Automated Weather Observations from Automated Weather Observations from Ships and Buoys:Ships and Buoys:

A Future Resource for ClimatologistsA Future Resource for Climatologists

Shawn R. Smith

Center for Ocean-Atmospheric Prediction StudiesFlorida State University

Tallahassee, FL USA

OverviewOverview The need for in-situ climate data is not limited to land stations

Knowledge of air-sea fluxes (e.g., heat, water, carbon) is essential for understanding global climate processes

NOAA is spearheading the U. S. effort to expand and improve the network of in-situ observations from the global oceans

Image from NOAA OGP

Example: ENSO MonitoringExample: ENSO Monitoring Prior to the 1982/83 El Niño, in-situ observations of the tropical

Pacific were limited to merchant ships and island stations.

Along came TAO/TRITON– PMEL began installing

and maintaining a continuous network of moored buoys

– Data from these buoys improved analyses (e.g., FSU winds) used to force models

– Provided a data resource to better understand ENSO as part of the climate

Recently this array is transitioning from a research mode to become part of an operational observing system

Photo credit: NOAA/PMEL/TAO Project Office

Needed ObservationsNeeded Observations Ideally in-situ measurements near the ocean surface should provide

all parameters needed to resolve air-sea fluxes– Meteorology: Winds, air temperature, humidity, pressure, precipitation,

radiation (multiple components)

– Sea surface: Temperature, salinity, sea state, ice cover

– Precise platform navigation (location, orientation, earth-relative motion)

High data accuracy and sampling rates are desired

Detailed metadata are also essential (instrument heights, exposures, etc.)

Must go beyond the tropics, into harsh operational environments (e.g., Southern Ocean, North Pacific) Photo credit: USCG

For the last century, the primary source of weather data over the ocean was observations made by merchant vessel operators

Data primarily collected manually and submitted upon arrival in suitable port

GTS provided for real-time data transmission

Limitations:– Low sampling rates (3-

6 hr)

– Minimal navigation information

– Incomplete metadata

Ships: The early daysShips: The early days

More recently advancements in computer technology has led to the deployment of automated weather systems (AWS)

First deployed on research vessels and buoys

In the past 5 years, new initiatives have deployed sensors on volunteer observing ships (merchant ships, yachts, cruise ships)

Initial development underway for moored platforms in extreme environments

Ships: AutomationShips: Automation

Photo credit: WHOIPhoto credit: WHOI

Photo credit: NOAA

Typical AWSTypical AWS High-resolution marine AWS

– Sampling rates 1-60 minutes

– Continuous recording

– Typically bow or mast mounted on R/V

Photo credit: WHOI

– Data rarely available in real-time (good for independent validation)

Automation: futureAutomation: future Standard meteorological

package

– Fluxes are determined using a bulk modeling approach

Experimental system

– Directly measure fluxes

– Example: Southampton Oceanography Center AutoFlux

– Hourly fluxes sent in real time

Photo credit: Southampton Oceanography CentrePhoto Credit: WHOI

AWS ApplicationAWS Application Quality processed AWS data are ideal for evaluation of global reanalysis

fluxes (e.g., Smith et al., 2001, J. Climate) Sampling rates allow accurate estimation of 6 hourly integrated fluxes

AWS ApplicationAWS Application R/V-AWS observations have also been used for validating satellite

wind sensors (e.g., Bourassa et al., 2003, J. Geophys. Res.)

Wind Direction Wind SpeedSeaWinds on Midori

Final ThoughtsFinal Thoughts A new initiative is underway to ensure routine delivery of

calibrated, quality assured, surface meteorological data collected using AWS on research vessels, volunteer observing ships, and new moored platforms.

User input is essential

– Marine AWS data are a new resource for climatologists

– Climatologists are asked to provide input to network design Sampling rates, platform locations, parameters desired

Second workshop on role of marine AWS in a sustained ocean observing system is planned for 17-18 April 2004 (Silver Spring, MD)

– Plan to open discussions with user community (modelers, satellite programs, etc.)

– Discussion will focus on implementation plans, data user needs, and coordination between R/V, VOS, and buoy programs

– Interested participants should contact (smith@coaps.fsu.edu)