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  • Author or Editor: D. Baumgardner x
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D. Baumgardner
,
L. Avallone
,
A. Bansemer
,
S. Borrmann
,
P. Brown
,
U. Bundke
,
P. Y. Chuang
,
D. Cziczo
,
P. Field
,
M. Gallagher
,
J.-F. Gayet
,
A. Heymsfield
,
A. Korolev
,
M. Krämer
,
G. McFarquhar
,
S. Mertes
,
O. Möhler
,
S. Lance
,
P. Lawson
,
M. D. Petters
,
K. Pratt
,
G. Roberts
,
D. Rogers
,
O. Stetzer
,
J. Stith
,
W. Strapp
,
C. Twohy
, and
M. Wendisch

No abstract available.

Full access
M. Wendisch
,
H. Coe
,
D. Baumgardner
,
J.-L. Brenguier
,
V. Dreiling
,
M. Fiebig
,
P. Formenti
,
M. Hermann
,
M. Krämer
,
Z. Levin
,
R. Maser
,
E. Mathieu
,
P. Nacass
,
K. Noone
,
S. Osborne
,
J. Schneider
,
L. Schütz
,
A. Schwarzenböck
,
F. Stratmann
, and
J. C. Wilson

Aircraft inlets connect airborne instruments for particle microphysical and chemical measurements with the ambient atmosphere. These inlets may bias the measurements due to their potential to enhance or remove certain particle size fractions in the sample. The aircraft body itself may disturb the ambient air streamlines and, hence, the particle sampling. Also, anisokinetic sampling and transmission losses within the sampling lines may cause the sampled aerosol to differ from the ambient aerosol. In addition, inlets may change the particle composition and size through the evaporation of water and other volatile materials due to compressibility effects or heat transfer. These problems have been discussed at an international workshop that was held at the Leibniz-Institute for Tropospheric Research (IfT) in Leipzig, Germany, on 12–13 April 2002. The discussions, conclusions, and recommendations from this workshop are summarized here.

Full access
M. Wendisch
,
H. Coe
,
D. Baumgardner
,
J.-L. Brenguier
,
V. Dreiling
,
M. Fiebig
,
P. Formenti
,
M. Hermann
,
M. Krämer
,
Z. Levin
,
R. Maser
,
E. Mathieu
,
P. Nacass
,
K. Noone
,
S. Osborne
,
J. Schneider
,
L. Schütz
,
A. Schwarzenböck
,
F. Stratmann
, and
J. C. Wilson

Aircraft inlets connect airborne instruments for particle microphysical and chemical measurements with the ambient atmosphere. These inlets may bias the measurements due to their potential to enhance or remove certain particle size fractions in the sample. The aircraft body itself may disturb the ambient air streamlines and, hence, the particle sampling. Also, anisokinetic sampling and transmission losses within the sampling lines may cause the sampled aerosol to differ from the ambient aerosol. In addition, inlets may change the particle composition and size through the evaporation of water and other volatile materials due to compressibility effects or heat transfer. These problems have been discussed at an international workshop that was held at the Leibniz-Institute for Tropospheric Research (IfT) in Leipzig, Germany, on 12–13 April 2002. The discussions, conclusions, and recommendations from this workshop are summarized here.

Full access
Thara Prabhakaran
,
P. Murugavel
,
Mahen Konwar
,
Neelam Malap
,
K. Gayatri
,
Shivsai Dixit
,
Soumya Samanta
,
Subharthi Chowdhuri
,
Sudarsan Bera
,
Mercy Varghese
,
J. Rao
,
J. Sandeep
,
P. D. Safai
,
A. K. Sahai
,
Duncan Axisa
,
A. Karipot
,
Darrel Baumgardner
,
Benjamin Werden
,
Ed Fortner
,
Kurt Hibert
,
Sathy Nair
,
Shivdas Bankar
,
Dinesh Gurnule
,
Kiran Todekar
,
Jerry Jose
,
V. Jayachandran
,
Pawan S. Soyam
,
Abhishek Gupta
,
Harish Choudhary
,
Aravindhavel
,
Suresh Babu Kantipudi
,
P. Pradeepkumar
,
R. Krishnan
,
K. Nandakumar
,
Peter F. DeCarlo
,
Doug Worsnop
,
G. S. Bhat
,
M. Rajeevan
, and
Ravi Nanjundiah

Abstract

The demand for effective methods to augment precipitation over arid regions of India has been increasing over the past several decades as the changing climate brings warmer average temperatures. In the fourth phase of the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX IV), a scientific investigation was conducted over a rain-shadow region of the Western Ghats mountains in India. The primary objective was to investigate the efficacy of hygroscopic seeding in convective clouds and to develop a cloud seeding protocol. CAIPEEX IV followed the World Meteorological Organization (WMO) recommendations in a peer-reviewed report with physical, statistical, and numerical investigations. The initial results of the campaign in the monsoon period of 2018 and 2019 with two instrumented aircraft, a ground-based dual-polarization C-band radar, a network of rain gauges, radiosondes, and surface aerosol measurements are reported here. The hygroscopic seeding material was detected in cloud droplets and key cloud microphysical processes in the seeding hypothesis were tracked. The formidable challenges of assessing seeding impacts in convective clouds and the results from 150 seed and 122 no-seed samples of randomized experiments are illustrated. Over 5,000 cloud passes from the airborne campaign provided details about the convective cloud properties as the key indicators for a seeding strategy and the evaluation protocol. The experimental results suggest that cloud seeding can be approached scientifically to reduce uncertainty. The results from this study should interest the scientific community and policymakers concerned with climate change’s impact on precipitation and how to mitigate rainfall deficiencies.

Open access