Report and
Recommendations
from the
Workshop on High-Resolution Marine
Meteorology
3-5 March 2003
Shawn R. Smith1 and R.
Michael Reynolds2
(co-chairs)
James J. O'Brien1
(host)
1Center for Ocean-Atmospheric
Prediction Studies
The Florida State University
Tallahassee, FL 32306-2840
USA
2Brookhaven National
Laboratory
Upton, NY 11973
Funded and sponsored by Michael
Johnson
NOAA Office of Global
Programs
COAPS Report 03-1
July 2003
The report presents a summary of the discussions and recommendations from the
"Workshop on High Resolution Marine Meteorology" held in Tallahassee,
Florida, USA from 3-5 March 2003. Workshop objective and format are described.
Abstracts for the invited talks are included along with a synopsis of the round
table discussions. The thirteen workshop recommendations are listed and a
discussion of each is included. The report concludes with action items and a
time table to begin implementation of the workshop
recommendations.
On 3-5 March 2003, the Center for
Ocean-Atmospheric Prediction Studies (COAPS), directed by Dr. James J. O'Brien,
hosted the "Workshop on High-resolution Marine Meteorology" in
Tallahassee, Florida. The workshop was sponsored by the NOAA Office of Global
Programs to identify scientific objectives that require high-resolution,
high-accuracy marine meteorological observations and to discuss a sustained
U.S. effort to obtain and disseminate these data in a manner consistent with
the identified scientific goals. The workshop focused on
in-situ marine meteorological observations from ships and
buoys. Central discussions included data accuracy, calibration and
inter-calibration, improved access to quality-assured, high-resolution
(sampling interval < 1 hr.) observations for the scientific community, and a
sustained observing system to meet short- and long-term science
objectives.
Co-chairs Dr. R. Michael Reynolds (Brookhaven National Laboratory) and Mr. Shawn R. Smith
(COAPS) organized a workshop panel with representatives from both the
scientific and operational marine observation communities. Participants
included personnel from four NOAA laboratories, the Naval Research Laboratory,
the U. S. Coast Guard, and the U. S. CLIVAR Office. The university community
was represented by the Woods Hole Oceanographic Institution, the Scripps
Institution of Oceanography, the University of Miami, Oregon State University,
and the Florida State University. International attendees included
representatives from CSIRO (Australia) and the Southampton Oceanography Centre
(United Kingdom).
The workshop was organized around four main topics: (1) science objectives; (2)
status of U.S. high-resolution observing programs; (3) accuracy, calibration,
and inter-calibration; and (4) a sustained data collection, distribution, and
archival system. Invited speakers began each session with talks to stimulate
topic-oriented discussions. Round-table discussions provided a free exchange of
ideas for improving both the quantity and quality of marine observations.
Several discussions focused on the need to improve instrument
calibration and to provide for routine inter-calibration between instrument systems and platforms
(e.g., ships versus buoys). Currently, only a select set of well maintained
ships and buoys are capable of determining air-sea interaction variables to a
sufficient degree of accuracy for climate studies (e.g., 10 Wm-2 net
heat flux uncertainty for monthly averages desired by CLIVAR). Participants
noted that while research vessels are able to provide the highest quality data,
often in under-sampled regions of the ocean, this resource is not being
effectively utilized and data essential to climate studies are being lost.
Discussions included the need to improve instrument siting on ships and to
standardize measurement of meteorological and ship motion parameters and
metadata formats. In addition, attendees addressed improving data quality and
access for the user community. The discussions resulted in thirteen
recommendations that the attendees agreed to disseminate widely through the
scientific and operational marine communities and at the program
level.
1. Develop a sustained system of calibrated, quality-assured marine meteorological observations built around the surface flux reference sites, drifting buoys, research vessels (R/Vs), and volunteer observing ships (VOS) to support science objectives of national and international climate programs.
2. Improve global data coverage, especially from important but data sparse regions (e.g., Southern Ocean), by working with and making use of national and international observing efforts, research programs, and infrastructure development initiatives.
3. Establish a data assembly center (DAC) for U.S. R/V (e.g., UNOLS, NOAA, Navy, Coast Guard) meteorological observations to unify data collection, quality assurance (QA), and distribution. The DAC will also provide for permanent data archiving and long-term availability of data at national archive centers.
4. Establish standards for sensor calibration and data collection on ships and moorings, including accuracy and resolution, sampling rates and averaging periods, data acquisition and display software, data transmission, recommended instrument siting, and provision of metadata.
5. Produce a reference manual of best procedures and practices for the observation and documentation of meteorological parameters, including radiative and turbulent fluxes, in the marine environment. The manual will be maintained online and will be a resource for marine weather system standards.
6. Develop a portable, state-of-the-art, standard instrument suite and implement on-board inter-comparison between the portable standard and shipboard instruments to improve R/V and VOS automated meteorological observations.
7. Endorse development of robust sensors for use in severe environments to improve data accuracy and allow accurate data to be collected from data sparse regions.
8. Implement a program in computational fluid dynamics (CFD) modeling of the wind flow regime over ships to determine optimal wind sensor siting, wind correction factors, and effective measurement heights.
9. Encourage (i.e. fund) R/Vs to schedule meteorological inter-comparisons with surface flux reference sites and, where appropriate, with one another.
10. Recommend that certain ship data not currently logged be made available to researchers (e.g., pitch/roll, heading, currents, speed of ship in water). These data should be routinely recorded to improve flux calculations and QA.
11. Encourage funding agencies to require that new shipboard meteorological instrumentation purchased within research grants be installed and operated, and the measurements distributed and archived according to the principles embodied in points 3-6 above.
12. Establish sources/contacts where expertise can be obtained by operators and made available for QA development.
13. Strongly encourage funding agencies to support human capital development through education and training.
A "Workshop on High-Resolution Marine Meteorology" was held at
the Center for Ocean-Atmospheric Prediction Studies (COAPS) from 3-5 March 2003.
The purpose of the workshop was to identify scientific objectives addressable
using high-resolution (sampling rates < 60 minutes), high-accuracy marine
meteorological observations and to discuss a sustained U. S. effort to obtain
these data in a manner consistent with the identified scientific goals. The
workshop was attended by members of the scientific and operational marine
observation communities, including representatives from government laboratories
and agencies, the university community, and two international oceanographic
institutions.
Workshop goals included: (1) identifying scientific objectives which can be
best achieved using high-resolution marine observations, (2) providing the community
with a current status of U. S. sponsored, high-temporal frequency, shipboard
meteorological data collection (including data distribution, availability to
meet science objectives, and current quality control practices), (3)
identifying technical and management issues related to instrument accuracy,
calibration, and inter-calibration that will benefit scientific application of
high frequency shipboard data, (4) developing a plan that insures routine
delivery (real-time and delayed) of calibrated, high quality surface
meteorological observations consistent with science objectives, (5) identifying
areas where a sustained high-resolution observing system can evolve to better
meet science objectives in the future, and (6) identifying areas where
collaboration and joint activities would increase both the quality and quantity
of data to better meet science objectives.
The workshop focused on in-situ marine meteorological measurements
collected at wide range of sampling rates on ships and moored buoys. Shipboard measurements
primarily include two groups of vessels: Volunteer Observing Ships (VOS) and
oceanographic research vessels (R/V). Until recently VOS weather observations
were collected by the ship's bridge officers at sampling intervals of one,
three, or six hours. These VOS reports were logged onboard the ship and
frequently were transmitted to shore via satellite or other communication
system. The advent of automated weather systems (AWS) for marine applications
has made it possible for VOS to continuously record meteorological
observations. This new class of VOS-AWS can provide data at multiple sampling
rates. Typically data are recorded onboard at one to ten minute intervals (some
may record even higher sampling rates); however, it is currently not cost
effective to transfer these high-resolution data to shore via satellite.
Instead, VOS-AWS often transmit hourly samples via INMARSAT or some other
transmission service. The high-resolution data are collected from the vessels
at regular intervals when the VOS-AWS reach a suitable port. R/Vs are
frequently outfitted with one or more suites of meteorological instrumentation
and are the test bed for new marine AWS systems. The R/Vs typically record
meteorological data continuously at sampling rates of one minute or less and
these data are logged through an onboard computer system. These high-resolution
R/V data are collected from the vessel's computer at the end of each cruise. It
is worth noting that these "scientific AWS" data are often logged
independently of the standard bridge observations collected by the crew of the
R/V. The scientific data are rarely sub-sampled and transmitted from the ship
in real-time.
The classes of shipboard platforms discussed at the workshop are listed in
Table 1. A number of shipboard data collection programs are listed for each data class
along with some typical applications for each type of data. VOS data and some
VOS-AWS data (e.g., SeaKeepers) are the primary real-time data to be
assimilated into models and used for numerical weather prediction forecasts.
The delayed-mode, higher sampling rate data from AWS are used for a wide range
of validation studies (e.g., model fields, satellite observations) and in the
case of R/V-AWS for regional process studies.
|
Table 1: Sampling
rates, representative programs/systems, and common uses of three classes of
marine meteorological observations from vessels. |
||||
|
Data Class |
Real-time sampling |
Delayed-mode sampling |
Data Programs or Sensor Systems |
Uses |
|
VOS |
1 to 6
hour |
N/A |
VOSClim |
Assimilation |
|
|
|
|
PMOs |
NWP
Forecasts |
|
|
|
|
GOOS |
|
|
VOS-AWS |
1
hour |
>10
min. |
ASIMET |
Assimilation |
|
|
|
|
AutoIMET |
Validation |
|
|
|
|
SEAS |
|
|
|
|
|
SeaKeepers |
|
|
R/V-AWS |
Rare |
1 min. or
less |
AutoFlux |
Independent
Validation |
|
|
|
|
ETL Flux
System |
Climate
products |
|
|
|
|
SCS
(NOAA/USCG) |
|
|
|
|
|
R/V specific
systems |
|
|
|
|
|
IMET |
|
Buoys can be separated into two large groups, moorings and drifters.
Moorings are nearly-stationary in space and provide a platform that can measure most
parameters observed on ships. Limitations to operating AWS on buoys include the
size of an instrument, instrument power requirements, and the ability of an
instrument to operate unattended for long periods of time. Moorings can further
be divided into research and operational categories. Operational moorings
(e.g., NBDC buoys, TAO/TRITON) typically record data onboard the buoy and
regularly transmit a subset of their data in real-time via satellite. Research
mooring collect data at high sampling rates (<10 min) and record these data
onboard until the buoy is retrieved. The research moorings may also transmit a
subset of data in real time, but these data are often withheld from NWP
products for validation purposes. Drifters provide a more limited suite of
meteorological observations (pressure, SST, and sometimes winds) that are
typically transmitted via satellite; however, drifters were not a primary focus
of the workshop.
AWS are deployed on ships and buoys to provide observations in support of
both operational and research science objectives. Although improvements are made
yearly, the spatial and temporal coverage by AWS is still limited in large
regions of the oceans (especially outside the tropics). Supporting current and
future science objectives for the operational and research communities requires
a commitment to improving both the quantity and quality of AWS observations in
the marine environment. For example, R/Vs are often equipped with AWS, but
access to these climate data are currently limited. Expanding access to R/V
data will provide researchers potentially valuable climate data far outside
normal VOS shipping lanes. Achieving the full potential of AWS on marine
platforms requires a sustained, end-to-end measurement system that includes
improved sensor calibration, platform inter-calibration, standardized data
collection, quality assurance, distribution, and archival. The requirements of
and recommendations for this system were the focus of discussions at the
"Workshop on High-Resolution Marine
Meteorology".
The meeting was formulated around four topic areas (1) science objectives,
(2) status of U. S. high-resolution data programs, (3) accuracy, calibration, and
inter-calibration, and (4) developing a sustained data collection and
distribution system. The meeting was opened with a welcome from the local host,
James J. O'Brien, and from the co-chairs, Shawn R. Smith and R. Michael
Reynolds. Michael Johnson, the workshop sponsor, followed with a brief
introduction of issues that NOAA wished to receive input from the workshop
participants. The four topic-oriented sessions followed these introductory
remarks, and each session began with talks by invited speakers. Abstracts for
each talk are included in the following section and portable document format
(PDF) files of the speakers talks are available online at
coaps.fsu.edu/RVSMDC/
marine_workshop/Workshop.html. At the end of each session, round table discussions provided for a free exchange
of ideas relevant to the four topic areas.
Several scientific objectives that require high-resolution, high-quality
marine meteorological data were discussed. One primary objective was
producing accurate estimates of the air-sea fluxes. All components of air-sea heat, momentum,
radiation, and carbon fluxes were discussed as important to achieving short and
long term science objectives. The need for both continuous direct flux
measurements and estimates using bulk algorithms was raised. High-quality
air-sea fluxes from vessels and buoys are essential to address problems of
validating new satellite sensors and providing uncertainty estimates for
operational and research flux fields (from GCMs or other data assimilation
methods). The goal of reducing uncertainties in flux fields is an essential
component of several international climate initiatives (e.g., CLIVAR, GODAE).
Participants discussed the need for more interaction and collaboration between
the in-situ marine data and modeling communities. Another scientific activity
addressable with high resolution marine data is the investigation of diurnal
cycles over the oceans.
A current status of their high-resolution meteorological measurements
programs was provided by NOAA/ETL, NOAA/AOML, NOAA/MAO, NOAA/PMEL, U.S. Coast Guard,
U.S. Navy, SIO, WHOI, UM/RSMAS, and OSU. The presentations revealed a diverse
level of both scientific and technical expertise that is devoted to collecting
marine meteorological measurements with a wide range of instrumentation
deployed on R/V, VOS, and buoys. In some cases, there was concern raised that
personnel collecting the data were lacking sufficient scientific and technical
input on critical elements including, but not limited to, sampling rate, data
accuracy, and instrument siting. Calibration practices and the level of data
quality control also varied widely between organizations. Some institutions
noted that data collection and QC have been explicitly separated in the funding
process, with QC falling on the shoulders of the chief scientist, not the data
collector. The presentations and subsequent discussions also showed that a
level of duplication in efforts to develop instrumentation, data logging and
display software, and other technology existed between the groups. Finally, a
large number of R/Vs (e.g., additional UNOLS vessels) and some mooring programs
(e.g., NDBC) were not represented at the workshop that clearly are a part of
the U. S. effort. Round table discussions made it clear that further work (see
action items) was needed to evaluate the current status of the U. S.
high-resolution observing program.
The technical discussion on accuracy, calibration, and inter-calibration of
high-resolution marine systems highlighted several areas where improvements and
new initiatives would lead to more, higher quality observations. Discussions
showed a clear need to improve lab calibration practices for marine AWS. Better
calibration will lead to improved accuracy of fluxes calculated from
high-resolution ship and buoy data. The need for uniform calibrations practices
across marine platforms and the need to better distribute information on these
practices was discussed. Platform to platform and instrument to instrument
inter-calibrations were both topics of many of the round table discussions.
Plans are moving forward to develop ocean flux reference sites and the workshop
participants agreed that inter-comparisons between these sites and nearby
vessels is essential. Further discussions centered around development of a
reference AWS to be used for onboard inter-comparison with different AWS
deployed on the U. S. R/V fleet.
Discussions related to data collection, quality assurance, distribution and
archival varied by data class. Much of the needs for VOS are being handled through long
established data pipelines. The VOSClim program is working to improve metadata
for the VOS fleet and has been working with a subset of the VOS fleet to
provide validation data for models. A wide range of QA practices exist for the
VOS-AWS programs. For example, SeaKeepers completes manual QA of data retrieved
for submission onto the GTS while VOS-IMET observations undergo post-cruise
evaluation at WHOI. Currently R/V data collection and distribution is handled
on a ship-by-ship, institute-by-institute basis, making high-quality R/V data
difficult to obtain and harder to use for operational and research purposes.
Data pathways, QA, distribution to users, and long term archival of both
real-time and delayed-mode VOS-AWS and R/V -AWS data are key issues that were
discussed as part of an overall management plan for U. S. sponsored
high-resolution marine meteorological data.
Climate Quality Buoy and Ship
Observations
Robert Weller, Dave Hosom, Frank Bahr,
Lisan Yu
Woods Hole Oceanographic
Institution
The state of the art of high resolution buoy and ship observations of marine
meteorology is briefly reviewed as are plans for the elements of the global
ocean observing system using these techniques. The motivations for collecting
these data and payoffs associated with using the data are summarized. Finally
the next steps associated with resolving present issues and continuing to make
progress are listed.
Surface moorings are now deployed for up to 1-year, instrumented to obtain the fluxes
of heat, moisture, and momentum by bulk formulae methods. Most locations in the
world's oceans are now accessible, but high current, high sea state, and
ice-covered regions are not. National and international planning has been done
to identify locations for a global array of time series stations, a subset of
which (known as Surface Flux Reference Sites) would have as one goal to collect
high quality, rapidly sampled (~1 minute) surface meteorological and air-sea
flux time series. High quality observations are also made on research vessels
and Volunteer Observing Ships (VOS), a subset of which are being equipped with
IMET systems. The intent is to eventually upgrade the surface
meteorological/air-sea flux capability of the ships that carry out the
high-resolution XBT lines in each basin. Well-equipped research vessels
complement these data by going to sparsely sampled regions and be being able to
carry out more sophisticated observations, such as turbulent
fluxes.
Accuracy that can be achieved in air-sea fluxes using mean meteorological sensors and
bulk formulae has greatly improved over the last 20 years. The accuracy of
weekly averages of the net heat flux now approaches 10 Wm-2. With
that accuracy buoy observations have proven to be very valuable in identifying
biases and errors in numerical weather prediction and climatological fluxes,
pointing to the monthly averages of net heat flux from these sources as
sometimes having the wrong sign and being in error by up to 100
Wm-2.
This capability has led to the development of a strategy to improve basin scale
air-sea flux fields in which high quality time series stations are used as
anchor points to identify problems with gridded fields from models and remote
sensing and where high quality ship observations are used to quantify the
spatial structure of those errors. The goal is to produce daily, 1°x1° gridded
fields of improved fluxes. This is being done in a pilot project in the
Atlantic and has been done as a trial example in the Indian Ocean for
1988-1994.
At
this point there is the need to work on sensor improvements (particularly
incoming longwave radiation and gimbaling/correction of incoming shortwave for
motion an/or tilt), for implementing a sonic anemometer as a more robust sensor
for mean winds, and for measuring platform tilts (mean and instantaneous) to
allow correction of errors associated with tilt and to develop the capability
to measure surface waves. We should also work to implement the capability to
measure turbulent fluxes on buoys to continue to address the uncertainties in
the bulk formulae and to continue to evaluate, test, and perfect the
calibration of all sensors. Communication bandwidth from buoys should be
improved as should on board power generation capability. Buoys are being
developed under the NSF Ocean Observatories Initiative (OOI) that should
address some of these issues and also provide improved access to
severe environments.
The observing programs need to engage the following communities in the effort
to develop basin scale fluxes:
remote sensing, numerical weather prediction and more generally the
atmospheric modelers, climate modelers and investigators, and those using
surface meteorological and air-sea flux fields to force ocean models and
quantify air-sea coupling.
Actions items are thus: work on sensors,
work on calibration and inter-calibration across the observing elements, work
of performance characteristics of the platforms (flow disturbance, heat island
effects, RF radiation issues, motion effects), work on turbulent observing
capability and flux algorithms, and attention to working with users including
developing data archiving and quality control.
Uses of high quality meteorological
observations in climate studies
Elizabeth Kent, Peter Taylor, Margaret Yelland,
and David Berry
Southampton Oceanography
Centre
This abstract describes some of the research projects at the Southampton
Oceanography Centre which use surface meteorological data in climate-related
studies.
AutoFlux is an autonomous atmospheric measuring system developed by a group
of partners under the MAST-3 programme of the European Union. AutoFlux measures surface stress, sensible and latent heat
flux and also carbon dioxide flux along with mean surface meteorological
parameters. The system is aimed
primarily towards unattended use on Voluntary Observation Ship (VOS) and buoys
and has been successfully deployed unattended on research ships. The fluxes are derived from the
turbulence spectra using the "inertial dissipation" method. Hourly summaries of flux and
meteorological information are transmitted by satellite and received
by email to allow remote routine monitoring and maintenance planning. The system is modular and so will take
advantage of improved flux instruments as they are
developed.
VOSClim is the World Meteorological Organization VOS Climate Project. The aim is to provide a high-quality
set of marine meteorological observations from VOS with detailed information on
how the data were obtained. The
VOSClim data will be used for operational marine forecasting and provide
high-quality data for model validation and ground truth for the calibration of
satellite observations. A further
use for the data will be the characterization of meteorological data from VOS
necessary for climate studies.
Currently more than 70 ships are providing 6-hourly meteorological
reports which are collected in real time by the UK Met Office and merged with
the output of their numerical weather prediction model. The merged data are then sent to NCDC
(the US National Climatic Data Centers) along with delayed mode data containing
extra parameters which the ships have agreed to report. Port Meteorological Officers are
collecting extensive metadata which will allow us to understand the factors
that affect the quality of marine meteorological observations from this subset
of VOS. It is expected that the
VOSClim dataset will be available in the spring of 2003 with regular updates as
the project continues.
Marine meteorological data with high time resolution are particularly important for studies where the diurnal cycle is important. An example is an attempt to remove the effects of radiative heating from ships measurements of air temperature. The aim of this research is to model the effects of solar radiation on the air temperature using an analytical model with empirically fitted coefficients. The model will be used to correct VOS air temperatures which are reported every 6-hours but testing of the model has started with higher resolution data to ensure the diurnal cycle is adequately modeled.
Near-real-time wind and surface pressure from
SeaWinds
James J. O'Brien
COAPS, The Florida State
University
Abstract not available.
Partial pressure of CO2 measurements
from VOS:
Why do we need high-resolution
observations?
Rik Wanninkhof
NOAA/AOML
The overall objective of the interagency US Carbon Cycle Science Program is
to reduce uncertainties in fluxes between the major labile carbon reservoirs. The
ocean is the largest of the three reservoirs containing approximately fifty
times more carbon than either the atmosphere or the terrestrial biosphere. A
focus of the ocean work is quantification of exchange of CO2 between
the ocean and atmosphere on regional and seasonal basis to 0.2 Pg C
yr-1 (1 Pg = 1015 gr). To determine this exchange on seasonal time
scales, the surface water gaseous partial pressure of CO2
(pCO2)
must be determined along with the gas transfer velocity, which is the kinetic
driving force of gas fluxes. The latter is often parameterized with
wind.
To increase the number of pCO2 samples and create regional pCO2 maps, autonomous measurements are being started on research ships and volunteer observing ships (VOS). The calculation of the pCO2 from the instrument readings on the ships requires accurate co-located temperature and salinity information. Quality controlled temperature and salinity has often been the Achilles heel for the overall accuracy of the pCO2 measurements. Translating the pCO2 to an air-sea flux requires high-resolution winds on time scales of hours. Interpolation over larger space and time domains can be done with regional temperature, salinity and wind products. Therefore, measurements of surface physical parameters and marine meteorology both in-situ and remotely is a high priority for ocean carbon research.
Role of high-resolution marine meteorological
observations
in global climate
research
David M. Legler
U.S. CLIVAR Office
The Climate Variability and Predictability program (CLIVAR) focuses on the
physical aspects of the coupled climate system, and addresses the question: What causes the changes of the earth's
climate on time scales from seasons to centuries and can we predict it?
Examples of changes (or variability) can be found in the worlds ocean basins.
Mechanisms that govern and generate modes of variability such as El
Niņo-Southern Oscillation (ENSO), Pacific Decadal Oscillation, Northern Annular
Mode (i.e. NAO), and the Tropical Atlantic Variability (TAV) are not well
known, but the ocean plays a critical role, and the coupling between the ocean
and atmosphere in particular must be better quantified, described, and
monitored in order to accurately model the coupled system
(particularly the ocean) and indicate any change. Air-sea fluxes of heat, momentum, and fresh water are
the measures of this coupling, but global fields of these variables are
difficult to obtain and the uncertainties of many currently available fields are unacceptably
large. The prospect of a network of high-resolution, high-quality surface
marine meteorology observations that will anchor flux fields at select
locations and also provide characteristics of these fields in the spatial
domain is especially welcomed by CLIVAR. Such an observation network could be
used to validate any number of flux fields (satellite, NWP) and products, on a
wide variety of time and space scales. A plan to develop this network address
these needs of the climate research community:
Consistent data and metadata
Data quality attributes and better inter-calibration within
the network
Delivery of data as much as possible in real-time
Value-added products helpful to users, and
Assessment of these observations in context of other observing systems
and products (routine VOS, satellite, other products)
An example of the use of
high-resolution research vessel data was the recent comparison of a large
collection of this data to the NCEP reanalysis surface meteorology and air-sea
flux fields. The study highlighted numerous deficiencies in the NCEP fields and
the NCEP flux algorithms.
Shipboard monitoring of
stratocumulus cloud properties in the PACS region
Chris W. Fairall
NOAA Environmental Technology
Laboratory
In this project we implemented a modest ship-based cloud and flux measurement
program to obtain statistics on key surface, mean boundary layer (MBL), and
low-cloud macrophysical, microphysical, and radiative properties. The
measurements were made as part of the PACS/EPIC monitoring program for the 95°W
and 110°W TAO buoy lines in the tropical eastern Pacific (Cronin et al. 2002).
Our goal was to acquire a good sample of most of the relevant bulk variables
that are commonly used in GCM parameterizations of these processes. These data
are being compared to known relationships in other well-studied regimes. While
not comprehensive, these data are useful for MBL/cloud modelers (both
statistically and for specific simulations) and to improve satellite retrieval
methods for deducing MBL and cloud properties on larger spatial and temporal
scales.
The
primary objectives are to
1.
Obtain
new measurements of near-surface, cloud, and MBL statistics for comparison to
existing data on northern hemisphere stratocumulus
systems.
2.
Obtain
quantitative information on cloud droplet and drizzle properties and
probability of occurrence of drizzle and possible links to deviations from
adiabatic values for integrated cloud liquid water
content.
3.
Examine
applicability of existing bulk parameterizations of stratocumulus radiative
properties for the Peruvian/Equatorial regime.
4.
Characterize
surface cloud forcing and possible ocean-atmosphere coupling through
stratocumulus SST interactions.
5.
Provide
periodic high quality near-surface data for inter-comparison with ship-based
IMET and buoy-based meteorological measurements.
6.
Provide
high quality measurements of basic surface, MBL and cloud parameters for
'calibration' of satellite retrieval techniques.
Status of the SEAS
program
Steve Cook
NOAA/AOML
NOAA's Global Ocean Observing Systems (GOOS) Center has developed
the SEAS 2000 software package which will support the automated real-time
transmission of high resolution meteorological data from those selected vessels
(both research and Voluntary Observing Ships) outfitted with climate quality
sensor packages. Plans are to have three Voluntary Observing Ships on line by
the end of 2003. Additionally, plans are evolving to integrate the NOAA
research fleet as high resolution reporters. The GOOS Center will continue to
integrate sampling systems into SEAS 2000, assist in the data QC, management
and coordination of those systems as well as continue to act a focal point to
the Voluntary Observing Ship network.
Underway systems on SIO
vessels
Woody Sutherland and Carl
Mattson
Scripps Institution of
Oceanography
Abstract not available.
Overview of the R/V
Wecoma DAS
system
Linda Fayler
Oregon State
University/COAS
The manner in which the meteorological and flow-through systems
are implemented on the UNOLS
intermediate class research vessel Wecoma is detailed. A quick overview of the
various types of equipment used and their placement on the ship is included. The manner in which the data are collected, including the
sampling rates, periods over which data is averaged, and the program language
is described. Data record structure is presented along with the other types of
documentation files, which are included with the data CD created for each
science cruise. Why this system is not a high-resolution system is then
discussed. In summary, ways in which the system on Wecoma might be improved are
outlined.
Status of vessels operating with
SCS
Dennis Shields (presented by M.
Reynolds)
NOAA/MAO
Abstract not available.
Marine Meteorological Measurements
from the USCG Polar Class Icebreakers.
Phil McGillivary
US Coast Guard Icebreaker Science
Liaison
The USCG operates three icebreakers for high latitude logistics
and research for the U. S. government and all federal agencies, with the ships
based out of Seattle, Washington. These vessels include two 399 ft. Polar class
icebreakers, Polar Star (NBTM) and Polar Sea (NRUO), which are the principal ships tasked with the annual
mission to break an ice channel in to McMurdo Station in the Ross Sea,
Antarctica, to permit re-supply of the base during the austral summer (northern
winter). Typically this mission is carried out by one of the Polar icebreakers,
with the second vessel held in reserve. However in the past two years, heavy
ice conditions have required the use of two icebreakers, a condition
anticipated to persist for the foreseeable future. Normally, one or both of the
Polar Class icebreakers also conducts research in the arctic during the
northern summer, typically calling at Barrow, Alaska, during their summer
missions. A new icebreaker, the 420 ft. Healy (5LZE), began its' mission as an
arctic research vessel in 2001. In transiting from the eastern to the western
arctic, the Healy
has gone through the Canadian Northwest Passage once, and once transited
through the Panama Canal. Future transits of the arctic will likely involve
these routes again, as well as periodic transits across the North
Pole.
The annual cruise track of the Polar class icebreakers from
Seattle to
Antarctica to
Seattle to Barrow, Alaska, provides them an annual latitudinal range of
standard operations greater than any other U. S. research vessel. This great
latitudinal range drives many of the research objectives of meteorological
measurements from these ships. Principal research objectives for which marine
meteorological measurements from the icebreakers have been or can be used
include: (1) high latitude inputs to weather/climate models; (2) satellite
calibration/validation of existing and newly launched environmental observing
satellites (including taking identical satellite sensor systems aboard the
ship); (3) air-sea flux measurements involving elemental budgets, including
hydrogen, carbon (as CO2), sulfur, and halogens; (4) correlation of ship
sensors with those from radiosondes, Global Ocean Observing System (GOOS)
floats, ARGO floats, SOLO floats, ice buoys, and autonomous underwater vehicles
(AUVs) deployed during icebreaker missions; (5) comparison with data from high
latitude underwater observatories now existing (e.g., on Little Diomede Island)
and planned (the PRIMO observatory in McMurdo Sound, Ross Sea, Antarctica);
and, finally, (6) studies of physical and chemical fluxes relating to "ice
breeze" phenomena at the edge of pack ice, as well as similar flux studies
at leads and polyn'yas in the ice. In the future, high latitude ship-collected
marine meteorological data can be useful for several studies proposed to focus
on the relation of solar/sunspot maxima to Earth's meteorological fields as
well as "space weather" (c.f. CAWES, the 2003-2007 program on Climate
And Weather in the Sun-Earth System).
A wide range of issues are presented related to sensor calibration, data
management, and the complications of placing additional sensors on the
icebreakers. Sensor calibration is typically done before and after each
scientific cruise. The annual track of the ship to Barrow, Alaska combined with
the fact that the ship instrumentation are identical to those installed at the
Barrow ARM site allows for regular sea-truth and instrument inter-calibration
with the Barrow ARM instruments. Onboard data management is handled by the NOAA
SEAS-V software. Standard data are transmitted via INMARSAT at four hour
intervals to NODC. At the end of each mission, a CDROM of all data collected
are provided to scientists involved. Requests to improve or add sensors to the
icebreakers have been increasing; however, maintaining additional sensors
properly is beyond the ship's current force capabilities. Deployment and use of
new sensors can be accommodated when personnel serving as instrument minders
are provided through separate funding (e.g., university or government
agencies).
An important value of marine meteorological sensors on the Polar
Class icebreakers is to provide data for satellite calibration and validation
over the great latitudinal range they cover during their annual transits. Ship
wind sensor data can be used for validation of winds obtained from the
currently operational QuikScat satellite. Calibration/validation of these winds
over the sea will soon be of increasing importance as QuikScat winds are about
to be incorporated into Navy global operational wind and weather models. In the
near future shipboard wind data may be used to calibrate/validate wind data
obtained from the NASA SeaWinds sensor on the Japanese ADEOS-II satellite.
Currently all three USCG icebreakers have been active in providing sea truth
data for ENVISAT, the first satellite to be able to distinguish snow depth as
separate from sea ice thickness when sea ice is snow-covered. A radar system
similar to that on ENVISAT was mounted on the Healy in summer of 2001 in the eastern
arctic by ENVISAT PI Son Nghiem (NASA JPL). Similarly the icebreakers will be
used during the 2003 and subsequent seasons to measure sea ice thickness for
calibration/validation of ICESat, launched by NASA in March 2003, and can
provide similar data for ice thickness estimates from the MODIS sensors on
NASA's AQUA satellite. Atmospheric moisture and aerosols are particularly
important aliasing components of satellite remote sensing data, and additional
sensor information on these parameters can further broaden the range of
satellite calibration and validation information for the new suite of
NASA-launched earth-observing satellites.
In summary, the annual cruise tracks of the Polar Class
icebreakers, Polar Sea and Polar Star, from 70°North to 70°South latitudes permit collection of high
resolution marine meteorology data that can make a significant contribution to
a wide range of scientific community interests, as well as global weather and
environmental models.
Aerosol Observations and Modeling
Briefing: T-AGS 60 Class Ship Battle-space
Characterization
Jeff S. Reid
Aerosol and Radiation Modeling
Section, NRL Monterey CA
The Marine Meteorology Division of the Naval Research Laboratory
in Monterey, CA has an ongoing program to model and monitor significant aerosol
events globally. The Navy Aerosol Analysis and Prediction System (NAAPS) is a
global 1x1 degree prognostic aerosol model that runs out to 120 hours. Current
aerosol species modeled include dust, smoke and urban pollution. While NAAPS
captures large visibility reducing events well, there is an ever-increasing
need to predict visibility to finer and finer resolution. Hence, a development
program has begun using 9 km mesoscale models. As aerosol forecasts move to
high resolution, validation methods must follow similarly. Our section intends
to develop a mobile package capable of deployment on the Naval Oceanographic
Office (NAVOCEANO) T-AGS 60 survey vessels. In this talk, we describe our
package for measuring visibility, aerosol particle size and chemistry,
micro-pulse lidar, and high resolution meteorology.
IMET (Improved METeorology) Status for Buoys,
Research Vessels, and Voluntary Observing Ships
David Hosom
Woods Hole Oceanographic
Institution
IMET was designed starting in 1988 to meet the WOCE standards for measuring heat
flux to 10 Wm-2. The sensors were tested to meet these standards and
consist of: wind speed and
direction, barometric pressure, relative humidity and air temperature,
precipitation, sea surface temperature, shortwave radiation, and longwave
radiation. The system architecture consists of individual modules that can be
polled using a modified SAIL protocol, using a central data logger via RS485 or
RS232. Calibration constants are internal to the module for ease of replacement
in the field.
There are three versions of IMET. (1) The original "Old IMET" consisting of the
selected sensors and a set of PC boards for analog interface, A/D conversion,
and communications. (2) ASIMET
uses the same sensors with lower power improved electronics and more rugged
titanium housings. These modules can be polled by an external computer as well
as operating stand-alone using internal batteries and a data logger. (3)
AutoIMET (for VOS) uses the same sensors and electronics as ASIMET in a lower
power integrated package that operates from batteries and has wireless
communications to the ship bridge and to the sea surface temperature located
inside the hull at the waterline. Of special interest is the HullCom acoustic
modem that uses the ship hull as a data path for SST. A 99% data return has
been achieved on ocean cruises from this device.
A