scholarly journals Deep convective injection of boundary layer air into the lowermost stratosphere at midlatitudes

2002 ◽  
Vol 2 (6) ◽  
pp. 2003-2019 ◽  
Author(s):  
H. Fischer ◽  
M. de Reus ◽  
M. Traub ◽  
J. Williams ◽  
J. Lelieveld ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Background Concentrations ◽  
Upper Troposphere ◽  
German Research ◽  
Research Aircraft ◽  
The Mediterranean

Abstract. On 22 August 2001 a measurement flight was performed with the German research aircraft FALCON from Sardinia to Crete as part of the Mediterranean Oxidant Study (MINOS). Cruising at 8.2 km, the aircraft was forced to climb to 11.2 km over the southern tip of Italy to stay clear of the anvil of a large cumulonimbus tower. During ascent into the lowermost stratosphere in-situ measurements onboard the FALCON indicated several sharp increases in the concentrations of tropospheric trace gases, e.g. CO, acetone, methanol, benzene and acetonitrile, above the anvil. During one particular event deep in the stratosphere, at O3 concentrations exceeding 200 ppv, CO increased from about 60 to 90 ppv, while the concentration of acetone and methanol increased by more than a factor of 2 (0.7 to 1.8 ppv for acetone; 0.4 to 1.4 ppv for methanol). Enhancements for the short lived species benzene are even higher, increasing from 20 pptv in the stratosphere to approx. 130 pptv. The concentrations during the event were higher than background concentrations in the upper troposphere, indicating that polluted boundary layer air was directly mixed deep into the lowermost stratosphere.

scholarly journals Deep convective injection of boundary layer air into the lowermost stratosphere at midlatitudes

2003 ◽  
Vol 3 (3) ◽  
pp. 739-745 ◽  
Author(s):  
H. Fischer ◽  
M. de Reus ◽  
M. Traub ◽  
J. Williams ◽  
J. Lelieveld ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Background Concentrations ◽  
Upper Troposphere ◽  
German Research ◽  
Research Aircraft ◽  
The Mediterranean

Abstract. On 22 August 2001 a measurement flight was performed with the German research aircraft FALCON from Sardinia to Crete as part of the Mediterranean Oxidant Study (MINOS). Cruising at 8.2 km, the aircraft was forced to climb to 11.2 km over the southern tip of Italy to stay clear of the anvil of a large cumulonimbus tower. During ascent into the lowermost stratosphere in-situ measurements onboard the FALCON indicated several sharp increases in the concentrations of tropospheric trace gases, e.g. CO, acetone, methanol, benzene and acetonitrile, above the anvil. During one particular event deep in the stratosphere, at O3 concentrations exceeding 200 ppv, CO increased from about 60 to 90 ppv, while the concentration of acetone and methanol increased by more than a factor of 2 (0.7 to 1.8 ppv for acetone; 0.4 to 1.4 ppv for methanol). Enhancements for the short lived species benzene are even higher, increasing from 20 pptv in the stratosphere to approx. 130 pptv. The concentrations during the event were higher than background concentrations in the upper troposphere, indicating that polluted boundary layer air was directly mixed into the lowermost stratosphere.

scholarly journals The Convective Transport of Active Species in the Tropics (CONTRAST) Experiment

2017 ◽  
Vol 98 (1) ◽  
pp. 106-128 ◽  
Author(s):  
L. L. Pan ◽  
E. L. Atlas ◽  
R. J. Salawitch ◽  
S. B. Honomichl ◽  
J. F. Bresch ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Limit Of Detection ◽  
Trace Gases ◽  
Regional Distribution ◽  
Active Species ◽  
Convective Transport ◽  
In Situ Measurements ◽  
Upper Troposphere ◽  
The Tropics

Abstract The Convective Transport of Active Species in the Tropics (CONTRAST) experiment was conducted from Guam (13.5°N, 144.8°E) during January–February 2014. Using the NSF/NCAR Gulfstream V research aircraft, the experiment investigated the photochemical environment over the tropical western Pacific (TWP) warm pool, a region of massive deep convection and the major pathway for air to enter the stratosphere during Northern Hemisphere (NH) winter. The new observations provide a wealth of information for quantifying the influence of convection on the vertical distributions of active species. The airborne in situ measurements up to 15-km altitude fill a significant gap by characterizing the abundance and altitude variation of a wide suite of trace gases. These measurements, together with observations of dynamical and microphysical parameters, provide significant new data for constraining and evaluating global chemistry–climate models. Measurements include precursor and product gas species of reactive halogen compounds that impact ozone in the upper troposphere/lower stratosphere. High-accuracy, in situ measurements of ozone obtained during CONTRAST quantify ozone concentration profiles in the upper troposphere, where previous observations from balloonborne ozonesondes were often near or below the limit of detection. CONTRAST was one of the three coordinated experiments to observe the TWP during January–February 2014. Together, CONTRAST, Airborne Tropical Tropopause Experiment (ATTREX), and Coordinated Airborne Studies in the Tropics (CAST), using complementary capabilities of the three aircraft platforms as well as ground-based instrumentation, provide a comprehensive quantification of the regional distribution and vertical structure of natural and pollutant trace gases in the TWP during NH winter, from the oceanic boundary to the lower stratosphere.

In situ measurements of microphysical properties and trace gases in two cumulonimbus anvils over western Europe

1999 ◽  
Vol 104 (D10) ◽  
pp. 12221-12226 ◽  
Author(s):  
Johan Ström ◽  
Horst Fischer ◽  
Jos Lelieveld ◽  
Franz Schröder
Keyword(s):  
Western Europe ◽  
Trace Gases ◽  
In Situ Measurements ◽  
Microphysical Properties

scholarly journals Observationally constrained analysis of sea salt aerosol in the marine atmosphere

2019 ◽  
Author(s):  
Huisheng Bian ◽  
Karl Froyd ◽  
Daniel M. Murphy ◽  
Jack Dibb ◽  
Mian Chin ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Chemistry ◽  
Marine Boundary Layer ◽  
Model Simulation ◽  
In Situ Measurements ◽  
Sea Salt ◽  
Boreal Summer ◽  
Integrated Analysis ◽  
Marine Atmosphere

Abstract. Atmospheric sea salt plays important roles in marine cloud formation and atmospheric chemistry. We performed an integrated analysis of NASA GEOS model simulations run with the GOCART aerosol module, in situ measurements from the PALMS and SAGA instruments obtained during the NASA ATom campaign, and aerosol optical depth (AOD) measurements from AERONET Marine Aerosol Network (MAN) sun photometers and from MODIS satellite observations to better constrain sea salt in the marine atmosphere. ATom measurements and GEOS model simulation both show that sea salt concentrations over the Pacific and Atlantic oceans have a strong vertical gradient, varying up to four orders of magnitude from the marine boundary layer to free troposphere. The modeled residence times suggest that the lifetime of sea salt particles with dry diameter less than 3 μm is largely controlled by wet removal, followed next by turbulent process. During both boreal summer and winter, the GEOS simulated sea salt mass mixing ratios agree with SAGA measurements in the marine boundary layer (MBL) and with PALMS measurements above the MBL. However, comparison of AOD from GEOS with AERONET/MAN and MODIS aerosol retrievals indicated that the model underestimated AOD over the oceans where sea salt dominates. The apparent discrepancy of slightly overpredicted concentration and large underpredicted AOD could not be explained by biases in the model RH, which was found to be comparable to or larger than the in-situ measurements. This conundrum is at least partially explained by the sea salt size distribution; where the GEOS simulation has much less sea salt percentage-wise in the smaller particles than was observed by PALMS. Model sensitivity experiments indicated that the simulated sea salt is better correlated with measurements when the sea salt emission is calculated based on the friction velocity and with consideration of sea surface temperature dependence than that parameterized with the 10-m winds.

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 Vertical profile of peroxyacetyl nitrate (PAN) from MIPAS-STR measurements over Brazil in February 2005 and its contribution to tropical UT NO<sub>y</sub> partitioning

2008 ◽  
Vol 8 (16) ◽  
pp. 4891-4902 ◽  
Author(s):  
C. Keim ◽  
G. Y. Liu ◽  
C. E. Blom ◽  
H. Fischer ◽  
T. Gulde ◽  
...  
Keyword(s):  
Vertical Profile ◽  
Trace Gases ◽  
Simultaneous Measurements ◽  
Remote Sensor ◽  
Research Aircraft ◽  
Careful Handling ◽  
Tropical Troposphere ◽  
Selection Of ◽  
Made In

Abstract. We report on the retrieval of PAN (CH3C(O)OONO2) in the upper tropical troposphere from limb measurements by the remote-sensor MIPAS-STR on board the Russian high altitude research aircraft M55-Geophysica. The measurements were performed close to Araçatuba, Brazil, on 17 February 2005. The retrieval was made in the spectral range 775–820 cm−1 where PAN exhibits its strongest feature but also more than 10 species interfere. Especially trace gases such as CH3CCl3, CFC-113, CFC-11, and CFC-22, emitting also in spectrally broad not-resolved branches, make the processing of PAN prone to errors. Therefore, the selection of appropriate spectral windows, the separate retrieval of several interfering species and the careful handling of the water vapour profile are part of the study presented. The retrieved profile of PAN has a maximum of about 0.14 ppbv at 10 km altitude, slightly larger than the lowest reported values (<0.1 ppbv) and much lower than the highest reported in the literature (0.65 ppbv). Besides the NOy constituents measured by MIPAS-STR (HNO3, ClONO2, HO2NO2, PAN), the in situ instruments aboard the Geophysica provide simultaneous measurements of NO, NO2, and the sum NOy. Comparing the sum of in-situ and remotely derived NO+NO2+HNO3+ClONO2+HO2NO2+PAN with total NOy a deficit of 30–40% (0.2–0.3 ppbv) in the troposphere remains unexplained whereas the values fit well in the stratosphere.

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