Review of aircraft measurements over China: aerosol, atmospheric photochemistry, and cloud

2020 ◽  
Vol 243 ◽  
pp. 104972
Author(s):  
Jiannong Quan ◽  
Xingcan Jia
Keyword(s):  
Aircraft Measurements ◽  
Atmospheric Photochemistry

scholarly journals Aircraft measurements of polar organic tracer compounds in tropospheric particles (PM<sub>10</sub>) over central China

2014 ◽  
Vol 14 (8) ◽  
pp. 4185-4199 ◽  
Author(s):  
P. Q. Fu ◽  
K. Kawamura ◽  
Y. F. Cheng ◽  
S. Hatakeyama ◽  
A. Takami ◽  
...  
Keyword(s):  
Organic Nitrogen ◽  
Ground Surface ◽  
Organic Aerosol ◽  
Central China ◽  
Gas Chromatography Mass Spectrometry ◽  
Strong Positive Correlation ◽  
Aircraft Measurements ◽  
Nitrogen Species ◽  
West China ◽  
Biological Aerosols

Abstract. Atmospheric aerosol samples were collected by aircraft at low to middle altitudes (0.8–3.5 km a.g.l.) over central East to West China during summer 2003 and spring 2004. The samples were analyzed for polar organic compounds using a technique of solvent extraction/BSTFA derivatization/gas chromatography–mass spectrometry. Biogenic secondary organic aerosol (SOA) tracers from the oxidation of isoprene were found to be more abundant in summer (3.3–138 ng m−3, mean 39 ng m−3) than in spring (3.2–42 ng m−3, 15 ng m−3), while α/β-pinene and β-caryophyllene SOA tracers showed similar abundances between these two seasons. A strong positive correlation (R2 = 0.83) between levoglucosan and β-caryophyllinic acid was found in the spring samples vs. a weak correlation (R2 = 0.17) in the summer samples, implying substantial contributions from biomass burning to the β-caryophyllinic acid production in spring. Two organic nitrogen species (oxamic acid and carbamide) were detected in the aircraft aerosol samples, and their concentrations were comparable to those of biogenic SOA tracers. Most of the primary organic aerosol (POA) and SOA tracers were less abundant at higher altitudes, suggesting they are of ground surface origin, either being directly emitted from anthropogenic/natural sources on the ground surface, or rapidly formed through photooxidation of their precursors emitted from the ground surface and then diluted during uplifting into the troposphere. This study demonstrates that primary biological aerosols, biogenic SOA, and organic nitrogen species are important components of organic aerosols in the troposphere over central China during warm seasons.

scholarly journals A Polar Low Pair over the Norwegian Sea

2009 ◽  
Vol 137 (8) ◽  
pp. 2559-2575 ◽  
Author(s):  
Burghard Brümmer ◽  
Gerd Müller ◽  
Gunnar Noer
Keyword(s):  
Heat Budget ◽  
Cloud Layer ◽  
Sea Surface ◽  
Cloud Base ◽  
Aircraft Measurements ◽  
Polar Lows ◽  
The North ◽  
Polar Low ◽  
Upper Level Jet ◽  
Almost All

Abstract During the Lofotes cyclone experiment (LOFZY 2005), two polar lows developed one behind the other inside a cold-air outbreak from the north in the lee of Spitsbergen on 7 March 2005. Buoys, ship, and aircraft measurements as well as satellite imagery are applied to analyze the polar low bulk properties, the horizontal and vertical structure, and the mass, moisture, and heat budget. The lifetime of the system until landfall at northern Norway was 12 h. The generation occurred under the left exit region of an upper-level jet with 70 m s−1. Both polar lows had a radius of 100–130 km and extended to a height of about 2.5 km. The propagation speeds were within 14–17 m s−1 and correspond to the vertically averaged wind velocity of the lowest 2.5 km. In the polar low centers the pressure was about 2–3 hPa lower and the air was 1–2 K warmer and drier than in the surroundings. Aircraft measurements in the second of the two polar lows show an embedded frontlike precipitation band north of the center. Here, the highest low-level winds with 25 m s−1 and the largest fluxes of sensible and latent heat with 290 and 520 W m−2, respectively, were measured (areal averages amounted to 115 and 190 W m−2). Aircraft data show mass convergence in the subcloud layer (0–900 m) and divergence in the cloud layer (900–2500 m). Moisture supply by evaporation from the sea surface was about twice as large as that by convergence in the subcloud layer. The condensation rate in the cloud layer nearly equaled the rate of evaporation at the sea surface. Almost all condensed cloud water was converted to precipitation water. Only half of the precipitation at the cloud base reached the sea surface.

scholarly journals Aircraft measurements of gravity waves in the upper troposphere and lower stratosphere during the START08 field experiment

2015 ◽  
Vol 15 (13) ◽  
pp. 7667-7684 ◽  
Author(s):  
Fuqing Zhang ◽  
Junhong Wei ◽  
Meng Zhang ◽  
K. P. Bowman ◽  
L. L. Pan ◽  
...  
Keyword(s):  
Power Law ◽  
Gravity Waves ◽  
Lower Stratosphere ◽  
Potential Temperature ◽  
Shear Instability ◽  
Aircraft Measurements ◽  
Upper Troposphere ◽  
Airborne Measurements ◽  
Wide Range

Abstract. This study analyzes in situ airborne measurements from the 2008 Stratosphere–Troposphere Analyses of Regional Transport (START08) experiment to characterize gravity waves in the extratropical upper troposphere and lower stratosphere (ExUTLS). The focus is on the second research flight (RF02), which took place on 21–22 April 2008. This was the first airborne mission dedicated to probing gravity waves associated with strong upper-tropospheric jet–front systems. Based on spectral and wavelet analyses of the in situ observations, along with a diagnosis of the polarization relationships, clear signals of mesoscale variations with wavelengths ~ 50–500 km are found in almost every segment of the 8 h flight, which took place mostly in the lower stratosphere. The aircraft sampled a wide range of background conditions including the region near the jet core, the jet exit and over the Rocky Mountains with clear evidence of vertically propagating gravity waves of along-track wavelength between 100 and 120 km. The power spectra of the horizontal velocity components and potential temperature for the scale approximately between ~ 8 and ~ 256 km display an approximate −5/3 power law in agreement with past studies on aircraft measurements, while the fluctuations roll over to a −3 power law for the scale approximately between ~ 0.5 and ~ 8 km (except when this part of the spectrum is activated, as recorded clearly by one of the flight segments). However, at least part of the high-frequency signals with sampled periods of ~ 20–~ 60 s and wavelengths of ~ 5–~ 15 km might be due to intrinsic observational errors in the aircraft measurements, even though the possibilities that these fluctuations may be due to other physical phenomena (e.g., nonlinear dynamics, shear instability and/or turbulence) cannot be completely ruled out.

Real-time estimation of atmospheric turbulence severity from in-situ aircraft measurements

1995 ◽  
Vol 32 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Larry B. Cornman ◽  
Corinne S. Morse ◽  
Gary Cunning
Keyword(s):  
Real Time ◽  
Atmospheric Turbulence ◽  
Time Estimation ◽  
Aircraft Measurements ◽  
Real Time Estimation

scholarly journals A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor

2016 ◽  
Vol 9 (2) ◽  
pp. 423-440 ◽  
Author(s):  
K.-E. Min ◽  
R. A. Washenfelder ◽  
W. P. Dubé ◽  
A. O. Langford ◽  
P. M. Edwards ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Cross Sections ◽  
Nitrous Acid ◽  
Aircraft Measurements ◽  
Charge Coupled Device ◽  
Light Emitting ◽  
Enhanced Absorption ◽  
Field Campaigns ◽  
A Charge ◽  
Absorption Spectrometer

Abstract. We describe a two-channel broadband cavity enhanced absorption spectrometer (BBCEAS) for aircraft measurements of glyoxal (CHOCHO), methylglyoxal (CH3COCHO), nitrous acid (HONO), nitrogen dioxide (NO2), and water (H2O). The instrument spans 361–389 and 438–468 nm, using two light-emitting diodes (LEDs) and a single grating spectrometer with a charge-coupled device (CCD) detector. Robust performance is achieved using a custom optical mounting system, high-power LEDs with electronic on/off modulation, high-reflectivity cavity mirrors, and materials that minimize analyte surface losses. We have successfully deployed this instrument during two aircraft and two ground-based field campaigns to date. The demonstrated precision (2σ) for retrievals of CHOCHO, HONO and NO2 are 34, 350, and 80 parts per trillion (pptv) in 5 s. The accuracy is 5.8, 9.0, and 5.0 %, limited mainly by the available absorption cross sections.

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