Global Drifter Program

Global Drifter Program

Cornerstone of the Global Ocean Observing System

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Who We Are

What We Do

The Global Drifter Program is a branch of NOAA’s Global Ocean Observing System and a scientific project of the Data Buoy Cooperation Panel. It has two components: the Global Drifter Center at AOML and the Lagrangian Drifter Laboratory (LDL) at Scripps Institute of Oceanography, managed by Dr. Luca Centurioni. The LDL supervises drifter production, designs and tests new types of drifters, and manages the real-time data flow on the Global Telecommunications System.

Objectives of the Global Drifter Center

  1. Maintain a global 5° x 5° gridded array of ~1,300 satellite-tracked surface drifting buoys to meet the need for an accurate and globally dense set of in-situ observations of mixed layer currents, sea surface temperature, atmospheric pressure, winds, waves, and salinity.
  2. Provide a data processing system for the use of these data.

| Rick Lumpkin, Ph.D

Manager, Global Drifter Center

| Shaun Dolk

Manager, Drifter Operations Center

| Mayra Pazos

Manager, Drifter Data Assembly Center

| Caridad Gonzalez

Data Processing

| Bertrand Dano, Ph.D

Data Processing

Top News

The Global Drifter Program Launches a New Interactive Map Tool

The Global Drifter Program’s (GDP) Drifter Data Assembly Center (DAC) at AOML has launched a new interactive map of the global drifter array. This new tool features the ability to zoom and scroll, hover the cursor over drifters to get their identification numbers, and click to see data and metadata including deployment information, manufacturer, and drifter type in an ID card that can be viewed as a high-resolution image with an additional click.

Screenshot of the Global Drifter Program's drifter array map.

Read More News

A photo shows a cloudy seascape and deep ocean waters. Photo Credit: NOAA AOML.
Global Drifter in Water Mt. Rainer

Drifters Provide Critical Data to Improve Forecasts

Drifters Validate Satellite Sea Surface Temperature

Drifters have a thermistor that measures water temperature at the base of the surface float.  These data are used to calibrate and validate temperature measurements made from satellites, which can be thrown off by atmospheric particles or biased by the day-to-night changes in temperature sampled only while the satellite is passing overhead.

Drifters can Weather the Storm

Global drifters can survive large and destructive waves in the open ocean, sending data as they pass through storm after storm, even from the heart of passing hurricanes.  The drifter data also greatly increase the accuracy of forecasting one of the most dangerous marine phenomenon: the “bomb cyclone”, a winter storm that quickly explodes into a life-threatening monster.

Drifters Improve Hurricane Intensity Forecasts

Each year, Air Force “Hurricane Hunter” aircraft deploy drifters ahead of some Atlantic hurricanes with a goal of measuring upper ocean and sea surface conditions.  These drifters measure pressure, wind, and temperature as the storm passes above. These data are used to improve hurricane intensity forecasts, and they are a rigorous way of determining if the forecast models are accurately representing the interaction between the atmosphere and the ocean.

Drifter Data Improves Weather Models

Drifter measurements of barometric pressure have been shown to be the single most important observation in the observing system to improve weather forecasts, on a per-observation basis.  They are particularly valuable to accurately forecast rapidly-strengthening winter storms at high latitudes, which pose significant threats to mariners.

Drifters Quantify Marine Transport

Drifters show us where the ocean carries floating objects such as marine debris, fish plankton, and oil.  By examining the trajectories of all the drogued and undrogued drifters, studies have determined where debris such as plastic piles up in the great “garbage patches” of the Atlantic, Pacific, and Indian oceans.

Background

Recognizing the Need for a Global Ocean Observing System

As weather forecasters developed numerical models to predict weather in the 1950s and 1960s, they realized that the greatest limitation to improving forecast accuracy was not computer power, but the scarcity of observations.  Land stations measure air pressure over land and transmit the observations to the forecasters, but over 70% of the earth’s surface is covered by oceans. To address this, NOAA’s Global Drifter Program (GDP) maintains an array of over 1,000 drifting buoys that measure air pressure over the ocean and send these data to satellites passing overhead, which then transmit the data within an hour to the forecasters.  Drifters are deployed by national and international partners of the GDP, coordinated by the GDP’s Drifter Operations Center at AOML. The data are then processed and quality controlled at the GDP’s Data Assembly Center, also located at AOML.

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The Global Drifter Program

The program manages the collection, analysis, and distribution of the data acquired by these drifters. The program reached its goal of 1250 operational drifters on September 18th, 2005 and has maintained these drifters since. It was the first component of the Global Ocean Observing System to reach completion. 

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Components of a Drifter

Drifter Illustration. Image Credit, NOAA.

All drifters measure sea surface temperature, but most are also equipped to measure other variables. As the drifter moves around, guided by ocean currents, measurements of atmospheric pressure, winds, wave height, and salinity can be taken. This data is collected by sensors in the drifter and transmitted to overhead satellites. Tracking the location of drifters over time allows scientists to build a profile of ocean currents.

A drifter’s drogue, also known as a sea anchor, extends 20 meters (or 65 feet) deep and is designed to move with the near-surface ocean currents. The drogue and surface float move together, connected by a long tether. Without a drogue, the drifter will be transported by wind and waves, much as a ping pong ball or beach ball is pushed across the surface of a pool.

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New Interactive Map & Data Visualization

The Global Drifter Program’s (GDP) Drifter Data Assembly Center (DAC) at AOML has launched a new interactive map of the global drifter array. This new tool features the ability to zoom and scroll, hover the cursor over drifters to get their identification numbers, and click to see data and metadata including deployment information, manufacturer, and drifter type in an ID card that can be viewed as a high-resolution image with an additional click. Visit the new tool

More Drifter Maps

About 1000 drifters are deployed each year by the Global Drifter Program and its international partners to maintain the global 5° x 5° gridded array of ~1300 drifters. To view the number of deployments per year and their locations, please visit the reports archive

Drifter Deployment

Instructions & Value Maps

The goal of the drifter program is to implement one drifter in each 5° x 5° grid section of the oceans across the globe. Of course, with strong convergent and divergent currents to contend with, as well as limited access to deployment vessels, the Global Drifter Program works closely with more than fifty domestic and international agencies to coordinate deployment efforts.

To maximize spatial drifter coverage the Global Drifter Program created a set of Drifter Deployment Value Maps which are used throughout the community to identify the highest value deployment locations. Since drifters are shipped via ocean freight, it can take two weeks to four months to ship a drifter, depending on the destination.

View the maps below, or download our drifter deployment value text file, which shows values by latitude and longitude.

Regional Value Maps

Note: NaN values have been replaced with 999, while closed basis, areas shallower than 25m, and ice-covered regions are designated with a zero value.

The Arctic

Global Drifter Arctic Deployment Value Map. Image Credit, NOAA.

The North Atlantic

Global Drifter Program North Atlantic Deployment Value Map. Image Credit, NOAA.

The Tropical Atlantic

Global Drifter Tropical Atlantic Deployment Value Map. Image Credit, NOAA.

The South Atlantic

Global Drifter Program South Atlantic Deployment Value Map. Image Credit: NOAA.

The Indian Ocean

Global Drifter Program Deployment Value Map, Indian Ocean. Image Credit, NOAA.

The North Pacific

Global Drifter Program Deployment Value Map, North Pacific. Image Credit, NOAA.

The Equatorial Pacific

Global Drifter Equatorial Pacific Deployment Value Map. Image Credit, NOAA.

The South Pacific

Global Drifter Deployment Value Map, South Pacific. Image Credit, NOAA.

We are strong because of our community.

Deploy Your Own Drifter.

Deployments can be reported by clicking report deployment or by emailing drifter.deployment@noaa.gov.

Deployment Instructions

Click on the desired language below for PDF instructions on deploying drifters in the field.

Adopt a Drifter Program

Drifters Teach Kids about Ocean Currents

Global Ocean Monitoring and Observing Program established the Adopt a Drifter Program  in December 2004 for K-16 teachers from the United States along with international educators. This free program provides teachers with an educational opportunity to infuse ocean observing system data into their curriculum.

Participating teachers develop lesson plans to encourage their students to analyze and apply the drifting buoy data. Students in the teachers’ classes receive a drifter tracking chart to plot the coordinates of the drifter as it moves freely in the surface ocean currents. This enables teachers and students to more easily make connections between the drifter data maps accessed online and other maps showing currents, winds, and other factors.

Kids Deploying Global Drifters

Outreach Partnerships

Sailors from Team Alvimedica deploy a drifter in the Southern Ocean. Image credit: Amory Ross/Volvo Ocean Race

The Ocean Race

Since 1973, competitors aboard world class sailing vessels have circumnavigated the globe during the Ocean Race (formerly known as the Volvo Ocean Race). While competition is fierce and victory is the ultimate goal, these competitors are generating legacies greater than their performance on the water. Race coordinators and competitors have worked tirelessly to incorporate scientific advancements and increase oceanographic and atmospheric data acquisition, including the deployment of drifting buoys.

International SeaKeepers Society

The Global Drifter Program is working with private vessel owners to deploy drifting buoys throughout the worlds oceans. The International SeaKeepers Society promotes oceanographic research, conservation, and education through direct involvement with the yachting community.

Semester at Sea

The MV World Odyssey is the Semester At Sea campus. Outfitted as a globe-exploring university, the MV World Odyssey is a living-learning community that provides a platform for discussion, coursework and deep connections all while traveling to new locations. During these voyages, the Semester At Sea and the Global Drifter Program have partnered to deploy drifters throughout the worlds oceans.

drifterdata

Drifter Data

Driving Innovative Science with Data

The array of global drifters has created a vast network of time-series data about our oceans and how they move. This data has been used all over the world to study ocean basins, seas, and ocean features. Drifters are ideal for studying surface dispersion of any buoyant particles (such as fish larvae, oil spills, or marine debris) and for looking at how small ocean features contribute to the movement of larger ones. In addition, real-world drifter data has been used by scientists to improve the physics of water movement in ocean models.. Scientists do this by using real-world drifter observations to improve model accuracy.

Temperature data from drifters has been used by scientists to study ocean processes, such as the heat content in the equatorial Pacific and how it impacts the equatorial cold-tongue of El Nino. Lastly, by combining drifter observations with satellite altimetry, some researchers have been able to produce topographical maps of ocean sea surface height over a set of years. To read a technical summary of how scientists use drifter data to detect changes in the ocean and atmosphere, expand the box below.

“On an impact per observation basis, drifter observations are the most valuable contribution of the entire ocean observing system to improving weather forecasts”

Real-Time Data

Real time drifter data are distributed on the Global Telecommunication System for improved weather forecasting and ocean state estimation. On this page, we provide instructions on how to obtain these Global Telecommunication System data streams using NOAA’s Observing System Monitoring Center.

6-Hour Interpolated Data

The Drifter Data Assembly Center at AOML applies quality control procedures to edit drifter data (position and temperature) and interpolates them to 6-hour intervals as described in Hansen and Poulain (1996). These data are ideal for climate research and span the period February 1979 to the most recent quality-controlled data.

Hourly Data

These data are quality controlled and interpolated to hourly positions as described in Elipot et al. (2016), and are ideal for studying high-frequency motion. They are a subset of the 6-hourly data, as most drifter data before 2005 were too coarse to interpolate to hourly values.

Drifter Data Frequently Asked Questions

Who uses drifter data?

  • Primarily oceanographers, meteorologists, and climatologists deploy and utilize drifter data. However, because drifter data can be used to track oil spills, marine debris, larval fish dispersion, etc. there is a growing list of deploying partners and data consumers.
  • Oceanographic and climate researchers analyze the data to find aspects of the data that can be applied to other observations or explain phenomena.
  • In an effort to better educate K-12 students about the importance of the ocean and how drifters provide invaluable data, the GDP works closely with NOAA’s Adopt a Drifter Program. Through the Adopt a Drifter Program, the GDP encourages young scientists how to access drifter data and its many applications.

What is a data fix?

While possible to increase/decrease the time interval between data transmissions, the standard transmission rate for drifting buoys is one transmission per hour, at the top of each hour. A fix is when a satellite receives a particular transmission and relays it to a land-based data center.

What is kriging?

Kriging is an optimum interpolation procedure which is commonly used for two and three-dimensional analyses. It is the method used at the drifter Data Assembly Center to interpolate (fill in the gaps in the data) and make them equally spaced into six hour intervals.

See Hansen, D.V. and Poulain, P.M., 1996, [PDF] for a complete description of the quality controlled and interpolation procedures applied to the drifter data in this database.

What is a Weighted Maximum Likelihood Estimate (WMLE)?

WMLE is an optimized model for the most likely location of a drifter given an estimate and a known error range. It is the method used at the drifter Data Assembly Center to interpolate (fill in the gaps in the data) and make them equally spaced into hourly intervals.

For more information, see Elipot et al. (2016) [PDF].

What is the difference between drifter ID numbers and World Meteorological Organization (WMO) numbers?

WMO numbers are used when the data is transmitted on the Global Telecommunications System for weather forecasting models, and in the past were reused.  Drifter ID numbers are unique to each drifter and are not reused.

How and when are WMO numbers assigned?

WMO numbers are assigned after the deployment region is identified. WMO numbers are seven digit numbers used to reference data placed onto the Global Telecommunication System (GTS), for public distribution and archive. The first two digits of the WMO number correspond to the deployment region, which can be found on the map below.

Where do you find a WMO number for a particular drifter?

Where do you find a WMO number for a particular drifter?

 

WMO numbers can be found in two places.

  1. If you already know the ID number of your particular drifter(s), please utilize the table found at:
    aoml.noaa.gov/phod/dac/wmoid.
  2. To find drifters within a specific region, or timeframe, please reference the GDP Directory File, at:
    aoml.noaa.gov/phod/dac/dirall.
    • The WMO number is shown in the second column, immediately to the right of the corresponding ID number.

Where do I find drifter data and how much does it cost?

  • Happily, the drifter data is FREE and accessible to the public, courtesy of NOAA’s Climate Program Office!
  • Drifter data are quality controlled and stored at AOML’s Drifter Data Assembly Center, then sent to Canada’s Marine Environmental Data Service for archiving and public distribution.

Where do I find real-time drifter data?

How do I search for drifter data at a specific time and/or location?

How often is the quality-controlled drifter database updated?

  • The quality controlled drifter data is updated every 2-3 months. Therefore quality controlled drifter data is available delayed mode, with notifications of these updates found at aoml.noaa.gov/phod/gdp.

How do I download the entire quality-controlled drifter database?

Where do I find metadata files, with details about the drifters?

Hardware metadata are available at:

What is oldest drifter data available?

  • The Global Drifter Program was established in 1979. While it took several decades to develop the program and reach its current state, with roughly 31,200 transmissions per day, the first drifter to transmit data was deployed on February 14, 1979.

How do I determine if a drifter has lost its drogue? Why is this important?

Determining drogue presence is vitally important, as this component of the drifter is what allows researchers to measure ocean current velocities at 15 meters depth. Without the drogue, which is centered at 15m, wind plays a greater roll in transporting drifters.
For this reason, AOML’s Data Assembly Center spends a tremendous amount of time and resources to pinpoint exactly when, and where, each drifter loses its drogue.

While sensor failures are identified and listed within the quality controlled dataset, you can determine real-time sensor functionality by using the WMO number from a particular drifter and visiting meteo.shom.fr/qctools.

An example of a drifter that has lost its drogue is shown in the figure below. Notice, the amount of strain on the lower hull of the surface float decreases significantly after drogue loss. At the same time, the time to first fix (how long it takes to acquire a GPS location fix) decreases significantly because the drogue is no longer pulling the surface float underwater with each passing wave.

How do I determine if the sea surface temperature sensor has failed?

All drifters are equipped with a sea surface temperature sensor at the base of the surface float.

While sensor failures are identified and listed within the quality controlled dataset, you can determine real-time sensor functionality by using the WMO number from a particular drifter and visiting meteo.shom.fr/qctools.

An example of a failed sea surface temperature sensor is shown in the figure below. Notice, the structured diurnal pattern becomes erratic and irregular on Aug. 4th, 2015.

How do I determine if the barometric pressure sensor has failed?

While not all drifters are equipped with barometric pressure sensors, nearly half of the global drifter array measures sea-level pressure, which feeds into weather forecasting models.

While sensor failures are identified and listed within the quality controlled dataset, you can determine real-time sensor functionality by using the WMO number from a particular drifter and visiting meteo.shom.fr/qctools.

An example of a failed pressure sensor is shown in the figure below. Notice, the slight pressure fluctuations begin on August 4th, 2015, then the sensor experiences complete failure on August 6th, 2015.

Drifter Recovery

Did you find a drifter?

If you find a drifting buoy, please contact a member of the Global Drifter Program with the information listed on the surface float. If the drifter remains active, with functional batteries and operational sensors, we’ll attempt to have the drifter re-deployed. 

If the batteries and/or sensors are no longer operational, the drifter can be disposed of. Drifters contain no hazardous material, so simply dispose of the drifter as you would any other alkaline battery product.

Drifter ID#26028

The longest lasting drifter on record transmitted for 10 years, 4 months, and 21 days.

10.3

YEARS

124

MONTHS

3792

DAYS

Featured Publication

First page of 'Dispersion of Surface Drifters in the Tropical Atlantic' publication

Van Sebille, E., Zettler, E., Wienders, N., Amaral-Zettler, L., Elipot, S., & Lumpkin, R. (2021). Dispersion of surface drifters in the Tropical Atlantic. Frontiers in Marine Science, 7, 1243.

Abstract: The Tropical Atlantic Ocean has recently been the source of enormous amounts of floating Sargassum macroalgae that have started to inundate shorelines in the Caribbean, the western coast of Africa and northern Brazil. It is still unclear, however, how the surface currents carry the Sargassum, largely restricted to the upper meter of the ocean, and whether observed surface drifter trajectories and hydrodynamical ocean models can be used to simulate its pathways. Here, we analyze a dataset of two types of surface drifters (38 in total), purposely deployed in the Tropical Atlantic Ocean in July, 2019. Twenty of the surface drifters were undrogued and reached only ∼8 cm into the water, while the other 18 were standard Surface Velocity Program (SVP) drifters that all had a drogue centered around 15 m depth….

Read Full Paper.

Dispersion of Surface Drifters in the Tropical Atlantic

Van Sebille, E., Zettler, E., Wienders, N., Amaral-Zettler, L., Elipot, S., & Lumpkin, R. (2021). Dispersion of surface drifters in the Tropical Atlantic. Frontiers in Marine Science, 7, 1243.

Abstract: The Tropical Atlantic Ocean has recently been the source of enormous amounts of floating Sargassum macroalgae that have started to inundate shorelines in the Caribbean, the western coast of Africa and northern Brazil. It is still unclear, however, how the surface currents carry the Sargassum, largely restricted to the upper meter of the ocean, and whether observed surface drifter trajectories and hydrodynamical ocean models can be used to simulate its pathways. Here, we analyze a dataset of two types of surface drifters (38 in total), purposely deployed in the Tropical Atlantic Ocean in July, 2019. Twenty of the surface drifters were undrogued and reached only ∼8 cm into the water, while the other 18 were standard Surface Velocity Program (SVP) drifters that all had a drogue centered around 15 m depth….

Read Full Paper.

First page of 'Dispersion of Surface Drifters in the Tropical Atlantic' publication

Drifter Bibliography

Driving Innovative Science with Data.

Our Contribution to Global Ocean Observing.

The following is a list of scientific publications that reference Global Drifter Program (GDP) data. If your drifter publication is not listed within, please email the Drifter Program with the complete reference.

Please contact publication authors to obtain an electronic or printed version of the articles. Alternatively, you may conduct a Google search of the publication title, which may direct you to an electronic version of the article.

View PDF list by year or alphabetically by author.

Partners

Sharing Resources Delivers Results.

Expanding Reach Through Partnerships.

26

Countries

Countries collaborating with AOML to deploy drifters for the Global Drifter Program

696

Drifters

Drifters currently deployed by partnering international organizations.

More National & International Partners

Together with partners around the world, the GDP deploys nearly 1,000 drifters per year, throughout the world’s oceans. While not a complete list of GDP partners, below is a list of key contributors:

Argentina

Australia

Brazil

Canada

Chile

France

Gabon

Hong Kong

India

Italy

Japan

Kenya

Republic of Korea

Mexico

New Zealand

South Africa

Spain

United Kingdom

United States

International Collaborators

Key Accomplishments

  • OceanObs’19 held in Honolulu, HI, with goal to improve governance of the Global Ocean Observing System by improving advocacy, funding, and alignment with best practices.

    September 2019

  • Deployment of 25,000th GDP drifter, from a sailing ship of The Ocean Race (formerly Volvo Ocean Race).

    May 2018

  • The Global Drifter Program created and distributed deployment value maps, which clearly communicate where drifters are needed to be deployed to maximize their value.

    July 2013

  • The drifter Data Assembly Center at AOML completed a systematic reevaluation of drogue presence for all of the drifters in the historical data base.  Before this, a large fraction of the drifters did not have correct drogue loss dates due to problems with the drogue detection sensor.

    July 2012

  • Death of professor Peter Niiler, creator of the Global Drifter Program

    October 2010

  • Deployment of 36 drifters in the Gulf of Mexico in response to the Deepwater Horizon disaster.

    June 2010

  • OceanObs’09 held in Venice, Italy; community vision expressed for the Global Ocean Observing System.

    September 2009

  • Deployment of 21 drifters in front of hurricanes Gustav and Ike to measure air-sea interactions during passage of a major hurricane.

    August-September 2008

  • The Global Drifter Program becomes the first completed component of the Global Ocean Observing System with the deployment of drifter #1250.

    September 2005

  • OceanObs’99 held in St. Raphael, France; vision of a global array of 1250 drifters proposed by Peter Niiler.

    October 1999

  • The first deployment of drifters in an effort that will evolve into the Global Drifter Program.

    1979