Instrument

CWM
Johnson-Williams Cloud Water Meter

The Johnson-Williams Cloud Water Meter (CWM) is an airborne hot-wire probe designed by Johnson-Williams, Inc. The CWM measures the liquid water content (LWC) of clouds by detecting resistivity changes caused by cloud droplets evaporating from an exposed heated wire. It measures LWC from 0 to 6 grams per cubic meter and operates at airspeeds between 50 and 150 meters per second. The device operates on a constant current and typically records data at 2 Hz.

NASA's DC-8 flying laboratory passes Antarctica's tallest peak, Mount Vinson, on Oct. 22, 2012, during a flight over the continent to measure changes in the massive ice sheet and sea ice. Credit: NASA/Michael Studinger (Photography courtesy NASA Images)

Overview

Instrument Details

Measurement Type

Meter/Analyzer

Measurement/Variables

Earth Science > Atmosphere > Clouds > Cloud Microphysics > Cloud Liquid Water/ice

Earth Science > Atmosphere > Clouds > Cloud Microphysics

Vertical Measurement Regions

Troposphere

Temporal Resolution

2 Hz

Spatial Resolution

Point

Measurement Frequency

N/A

Calibration Details

https://doi.org/10.1175/1520-0450(1982)021%3C0098:COJWLW%3E2.0.CO;2

Online Information

Lead Investigator
Currently unavailable
Technical Contact
Currently unavailable
Instrument Maker
Johnson-Williams, Inc.
Funding Source
Currently unavailable
Overview Publications
Currently unavailable
Repository
- Unpublished

Instrument Operation

Platform

Campaigns, where the platform was used with this instrument

C-131A

Convair C-131 Samaritan

5 Campaigns · 32 Instruments

TARFOX

Tropospheric Aerosol Radiative Forcing Observational Experiment

1996

Western Atlantic Ocean, US Eastern Seaboard

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· 5 Data Products

FIRE

First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

1986—1998

Central and Midwest United States, California Coast, Northwest Africa, Alaska

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· 131 Data Products

MAST

Monterey Area Ship Track

1994

Central California Coast, Pacific Ocean

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· 0 Data Products

B-200

Beechcraft B-200 King Air

39 Campaigns · 84 Instruments

FIRE

First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

1986—1998

Central and Midwest United States, California Coast, Northwest Africa, Alaska

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· 131 Data Products

CaPE

Convection and Precipitation/Electrification Experiment

1991

East-Central Florida

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· 0 Data Products

FIFE

First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment

1987—1989

Central Kansas

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· 115 Data Products

Sabreliner

NCAR Sabreliner

3 Campaigns · 21 Instruments

FIRE

First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

1986—1998

Central and Midwest United States, California Coast, Northwest Africa, Alaska

view all deployment dates

· 131 Data Products

Citation

Cessna Citation II

10 Campaigns · 25 Instruments

FIRE

First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

1986—1998

Central and Midwest United States, California Coast, Northwest Africa, Alaska

view all deployment dates

· 131 Data Products

CV-580

Convair-580

8 Campaigns · 45 Instruments

FIRE

First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

1986—1998

Central and Midwest United States, California Coast, Northwest Africa, Alaska

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· 131 Data Products

SAFARI 2000

Southern African Regional Science Initiative

1999—2001

Southern Africa

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· 110 Data Products

C-130

C-130 Hercules

17 Campaigns · 96 Instruments

FIRE

First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

1986—1998

Central and Midwest United States, California Coast, Northwest Africa, Alaska

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· 131 Data Products

Learjet

SPEC Inc. Learjet 25

8 Campaigns · 30 Instruments

CEPEX

Central Equatorial Pacific Experiment

1993

Central Pacific Ocean

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· 0 Data Products

P-3

P-3 Orion

30 Campaigns · 153 Instruments

CEPEX

Central Equatorial Pacific Experiment

1993

Central Pacific Ocean

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· 0 Data Products

CAMEX

Convection and Moisture Experiment

1993—2001

US Atlantic coast, Gulf of Mexico, Caribbean

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· 70 Data Products

Data Products

Filter data products from this instrument by specific campaigns, platforms, or formats.

Campaigns

Platforms

Formats

Tropospheric Aerosol Radiative Forcing Observational eXperiment - University of Washington instrumented C-131A aircraft Data Set10.5067/ASDC_DAAC/TARFOX/0002

CampaignsTropospheric Aerosol Radiative Forcing Observational Experiment

PlatformsConvair C-131 Samaritan

CAMEX-4 NOAA WP-3D CLOUD PHYSICS V110.5067/CAMEX-4/MULTIPLE/DATA103

CampaignsConvection and Moisture Experiment

PlatformsP-3 Orion

First ISCCP Regional Experiment (FIRE) Cirrus Phase II University of North Dakota Citation Aircraft 5 Second Data10.5067/ASDC_DAAC/FIRE/0089

CampaignsFirst International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

PlatformsCessna Citation II

FormatsNative

FIRE_CI2_CITATN_1HZ10.5067/ASDC_DAAC/FIRE/0087

CampaignsFirst International Satellite Cloud Climatology Project (ISCCP) Regional Experiment

PlatformsCessna Citation II