Ten years of atmospheric methane observations at a high elevation site in Western China

2004 ◽  
Vol 38 (40) ◽  
pp. 7041-7054 ◽  
Author(s):  
L.X. Zhou ◽  
D.E.J. Worthy ◽  
P.M. Lang ◽  
M.K. Ernst ◽  
X.C. Zhang ◽  
...  
Keyword(s):  
High Elevation ◽  
Western China ◽  
Atmospheric Methane ◽  
High Elevation Site

Stopover Site Fidelity by Tennessee Warblers at a Southern Appalachian High-elevation Site

2012 ◽  
Vol 124 (2) ◽  
pp. 366-370 ◽  
Author(s):  
David F. Vogt ◽  
Mark E. Hopey ◽  
G. Rad Mayfield ◽  
Eric C. Soehren ◽  
Laura M. Lewis ◽  
...  
Keyword(s):  
Site Fidelity ◽  
High Elevation ◽  
Stopover Site ◽  
Southern Appalachian ◽  
High Elevation Site

Environmental correlates of herpetofaunal diversity in Costa Rica

2010 ◽  
Vol 26 (5) ◽  
pp. 521-531 ◽  
Author(s):  
David Laurencio ◽  
Lee A. Fitzgerald
Keyword(s):  
Costa Rica ◽  
Species Diversity ◽  
Beta Diversity ◽  
Geographic Distance ◽  
Alpha Diversity ◽  
High Elevation ◽  
Diversity Patterns ◽  
Regional Diversity ◽  
Environmental Correlates ◽  
High Elevation Site

Abstract:Disentangling local and historical factors that determine species diversity patterns at multiple spatial scales is fundamental to elucidating processes that govern ecological communities. Here we investigated how environmental correlates may influence diversity at local and regional scales. Primarily utilizing published species lists, amphibian and reptile alpha and beta diversity were assessed at 17 well-surveyed sites distributed among ecoregions throughout Costa Rica. The degree to which regional species diversity patterns were related to environmental variables and geographic distance was determined using Canonical Correspondence Analysis and Mantel tests. Amphibian alpha diversity was highest in lowland Pacific sites (mean = 43.3 species) and lowest at the high elevation site (9 species). Reptile alpha diversity values were high for both lowland Atlantic (mean = 69.5 species) and lowland Pacific (mean = 67 species) sites and lowest for the high elevation site (8 species). We found high species turnover between local sites and ecoregions, demonstrating the importance of beta diversity in the determination of regional diversity. For both amphibians and reptiles, beta diversity was highest between the high-elevation site and all others, and lowest among lowland sites within the same ecoregion. The effect of geographic distance on beta diversity was minor. Ecologically significant climatic variables related to rain, temperature, sunshine and insolation were found to be important determinants of local and regional diversity for both amphibians and reptiles in Costa Rica.

The first meteorological observations at a tropical high elevation site: Antisana, 1846

2016 ◽  
Vol 13 (6) ◽  
pp. 1047-1055 ◽  
Author(s):  
Ana Mª M. Farrona ◽  
Fernando Domínguez-Castro ◽  
Mª Cruz Gallego ◽  
José M. Vaquero
Keyword(s):  
High Elevation ◽  
High Elevation Site ◽  
Meteorological Observations

YIELD AND QUALITY OF RED STIGMAS FROM DIFFERENT SAFFRON STRAINS AT CONTRASTING MEDITERRANEAN SITES

2006 ◽  
Vol 42 (4) ◽  
pp. 399-409 ◽  
Author(s):  
S. K. YAU ◽  
M. NIMAH ◽  
I. TOUFEILI
Keyword(s):  
Field Experiments ◽  
High Elevation ◽  
Crocus Sativus ◽  
Coastal Site ◽  
Yield And Quality ◽  
High Elevation Site ◽  
Colour Strength ◽  
Semi Arid

Three different saffron strains (Crocus sativus, C. sativus var. ‘cashmerianus’ and C. cartwrightianus) were tested for two years in field experiments to study their red stigma yield and quality. The experiments were performed at a high-elevation (rainfed or irrigated) site and a coastal site in Lebanon. On average, the two C. sativus strains gave more flowers and stigma yield than C. cartwrightianus. The former was more productive in the more favourable environments, especially at the warmer coastal site, than the latter. C. sativus ‘cashmerianus’, which yielded better at the coastal site in 2004 and gave a stronger colour strength and aroma, appeared to be the better choice for the area. Mean yield at the coastal site was twice that at the non-irrigated high-elevation site. On average, saffron produced at the coastal site had more colouring strength and bitterness than that produced at the high-elevation site. Nevertheless, viable commercial saffron production may still be possible in the semi-arid, high-elevation Bekaa Valley if irrigation can be provided.

scholarly journals Soil, plant, and transport influences on methane in a subalpine forest under high ultraviolet irradiance

2009 ◽  
Vol 6 (7) ◽  
pp. 1311-1324 ◽  
Author(s):  
D. R. Bowling ◽  
J. B. Miller ◽  
M. E. Rhodes ◽  
S. P. Burns ◽  
R. K. Monson ◽  
...  
Keyword(s):  
High Elevation ◽  
Subalpine Forest ◽  
Atmospheric Methane ◽  
Vegetation Canopy ◽  
Conifer Forest ◽  
Uv Irradiance ◽  
Plant Foliage ◽  
Net Uptake ◽  
Scalar Similarity ◽  
Ultraviolet Irradiance

Abstract. Recent studies have demonstrated direct methane emission from plant foliage under aerobic conditions, particularly under high ultraviolet (UV) irradiance. We examined the potential importance of this phenomenon in a high-elevation conifer forest using micrometeorological techniques. Vertical profiles of methane and carbon dioxide in forest air were monitored every 2 h for 6 weeks in summer 2007. Day to day variability in above-canopy CH4 was high, with observed values in the range 1790 to 1910 nmol mol−1. High CH4 was correlated with high carbon monoxide and related to wind direction, consistent with pollutant transport from an urban area by a well-studied mountain-plain wind system. Soils were moderately dry during the study. Vertical gradients of CH4 were small but detectable day and night, both near the ground and within the vegetation canopy. Gradients near the ground were consistent with the forest soil being a net CH4 sink. Using scalar similarity with CO2, the magnitude of the summer soil CH4 sink was estimated at ~1.7 mg CH4 m−2 h−1, which is similar to other temperate forest upland soils. The high-elevation forest was naturally exposed to high UV irradiance under clear sky conditions, with observed peak UVB irradiance >2 W m−2. Gradients and means of CO2 within the canopy under daytime conditions showed net uptake of CO2 due to photosynthetic drawdown as expected. No evidence was found for a significant foliar CH4 source in the vegetation canopy, even under high UV conditions. While the possibility of a weak foliar source cannot be excluded given the observed soil sink, overall this subalpine forest was a net sink for atmospheric methane during the growing season.

scholarly journals Accumulation Studies at a High Elevation Glacier Site in Central Karakoram

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Christoph Mayer ◽  
Astrid Lambrecht ◽  
Hans Oerter ◽  
Margit Schwikowski ◽  
Elisa Vuillermoz ◽  
...  
Keyword(s):  
Large Scale ◽  
Atmospheric Transport ◽  
Layer Structure ◽  
Ice Cores ◽  
High Elevation ◽  
Reanalysis Data ◽  
Early Summer ◽  
Western China ◽  
Minor Role ◽  
Seasonal Signals

The precipitation conditions in central Karakoram are investigated on the basis of snow samples from high elevated snow pits at Urdok glacier from 2006 and the analysis of atmospheric transport trajectories in combination with the general, large scale pressure distribution. Our analysis shows that accumulation at the high elevated regions of the central Karakoram is dominated by the west wind circulation (WWC). Incursions of the South Asian monsoon (SAM) occur sometimes during the summer months accompanied by strong precipitation but play a minor role for the total accumulation amount. Dust layers found in the snow pits show a rare earth elements signature which indicates that the dust very likely originates from the arid regions of western China and Central Asia. Our trajectory calculations based on NCEP/NCAR reanalysis data confirm that especially during late spring and early summer the westerly flow is redirected over the Tarim basin to reach central Karakoram from an East/Southeast direction. The preservation of the layer structure and the clear seasonal signals in the snow pits indicate that locations above 5200 m in central Karakoram will be suitable places for retrieving longer climate records from ice cores.

scholarly journals Characterization of Airborne Microbial Communities at a High-Elevation Site and Their Potential To Act as Atmospheric Ice Nuclei

2009 ◽  
Vol 75 (15) ◽  
pp. 5121-5130 ◽  
Author(s):  
Robert M. Bowers ◽  
Christian L. Lauber ◽  
Christine Wiedinmyer ◽  
Micah Hamady ◽  
Anna G. Hallar ◽  
...  
Keyword(s):  
Microbial Communities ◽  
High Elevation ◽  
Small Subunit ◽  
Microbial Community Analysis ◽  
Rrna Gene ◽  
Atmospheric Conditions ◽  
Small Subunit Rrna ◽  
Ice Nuclei ◽  
High Elevation Site ◽  
Bacteria And Fungi

ABSTRACT Bacteria and fungi are ubiquitous in the atmosphere. The diversity and abundance of airborne microbes may be strongly influenced by atmospheric conditions or even influence atmospheric conditions themselves by acting as ice nucleators. However, few comprehensive studies have described the diversity and dynamics of airborne bacteria and fungi based on culture-independent techniques. We document atmospheric microbial abundance, community composition, and ice nucleation at a high-elevation site in northwestern Colorado. We used a standard small-subunit rRNA gene Sanger sequencing approach for total microbial community analysis and a bacteria-specific 16S rRNA bar-coded pyrosequencing approach (4,864 sequences total). During the 2-week collection period, total microbial abundances were relatively constant, ranging from 9.6 × 105 to 6.6 × 106 cells m−3 of air, and the diversity and composition of the airborne microbial communities were also relatively static. Bacteria and fungi were nearly equivalent, and members of the proteobacterial groups Burkholderiales and Moraxellaceae (particularly the genus Psychrobacter) were dominant. These taxa were not always the most abundant in freshly fallen snow samples collected at this site. Although there was minimal variability in microbial abundances and composition within the atmosphere, the number of biological ice nuclei increased significantly during periods of high relative humidity. However, these changes in ice nuclei numbers were not associated with changes in the relative abundances of the most commonly studied ice-nucleating bacteria.

scholarly journals Snow-to-Liquid Ratio Variability and Prediction at a High-Elevation Site in Utah’s Wasatch Mountains

2010 ◽  
Vol 25 (1) ◽  
pp. 323-337 ◽  
Author(s):  
Trevor I. Alcott ◽  
W. James Steenburgh
Keyword(s):  
North American ◽  
Snow Water Equivalent ◽  
Winter Season ◽  
Predictive Ability ◽  
High Elevation ◽  
Reanalysis Data ◽  
Precipitation Forecast ◽  
Atmospheric Conditions ◽  
Liquid Ratio ◽  
High Elevation Site

Abstract Contemporary snowfall forecasting is a three-step process involving a quantitative precipitation forecast (QPF), determination of precipitation type, and application of a snow-to-liquid ratio (SLR). The final step is often performed using climatology or algorithms based primarily on temperature. Based on a record of consistent and professional daily snowfall measurements, this study 1) presents general characteristics of SLR at Alta, Utah, a high-elevation site in interior North America with frequent winter storms; 2) diagnoses relationships between SLR and atmospheric conditions using reanalysis data; and 3) develops a statistical method for predicting SLR at the study location. The mean SLR at Alta is similar to that observed at lower elevations in the surrounding region, with substantial variability throughout the winter season. Using data from the North American Regional Reanalysis, temperature, wind speed, and midlevel relative humidity are shown to be related to SLR, with the strongest correlation occurring between SLR and near-crest-level (650 hPa) temperature. A stepwise multiple linear regression (SMLR) equation is constructed that explains 68% of the SLR variance for all events, and 88% for a high snow-water equivalent (>25 mm) subset. To test predictive ability, the straightforward SMLR approach is applied to archived 12–36-h forecasts from the National Centers for Environmental Prediction Eta/North American Mesoscale (Eta/NAM) model, yielding an improvement over existing operational SLR prediction techniques. Errors in QPF over complex terrain, however, ultimately limit skill in forecasting snowfall amount.

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