The Moon as a light source for FTIR measurements of stratospheric trace gases during the polar night: Application for HNO3in the Arctic

1994 ◽  
Vol 99 (D2) ◽  
pp. 3607 ◽  
Author(s):  
J. Notholt
Keyword(s):  
Light Source ◽  
Trace Gases ◽  
The Arctic ◽  
The Moon ◽  
Polar Night ◽  
Stratospheric Trace Gases

stratospheric trace gas concentrations in the Arctic polar night derived by FTIR-spectroscopy with the Moon as IR light source

1993 ◽  
Vol 20 (19) ◽  
pp. 2059-2062 ◽  
Author(s):  
J. Notholt ◽  
R. Neuber ◽  
O. Schrems ◽  
T. V. Clarmann
Keyword(s):  
Ftir Spectroscopy ◽  
Light Source ◽  
The Arctic ◽  
Trace Gas ◽  
The Moon ◽  
Polar Night ◽  
Ir Light

scholarly journals Polar night retrievals of trace gases in the Arctic using the Extended-range Atmospheric Emitted Radiance Interferometer

2013 ◽  
Vol 6 (1) ◽  
pp. 547-586
Author(s):  
Z. Mariani ◽  
K. Strong ◽  
M. Palm ◽  
R. Lindenmaier ◽  
C. Adams ◽  
...  
Keyword(s):  
Sea Level ◽  
Trace Gases ◽  
The Other ◽  
The Arctic ◽  
Retrieval Algorithm ◽  
Polar Night ◽  
Lower Altitude ◽  
Extended Range ◽  
Ch4 And N2o ◽  
Total Column

Abstract. The Extended-range Atmospheric Emitted Radiance Interferometer (E-AERI) was installed at the Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka, Nunavut, Canada in October 2008. Spectra from the E-AERI provide information about the radiative balance and budgets of trace gases in the Canadian high Arctic. Measurements are taken every seven minutes year-round, including polar night when the solar-viewing spectrometers at PEARL are not operated. This allows E-AERI measurements to fill the gap in the PEARL dataset during the four months of polar night. Measurements were taken year-round in 2008–2009 at the PEARL Ridge Lab, which is 610 m above sea-level, and from 2011-onwards at the Zero-Altitude PEARL Auxiliary Lab (0PAL), which is 15 km from the Ridge Lab at sea level. Total columns of O3, CO, CH4, and N2O have been retrieved using a modified version of the SFIT2 retrieval algorithm adapted for emission spectra. This provides the first nighttime measurements of these species at Eureka. Changes in the total columns driven by photochemistry and dynamics are observed. Analyses of E-AERI retrievals indicate accurate spectral fits (root-mean-square residuals < 1.5%) and a 10–15% uncertainty in the total column, depending on the trace gas. O3 comparisons between the E-AERI and a Bruker IFS 125HR Fourier transform infrared (FTIR) spectrometer, three Brewer spectrophotometers, two UV-visible ground-based spectrometers, and a System D'Analyse par Observations Zenithales (SAOZ) at PEARL are made from 2008–2009 and for 2011. 125HR CO, CH4, and N2O columns are also compared with the E-AERI measurements. Mean relative differences between the E-AERI and the other spectrometers are 1–14% (depending on the gas), which are less than the E-AERI's total column uncertainties. The E-AERI O3 and CO measurements are well correlated with the other spectrometers; the best correlation is with the 125HR (r > 0.92). The 24-h diurnal cycle and 365-day seasonal cycle of CO are observed and their amplitudes are quantified by the E-AERI (6–12% and 46%, respectively). The seasonal variability of H2O has an impact on the retrievals, leading to larger uncertainties in the summer months. Despite increased water vapour at the lower-altitude site 0PAL, measurements at 0PAL are consistent with measurements at PEARL.

Stratospheric OClO observed with ground-based DOAS over Kiruna in the Arctic winters 1996/1997 – 2019/2020

2021 ◽  
Author(s):  
Myojeong Gu ◽  
Carl-Fredrik Enell ◽  
Janis Pukite ◽  
Ulrich Platt ◽  
Uwe Raffalski ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Trace Gases ◽  
Polar Vortex ◽  
The Arctic ◽  
Future Evolution ◽  
Measurement Site ◽  
Remote Sensing Techniques ◽  
Stratospheric Trace Gases ◽  
Do So

&lt;p&gt;Recent research on stratospheric ozone indicates signs of ozone recovery, but on the other hand, ozone recovery is also expected to be delayed by many aspects (e.g climate change). Therefore, it is important to monitor continuously stratospheric trace gases to predict the future evolution of the Arctic ozone and other trace gases which are involved in the ozone depletion chemistry. OClO is well known as an indicator of the stratospheric chlorine activation and can be measured using remote sensing techniques.&lt;/p&gt;&lt;p&gt;In this study, we present long-term measurements of OClO slant column densities at Kiruna, Sweden (67.84&amp;#176;N, 20.41&amp;#176;E) which were obtained from the ground-based zenith sky DOAS instruments since 1997. The measurement site is located north of the polar circle in which the variability of the OClO abundance depends on the state of stratospheric chlorine activation but also whether the polar vortex is located above the measurement site.&lt;/p&gt;&lt;p&gt;The aim of this study is to give an overview of the measured stratospheric OClO abundance for 19 years, and to investigate the dominant parameters affecting ozone and OClO during periods of stratospheric chlorine activation. One particular focus is on the parameters which trigger the activation and de-activation at the beginning and the end of the polar winter.&lt;/p&gt;&lt;p&gt;To do so, we compare the general dependencies of OClO on other trace gases and meteorological conditions.&lt;/p&gt;

scholarly journals Year-round retrievals of trace gases in the Arctic using the Extended-range Atmospheric Emitted Radiance Interferometer

2013 ◽  
Vol 6 (6) ◽  
pp. 1549-1565 ◽  
Author(s):  
Z. Mariani ◽  
K. Strong ◽  
M. Palm ◽  
R. Lindenmaier ◽  
C. Adams ◽  
...  
Keyword(s):  
Sea Level ◽  
Trace Gases ◽  
The Other ◽  
The Arctic ◽  
Retrieval Algorithm ◽  
Polar Night ◽  
Lower Altitude ◽  
Extended Range ◽  
Ch4 And N2o ◽  
Total Column

Abstract. The Extended-range Atmospheric Emitted Radiance Interferometer (E-AERI) was installed at the Polar Environment Atmospheric Research Laboratory (PEARL) at Eureka, Nunavut, Canada in October 2008. Spectra from the E-AERI provide information about the radiative balance and budgets of trace gases in the Canadian high Arctic. Measurements are taken every 7 min year-round, including polar night when the solar-viewing spectrometers at PEARL are not operated. This allows E-AERI measurements to fill the gap in the PEARL dataset during the four months of polar night. Measurements were taken year-round in 2008–2009 at the PEARL Ridge Lab, which is 610 m a.s.l. (above sea-level), and from 2011 onwards at the Zero-Altitude PEARL Auxiliary Lab (0PAL), which is at sea level 15 km from the Ridge Lab. Total columns of O3, CO, CH4, and N2O have been retrieved using a modified version of the SFIT2 retrieval algorithm adapted for emission spectra. This provides the first ground-based nighttime measurements of these species at Eureka. Changes in the total columns driven by photochemistry and dynamics are observed. Analyses of E-AERI retrievals indicate accurate spectral fits (root-mean-square residuals consistent with noise) and a 10–15% uncertainty in the total column, depending on the trace gas. O3 comparisons between the E-AERI and a Bruker IFS 125HR Fourier transform infrared (FTIR) spectrometer, three Brewer spectrophotometers, two UV-visible ground-based spectrometers, and a System D'Analyse par Observations Zenithales (SAOZ) at PEARL are made from 2008–2009 and for 2011. 125HR CO, CH4, and N2O columns are also compared with the E-AERI measurements. Mean relative differences between the E-AERI and the other spectrometers are 1–10% (14% is for the un-smoothed profiles), which are less than the E-AERI's total column uncertainties. The E-AERI O3 and CO measurements are well correlated with the other spectrometers (r > 0.92 with the 125HR). The 24 h diurnal cycle and 365-day seasonal cycle of CO are observed and their amplitudes are quantified by the E-AERI (6–12 and 46%, respectively). The seasonal variability of H2O has an impact on the retrievals, leading to larger uncertainties in the summer months. Despite increased water vapour at the lower-altitude site 0PAL, measurements at 0PAL are consistent with measurements at PEARL.

The Visibility of Stars during Twilight

1957 ◽  
Vol 10 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Peter M. Millman
Keyword(s):  
Magnetic Compass ◽  
The Arctic ◽  
Relative Importance ◽  
The Moon ◽  
Heavenly Body ◽  
Flight Planning ◽  
Arctic Navigation

One of the problems in arctic navigation by astro is the twilight period. At this time, if the Moon is below the horizon, suitable objects for sextant observation are not easy to find. The difficulty is aggravated by the fact that on certain flight paths the arctic twilight may last for many hours. It must also be remembered that in these areas the behaviour of the magnetic compass and of radio aids are often unreliable and this increases the relative importance of astro-navigation. With the introduction of the periscopic sextant into air navigation it has become possible to pre-set the instrument for a given star or planet and satisfactory observations may be possible when the heavenly body is still below the level of casual perception for the unaided eye. In this connection it is necessary to know what stars are likely to be seen under twilight conditions if efficient flight-planning is to be carried out.

Development of a new methodology for the retrieval of in-situ stratospheric trace gases concentration from airborne limb-absorption measurements

2002 ◽  
Author(s):  
Andrea Petritoli ◽  
Giorgio Giovanelli ◽  
Fabrizio Ravegnani ◽  
Daniele Bortoli ◽  
Ivan K. Kostadinov ◽  
...  
Keyword(s):  
Trace Gases ◽  
Stratospheric Trace Gases ◽  
Absorption Measurements

scholarly journals The wintertime two-day wave in the polar stratosphere, mesosphere and lower thermosphere

2008 ◽  
Vol 8 (3) ◽  
pp. 749-755 ◽  
Author(s):  
D. J. Sandford ◽  
M. J. Schwartz ◽  
N. J. Mitchell
Keyword(s):  
Lower Thermosphere ◽  
Radar Data ◽  
The Arctic ◽  
Horizontal Wind ◽  
Meteor Radar ◽  
Polar Night ◽  
Zonal Wavenumber ◽  
Mesosphere And Lower Thermosphere ◽  
Polar Stratosphere ◽  
Striking Contrast

Abstract. Recent observations of the polar mesosphere have revealed that waves with periods near two days reach significant amplitudes in both summer and winter. This is in striking contrast to mid-latitude observations where two-day waves maximise in summer only. Here, we use data from a meteor radar at Esrange (68° N, 21° E) in the Arctic and data from the MLS instrument aboard the EOS Aura satellite to investigate the wintertime polar two-day wave in the stratosphere, mesosphere and lower thermosphere. The radar data reveal that mesospheric two-day wave activity measured by horizontal-wind variance has a semi-annual cycle with maxima in winter and summer and equinoctial minima. The MLS data reveal that the summertime wave in the mesosphere is dominated by a westward-travelling zonal wavenumber three wave with significant westward wavenumber four present. It reaches largest amplitudes at mid-latitudes in the southern hemisphere. In the winter polar mesosphere, however, the wave appears to be an eastward-travelling zonal wavenumber two, which is not seen during the summer. At the latitude of Esrange, the eastward-two wave reaches maximum amplitudes near the stratopause and appears related to similar waves previously observed in the polar stratosphere. We conclude that the wintertime polar two-day wave is the mesospheric manifestation of an eastward-propagating, zonal-wavenumber-two wave originating in the stratosphere, maximising at the stratopause and likely to be generated by instabilities in the polar night jet.

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