Extrapolation of synoptic meteorological data in mountainous terrain and its use for simulating forest evapotranspiration and photosynthesis

1987 ◽  
Vol 17 (6) ◽  
pp. 472-483 ◽  
Author(s):  
Steven W. Running ◽  
Ramakrishna R. Nemani ◽  
Roger D. Hungerford
Keyword(s):  
Air Temperature ◽  
Meteorological Data ◽  
Dew Point ◽  
Shortwave Radiation ◽  
Standard Errors ◽  
Semiarid Region ◽  
Mountainous Terrain ◽  
The North ◽  
South Slope ◽  
Study Sites

A model for calculating daily microclimate conditions in mountainous terrain is presented. Maximum–minimum daily air temperatures, precipitation, and dew point are extrapolated from valley stations to adjacent mountain slopes, after making elevation- and aspect-related corrections. The model (MT-CLIM) produces estimates of daily incoming shortwave radiation, air temperature, humidity and vapor pressure deficit, and precipitation for any mountain study site. MT-CLIM was tested against measured meteorological data on six study sites consisting of three north–south slope pairs in western Montana. Correlations between predicted and observed daily conditions on the six study sites for the period April–November 1983 were air temperature, R2 = 0.88–0.92 with standard errors <0.48 °C; relative humidity R2 = 0.63–0.72 with standard errors <15%; radiation R2 = 0.60–0.78 with standard errors <100 W m−2. To test the utility of the model, data from MT-CLIM were used to run the DAYSTRANS/PSN model of evapotranspiration (ET) and photosynthesis (PSN) for western coniferous forests. Seasonal ET calculated from MT-CLIM data deviated by less than 5% from ET calculated from measured meteorological conditions on the six sites. Estimates of seasonal PSN agreed to within 10% of estimates derived from measured meteorological data on all sites except one. For each of the north–south slope study pairs, the combined MT-CLIMDAYTRANS/PSN simulation predicted that north slopes would have higher (5–31%) seasonal PSN than the comparable south slopes, which agrees with observed patterns of forest productivity in this semiarid region.

scholarly journals Regional characteristics of snowpacks related to avalanches in the central mountains of Japan

2013 ◽  
Vol 54 (62) ◽  
pp. 282-290
Author(s):  
Shinji Ikeda ◽  
Tomoyuki Noro
Keyword(s):  
Air Temperature ◽  
Snow Depth ◽  
Meteorological Data ◽  
The Sea Of Japan ◽  
Dominant Type ◽  
Near Surface ◽  
Regional Characteristics ◽  
The North ◽  
Diurnal Range ◽  
Study Sites

AbstractTo identify the regional characteristics of mountain snowpacks related to avalanches in the central mountains of Japan, snow-pit observations were carried out over a period of between two and five winters at six study sites in three major mountain ranges: the north, central and south alps. The relationship between snowpack characteristics and meteorological properties was then examined to suggest indicators that could determine the snowpack characteristics in the region using meteorological data. On the basis of the dominant type of persistent weakness found within snowpacks, the study sites were divided into three regions: (1) the mountains on the Sea of Japan side - the persistent weakness was caused mainly by the presence of melt-freeze crust (MFcr) layers; (2) the inland mountains - the persistent weakness was caused mainly by the presence of weak layers consisting of near-surface faceted crystals (FCsf); and (3) the mountains on the Pacific Ocean side - the persistent weakness was caused mainly by the formation of thick weak layers consisting of depth hoar (DH) near the ground. The results also suggest that certain meteorological elements are useful indicators of the tendency of a persistent weakness to form within the snowpack: (1) DH layers: TG (°C m−1) = |average air temperature |/average snow depth (notable weakness in DH layers is found in areas where the TG exceeds 10°C m−1, but in such areas rainfall prevents the development of DH layers); (2) FCsf layers: FCsf index (CC m) = average diurnal range of air temperature × snow depth (notable weakness in FCsf layers is found in areas where the FCsf index is ∼10°C m); (3) MFcr layers: MFcr index (day m) = number of days that exceed 0°C × snow depth (notable weakness in MFcr layers is found in areas where the MFcr index exceeds 40 day m).

scholarly journals Effects of clouds on surface melting of Laohugou glacier No. 12, western Qilian Mountains, China

2018 ◽  
Vol 64 (243) ◽  
pp. 89-99 ◽  
Author(s):  
JIZU CHEN ◽  
XIANG QIN ◽  
SHICHANG KANG ◽  
WENTAO DU ◽  
WEIJUN SUN ◽  
...  
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Meteorological Data ◽  
Water Vapor Pressure ◽  
Longwave Radiation ◽  
Turbulent Heat Flux ◽  
Qilian Mountains ◽  
Shortwave Radiation ◽  
Turbulent Heat ◽  
Glacier Melt

ABSTRACTWe analyzed a 2-year time series of meteorological data (January 2011–December 2012) from three automatic weather stations on Laohugou glacier No. 12, western Qilian Mountains, China. Air temperature, humidity and incoming radiation were significantly correlated between the three sites, while wind speed and direction were not. In this work, we focus on the effects of clouds on other meteorological parameters and on glacier melt. On an average, ~18% of top-of-atmosphere shortwave radiation was attenuated by the clear-sky atmosphere, and clouds attenuated a further 12%. Most of the time the monthly average increases in net longwave radiation caused by clouds were larger than decreases in net shortwave radiation but there was a tendency to lose energy during the daytime when melting was most intense. Air temperature and wind speed related to turbulent heat flux were found to suppress glacier melt during cloudy periods, while increased water vapor pressure during cloudy days could enhance glacier melt by reducing energy loss by latent heat. From these results, we have increased the physical understanding of the significance of cloud effects on continental glaciers.

scholarly journals Spatiotemporal Characteristics of the Dominant Modes of Surface Air Temperature Interannual Variations over South China during the Spring-to-Summer Transition

Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 65
Author(s):  
Fen Wang ◽  
Yaokun Li ◽  
Jianping Li
Keyword(s):  
Heat Flux ◽  
Air Temperature ◽  
South China ◽  
Surface Heat Flux ◽  
Surface Air Temperature ◽  
Surface Heat ◽  
Shortwave Radiation ◽  
Northerly Wind ◽  
The North ◽  
Land Surfaces

The surface air temperature (SAT) interannual variability during the spring-to-summer transition over South China (SC) has been decomposed into two dominant modes by applying empirical orthogonal function (EOF) analysis. The first EOF mode (EOF1) is characterized by homogenous SAT anomalies over SC, whereas the second EOF mode (EOF2) features a dipole SAT anomaly pattern with opposite anomalies south and north of the Yangtze River. A regression analysis of surface heat flux and advection anomalies on the normalized principle component time series corresponding to EOF1 suggests that surface heat flux anomalies can explain SAT anomalies mainly by modulating cloud-shortwave radiation. Negative cloud anomalies result in positive downward shortwave radiation anomalies through the positive shortwave cloud radiation effect, which favor warm SAT anomalies over most of SC. For EOF2, the distribution of advection anomalies resembles the north–south dipole pattern of SAT anomalies. This suggests that wind-induced advection plays an important role in the SAT anomalies of EOF2. Negative SAT anomalies are favored by cold advection from northerly wind anomalies over land surfaces in high-latitude regions. Positive SAT anomalies are induced by warm advection from southerly wind anomalies over the ocean in low-latitude regions.

scholarly journals Multi-trait Analysis of Agroclimate Variations During the Growing Season in East-Central Poland (1971-2005)

2015 ◽  
Vol 29 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Elżbieta Radzka ◽  
Katarzyna Rymuza
Keyword(s):  
Principal Component Analysis ◽  
Air Temperature ◽  
Meteorological Data ◽  
Principal Component ◽  
Growing Season ◽  
Component Analysis ◽  
The South ◽  
East Central ◽  
Central Poland ◽  
The North

Abstract The work is based on meteorological data recorded by nine stations of the Institute of Meteorology and Water Management located in east-central Poland from 1971 to 2005. The region encompasses the North Podlasian Lowland and the South Podlasian Lowland. Average values of selected agroclimate indicators for the growing season were determined. Moreover, principal component analysis was conducted to indicate elements that exerted the greatest influence on the agroclimate. Also, cluster analysis was carried out to select stations with similar agroclimate. Ward method was used for clustering and the Euclidean distance was applied. Principal component analysis revealed that the agroclimate of east-central Poland was predominantly affected by climatic water balance, number of days of active plant growth, length of the farming period, and the average air temperature during the growing season (Apr-Sept). Based on the analysis, the region of east-central Poland was divided into two groups (areas) with different agroclimatic conditions. The first area comprized the following stations: Szepietowo and Białowieża located in the North Podlasian Lowland and Biała Podlaska situated in the northern part of the South Podlasian Lowland. This area was characterized by shorter farming periods and a lower average air temperature during the growing season. The other group included the remaining stations located in the western part of both the Lowlands which was warmer and where greater water deficits were recorded.

Season and ambient air temperature influence the distribution of mites (Proctophyllodes stylifer) across the wings of blue tits (Parus caeruleus)

2000 ◽  
Vol 78 (8) ◽  
pp. 1397-1407 ◽  
Author(s):  
P R Wiles ◽  
J Cameron ◽  
J M Behnke ◽  
I R Hartley ◽  
F S Gilbert ◽  
...  
Keyword(s):  
Air Temperature ◽  
Meteorological Data ◽  
Ambient Air ◽  
Parus Caeruleus ◽  
Wing Feather ◽  
Ambient Air Temperature ◽  
Air Temperatures ◽  
West Midlands ◽  
Study Sites ◽  
Blue Tits

Changes in the distribution of the wing-feather mite Proctophyllodes stylifer (Buckholz 1869) on the flight feathers of blue tits (Parus caeruleus) were studied throughout the seasons and in relation to ambient air temperature at three combinations of study sites (Lancashire, West Midlands, and South Midlands). We tested the hypotheses that the distribution of mites is influenced in part by season and ambient air temperature. In the winter months mites clustered predominantly on the tertiary feathers, whereas in late spring, summer, and autumn, mite-infestation scores were higher on the proximal primary and secondary feathers. Three approaches were employed to determine whether this seasonal redistribution of mites arose as a response to changes in microclimate, probably ambient air temperature, rather than to season per se. Firstly, meteorological data for the Lancashire study sites, and our own monitoring of the precise air temperature at the time of handling and inspection at the West Midlands study sites, enabled us to establish a link between distribution pattern and ambient temperature. Secondly, limited observations on the distribution of mites on birds recaptured when ambient air temperatures differed by 5°C or more between first and second nettings, one temperature being below 10°C and the other above, supported the idea that the change in distribution was associated with air temperature. Finally, the results of a small experiment in which heavily infested birds caught on a day when air temperatures ranged from 9 to 11°C were taken indoors and temporarily subjected to a higher ambient air temperature (20 min) prior to re-inspection and release also confirmed that mite movement was associated with the temperature of their environment. We conclude that the seasonal changes in distribution were driven by microclimatic changes, in part by temperature.

scholarly journals Fluctuations of Glaciar Esperanza Norte in the north Patagonian Andes of Argentina during the past 400 yr

2012 ◽  
Vol 8 (3) ◽  
pp. 1079-1090 ◽  
Author(s):  
L. Ruiz ◽  
M. H. Masiokas ◽  
R. Villalba
Keyword(s):  
Meteorological Data ◽  
17Th Century ◽  
Ice Age ◽  
Aerial Photographs ◽  
Additional Information ◽  
The Past ◽  
The North ◽  
Study Sites ◽  
A Minor ◽  
Patagonian Andes

Abstract. The number of studies of Little Ice Age (LIA) glacier fluctuations in southern South America has increased in recent years but is largely biased towards sites in the south Patagonian Andes. In this paper we present a detailed record of length and areal fluctuations of Glaciar Esperanza Norte (GEN) in the north Patagonian Andes of Argentina during the past four centuries. The GEN record was reconstructed through the dendro-geomorphological dating of moraines and the analysis of satellite imagery, aerial photographs and documentary material complemented with extensive field surveys. The maximum LIA extent at GEN was associated with an outer moraine dated to the mid 17th century. At least 19 subsequent readvances or standstills evidenced by morainic ridges were identified inside the most extensive LIA moraine. The dating and spacing of these moraines and the additional information available indicate that the ice front retreated much more rapidly during the 20th century than during earlier centuries. Comparison with the record of LIA fluctuations of Glaciar Frías, an ice mass of similar characteristics located 110 km to the north of GEN, shows a similar pattern of recession over the past 400 yr. Both glacier records have the peak LIA event occurring roughly during the same interval (early-mid 17th century) and show a minor readvance during the 1970s, but there are still a few discrepancies in the dating of some inner moraines. These differences may be due to local, specific factors or associated with the inherent uncertainties in the dating of the moraines. The chronologies of GEN and Frías are among the most detailed currently available in Patagonia, but a larger number of study sites is needed to develop robust, regionally representative glacier chronologies. Detailed glaciological, geomorphological and meteorological data are also needed to understand the glacier-climate relationships in this region and develop reliable paleoclimatic reconstructions.

scholarly journals Fluctuations of Glaciar Esperanza Norte in the North Patagonian Andes of Argentina during the past 400 yr

2011 ◽  
Vol 7 (6) ◽  
pp. 4073-4104
Author(s):  
L. Ruiz ◽  
M. H. Masiokas ◽  
R. Villalba
Keyword(s):  
Meteorological Data ◽  
Ice Age ◽  
Aerial Photographs ◽  
Additional Information ◽  
The Past ◽  
The North ◽  
Extensive Field ◽  
Study Sites ◽  
A Minor ◽  
Patagonian Andes

Abstract. The number of studies of Little Ice Age (LIA) glacier fluctuations in Southern South America has increased in recent years but is largely biased towards sites in the South Patagonian Andes. In this paper we present a detailed record of length and areal fluctuations of Glaciar Esperanza Norte (GEN), in the North Patagonian Andes of Argentina, during the past four centuries. The GEN record was reconstructed through the dendro-geomorphological dating of moraines and the analysis of satellite imagery, aerial photographs and documentary material complemented with extensive field surveys. The maximum LIA extent at GEN was associated with an outer moraine dated to the mid 17th century. At least 19 subsequent readvances or standstills evidenced by morainic ridges were identified inside the most extensive LIA moraine. The dating and spacing of these moraines and the additional information available indicate that the ice front retreated much more rapidly during the 20th century than during earlier centuries. Comparison with the record of LIA fluctuations of Glaciar Frías, an ice mass of similar characteristics located 110 km to the north of GEN, shows a similar pattern of recession over the past 400 yr. Both glacier records have the peak LIA event occurring roughly during the same interval and show a minor readvance during the 1970s, but there are still a few discrepancies in the dating of some inner moraines. These differences may be due to local, specific factors or associated with the inherent uncertainties in the dating of the moraines. The chronologies of GEN and Frías are among the most detailed currently available in Patagonia, but a larger number of study sites is needed to develop robust, regionally representative glacier chronologies. Detailed glaciological, geomorphological and meteorological data are also needed to understand the glacier-climate relationships in this region and develop reliable paleoclimatic reconstructions.

scholarly journals Comparação de Modelos de Estimativa da Radiação de Onda Curta a partir de dados MODIS/Terra (Comparision Models for estimating the Shortwave Radiation from MODIS / Terra data)

2013 ◽  
Vol 6 (5) ◽  
pp. 1037 ◽  
Author(s):  
Francineide Amorim Santos ◽  
Bernardo Barbosa da Silva ◽  
Argemiro Lucena Araújo ◽  
Madson Tavares Silva ◽  
Alexandra Chaves Braga
Keyword(s):  
Relative Humidity ◽  
Key Words ◽  
Relative Error ◽  
Air Temperature ◽  
Cane Sugar ◽  
Dew Point ◽  
Shortwave Radiation ◽  
Weather Station ◽  
Error Percentage ◽  
Relative Humidity Data

O objetivo do presente estudo é analisar a precisão de diferentes metodologias na estimativa da radiação de onda curta incidente a partir de dados MODIS/TERRA em diferentes ecossistemas (cerrado e cana-de-açúcar). Foram utilizados três métodos que se convencionou denominar SEBAL (S), METRIC (M) e Bisht (B). Para aplicação do método SEBAL são necessários apenas dados de temperatura do ar e para o METRIC, de temperatura do ar e umidade relativa, dados que são facilmente obtidos em estações meteorológicas. A metodologia Bisht, porém, processou-se de forma totalmente autônoma, pois a temperatura do ar, assim como a temperatura do ponto do orvalho, foram obtidas de dados MODIS. O método que demonstrou maior precisão foi Bisht, com erro relativo percentual (ERP) de 3,94% no Cerrado e de 7,6% na cana-de-açúcar, seguido do METRIC e do SEBAL. No entanto, o METRIC foi o que proporcionou melhor correlação entre observações versus estimativas para a área do cerrado (R2 = 0,897) contra R2 = 0,847 do Bisht. Já para a área de cana-de-açúcar, o Bisht apresentou melhor correlação (R2 = 0,772), enquanto a correlação obtida com o METRIC foi de 0,744. A B S T R A C T The objective of this study is to analyze the accuracy of different methodologies to estimate the incident shortwave radiation from MODIS / TERRA in different ecosystems (savanna and cane sugar). Were used three methods that been conventionally called SEBAL (S), METRIC (M) and Bisht (B). To apply the method SEBAL requires only data of air temperature and for the METRIC, air temperature and relative humidity, data that are easily obtained from weather station. The methodology Bisht, however, was processed in a totally autonomous because the air temperature as well as the temperature of the dew point, were obtained from MODIS data. The method Bisht demonstrated greater accuracy, with relative error percentage (REP) of 3.94% in the Cerrado and 7.6% in cane sugar, followed by METRIC and SEBAL. However, METRIC was what provided the best correlation between observations versus estimates for the area of cerrado (R2 = 0.897) against R2 = 0.847 the Bisht. Already for the area of cane sugar, Bisht showed better correlation (R2 = 0.772), whereas the correlation with the METRIC obtained was 0.744. Key-Words: ecosystem, methodologies, accuracy, autonomous

scholarly journals Oxygen-18 isotopes in precipitation on the eastern Tibetan Plateau

2006 ◽  
Vol 43 ◽  
pp. 263-268 ◽  
Author(s):  
Yu Wusheng ◽  
Yao Tandong ◽  
Tian Lide ◽  
Wang Yu ◽  
Li Zexia ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Air Temperature ◽  
Surface Pressure ◽  
Meteorological Station ◽  
Dew Point ◽  
Monsoon Precipitation ◽  
Eastern Tibetan Plateau ◽  
Monsoon Period ◽  
The North ◽  
Monsoon Intensity

AbstractThis study examines precipitation samples collected at the Yushu meteorological station on the eastern Tibetan Plateau from November 2000 to November 2002. Results show that air-temperature effects control δ18O in precipitation in this area. Values of δ18O in precipitation positively correlate with air temperature, especially for monthly averages. Our data also show δ18O values in precipitation positively correlate with dew point and surface pressure in the Yushu region. Similar to other stations (Tuotuohe, Nagqu, Gaize and Shiquanhe) lying in the transition zone between the regions in the south dominated by the monsoon and those in the north dominated by the westerlies, because of the effect of monsoon precipitation, precipitation rates are high, and heavy isotopes are more depleted in summer at the Yushu station. Accordingly, values of δ18O in precipitation correlate more strongly with air temperature and dew point before the monsoon onset and after the monsoon retreat than during the monsoon period. That is, intense monsoon activities weaken the correlations between δ18O and air temperature and dew point. Clearly, dew point, surface pressure and the monsoon intensity contribute to controlling the δ18O values in precipitation at the Yushu station.

scholarly journals The effect of air temperature on hospital admission of adults with community acquired pneumonia in Baotou, China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenfang Guo ◽  
Letai Yi ◽  
Peng Wang ◽  
Baojun Wang ◽  
Minhui Li
Keyword(s):  
Hospital Admission ◽  
Air Temperature ◽  
Meteorological Data ◽  
Community Acquired Pneumonia ◽  
Adult Patients ◽  
Distributed Lag ◽  
Specific Effects ◽  
Lower Temperature Range ◽  
Lower Temperature ◽  
Inner Mongolia Autonomous Region

AbstractThe relationship between air temperature and the hospital admission of adult patients with community-acquired pneumonia (CAP) was analyzed. The hospitalization data pertaining to adult CAP patients (age ≥ 18 years) in two tertiary comprehensive hospitals in Baotou, Inner Mongolia Autonomous Region, China from 2014 to 2018 and meteorological data there in the corresponding period were collected. The exposure–response relationship between the daily average temperature and the hospital admission of adult CAP patients was quantified by using a distributed lag non-linear model. A total of 4466 cases of adult patients with CAP were admitted. After eliminating some confounding factors such as relative humidity, wind speed, air pressure, long-term trend, and seasonal trend, a lower temperature was found to be associated with a higher risk of adult CAP. Compared to 21 °C, lower temperature range of 4 to –12 °C was associated with a greater number of CAP hospitalizations among those aged ≥ 65 years, and the highest relative risk (RR) was 2.80 (95% CI 1.15–6.80) at a temperature of − 10 °C. For those < 65 years, lower temperature was not related to CAP hospitalizations. Cumulative lag RRs of low temperature with CAP hospitalizations indicate that the risk associated with colder temperatures appeared at a lag of 0–7 days. For those ≥ 65 years, the cumulative RR of CAP hospitalizations over lagging days 0–5 was 1.89 (95% CI 1.01–3. 56). In brief, the lower temperature had age-specific effects on CAP hospitalizations in Baotou, China, especially among those aged ≥ 65 years.

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