Atmospheric Soundings:
Radiosondes, Dropsondes and Driftsondes
Kate Young & Junhong Wang
kbeierle@ucar.edu
NCAR Earth Observing Laboratory
National Center for
Atmospheric Research
Weather/Climate
Societal Impacts
Pollution/Air Chemistry
Ocean/Atmosphere
Space weather/Sun
Earth Observing Laboratory
Mission:
Develop of state-of-the-art technologies for
atmospheric research
Deploy instruments for scientific research projects
Data Services - providing high-quality project data for
scientific advancement and discovery
Discovery – promote curiosity about earth science and
educate others on atmospheric research
Atmospheric Profile
Wind barbs show
strength and
direction of wind
Space between lines
represents the
relative humidity
Dew-point
Temperature
(degC)
Atmospheric
pressure
at sea level is
~1000
millibars and
decreases
with height
Temperature (degC)
Moist Layer with high
relative humidity
THERMOSPHERE
54
Mesopause
Altitude (mi)
MESOSPHERE
30
Stratopause
Maximum
~19 mi
radiosonde
height
Average ~10 mi
dropsonde
height
STRATOSPHERE
8
Tropopause
TROPOSPHERE
0
-120
-80
-40
0
40
Temperature (deg F)
80
120
Radiosondes
GPS – 1. allows us to track radiosondes
2. provide wind measurements
Temperature &
Relative humidity
Pressure
Antenna
Windy downdraft
NCAR GPS Dropsondes
Licensee (Vaisala) makes ~ 5,000 per year
Currently on 21 research aircraft
Driftsondes
Flight Altitude
Iridium LEO Satellite
Communications
125mb to 50mb (~58,000’)
Gondola
20-50 Sonde
Capacity
Hurricane Research
Courtesy of Dr. Chris Davis (NCAR/ASP)
T-PARC (airborne) Sounding Systems
Driftsonde Temperature versus Altitude (4 drops) from 30km!
Nominal Driftsonde
Drop altitude
Nominal Falcon and
DOTSTAR drop altitudes
Nominal C-130
Drop altitude
Nominal P-3
Drop altitude
Courtesy of Terry Hock and Steve Cohn
Number of Soundings
500
450
400
350
300
250
200
150
100
50
0
TCM90
GTE_TRACE
CASP_II
PRE_BOREAS
TOGA_COARE
KOFSE
CEPEX
AES_BASE
DLR
NASA_LITE
MACAWS
Snowband
INDOEX
MAP
DYCOMS II
EPIC
CAMEX IV
IHOP
Crystal Face
TELEX03
BAMEX
ATREC
Ocean Waves
TELEX04
RICO
RAINEX
T-REX
Progressive Science
AMMA
NAMMA
TC4
GISMOS
T-PARC (drift)
T-PARC (drop)
PLOWS
PREDICT
GRIP
ITOP
Concordiasi
WISPAR
EOL Dropsonde Projects 1990-2010
Total # of soundings= 8129
(1,577)
1990 1992
265
1993
1994
264
134
1995 1998 1999
17 102
247
2001
2002
363
462
2003
527
2004
2005
2006
102
395
686
Field Projects
2007 2008 2009
95
20
1,916
(558)
(698) (648)
2010
2,283
Quality Control of Radio/Dropsonde Data
In field data inspection by operator
Individual examination raw data profiles
warmer and drier sondes (sondes were launched in a
parking lot, sfc met was set up in vegetation)
T
Apply Radiation Correction
ASPEN
Takes into account solar angle at time of launch
and removes solar heating that could skew T.
Provides analysis tools (skew-t diagrams, xy-plot)
Removes suspect data pointsRH
Performs smoothing
Batch mode for processing large datasets
Comparisons of prelaunch
and surface data
P
wind speed
Histograms of PTU and Wind
Timeseries plots of PTU and Wind
Wind direction
Visually examine QC sounding profiles
How is this data useful?
It allows us to:
• Examine changes in weather patterns
• Create long term records for climate change research
• Develop local severe storm, aviation, and marine
forecasts
• Improve weather prediction models using near real-time
data assimilation
• Validate satellite data
• Provide feedback to EOL engineers on instrument
performance