scholarly journals Modelling runoff from a Himalayan debris-covered glacier

2014 ◽  
Vol 11 (2) ◽  
pp. 2441-2482 ◽  
Author(s):  
K. Fujita ◽  
A. Sakai
Keyword(s):  
Thermal Properties ◽  
Air Temperature ◽  
Field Experiments ◽  
Melting Rate ◽  
Ice Melt ◽  
Total Runoff ◽  
Temperature And Precipitation ◽  
Covered Area ◽  
Glacier Ice ◽  
The Impact

Abstract. Although the processes by which glacial debris-mantles alter the melting of glacier ice have been well studied, the mass balance and runoff patterns of Himalayan debris-covered glaciers and the response of these factors to climate change are not well understood. Many previous studies have addressed mechanisms of ice melt under debris mantles by applying multiplicative parameters derived from field experiments, and other studies have calculated the details of heat conduction through the debris layer. However, those approaches cannot be applied at catchment scales because debris distributions are heterogeneous and difficult to measure. Here, we establish a runoff model for a Himalayan debris-covered glacier in which the spatial distribution of the thermal properties of the debris mantle is estimated from remotely sensed multi-temporal data. We validated the model for the Tsho Rolpa Glacial Lake–Trambau Glacier basin in the Nepal Himalaya, using hydro-meteorological observations obtained for a 3.5 yr period (1993–1996). We calculated long-term averages of runoff components for the period 1980–2007 using gridded reanalysis datasets. Our calculations suggest that excess meltwater from the debris-covered area contributes significantly to the total runoff, mainly because of its location at lower elevations. Uncertainties in runoff values due to estimations of the thermal properties and albedo of the debris-covered surface were assessed to be approximately 8% of the runoff from the debris-covered area. We evaluated the sensitivities of runoff components to changes in air temperature and precipitation. As expected, warmer air temperatures increase the total runoff by increasing the melting rate; however, increased precipitation slightly reduces the total runoff, as ice melting is suppressed by the increased snow cover and associated high albedo. The response of total runoff to changing precipitation is complex because of the different responses of individual components (glacier, debris, and ice-free terrain) to precipitation levels. The impact of air temperature on inter-annual variability is 23 times greater than that of precipitation.

scholarly journals Modelling runoff from a Himalayan debris-covered glacier

2014 ◽  
Vol 18 (7) ◽  
pp. 2679-2694 ◽  
Author(s):  
K. Fujita ◽  
A. Sakai
Keyword(s):  
Thermal Properties ◽  
Field Experiments ◽  
Melting Rate ◽  
Water Runoff ◽  
Catchment Scale ◽  
Runoff Simulation ◽  
Ice Melt ◽  
Total Runoff ◽  
Temperature And Precipitation ◽  
Covered Area

Abstract. Although the processes by which glacial debris mantles alter the melting of glacier ice have been well studied, the mass balance and runoff patterns of Himalayan debris-covered glaciers and the response of these factors to climate change are not well understood. Many previous studies have addressed mechanisms of ice melt under debris mantles by applying multiplicative parameters derived from field experiments, and other studies have calculated the details of heat conduction through the debris layer. However, those approaches cannot be applied at catchment scale because distributions of thickness and thermal property of debris are heterogeneous and difficult to measure. Here, we established a runoff model for a Himalayan debris-covered glacier in which the spatial distribution of the thermal properties of the debris mantle is estimated from remotely sensed multi-temporal data. We applied the model to the Tsho Rolpa Glacial Lake–Trambau Glacier basin in the Nepal Himalaya, using hydro-meteorological observations obtained for a 3.5-year period (1993–1996). We calculated long-term averages of runoff components for the period 1980–2007 using gridded reanalysis datasets. Our calculations suggest that excess meltwater, which implies the additional water runoff compared with the ice-free terrain, from the debris-covered area contributes significantly to the total runoff, mainly because of its location at a lower elevation. Uncertainties in runoff simulation due to estimations of the thermal properties and albedo of the debris-covered surface were assessed to be approximately 8% of the runoff from the debris-covered area. We evaluated the sensitivities of runoff components to changes in air temperature and precipitation. As expected, warmer air temperatures increase the total runoff by increasing the melting rate; however, increased precipitation slightly reduces the total runoff, as ice melting is suppressed by the increased snow cover and associated high albedo. The response of total runoff to changing precipitation is complex because of the different responses of individual components (glacier, debris, and ice-free terrain) to precipitation.

scholarly journals Seasonal Surface Air Temperature and Precipitation in the FSU Climate Model Coupled to the CLM2

2005 ◽  
Vol 18 (16) ◽  
pp. 3217-3228 ◽  
Author(s):  
D. W. Shin ◽  
S. Cocke ◽  
T. E. LaRow ◽  
James J. O’Brien
Keyword(s):  
Heat Flux ◽  
Air Temperature ◽  
Climate Model ◽  
Initial Conditions ◽  
Sensible Heat Flux ◽  
Surface Air Temperature ◽  
Community Land Model ◽  
Temperature And Precipitation ◽  
The Impact ◽  
Convective Scheme

Abstract The current Florida State University (FSU) climate model is upgraded by coupling the National Center for Atmospheric Research (NCAR) Community Land Model Version 2 (CLM2) as its land component in order to make a better simulation of surface air temperature and precipitation on the seasonal time scale, which is important for crop model application. Climatological and seasonal simulations with the FSU climate model coupled to the CLM2 (hereafter FSUCLM) are compared to those of the control (the FSU model with the original simple land surface treatment). The current version of the FSU model is known to have a cold bias in the temperature field and a wet bias in precipitation. The implementation of FSUCLM has reduced or eliminated this bias due to reduced latent heat flux and increased sensible heat flux. The role of the land model in seasonal simulations is shown to be more important during summertime than wintertime. An additional experiment that assimilates atmospheric forcings produces improved land-model initial conditions, which in turn reduces the biases further. The impact of various deep convective parameterizations is examined as well to further assess model performance. The land scheme plays a more important role than the convective scheme in simulations of surface air temperature. However, each convective scheme shows its own advantage over different geophysical locations in precipitation simulations.

scholarly journals Influence of meteorological conditions on the yield of winter oilseed rape in Lower Silesia

2013 ◽  
Vol 45 (2) ◽  
pp. 235-242
Author(s):  
Halina Dzieżyc ◽  
Kazimierz Chmura ◽  
Maciej Piotrowski
Keyword(s):  
Oilseed Rape ◽  
Air Temperature ◽  
Meteorological Conditions ◽  
Winter Period ◽  
Winter Oilseed Rape ◽  
Average Temperature ◽  
Temperature And Precipitation ◽  
Precipitation Total ◽  
The Impact ◽  
Lower Silesia

Abstract Influence of meteorological conditions on the yield of winter oilseed rape in Lower Silesia. This work uses the results of Post-registration Cultivar and Agricultural Experimentation conducted in 1999-2011 in Lower Silesia, on soils of very good and good wheat complex. The rape vegetation season was divided into five periods that approximately corresponded to the phenological phases of the plant, namely: September-November (from sowing to stemming the growing season in the autumn), December-March (stunted vegetation - renewal of vegetation), April (renewal of vegetation - the beginning of flowering), May (flowering), June (end of flowering - technical maturity). In the constructed regression model the following factors were included: the average air temperature and total precipitation in the periods, the content of phosphorus, potassium and pH of soil and fertilization with nitrogen, phosphorus and potassium. Comparing the impact of meteorological conditions in different growing periods of winter rape, it was found that the weakest impact on the yield had temperature and precipitation from September to November. During this period, the optimum for yield are the following conditions: average temperature 10.4°C and precipitation total 145 mm. The winter period (December- March) has the strongest impact on the yield of rape. The yield is conspicuously higher with lower average air temperatures. Optimal for yield is precipitation of 171 mm (highest tested) and a relatively low average air temperature (-0.9°C). In April, the decisive factor is rainfall. Its lower values (12 mm) favour higher yield. The optimum weather in this period is 12 mm precipitation and average temperature of 9.1°C. Rape yield increases with increasing average air temperature in May and is highest when its value is 15°C and rainfall in this month is above average (73 mm). The weather in June has less impact on rape crop than in the three previous periods. The optimal layout is: 27 mm precipitation and temperature 16°C, these values being the smallest tested

scholarly journals APPLICATION OF PRINCIPAL COMPONENT ANALYSIS TO DROUGHT INDICATORS OF THREE REPRESENTATIVE CROATIAN REGIONS

2021 ◽  
Vol 12 (22) ◽  
pp. 41-55
Author(s):  
Lidija Tadić ◽  
◽  
Tamara Brleković ◽  
Kristina Potočki ◽  
Marija Leko-Kos ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Air Temperature ◽  
Principal Component ◽  
Component Analysis ◽  
Homogeneity Test ◽  
Temperature And Precipitation ◽  
Standard Normal Homogeneity Test ◽  
Seasonal Basis ◽  
The Impact ◽  
Drought Occurrence

Drought has become a very frequent hydrological event globally, including in Croatia. It can generally be explained by air temperature and precipitation changes on an annual and seasonal basis, owing to climate change. To contribute to the knowledge on drought phenomena in Croatia, the changes in air temperature and precipitation over a relatively long period between 1951 and 2018 were analyzed. The meteorological stations included in the research were Osijek, Zagreb, and Split, which represented the climate of the entire country. Drought was estimated using the standardized precipitation evapotranspiration index, which is one of the most comprehensive drought indices. Furthermore, the drought severity and duration were calculated using run theory. These parameters were tested for homogeneity using the standard normal homogeneity test. Only the air temperature exhibited inhomogeneity, with a break year in 1991 (Zagreb and Split) and 1998 (Osijek). The existence of significant temporal trends was tested using the non-parametric Mann–Kendall trend test. The probability of drought occurrence with a certain duration and severity was calculated using the copula function. Finally, principal component analysis was applied to the computed standardized Mann–Kendall test statistic (ZMK ) to define the relevance of each parameter change and their combination in drought occurrence on a seasonal basis. Drought occurrence was less recognizable from 1951 to 1991 (1998). In the second sub-period, the impact of an increasing air temperature was the most significant variable, particularly in Zagreb.

Overview of current and expected seasonal climatic anomalies for the winter 2021/2022 with their possible impact on the economy, as estimated by the meteorological services of the CIS countries

2021 ◽  
Vol 4 ◽  
pp. 163-176
Author(s):  
V.M. Khan ◽  
◽  
Keyword(s):  
Air Temperature ◽  
Social Life ◽  
Large Scale ◽  
Winter Season ◽  
Northern Eurasia ◽  
Temperature And Precipitation ◽  
Skill Scores ◽  
Cis Countries ◽  
Temperature Impacts ◽  
The Impact

Based on assessments of the meteorological services of the CIS countries, the skill scores of the consensus forecast for the territory of Northern Eurasia for the summer of 2021 are presented. The results of monitoring circulation patterns in the stratosphere and troposphere over the past summer season are discussed. Climate monitoring and seasonal forecasting results for the current situation are presented. A probabilistic consensus forecast for air temperature and precipitation is presented for the upcoming winter season 2021/2022 in Northern Eurasia. Possible consequences of the impact of the expected anomalies of meteorological parameters on the economy sectors and social life are discussed. Keywords: North Eurasian Climate Forum, North Eurasian Climate Center, consensus forecast, air temperature, precipitation, large-scale atmospheric circulation, hydrodynamic models, sea surface temperature, impacts

The Impact of Covid-19 Lockdown on the Urban Micro-Climate of Major Coastal vs Inland Cities of India

2021 ◽  
Author(s):  
Sutapa Bhattacharjee ◽  
Rishikesh Bharti
Keyword(s):  
Air Temperature ◽  
Land Surface ◽  
Longwave Radiation ◽  
Peripheral Region ◽  
Maximum Temperature ◽  
Temperature And Precipitation ◽  
Rain Events ◽  
The Individual ◽  
The Impact ◽  
The City

<p>The climatic or meteorological characteristics over a city is significantly influenced by the city dynamics resulting in evolution of a typical micro-climatic condition enveloping the city and peripheral region. The shrinkage and expansion of the urban boundary layer depends on the dimension, design and functioning of a city and its physiographic setup. The lockdown that was enforced for varying durations globally to restrict the Covid-19 pandemic gave an extraordinary opportunity to understand the urban micro-climatic systems with substantially reduced urban operations. Therefore, the present study aims to evaluate the nature of temperature and precipitation conditions for 6 major cities in India, primarily accentuated by the urban fabric and design; during the strict as well as phased lockdown period in India (April – June, 2020). The principal objective of the study is to determine if moderation in transportation as well as commercial and industrial activities which are considered as the backbone of a metropolitan, can regulate the micro-climatic system it emanates. A comparative analysis has been attempted between the three coastal (Mumbai, Chennai, Kolkata) and three inland (Delhi, Hyderabad, Bangalore) cities to gather an understanding of the impact-magnitude, the sea has on urban meteorology. Meteorological reanalysis, satellite as well as in-situ Automatic Weather Station data products have been used for the analysis and validation of results. During the month of April when the lockdown was most stringent, there was an evident improvement in air quality with decrease in the concentration of PM2.5, PM10 and AOD (Aerosol Optical Depth) for all the cities in a range of 30 – 60 percent. To examine the direct and indirect impact of the decreased levels of air pollution on the shortwave as well as longwave radiation responsible for creating the UHI effect as well as abnormal rainfall intensity; the air temperature, land surface temperature (LST) and total amount of rainfall received by the individual cities on a daily as well as hourly basis have been considered. The study reveals that there is notable difference in LST and air temperature in the inland cities during the said period in comparison to the previous years, with relative decrease in both minimum and maximum temperature and significant increase in the number of days with lower temperatures. The pattern of high intensity rain events which is typical to intensive urbanization also experienced definite transformation in Bangalore and Delhi even during the phased lockdown period. However, the modification in all these meteorological parameters were observed to be relatively less significant in case of the coastal cities which solidifies the prominence of coastal influence in such metropolis. Therefore, the study concludes that the rapid strengthening of urban micro-climate and its consequences can be mitigated by implementing strategic reduction in core urban activities, especially for cities without external physiographic influence.</p>

scholarly journals The Impact of Weather Conditions on Economic Activity in Ukraine

2020 ◽  
pp. 25-49
Author(s):  
Hanna Yatsenko
Keyword(s):  
Air Temperature ◽  
Economic Activity ◽  
Statistical Data ◽  
Composite Index ◽  
Weather Conditions ◽  
Geophysical Observatory ◽  
Distributed Lag ◽  
Temperature And Precipitation ◽  
Autoregressive Distributed Lag ◽  
The Impact

This article explores the impact of weather conditions on core sectors of the Ukrainian economy and the composite index of economic activity in Ukraine. We build autoregressive distributed lag (ARDL) models using statistical data provided by the Central Geophysical Observatory named after Boris Sreznevsky (CGO) and the State Statistics Service of Ukraine for the period 2004-2019. The obtained outcomes show that fluctuations in the air temperature and precipitation are significant determinants of output in different sectors (specifically agriculture, construction, manufacturing, and energy). Therefore, the inclusion of weather conditions into models may potentially improve the modeling properties and forecasting of economic activity.

scholarly journals Should altitudinal gradients of temperature and precipitation inputs be inferred from key parameters in snow-hydrological models?

2019 ◽  
Author(s):  
Denis Ruelland
Keyword(s):  
Air Temperature ◽  
High Elevation ◽  
Hydrological Models ◽  
Altitudinal Gradients ◽  
Modelling Framework ◽  
Temperature And Precipitation ◽  
Snow Covered Area ◽  
Covered Area ◽  
Alpine Catchments ◽  
Correct Estimation

Abstract. This paper evaluates whether snow-covered area and streamflow measurements can help assess altitudinal gradients of temperature and precipitation in data-scarce mountainous areas more realistically than using the usual interpolation procedures. An extensive dataset covering 20 Alpine catchments is used to investigate this issue. Elevation dependency in the meteorological fields is accounted for using two approaches: (i) by estimating the local and time-varying altitudinal gradients from the available gauge network based on deterministic and geostatistical interpolation methods with an external drift; and (ii) by calibrating the local gradients using an inverse snow-hydrological modelling framework. For the second approach, a simple 2-parameter model is proposed to target the temperature/precipitation-elevation relationship and to regionalise air temperature and precipitation from the sparse meteorological network. The coherence of the two approaches is evaluated by benchmarking several hydrological variables (snow-covered area, streamflow and water balance) computed with snow-hydrological models fed with the interpolated datasets and checked against available measurements. Results show that accounting for elevation dependency from scattered observations when interpolating air temperature and precipitation cannot provide sufficiently accurate inputs for models. The lack of high-elevation stations seriously limits correct estimation of lapse rates of temperature and precipitation, which, in turn, affects the performance of the snow-hydrological simulations due to imprecise estimates of temperature and precipitation volumes. Instead, retrieving the local altitudinal gradients using an inverse approach enables increased accuracy in the simulation of snow cover and discharge dynamics, while limiting problems of over-calibration and equifinality.

scholarly journals Glacier albedo reduction and drought effects in the extratropical Andes, 1986–2020

2020 ◽  
pp. 1-12
Author(s):  
Thomas E. Shaw ◽  
Genesis Ulloa ◽  
David Farías-Barahona ◽  
Rodrigo Fernandez ◽  
Jose M. Lattus ◽  
...  
Keyword(s):  
Water Security ◽  
Late Summer ◽  
Severe Drought ◽  
Drought Period ◽  
Ice Melt ◽  
Mountain Glaciers ◽  
Snow Covered Area ◽  
Covered Area ◽  
Glacier Ice ◽  
Long Term Trends

Abstract Surface albedo typically dominates the mass balance of mountain glaciers, though long-term trends and patterns of glacier albedo are seldom explored. We calculated broadband shortwave albedo for glaciers in the central Chilean Andes (33–34°S) using end-of-summer Landsat scenes between 1986 and 2020. We found a high inter-annual variability of glacier-wide albedo that is largely a function of the glacier fractional snow-covered area and the total precipitation of the preceding hydrological year (up to 69% of the inter-annual variance explained). Under the 2010–2020 ‘Mega Drought’ period, the mean albedo, regionally averaged ranging from ~0.25–0.5, decreased by −0.05 on average relative to 1986–2009, with the greatest reduction occurring 3500–5000 m a.s.l. In 2020, differences relative to 1986–2009 were −0.14 on average as a result of near-complete absence of late summer snow cover and the driest hydrological year since the Landsat observation period began (~90% reduction of annual precipitation relative to the 1986–2009 period). We found statistically significant, negative trends in glacier ice albedo of up to −0.03 per decade, a trend that would have serious implications for the future water security of the region, because glacier ice melt acts to buffer streamflow shortages under severe drought conditions.

Factors Affecting the Outcrossing Rate between Clearfield™ Rice and Red Rice (Oryza sativa)

Weed Science ◽  
2009 ◽  
Vol 57 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Vinod K. Shivrain ◽  
Nilda R. Burgos ◽  
Marites A. Sales ◽  
Andy Mauromoustakos ◽  
David R. Gealy ◽  
...  
Keyword(s):  
Air Temperature ◽  
Field Experiments ◽  
Planting Date ◽  
Outcrossing Rate ◽  
Red Rice ◽  
Factors Affecting ◽  
Flowering Synchrony ◽  
Flowering Duration ◽  
Relative Contribution ◽  
The Impact

The commercialization of imazethapyr-resistant (Clearfield™, CL) rice in the southern United States has raised serious concerns about gene flow to red rice, producing imazethapyr-resistant red rice populations. Our objectives were to determine the impact of planting date, CL cultivars, and red rice biotypes on outcrossing rate; and to investigate the relative contribution of flowering time of CL rice and red rice biotypes, together with air temperature and relative humidity (RH), on outcrossing rate. Field experiments were conducted at Stuttgart, Rohwer, and Kibler, AR, from 2005 to 2007, at three or four planting times from mid-April to late May. ‘CL161’ (inbred cultivar) and ‘CLXL8’ (hybrid) rice were planted in nine-row plots, with red rice planted in the middle row. Twelve red rice biotypes were used. The flowering of red rice and CL rice, air temperature, and RH were recorded. Red rice seeds were collected at maturity. To estimate outcrossing rate, resistance to imazethapyr was evaluated in subsequent years and confirmed using rice microsatellite markers. CLXL8 rice flowered 2 to 4 d earlier than CL161 rice, and flowering was completed within 1 wk in all plantings. The flowering duration of most red rice biotypes ranged from 4 to 17 d. Flowering synchrony of red rice biotypes and CL rice ranged from 0 to 100% at different plantings. In general, CLXL8 had greater flowering overlap and higher outcrossing rate with red rice than did CL161 rice. The outcrossing rate of red rice biotypes ranged from 0 to 0.21% and 0 to 1.26% with CL161 and CLXL8 rice, respectively. The outcrossing rate differed within each planting date (P < 0.05). Outcrossing was generally lower in mid-May and late May than in mid-April and late April planting times. Flowering synchrony and outcrossing rate were not correlated (r2 < 0.01). Outcrossing with CL161 was primarily influenced by red rice biotype. A minimum air temperature of > 24 C in the evening also favors outcrossing with CL161. With CLXL8 rice, outcrossing was most affected by RH. When RH was < 54%, outcrossing was less (0.12%) than when RH was ≥ 54% (0.38%). With CLXL8 rice, a minimum RH of ≥ 54%, from mid-morning to noon, increased outcrossing with red rice. To fully understand the interaction effects of these factors on outcrossing with red rice, controlled experiments are needed.

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