28 research outputs found
Nitrogen dioxide and formaldehyde measurements from the GEOstationary Coastal and Air Pollution Events (GEO-CAPE) Airborne Simulator over Houston, Texas
The GEOstationary Coastal and Air Pollution Events (GEO-CAPE)
Airborne Simulator (GCAS) was developed in support of NASA's decadal survey
GEO-CAPE geostationary satellite mission. GCAS is an airborne push-broom
remote-sensing instrument, consisting of two channels which make
hyperspectral measurements in the ultraviolet/visible (optimized for air
quality observations) and the visibleânear infrared (optimized for ocean
color observations). The GCAS instrument participated in its first intensive
field campaign during the Deriving Information on Surface Conditions from
Column and Vertically Resolved Observations Relevant to Air Quality
(DISCOVER-AQ) campaign in Texas in September 2013. During this campaign, the
instrument flew on a King Air B-200 aircraft during 21Â flights on 11Â days to
make air quality observations over Houston, Texas. We present GCAS trace gas
retrievals of nitrogen dioxide (NO2) and formaldehyde
(CH2O), and compare these results with trace gas columns derived
from coincident in situ profile measurements of NO2 and
CH2O made by instruments on a P-3B aircraft, and with NO2
observations from ground-based Pandora spectrometers operating in direct-sun
and scattered light modes. GCAS tropospheric column measurements correlate
well spatially and temporally with columns estimated from the P-3B
measurements for both NO2 (r2â=â0.89) and CH2O
(r2â=â0.54) and with Pandora direct-sun (r2â=â0.85) and scattered light
(r2â=â0.94) observed NO2 columns. Coincident GCAS columns agree
in magnitude with NO2 and CH2O P-3B-observed columns to
within 10 % but are larger than scattered light Pandora tropospheric
NO2 columns by 33 % and direct-sun Pandora NO2
columns by 50 %.</p
Teorii ale categorizarii lumii si practici ale comunicarii/ Categorization of the World Theories and Communication Practice (Romanian Version)
The theme of communication leads to major changes in the way of conceptualizing the world and human behavior. The communication process turns into the game, and how everything is put into communication âwithout limitsâ (Codoban, 1995) everything is a game. Transforming reality into a playground makes the depth not to matter. As a result, transcendence is excluded and any ontological model of origins is denied. History itself, âbreak into piecesâ (Vattimo). No. pg. 198Communication Practice, human behavior, World Theories
Countering âArctificationâ: Dawson Cityâs âSourtoe Cocktailâ
Abstract
Purpose: The purpose of this paper is to focus on the Sourtoe Cocktail, a custom in Dawson City, Canadaâs Yukon, in which participants drink a shot of alcohol with a dehydrated human toe in it. Springing from a local legend, the thrill-inducing Sourtoe Cocktail has attracted the attention of tourists. The paper reveals insights from this particular case study in order to discuss potential future tourism trends within the Arctic, especially in regard to the development of a sustainable tourism industry. Additionally, it illustrates how local communities can avoid negative effects of âArctification.â
Design/methodology/approach: The case study is deconstructed through Dean MacCannellâs (1976) framework of sight sacralization. The Sourtoe Cocktail is analyzed based on the five stages of the framework, which helps to reveal the various elements at play at the local level. The framework specifically highlights linkages between society and the Sourtoe Cocktail as a product in order to understand how it became a tourist attraction.
Findings: The use of MacCannellâs sight sacralization framework reveals the intricate relationship of the Sourtoe Cocktail to both the Arctic and the local folklore of the Klondike Gold Rush. In addition, it is argued that the activity can serve as an example of avoiding âArctificationâ processes for northern communities.
Originality/value: The originality of the study lies in the application of the sight sacralization framework to an ordinary object â a toe â instead of an object of inherent historical, aesthetic or cultural value. The paper proposes a complementary study to the recommendations provided in the Arctic Tourism in Times of Change: Seasonality report (2019) for the development of sustainable Arctic societies
The use of NO<sub>2</sub> absorption cross section temperature sensitivity to derive NO<sub>2</sub> profile temperature and stratosphericâtropospheric column partitioning from visible direct-sun DOAS measurements
This paper presents a temperature sensitivity method (TESEM) to
accurately calculate total vertical NO<sub>2</sub> column, atmospheric
slant NO<sub>2</sub> profile-weighted temperature (<i>T</i>), and to
separate stratospheric and tropospheric columns from direct-sun (DS),
ground-based measurements using the retrieved <i>T</i>. TESEM is based on
differential optical absorption spectroscopy (DOAS) fitting of the
linear temperature-dependent NO<sub>2</sub> absorption cross section,
Ï (<i>T</i>), regression model (Vandaele et al., 2003). Separation
between stratospheric and tropospheric columns is based on the
primarily bimodal vertical distribution of NO<sub>2</sub> and an assumption
that stratospheric effective temperature can be represented by temperature
at 27 km ± 3 K, and tropospheric effective temperature is equal to surface
temperature within 3â5 K. These assumptions were derived from the Global
Modeling Initiative (GMI) chemistry-transport model (CTM) simulations over
two northern midlatitude sites in 2011.
<br><br>
TESEM was applied to the Washington State University Multi-Function
DOAS instrument (MFDOAS) measurements at four midlatitude locations
with low and moderate NO<sub>2</sub> anthropogenic emissions: (1) the Jet Propulsion Laboratory's Table
Mountain Facility (JPL-TMF), CA, USA
(34.38° N/117.68° W); (2) Pullman, WA, USA
(46.73° N/117.17° W); (3) Greenbelt, MD, USA
(38.99° N/76.84° W); and (4) Cabauw, the
Netherlands (51.97° N/4.93° E) during July 2007,
JuneâJuly 2009, JulyâAugust and October 2011,
November 2012âMay 2013, respectively.
NO<sub>2</sub> <i>T</i> and total, stratospheric, and tropospheric
NO<sub>2</sub> vertical columns were determined over each site
Ground-based direct-sun DOAS and airborne MAX-DOAS measurements of the collision-induced oxygen complex, O<sub>2</sub>O<sub>2</sub>, absorption with significant pressure and temperature differences
The collision-induced O2 complex, O2O2, is a very important
trace gas for understanding remote sensing measurements of aerosols, cloud
properties and atmospheric trace gases. Many ground-based multi-axis differential optical absorption spectroscopy
(MAX-DOAS) measurements of
the O2O2 optical depth require correction factors of 0.75 ±
0.1 to reproduce radiative transfer modeling (RTM) results for a nearly pure
Rayleigh atmosphere. One of the potential causes of this discrepancy is
uncertainty in laboratory-measured O2O2 absorption cross section
temperature and pressure dependencies due to difficulties in replicating
atmospheric conditions in the laboratory environment.
This paper presents ground-based direct-sun (DS) and airborne multi-axis
(AMAX) DOAS measurements of O2O2 absorption optical depths under
actual atmospheric conditions in two wavelength regions (335â390 and
435â490 nm). DS irradiance measurements were made by the Washington State
University research-grade Multi-Function Differential Spectroscopy
Instrument instrument from 2007 to 2014 at seven
sites with significant pressure (778 to 1013 hPa) and O2O2
profile-weighted temperature (247 to 275 K) differences. Aircraft MAX-DOAS
measurements were conducted by the University of Colorado (CU) AMAX-DOAS
instrument on 29 January 2012 over the Southern Hemispheric subtropical
Pacific Ocean. Scattered solar radiance spectra were collected at altitudes
between 9 and 13.2 km, with O2O2 profile-weighted temperatures of
231 to 244 K and nearly pure Rayleigh scattering conditions.
Due to the well-defined DS air-mass factors during ground-based measurements
and extensively characterized atmospheric conditions during the aircraft
AMAX-DOAS measurements, O2O2 "pseudo" absorption cross sections,
Ï, are derived from the observed optical depths and estimated
O2O2 column densities. Vertical O2O2 columns are
calculated from the atmospheric sounding temperature, pressure and specific
humidity profiles.
Based on the ground-based atmospheric DS observations, there is no pressure
dependence of the O2O2 Ï within the measurement errors
(3%). Two data sets are combined to derive the peak Ï temperature
dependence of the 360 and 477 nm dimer absorption bands from 231 to 275 K.
DS and AMAX-derived peak Ï ( O2O2) as a function of T can be
described by a quadratic function at 360 nm and linear function at
477 nm
with about 9% ± 2.5% per 44 K rate.
Recent laboratory-measured O2O2 cross sections by Thalman and
Volkamer (2013) agree with these "DOAS apparent" peak Ï( O2O2) at
233, 253 and 273 K within 3%. Changes in the
O2O2 spectral band shape at colder temperatures are observed for
the first time in field data. Temperature effects on spectral band shapes
can introduce errors in the retrieved O2O2 column abundances if a
single room temperature Ï( O2O2) is used in the DOAS
analysis. Simultaneous fitting of Ï( O2O2) at temperatures
that bracket the ambient temperature range can reduce such errors.
Our results show that laboratory-measured Ï( O2O2) (Hermans, 2011, at 296 K and Thalman and Volkamer, 2013) are applicable for
observations over a wide range of atmospheric conditions. Column densities
derived using Hermans (2011) Ï at 296 K require very small
correction factors (0.94 ± 0.02 at 231 K and 0.99 ± 0.02 at 275 K)
to reproduce theoretically calculated slant column densities for DS
and AMAX-DOAS measurements. Simultaneous fitting of Ï( O2O2)
at 203 and 293 K further improved the results at UV and
visible wavelengths for AMAX-DOAS
Clinical and evolutive features of gouty arthritis
Introduction. Gout is a disease that may be associated with different comorbidities, which causes difficulties in their management and appreciation of clinical manifestations.
The objective of the study was to analyse the clinical and evolution peculiarities in patients with gout, from different age groups.
Material and methods. A descriptive, selective study of 237 patients with gout (mean age of men 60±8.0 years and 63±9.0 years in women) was conducted. The diagnosis of gout was carried out according to the American College of Rheumatology and European League Against Rheumatism 2015 criteria. The patients were separated into two groups, depending on the age at the gout onset: 60 years (group II, 146 patients). The raw data were processed in SPSS version 26.0.
Results. The mean duration of the disease was comparable in both groups: 11 [7.6; 18.6] years (from 1 month to 23.7 years (p = 0.7) in group I and 11.3 [8.3; 14] years (from 1.6 years to 21.8 years) in group II. The equivalent duration of arthritis allowed comparing the characteristics of evolution in the groups. The chronic form of gout arthritis was slightly more common in group II than in group I, with significant differences (24% and 34%, p<0.01).
Conclusions. With the increase of age, the frequency of risk factors for gout increases: taking small doses of acetylsalicylic acid increases from 6 to 40%, diuretics from 18 to 44%, alcohol intake from 14 to 28%, hypertension from 44 to 78%, consumption of saturated foods with purine from 51 to 68%, overweight and obesity from 58 to 76% in the groups of patients with gout onset at the age less then 60 years and 60 years and more
NO<sub>2</sub> and HCHO measurements in Korea from 2012 to 2016 from Pandora spectrometer instruments compared with OMI retrievals and with aircraft measurements during the KORUS-AQ campaign
Nine Pandora
spectrometer instruments (PSI) were installed at eight sites in
South Korea as part of the KORUS-AQ (Korea U.S.-Air Quality) field study
integrating information from ground, aircraft, and satellite measurements
for validation of remote sensing air-quality studies. The PSI made
direct-sun measurements of total vertical column NO2, C(NO2), with
high precision (0.05 DU, where 1 DU â=â2.69 Ă 1016 molecules cmâ2)
and accuracy (0.1 DU) that were retrieved using spectral fitting techniques.
Retrieval of formaldehyde C(HCHO) total column amounts were also obtained at
five sites using the recently improved PSI optics. The C(HCHO) retrievals have
high precision, but possibly lower accuracy than for NO2 because of
uncertainty about the optimum spectral window for all ground-based and
satellite instruments. PSI direct-sun retrieved values for C(NO2) and
C(HCHO) are always significantly larger than OMI (AURA satellite Ozone
Monitoring Instrument) retrieved C(NO2) and C(HCHO) for the OMI
overpass local times (KSTâ=â13.5 ± 0.5 h). In urban areas, PSI
C(NO2) 30-day running averages are at least a factor of two larger than
OMI averages. Similar differences are seen for C(HCHO) in Seoul and nearby
surrounding areas. Late afternoon values of C(HCHO) measured by PSI are even
larger, implying that OMI early afternoon measurements underestimate the
effect of poor air quality on human health. The primary cause of OMI
underestimates is the large OMI field of view (FOV) that includes regions
containing low values of pollutants. In relatively clean areas, PSI and OMI
are more closely in agreement. C(HCHO) amounts were obtained for five sites,
Yonsei University in Seoul, Olympic Park, Taehwa Mountain, Amnyeondo, and Yeoju.
Of these, the largest amounts of C(HCHO) were observed at Olympic Park and
Taehwa Mountain, surrounded by significant amounts of vegetation.
Comparisons of PSI C(HCHO) results were made with the Compact Atmospheric
Multispecies Spectrometer CAMS during overflights on the DC-8 aircraft for
Taehwa Mountain and Olympic Park. In all cases, PSI measured substantially more
C(HCHO) than obtained from integrating the CAMS altitude profiles. PSI
C(HCHO) at Yonsei University in Seoul frequently reached 0.6 DU and
occasionally exceeded 1.5 DU. The semi-rural site, Taehwa Mountain, frequently
reached 0.9 DU and occasionally exceeded 1.5 DU. Even at the cleanest site,
Amnyeondo, C(HCHO) occasionally exceeded 1 DU.</p
Comparisons of spectral aerosol single scattering albedo in Seoul, South Korea
Quantifying aerosol absorption at ultraviolet (UV)
wavelengths is important for monitoring air pollution and aerosol amounts
using current (e.g., Aura/OMI) and future (e.g., TROPOMI, TEMPO, GEMS, and
Sentinel-4) satellite measurements. Measurements of column average
atmospheric aerosol single scattering albedo (SSA) are performed on the
ground by the NASA AERONET in the visible (VIS) and near-infrared (NIR)
wavelengths and in the UV-VIS-NIR by the SKYNET networks. Previous
comparison studies have focused on VIS and NIR wavelengths due to the lack
of co-incident measurements of aerosol and gaseous absorption properties in
the UV. This study compares the SKYNET-retrieved SSA in the UV with the SSA
derived from a combination of AERONET, MFRSR, and Pandora (AMP) retrievals
in Seoul, South Korea, in spring and summer 2016. The results show that
the spectrally invariant surface albedo assumed in the SKYNET SSA retrievals
leads to underestimated SSA compared to AMP values at near UV wavelengths.
Re-processed SKYNET inversions using spectrally varying surface albedo,
consistent with the AERONET retrieval improve agreement with AMP SSA. The
combined AMP inversions allow for separating aerosol and gaseous (NO2
and O3) absorption and provide aerosol retrievals from the shortest
UVB (305âŻnm) through VIS to NIR wavelengths (870âŻnm)
On the effect of sea breeze regime on aerosols and gases properties in the urban area of Rome, Italy
Several ground-based remote sensing and in-situ instruments were used to investigate the development of the sea-breeze front and its effect on both the optical and physical aerosol properties, the Particulate Matter (PM) content and the tropospheric and near-surface NO2 concentrations. Most of the instruments belongs to the Boundary-layer Air Quality-analysis Using Network of Instruments (BAQUNIN) supersite, in the urban area of Rome (Italy). Two characteristic sea-breeze patterns were identified: the front days, in which the sea-breeze front develops in a few minutes, and the gentle breeze days, in which the onset of the front is gradual (more than 20 min). In the case of front days, Aerosol Optical Depth (AOD) increases during the onset of the breeze. The Ă
ngström Exponent (AE), tropospheric and near surface NO2 amounts are almost constant during the day, while the aerosols volume size distribution follows a trimodal distribution. PM2.5 and PM10 concentrations decrease before the development of the sea-breeze front and then increase. Conversely, during gentle breeze days, AOD and AE do not change significantly. The tropospheric and near surface amount of NO2, PM2.5 and PM10 concentrations decrease, suggesting a significant dispersion of pollutants, while the aerosol size distribution shows a trimodal predominance