Optical radar measurements of aerosol scattering in the lower stratosphere compared with balloon-borne in-situ measurements of aerosol concentration

2005 ◽  
Author(s):  
S. Melfi ◽  
M. McCormick ◽  
W. Fuller ◽  
J. Rosen ◽  
T. Pepin ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Aerosol Concentration ◽  
Aerosol Scattering ◽  
Radar Measurements ◽  
Optical Radar

scholarly journals Atmospheric Ice Particle Shape Estimates from Polarimetric Radar Measurements and In Situ Observations

2017 ◽  
Vol 34 (12) ◽  
pp. 2569-2587 ◽  
Author(s):  
Sergey Y. Matrosov ◽  
Carl G. Schmitt ◽  
Maximilian Maahn ◽  
Gijs de Boer
Keyword(s):  
Aspect Ratio ◽  
Particle Shape ◽  
Characteristic Size ◽  
In Situ Measurements ◽  
Department Of Energy ◽  
Depolarization Ratio ◽  
Suggested Approach ◽  
Aspect Ratios ◽  
Radar Measurements

AbstractA remote sensing approach to retrieve the degree of nonsphericity of ice hydrometeors using scanning polarimetric Ka-band radar measurements from a U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program cloud radar operated in an alternate transmission–simultaneous reception mode is introduced. Nonsphericity is characterized by aspect ratios representing the ratios of particle minor-to-major dimensions. The approach is based on the use of a circular depolarization ratio (CDR) proxy reconstructed from differential reflectivity ZDR and copolar correlation coefficient ρhυ linear polarization measurements. Essentially combining information contained in ZDR and ρhυ, CDR-based retrievals of aspect ratios are fairly insensitive to hydrometeor orientation if measurements are performed at elevation angles of around 40°–50°. The suggested approach is applied to data collected using the third ARM Mobile Facility (AMF3), deployed to Oliktok Point, Alaska. Aspect ratio retrievals were also performed using ZDR measurements that are more strongly (compared to CDR) influenced by hydrometeor orientation. The results of radar-based retrievals are compared with in situ measurements from the tethered balloon system (TBS)-based video ice particle sampler and the ground-based multiangle snowflake camera. The observed ice hydrometeors were predominantly irregular-shaped ice crystals and aggregates, with aspect ratios varying between approximately 0.3 and 0.8. The retrievals assume that particle bulk density influencing (besides the particle shape) observed polarimetric variables can be deduced from the estimates of particle characteristic size. Uncertainties of CDR-based aspect ratio retrievals are estimated at about 0.1–0.15. Given these uncertainties, radar-based retrievals generally agreed with in situ measurements. The advantages of using the CDR proxy compared to the linear depolarization ratio are discussed.

In situ measurements of hydrogen cyanide in the upper troposphere/lower stratosphere during Arctic spring 2000

2002 ◽  
Vol 107 (D5) ◽  
pp. SOL 47-1-SOL 47-6 ◽  
Author(s):  
A. A. Viggiano ◽  
D. E. Hunton ◽  
Thomas M. Miller ◽  
John O. Ballenthin
Keyword(s):  
Hydrogen Cyanide ◽  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Upper Troposphere

Remote and in situ measurements of aerosol concentration in the Arctic troposphere from the Yak-42D “Roshydromet” research aircraft

2016 ◽  
Vol 41 (5) ◽  
pp. 365-372
Author(s):  
A. S. Kuz’michev ◽  
T. I. Babukhina ◽  
A. V. Gan’shin ◽  
A. N. Luk’yanov ◽  
R. M. Markov ◽  
...  
Keyword(s):  
In Situ Measurements ◽  
Aerosol Concentration ◽  
The Arctic ◽  
Research Aircraft

scholarly journals Ground-based FTIR retrievals of SF<sub>6</sub> at Réunion Island

2017 ◽  
Author(s):  
Minqiang Zhou ◽  
Bavo Langerock ◽  
Corinne Vigouroux ◽  
Pucai Wang ◽  
Christian Hermans ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Annual Growth Rate ◽  
Retrieval Strategy ◽  
Satellite Measurements ◽  
Individual Layer ◽  
Time Period ◽  
Independent Information ◽  
Air Column

Abstract. SF6 total columns are successfully retrieved from FTIR measurements (Saint Denis and Maïdo) at Réunion Island (21° S, 55° E) between 2004–2016 using the SFIT4 algorithm: the retrieval strategy and the error budget are presented. The FTIR SF6 retrieval has independent information in only one individual layer, covering the whole troposphere and the lower stratosphere. The trend of SF6 is analysed based on the FTIR retrieved dry air column-averaged mole fractions (XSF6) at Réunion Island, the in-situ measurements at America Samoa (SMO) and the collocated satellite measurements (MIPAS and ACE-FTS) in the southern tropics. The SF6 annual growth rate from FTIR retrievals is 0.265 ± 0.013 pptv/year for 2004–2016, which is slightly weaker than that from the SMO in-situ measurements (0.285 ± 0.002 pptv/year) for the same time period. The SF6 trend in the troposphere from MIPAS and ACE-FTS observations is also close to the ones from the FTIR retrievals and the SMO in-situ measurements.

scholarly journals Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

2009 ◽  
Vol 9 (6) ◽  
pp. 24587-24628 ◽  
Author(s):  
S. Borrmann ◽  
D. Kunkel ◽  
R. Weigel ◽  
A. Minikin ◽  
T. Deshler ◽  
...  
Keyword(s):  
West Africa ◽  
Particle Number ◽  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Submicron Particles ◽  
Volatile Fraction ◽  
Vertical Profiles ◽  
Number Density ◽  
Long Distance

Abstract. Processes occurring in the tropical upper troposphere and lower stratosphere (UT/LS) are of importance for the global climate, for the stratospheric dynamics and air chemistry, and they influence the global distribution of water vapour, trace gases and aerosols. The mechanisms underlying cloud formation and variability in the UT/LS are of scientific concern as these still are not adequately described and quantified by numerical models. Part of the reasons for this is the scarcity of detailed in-situ measurements in particular from the Tropical Transition Layer (TTL) within the UT/LS. In this contribution we provide measurements of particle number densities and the amounts of non-volatile particles in the submicron size range present in the UT/LS over Southern Brazil, West Africa, and Northern Australia. The data were collected in-situ on board of the Russian high altitude research aircraft M-55 "Geophysica" using the specialised COPAS (COndensation PArticle counting System) instrument during the TROCCINOX (Araçatuba, Brazil, February 2005), the SCOUT-O3 (Darwin, Australia, December 2005), and SCOUT-AMMA (Ouagadougou, Burkina Faso, August 2006) campaigns. The vertical profiles obtained are compared to those from previous measurements from the NASA DC-8 and NASA WB-57F over Costa Rica and other tropical locations between 1999 and 2007. The number density of the submicron particles as function of altitude was found to be remarkably constant (even back to 1987) over the tropical UT/LS altitude band such that a parameterisation suitable for models can be extracted from the measurements. At altitudes corresponding to potential temperatures above 430 K a slight increase of the number densities from 2005/2006 results from the data in comparison to the 1987 to 2007 measurements. The origins of this increase are unknown. By contrast the data from Northern hemispheric mid latitudes do not exhibit such an increase between 1999 and 2006. Vertical profiles of the non-volatile fraction of the submicron particles were also measured by a COPAS channel and are presented here. The resulting profiles of the non-volatile number density fraction show a pronounced maximum of 50% in the tropical TTL over Australia and West Africa. Below and above this fraction is much lower attaining values of 10% and smaller. In the lower stratosphere the fine particles mostly consist of sulphuric acid which is reflected in the low numbers of non-volatile residues measured by COPAS. Without detailed chemical composition measurements the reason for the increase of non-volatile particle fractions cannot yet be given. The long distance transfer flights to Brazil, Australia and West-Africa were executed during a time window of 17 months within a period of relative volcanic quiescence. Thus the data measured during these transfers represent a "snapshot picture" documenting the status of a significant part of the global UT/LS aerosol (with sizes below 1 μm) at low concentration levels 15 years after the last major (i.e., the 1991 Mount Pinatubo) eruption. The corresponding latitudinal distributions of the measured particle number densities are also presented in this paper in order to provide input on the UT/LS background aerosol for modelling purposes.

Ozone variability and trends in the UTLS derived from the IAGOS- CARIBIC observatory using JETPAC

2020 ◽  
Author(s):  
Harald Boenisch ◽  
Andreas Zahn ◽  
Luis Millan
Keyword(s):  
Water Vapour ◽  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Research Infrastructure ◽  
European Research ◽  
Coordinate Systems ◽  
Upper Troposphere ◽  
Work In Progress

&lt;p&gt;The CARIBIC (Civil &amp;#160;Aircraft &amp;#160;for &amp;#160;the &amp;#160;Regular &amp;#160;Investigation &amp;#160;of the atmosphere Based on an&amp;#160;&lt;br&gt;Instrumented Container) project is part of the a European research infrastructure IAGOS (In-&lt;br&gt;Service Aircraft for a Global Observing System) making regular in-situ measurements of more&amp;#160;&lt;br&gt;than 100 atmospheric constituents, include ozone and water vapour, on-board of an in-service&amp;#160;&lt;br&gt;passenger &amp;#160;aircraft &amp;#160;operated &amp;#160;by &amp;#160;Lufthansa. &amp;#160;The &amp;#160;dataset &amp;#160;of &amp;#160;the &amp;#160;IAGOS-CARIBIC &amp;#160;is &amp;#160;therefore&amp;#160;&lt;br&gt;ideally suited as a testbed for the SPARC (Stratosphere-troposphere Processes And their Role&amp;#160;&lt;br&gt;in Climate) activity OCTAV-UTLS (Observed Composition Trends And Variability in the Upper&amp;#160;&lt;br&gt;Troposphere and Lower Stratosphere). One key aspect, shown here as work in progress, is to&amp;#160;&lt;br&gt;develop, define and apply common metrics for the comparison of different UTLS datasets&amp;#160;&lt;br&gt;using a variety of meteorological coordinate systems derived from reanalysis datasets. The&amp;#160;&lt;br&gt;focus here is on the variability of ozone in the upper troposphere and lower stratosphere&amp;#160;&lt;br&gt;(UTLS) on interannual and seasonal timescales and the observed trends. The in-situ ozone&amp;#160;&lt;br&gt;measurements by IAGOS-CARIBIC are analysed relative to different tropopause definitions&amp;#160;&lt;br&gt;and coordinate systems. All these meteorological information applied here are produced with&amp;#160;&lt;br&gt;the JETPAC tool &amp;#8210; Jet and Tropopause Products for Analysis and Characterization (Manney et&amp;#160;&lt;br&gt;al., 2011).&lt;/p&gt;

In situ measurements of HNO3, NOy, NO, and O3 in the lower stratosphere and upper troposphere

2001 ◽  
Vol 35 (33) ◽  
pp. 5789-5797 ◽  
Author(s):  
J.A. Neuman ◽  
R.S. Gao ◽  
D.W. Fahey ◽  
J.C. Holecek ◽  
B.A. Ridley ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Upper Troposphere

Airborne gas chromatograph for in situ measurements of long-lived species in the upper troposphere and lower stratosphere

1996 ◽  
Vol 23 (4) ◽  
pp. 347-350 ◽  
Author(s):  
J. W. Elkins ◽  
D. W. Fahey ◽  
J. M. Gilligan ◽  
G. S. Dutton ◽  
T. J. Baring ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements ◽  
Gas Chromatograph ◽  
Upper Troposphere

The NOx−HNO3System in the Lower Stratosphere:  Insights from In Situ Measurements and Implications of theJHNO3−[OH] Relationship

2001 ◽  
Vol 105 (9) ◽  
pp. 1521-1534 ◽  
Author(s):  
K. K. Perkins ◽  
T. F. Hanisco ◽  
R. C. Cohen ◽  
L. C. Koch ◽  
R. M. Stimpfle ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
In Situ Measurements
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