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measurement of atmospheric co2 column concentrations to cloud tops with a pulsed multi-wavelength airborne lidarWe have measured the column-averaged atmospheric CO2 mixing ratio to a variety of cloud tops by using an airborne pulsed multi-wavelength integrated-path differential absorption (IPDA) lidar. Airborne measurements were made at altitudes up to 13 km during the 2011, 2013 and 2014 NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) science campaigns flown in the United States West and Midwest and were compared to those from an in situ sensor. Analysis of the lidar backscatter profiles shows the average cloud top reflectance was approx. 5% for the CO2 measurement at 1572.335 nm except to cirrus clouds, which had lower reflectance. The energies for 1 micro-s wide laser pulses reflected from cloud tops were sufficient to allow clear identification of CO2 absorption line shape and then to allow retrievals of atmospheric column CO2 from the aircraft to cloud tops more than 90% of the time. Retrievals from the CO2 measurements to cloud tops had minimal bias but larger standard deviations when compared to those made to the ground, depending on cloud top roughness and reflectance. The measurements show this new capability helps resolve CO2 horizontal and vertical gradients in the atmosphere. When used with nearby full-column measurements to ground, the CO2 measurements to cloud tops can be used to estimate the partial-column CO2 concentration below clouds, which should lead to better estimates of surface carbon sources and sinks. This additional capability of the range-resolved CO2 IPDA lidar technique provides a new benefit for studying the carbon cycle in future airborne and space-based CO2 missions.
Document ID
20180002217
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Mao, Jianping
(Maryland Univ. College Park, MD, United States)
Ramanathan, Anand
(Maryland Univ. College Park, MD, United States)
Abshire, James B.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kawa, Stephan R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Riris, Haris
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Allan, Graham R.
(Sigma Space Corp. Lanham, MD, United States)
Rodriguez, Michael R.
(Science Systems and Applications, Inc. Lanham, MD, United States)
Hasselbrack, William E.
(Sigma Space Corp. Lanham, MD, United States)
Sun, Xiaoli
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Numata, Kenji
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Chen, Jeffrey R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Choi, Yonghoon
(Science Systems and Applications, Inc. Hampton, VA, United States)
Yang, Mei Ying Melissa
(Bay Area Environmental Research Inst. Moffett Field, CA, United States)
Date Acquired
April 10, 2018
Publication Date
January 10, 2018
Publication Information
Publication: Atmospheric Measurement Techniques
Volume: 11
Issue: 1
Subject Category
Earth Resources and Remote Sensing
Meteorology and Climatology
Report/Patent Number
GSFC-E-DAA-TN53248
Funding Number(s)
CONTRACT_GRANT: NNL16AA05C
CONTRACT_GRANT: 80GSFC17C0003
CONTRACT_GRANT: NNG15HQ01C
CONTRACT_GRANT: NNX17AE79A
CONTRACT_GRANT: NNX12AD05A
CONTRACT_GRANT: 80GSFC17C0003
Distribution Limits
Public
Copyright
Other
Keywords
atmospheric
cloud top
measurement
CO2