In situ measurements of BrO in the Arctic stratosphere

1990 ◽  
Vol 17 (4) ◽  
pp. 513-516 ◽  
Author(s):  
D. W. Toohey ◽  
J. G. Anderson ◽  
W. H. Brune ◽  
K. R. Chan
Keyword(s):  
In Situ Measurements ◽  
The Arctic

scholarly journals Sentinel-1 SAR Interferometry for Surface Deformation Monitoring in Low-Land Permafrost Areas

2018 ◽  
Vol 10 (9) ◽  
pp. 1360 ◽  
Author(s):  
Tazio Strozzi ◽  
Sofia Antonova ◽  
Frank Günther ◽  
Eva Mätzler ◽  
Gonçalo Vieira ◽  
...  
Keyword(s):  
Time Series ◽  
Surface Displacement ◽  
Deformation Monitoring ◽  
In Situ Measurements ◽  
River Delta ◽  
Sar Interferometry ◽  
The Arctic ◽  
Lena River ◽  
Lena River Delta

Low-land permafrost areas are subject to intense freeze-thaw cycles and characterized by remarkable surface displacement. We used Sentinel-1 SAR interferometry (InSAR) in order to analyse the summer surface displacement over four spots in the Arctic and Antarctica since 2015. Choosing floodplain or outcrop areas as the reference for the InSAR relative deformation measurements, we found maximum subsidence of about 3 to 10 cm during the thawing season with generally high spatial variability. Sentinel-1 time-series of interferograms with 6–12 day time intervals highlight that subsidence is often occurring rather quickly within roughly one month in early summer. Intercomparison of summer subsidence from Sentinel-1 in 2017 with TerraSAR-X in 2013 over part of the Lena River Delta (Russia) shows a high spatial agreement between both SAR systems. A comparison with in-situ measurements for the summer of 2014 over the Lena River Delta indicates a pronounced downward movement of several centimetres in both cases but does not reveal a spatial correspondence between InSAR and local in-situ measurements. For the reconstruction of longer time-series of deformation, yearly Sentinel-1 interferograms from the end of the summer were considered. However, in order to infer an effective subsidence of the surface through melting of excess ice layers over multi-annual scales with Sentinel-1, a longer observation time period is necessary.

scholarly journals Numerical simulation of extreme snow melt observed at the SIGMA-A site, northwest Greenland, during summer 2012

2015 ◽  
Vol 9 (1) ◽  
pp. 495-539
Author(s):  
M. Niwano ◽  
T. Aoki ◽  
S. Matoba ◽  
S. Yamaguchi ◽  
T. Tanikawa ◽  
...  
Keyword(s):  
Heat Flux ◽  
Grain Size ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
In Situ Measurements ◽  
The Arctic ◽  
Snow Surface ◽  
Near Surface ◽  
Surface Snow

Abstract. The surface energy balance (SEB) from 30 June to 14 July 2012 at site SIGMA (Snow Impurity and Glacial Microbe effects on abrupt warming in the Arctic)-A, (78°03' N, 67°38' W; 1490 m a.s.l.) on the northwest Greenland Ice Sheet (GrIS) was investigated by using in situ atmospheric and snow measurements, as well as numerical modeling with a one-dimensional, multi-layered, physical snowpack model called SMAP (Snow Metamorphism and Albedo Process). At SIGMA-A, remarkable near-surface snowmelt and continuous heavy rainfall (accumulated precipitation between 10 and 14 July was estimated to be 100 mm) were observed after 10 July 2012. Application of the SMAP model to the GrIS snowpack was evaluated based on the snow temperature profile, snow surface temperature, surface snow grain size, and shortwave albedo, all of which the model simulated reasonably well. However, comparison of the SMAP-calculated surface snow grain size with in situ measurements during the period when surface hoar with small grain size was observed on-site revealed that it was necessary to input air temperature, relative humidity, and wind speed data from two heights to simulate the latent heat flux into the snow surface and subsequent surface hoar formation. The calculated latent heat flux was always directed away from the surface if data from only one height were input to the SMAP model, even if the value for roughness length of momentum was perturbed between the possible maximum and minimum values in numerical sensitivity tests. This result highlights the need to use two-level atmospheric profiles to obtain realistic latent heat flux. Using such profiles, we calculated the SEB at SIGMA-A from 30 June to 14 July 2012. Radiation-related fluxes were obtained from in situ measurements, whereas other fluxes were calculated with the SMAP model. By examining the components of the SEB, we determined that low-level clouds accompanied by a significant temperature increase played an important role in the melt event observed at SIGMA-A. These conditions induced a remarkable surface heating via cloud radiative forcing in the polar region.

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 In situ measurements of mesospheric turbulence during spring transition of the Arctic mesosphere

2002 ◽  
Vol 29 (10) ◽  
pp. 115-1-115-4 ◽  
Author(s):  
Arno Müllemann ◽  
Markus Rapp ◽  
Franz-Josef Lübken ◽  
Peter Hoffmann
Keyword(s):  
In Situ Measurements ◽  
The Arctic ◽  
Spring Transition

Vertical distribution of aerosol particles over the Russian Arctic derived from in-situ aircraft measurements: the September 2020 campaign

2021 ◽  
Author(s):  
Mikhail Yu. Arshinov ◽  
Boris Belan ◽  
Denis Davydov ◽  
Artem Kozlov ◽  
Alexandr Fofonov
Keyword(s):  
Vertical Distribution ◽  
Lower Troposphere ◽  
In Situ Measurements ◽  
The Arctic ◽  
Future Climate Change ◽  
Russian Arctic ◽  
Size Distributions ◽  
Cloudy Weather ◽  
Wide Range

<p>The Arctic is warming much faster than other regions of the globe. In 2020, temperature anomalies in the Russian Arctic reached unprecedented high levels. The atmospheric composition in this key region still remains insufficiently studied that makes difficult predicting future climate change.</p><p>In September 2020, an extensive aircraft campaign was conducted to document the tropospheric composition over the Russian Arctic. The Optik Tu-134 research aircraft was equipped with instruments to carry out in-situ measurements of trace gases and aerosols, as well as with a lidar for profiling of aerosol backscatter. The aircraft flew over a vast area from Arkhangelsk to Anadyr. Six measurement flights with changing altitudes from 0.2 to 9.0 m were conducted over the waters of the Barents, Kara, Laptev, East Siberian, Chukchi, and Bering Seas. The weather was unusually warm for this period of the year, surface air temperatures were above 0°C through the campaign.</p><p>Here, we present the results of in-situ measurements of the vertical distribution of aerosol number concentrations in a wide range of sizes. A modified diffusional particle sizer (DPS) consisted of the Novosibirsk-type eight-stage screen diffusion battery connected to the TSI condensation particle counter Model 3756 was used to determine the number size distribution of particles between 0.003 mm and 0.2 mm (20 size bins). Distribution of particles in the size range from 0.25 µm to 32 µm (31 size bins) was measured by means of the Grimm aerosol spectrometer Model 1.109.</p><p>The flights over Barents and Kara Seas were predominantly performed under clear sky or partly cloudy weather conditions. Number size distributions were wide representing particles of almost all aerosol fractions. When flying in the upper troposphere with a constant altitude over these seas, some cases of enhanced concentrations of nucleation and Aitken mode particles comparable to ones in the lower troposphere were recorded, suggesting in situ new particle formation was likely to be taking place via gas-to-particle conversion aloft.</p><p>East of the Kara Sea, flights were conducted under mostly cloudy conditions resulting in a lower median aerosol number concentration and narrower size distributions.</p><p>This work was supported by the Russian Foundation for Basic Research (Grant No. 19-05-50024).</p>

scholarly journals In situ measurements of stratospheric ozone depletion rates in the Arctic winter 1991/1992: A Lagrangian approach

1998 ◽  
Vol 103 (D5) ◽  
pp. 5843-5853 ◽  
Author(s):  
M. Rex ◽  
P. von der Gathen ◽  
N. R. P. Harris ◽  
D. Lucic ◽  
B. M. Knudsen ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
In Situ Measurements ◽  
Lagrangian Approach ◽  
The Arctic ◽  
Stratospheric Ozone Depletion

scholarly journals Nitric Acid Trihydrate (NAT) formation at low NAT supersaturation in Polar Stratospheric Clouds (PSCs)

2005 ◽  
Vol 5 (5) ◽  
pp. 1371-1380 ◽  
Author(s):  
C. Voigt ◽  
H. Schlager ◽  
B. P. Luo ◽  
A. Dörnbrack ◽  
A. Roiger ◽  
...  
Keyword(s):  
Nitric Acid ◽  
High Altitude ◽  
Equilibrium Temperature ◽  
In Situ Measurements ◽  
The Arctic ◽  
Polar Stratospheric Clouds ◽  
Research Aircraft ◽  
Stratospheric Clouds ◽  
Polar Ozone

Abstract. A PSC was detected on 6 February 2003 in the Arctic stratosphere by in-situ measurements onboard the high-altitude research aircraft Geophysica. Low number densities (~10-4cm-3) of small nitric acid (HNO3) containing particles (d<6µm) were observed at altitudes between 18 and 20km. Provided the temperatures remain below the NAT equilibrium temperature TNAT, these NAT particles have the potential to grow further and to remove HNO3 from the stratosphere, thereby enhancing polar ozone loss. Interestingly, the NAT particles formed in less than a day at temperatures just slightly below TNAT (T>TNAT-3.1K). This unique measurement of PSC formation at extremely low NAT saturation ratios (SNAT≤10) constrains current NAT nucleation theories. We suggest, that the NAT particles have formed heterogeneously, but for certain not on ice. Conversely, meteoritic particles may be favorable candidates for triggering NAT nucleation at the observed low number densities.

scholarly journals Nitric acid trihydrate (NAT) formation at low NAT supersaturations

2004 ◽  
Vol 4 (6) ◽  
pp. 8579-8607 ◽  
Author(s):  
C. Voigt ◽  
H. Schlager ◽  
B. P. Luo ◽  
A. Dörnbrack ◽  
A. Roiger ◽  
...  
Keyword(s):  
Nitric Acid ◽  
High Altitude ◽  
Equilibrium Temperature ◽  
In Situ Measurements ◽  
The Arctic ◽  
Ozone Loss ◽  
Polar Stratospheric Cloud ◽  
Research Aircraft ◽  
Polar Ozone

Abstract. A polar stratospheric cloud (PSC) was observed on 6 February 2003 in the Arctic stratosphere by in-situ measurements onboard the high-altitude research aircraft Geophysica. Low number densities (~10−4 cm−3) of nitric acid (HNO3) containing particles – probably NAT – with diameters up to 6 µm were measured at altitudes between 18 and 20 km. These particles have the potential to grow further and to remove HNO3 from the stratosphere, thereby enhancing polar ozone loss. Interestingly, the NAT particles formed in less than a day at temperatures T>TNAT−3.5 K, just slightly below the NAT equilibrium temperature TNAT. This unique measurement of PSC formation at extremely low NAT saturation ratios (SNAT≤11) constrains current NAT nucleation theories. In particular, NAT formation on ice can for certain be excluded. Conversely, we suggest that meteoritic particles may be favorable candidates for triggering nucleation of NAT at the observed low number densities.

scholarly journals A test of our understanding of the ozone chemistry in the Arctic polar vortex based on in situ measurements of ClO, BrO, and O3in the 1994/1995 winter

1999 ◽  
Vol 104 (D15) ◽  
pp. 18755-18768 ◽  
Author(s):  
Thomas Woyke ◽  
Rolf Müller ◽  
Fred Stroh ◽  
Daniel S. McKenna ◽  
Andreas Engel ◽  
...  
Keyword(s):  
Polar Vortex ◽  
In Situ Measurements ◽  
The Arctic

scholarly journals Improved water vapour retrieval from AMSU-B and MHS in the Arctic

2020 ◽  
Vol 13 (7) ◽  
pp. 3697-3715
Author(s):  
Arantxa M. Triana-Gómez ◽  
Georg Heygster ◽  
Christian Melsheimer ◽  
Gunnar Spreen ◽  
Monia Negusini ◽  
...  
Keyword(s):  
Water Vapour ◽  
In Situ Measurements ◽  
The Arctic ◽  
Retrieval Algorithm ◽  
Polar Regions ◽  
Climate Trends ◽  
Arctic Conditions ◽  
Integrated Water Vapour ◽  
Ice Content

Abstract. Monitoring of water vapour in the Arctic on long timescales is essential for predicting Arctic weather and understanding climate trends, as well as addressing its influence on the positive feedback loop contributing to Arctic amplification. However, this is challenged by the sparseness of in situ measurements and the problems that standard remote sensing retrieval methods for water vapour have in Arctic conditions. Here, we present advances in a retrieval algorithm for vertically integrated water vapour (total water vapour, TWV) in polar regions from data of satellite-based microwave humidity sounders: (1) in addition to AMSU-B (Advanced Microwave Sounding Unit-B), we can now also use data from the successor instrument MHS (Microwave Humidity Sounder), and (2) artefacts caused by high cloud ice content in convective clouds are filtered out. Comparison to in situ measurements using GPS and radiosondes during 2008 and 2009, as well as to radiosondes during the N-ICE2015 campaign and to ERA5 reanalysis, show the overall good performance of the updated algorithm.

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