteorologists via weather balloons to measure wind, temperature, and humidity, burst and fall back to earth...
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Source: pmc.ncbi.nlm.nih.gov
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC9864114/Source snippet
PMCby H Hou · 2023 · Cited by 8 — HYSPLIT calculates forward and backward trajectories of particles based on wind speed, [wind direction]({{ 'wind-direction/' | relative_url }})...
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Source: youtube.com
Link: https://www.youtube.com/watch?v=rtMS7_9yNmMSource snippet
How to Run the NOAA HYSPLIT Model onlineHYSPLIT: The Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) is a compute...
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Source: instagram.com
Title: NOA A (@noaa) • Instagram photos and videos Official feed for the U.S
Link: https://www.instagram.com/noaa/?hl=enSource snippet
National Oceanic and Atmospheric Administration. Our mission: Science, Service and Stewardship. Join us on X @noaa. Great news out...Rea...
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Source: researchgate.net
Link: https://www.researchgate.net/publication/270514931_A_comparison_of_HYSPLIT_backward_trajectories_generated_from_two_GDAS_datasetsSource snippet
widely used to generate backward trajectories in given starting locations.Read more...
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Source: researchgate.net
Title: 229043431 Global radiosonde balloon drift statistics
Link: https://www.researchgate.net/publication/229043431_Global_radiosonde_balloon_drift_statisticsSource snippet
(PDF) Global radiosonde balloon drift statistics7 Apr 2011 — This study presents a comprehensive global climatology of radiosonde balloon...
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