scholarly journals Observations of large stratospheric ozone variations over Mendoza, Argentina

2002 ◽  
Vol 2 (3) ◽  
pp. 507-523 ◽  
Author(s):  
C. Puliafito ◽  
S. Enrique Puliafito ◽  
G. K. Hartmann
Keyword(s):  
Water Vapor ◽  
Case Studies ◽  
Gravity Waves ◽  
Stratospheric Ozone ◽  
Andes Mountains ◽  
Wind Effect ◽  
Radiometric Measurements ◽  
The Andes ◽  
Andes Region ◽  
Ozone Variations

Abstract. Since November 1993 up to present from Benegas Station, Mendoza, Argentina (site of IEMA Institute) and from high locations in the Andes region, ground based radiometric measurements of stratospheric ozone and tropospheric water vapor have been achieved. Ozone measurements are performed by using a radiometer-spectrometer tuned at 142 GHz and tropospheric water vapor by means of a 92 GHz radiometer. In this paper two case studies of large stratospheric ozone variations due to dynamical processes will be presented. These processes are very likely associated to gravity waves, generated by airflow over the Andes Mountains, or due to Zonda wind effect.

scholarly journals Orographic and convective gravity waves above the Alps and Andes Mountains during GPS radio occultation events – a case study

2018 ◽  
Vol 11 (6) ◽  
pp. 3523-3539 ◽  
Author(s):  
Rodrigo Hierro ◽  
Andrea K. Steiner ◽  
Alejandro de la Torre ◽  
Peter Alexander ◽  
Pablo Llamedo ◽  
...  
Keyword(s):  
Case Studies ◽  
Gravity Waves ◽  
Radio Occultation ◽  
Convective Activity ◽  
Mountain Waves ◽  
Gps Radio Occultation ◽  
Convective Systems ◽  
The Andes ◽  
The Alps

Abstract. Gravity waves (GWs) and convective systems play a fundamental role in atmospheric circulation, weather, and climate. Two usual main sources of GWs are orographic effects triggering mountain waves and convective activity. In addition, GW generation by fronts and geostrophic adjustment must also be considered. The utility of Global Positioning System (GPS) radio occultation (RO) observations for the detection of convective systems is tested. A collocation database between RO events and convective systems over subtropical to midlatitude mountain regions close to the Alps and Andes is built. From the observation of large-amplitude GW structures in the absence of jets and fronts, subsets of RO profiles are sampled. A representative case study among those considered at each region is selected and analyzed. The case studies are investigated using mesoscale Weather Research and Forecasting (WRF) simulations, ERA-Interim reanalysis data, and measured RO temperature profiles. The absence of fronts or jets during both case studies reveals similar relevant GW features (main parameters, generation, and propagation). Orographic and convective activity generates the observed GWs. Mountain waves above the Alps reach higher altitudes than close to the Andes. In the Andes case, a critical layer prevents the propagation of GW packets up to stratospheric heights. The case studies are selected also because they illustrate how the observational window for GW observations through RO profiles admits a misleading interpretation of structures at different altitude ranges. From recent results, the distortion introduced in the measured atmospheric vertical wavelengths by one of the RO events is discussed as an illustration. In the analysis, both the elevation angle of the sounding path (line of tangent points) and the gravity wave aspect ratio estimated from the simulations and the line of sight are taken into account. In both case studies, a considerable distortion, over- and underestimation of the vertical wavelengths measured by RO, may be expected.

On the enigmatic genus Oectropsis Blanchard (Coleoptera, Cerambycidae, Lamiinae): tribal allocation, synonymy, and new species

Zootaxa ◽  
2020 ◽  
Vol 4845 (2) ◽  
pp. 211-224
Author(s):  
FRANCISCO ERIBERTO DE L. NASCIMENTO ◽  
MIGUEL A. MONNÉ ◽  
ANTONIO SANTOS-SILVA
Keyword(s):  
New Species ◽  
North America ◽  
Taxonomic Status ◽  
Central Andes ◽  
Andes Mountains ◽  
The Andes ◽  
Andes Region ◽  
A New Species

The species of the genus Oectropsis Blanchard, 1851 (Cerambycidae, Lamiinae) are exclusively distributed west of the central Andes region (Chile) and were probably isolated due to phenomena caused by the Andes Mountains. Recent taxonomic revisions of the genus revealed that the species do not have the main features of Acanthocinini, the tribe in which this genus is currently allocated. Instead, they share characteristics with Pogonocherini, especially Pogonocherus Dejean, 1821, whose majority of species are distributed in North America. In addition to the tribal transference, we describe a new species, update a previous key, and we discuss the taxonomic status of some tribes. 

scholarly journals Spatial variability in soil properties on slow-forming terraces in the Andes region of Ecuador

2003 ◽  
Vol 72 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Gerd Dercon ◽  
Jozef Deckers ◽  
Gerard Govers ◽  
Jean Poesen ◽  
Henrry Sánchez ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Soil Properties ◽  
The Andes ◽  
Andes Region

scholarly journals Evidence of gravity waves into the atmosphere during the March 2006 total solar eclipse

2007 ◽  
Vol 7 (18) ◽  
pp. 4943-4951 ◽  
Author(s):  
C. S. Zerefos ◽  
E. Gerasopoulos ◽  
I. Tsagouri ◽  
B. E. Psiloglou ◽  
A. Belehaki ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Electron Density ◽  
Gravity Waves ◽  
Solar Eclipse ◽  
Stratospheric Ozone ◽  
Thermal Fluctuations ◽  
Ozone Layer ◽  
Total Solar Eclipse ◽  
Electron Content ◽  
Total Electron

Abstract. This study aims at providing experimental evidence, to support the hypothesis according to which the movement of the moon's shadow sweeping the ozone layer at supersonic speed, during a solar eclipse, creates gravity waves in the atmosphere. An experiment was conducted to study eclipse induced thermal fluctuations in the ozone layer (via measurements of total ozone column, ozone photolysis rates and UV irradiance), the ionosphere (Ionosonde Total Electron Content – ITEC, peak electron density height – hmF2), and the troposphere (temperature, relative humidity), before, during and after the total solar eclipse of 29 March 2006. We found the existence of eclipse induced dominant oscillations in the parameters related to the ozone layer and the ionosphere, with periods ranging between 30–40 min. Cross-spectrum analyses resulted to statistically significant square coherences between the observed oscillations, strengthening thermal stratospheric ozone forcing as the main mechanism for GWs. Additional support for a source below the ionosphere was provided by the amplitude of the oscillations in the ionospheric electron density, which increased upwards from 160 to 220 km height. Even though similar oscillations were shown in surface temperature and relative humidity data, no clear evidence for tropospheric influence could be derived from this study, due to the modest amplitude of these waves and the manifold rationale inside the boundary layer.

Population biology of the unusual thermoconforming lizards of the Andes Mountains of Peru (Squamata: Gymnophthalmidae)

2021 ◽  
Author(s):  
Tiffany M. Doan ◽  
Sara A. Sheffer ◽  
Nicholas R. Warmington ◽  
Eliot E. Evans
Keyword(s):  
Population Biology ◽  
Andes Mountains ◽  
The Andes

Globodera rostochiensis (yellow potato cyst nematode).

2021 ◽  
Author(s):  
Janet Rowe
Keyword(s):  
Potato Crop ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Winter Storms ◽  
Cyst Form ◽  
The Andes ◽  
Run Off ◽  
Top Soil ◽  
Irrigation Channels ◽  
Andes Region

Abstract G. rostochiensis is a world wide pest of temperate areas, including both temperate countries and temperate regions of tropical countries, for example India's Nigrilis region. Distribution is linked to that of the potato crop. Potato cyst nematode is considered to have originated from the Andes region of South America, from where it spread to Europe with potatoes. The ease with which it has been transported across continents proves what a resilient pest it is. The cyst form which adheres to host roots, stolons and tubers and to soil particles during transportation gives rise to new infestations where climate and food source are both available and favourable. Secondary means of dispersal is through the movement of contaminated farm machinery, farming implements and contaminated footwear. Cysts are also successfully spread by wind dispersal, during winter storms or sand storms where top soil is redistributed. Rain which causes flooding and water to run off fields into trenches or irrigation channels also redistributes cysts into adjoining areas.

scholarly journals Case studies of the impact of orbital sampling on stratospheric trend detection and derivation of tropical vertical velocities: solar occultation vs. limb emission sounding

2016 ◽  
Vol 16 (18) ◽  
pp. 11521-11534 ◽  
Author(s):  
Luis F. Millán ◽  
Nathaniel J. Livesey ◽  
Michelle L. Santee ◽  
Jessica L. Neu ◽  
Gloria L. Manney ◽  
...  
Keyword(s):  
Case Studies ◽  
Atmospheric Chemistry ◽  
Stratospheric Ozone ◽  
Sampling Bias ◽  
Nonuniform Sampling ◽  
Trend Detection ◽  
Trace Gas ◽  
Uniform Sampling ◽  
Solar Occultation ◽  
The Impact

Abstract. This study investigates the representativeness of two types of orbital sampling applied to stratospheric temperature and trace gas fields. Model fields are sampled using real sampling patterns from the Aura Microwave Limb Sounder (MLS), the HALogen Occultation Experiment (HALOE) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). The MLS sampling acts as a proxy for a dense uniform sampling pattern typical of limb emission sounders, while HALOE and ACE-FTS represent coarse nonuniform sampling patterns characteristic of solar occultation instruments. First, this study revisits the impact of sampling patterns in terms of the sampling bias, as previous studies have done. Then, it quantifies the impact of different sampling patterns on the estimation of trends and their associated detectability. In general, we find that coarse nonuniform sampling patterns may introduce non-negligible errors in the inferred magnitude of temperature and trace gas trends and necessitate considerably longer records for their definitive detection. Lastly, we explore the impact of these sampling patterns on tropical vertical velocities derived from stratospheric water vapor measurements. We find that coarse nonuniform sampling may lead to a biased depiction of the tropical vertical velocities and, hence, to a biased estimation of the impact of the mechanisms that modulate these velocities. These case studies suggest that dense uniform sampling such as that available from limb emission sounders provides much greater fidelity in detecting signals of stratospheric change (for example, fingerprints of greenhouse gas warming and stratospheric ozone recovery) than coarse nonuniform sampling such as that of solar occultation instruments.

Stratospheric ozone variations in the northern and the southern hemisphere during the period 1957?1990

1993 ◽  
Vol 60 (2) ◽  
pp. 109-125 ◽  
Author(s):  
John Xanthakis ◽  
Constantine Poulakos ◽  
Christos S. Zerefos
Keyword(s):  
Southern Hemisphere ◽  
Stratospheric Ozone ◽  
Ozone Variations
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