Atmospheric Soundings:Radiosondes, Dropsondes and Driftsondes

Kate Young & Junhong Wangkbeierle@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 LaboratoryMission:Develop of state-of-the-art technologies for atmospheric researchDeploy instruments for scientific research projectsData Services - providing high-quality project data for scientific advancement and discovery Discovery – promote curiosity about earth science and educate others on atmospheric research

Space between linesrepresents the relative humidity

Temperature (degC)Dew-point Temperature (degC)

Wind barbs show strength and direction of wind

Atmospheric pressure at sea level is ~1000 millibars and decreases with height

Moist Layer with high relative humidity

Atmospheric Profile

0 -120 -80 -40 0 40 80 120

Temperature (deg F)

TROPOSPHERE

30 Stratopause

STRATOSPHERE

Altitude (m

i)

54 Mesopause

THERMOSPHERE

MESOSPHERE

8 Tropopause

Average dropsondeheight

Maximum radiosondeheight

~19 mi

~10 mi

Radiosondes GPS – 1. allows us to track radiosondes

2. provide wind measurements

Temperature &Relative humidity

Pressure

Antenna

Windy downdraft

EOL PROJECTS WITH RADIOSONDES

NCAR GPS Dropsondes

Currently on 21 research aircraft

Licensee (Vaisala) makes ~ 5,000 per year

DriftsondesIridium LEO SatelliteCommunications

Gondola20-50 SondeCapacity

Flight Altitude125mb to 50mb (~58,000’)

Hurricane Research

Courtesy of Dr. Chris Davis (NCAR/ASP)

T-PARC (airborne) Sounding SystemsDriftsonde Temperature versus Altitude (4 drops) from 30km!

Nominal C-130 Drop altitude

Nominal P-3Drop altitude

Nominal DriftsondeDrop altitude

Nominal Falcon andDOTSTAR drop altitudes

Courtesy of Terry Hock and Steve Cohn

EOL PROJECTS WITH DROPSONDESTC

M90

GTE

_TR

AC

EC

ASP

_II

PRE_

BO

REA

STO

GA

_CO

AR

EK

OFS

EC

EPEX

AES

_BA

SED

LRN

ASA

_LIT

EM

AC

AW

SSn

owba

ndIN

DO

EXM

AP

DYC

OM

S II

EPIC

CA

MEX

IVIH

OP

Cry

stal

Fac

eTE

LEX0

3 B

AM

EXA

TREC

O

cean

Wav

es

TELE

X04

RIC

OR

AIN

EXT-

REX

Prog

ress

ive

Scie

nce

AM

MA

NA

MM

ATC

4G

ISM

OS

T-PA

RC

(drif

t)T-

PAR

C (d

rop)

PLO

WS

PRED

ICT

GR

IPIT

OP

Con

cord

iasi

WIS

PAR

050

100150200250300350400450500

EOL Dropsonde Projects 1990-2010

Field Projects

Num

ber o

f Sou

ndin

gs 20

Total # of soundings= 8129

2001 2002 2003 2004199919981990 1992 1993 19951994 2005 2006 2007 2008

(1,577)

265 264 134 17 102 247 363 462 527 102 395 686 95 1,916

2010

(648)(698)(558)

2,283

2009

warmer and drier sondes (sondes were launched in a parking lot, sfc met was set up in vegetation)

T

RH

P

Wind direction

wind speed

Quality Control of Radio/Dropsonde Data

Apply Radiation Correction

ASPENPerforms smoothingRemoves suspect data pointsProvides analysis tools (skew-t diagrams, xy-plot)

Batch mode for processing large datasets

Comparisons of prelaunch and surface data

Visually examine QC sounding profiles

Individual examination raw data profiles

In field data inspection by operator

Takes into account solar angle at time of launchand removes solar heating that could skew T.

Histograms of PTU and Wind

Timeseries plots of PTU and Wind

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