scholarly journals A study of the impact of synoptic weather conditions and water vapor on aerosol-cloud relationships over major urban clusters of China

2015 ◽  
Vol 15 (10) ◽  
pp. 14007-14026
Author(s):  
K. Kourtidis ◽  
S. Stathopoulos ◽  
A. K. Georgoulias ◽  
G. Alexandri ◽  
S. Rapsomanikis
Keyword(s):  
Water Vapor ◽  
Cloud Cover ◽  
Hydrological Cycle ◽  
Weather Conditions ◽  
Climatic Impact ◽  
Sea Level Pressure ◽  
Synoptic Weather ◽  
Cloud Top Pressure ◽  
The Impact

Abstract. The relationships between Aerosol Optical Depth (AOD) and Cloud Cover (CC) over 3 major urban clusters in China are studied under different Sea Level Pressure (SLP) and Water Vapor (WV) regimes using a decade (2003–2013) of MODIS observations. Over all urban clusters, for all SLP regimes, CC is found to increase with AOD, thus pointing out that the CC dependence on AOD is not solely due to meteorological co-variability. WV is found to have a stronger impact on CC than AOD. This impact is more pronounced at high aerosol load than at low aerosol load. Hence, studies of AOD-CC relationships based on satellite data, might greatly overestimate or underestimate the AOD impact on CC in regions where AOD and WV have similar or opposite seasonal variations, respectively. Further, this impact shows that the hydrological cycle interferes with the aerosol climatic impact and we need to improve our understanding of this interference. Our results also suggest that studies attributing Cloud Top Pressure (CTP) long-term changes to changes in aerosol load might have a WV bias.

scholarly journals A study of the impact of synoptic weather conditions and water vapor on aerosol–cloud relationships over major urban clusters of China

2015 ◽  
Vol 15 (19) ◽  
pp. 10955-10964 ◽  
Author(s):  
K. Kourtidis ◽  
S. Stathopoulos ◽  
A. K. Georgoulias ◽  
G. Alexandri ◽  
S. Rapsomanikis
Keyword(s):  
Water Vapor ◽  
Seasonal Variations ◽  
Hydrological Cycle ◽  
Weather Conditions ◽  
Climatic Impact ◽  
Sea Level Pressure ◽  
Synoptic Weather ◽  
Cloud Top Pressure ◽  
The Impact

Abstract. The relationships between aerosol optical depth (AOD), cloud cover (CC), and cloud top pressure (CTP) over three major urban clusters in China are studied under different sea level pressure (SLP) and water vapor (WV) regimes using a decade (2003–2013) of MODIS satellite-retrieved data. Over all urban clusters, for all SLP regimes, CC is found to increase with AOD, thus pointing out that the CC dependence on AOD cannot be explained by synoptic covariation, as approximated by SLP, alone. WV is found to have a stronger impact on CC than AOD. This impact is more pronounced at high aerosol load than at low aerosol load. Hence, studies of AOD–CC relationships, based on satellite data, will greatly overestimate the AOD impact on CC in regions where AOD and WV have similar seasonal variations, while they will probably underestimate the AOD impact in regions where AOD and WV have opposite seasonal variations. Further, this impact shows that the hydrological cycle interferes with the aerosol climatic impact and we need to improve our understanding of this interference. Our results also suggest that studies attributing CTP long-term changes to changes in aerosol load might have a WV bias.

Terrestrial Solar Radiation

2017 ◽  
pp. 191-293
Keyword(s):  
Solar Radiation ◽  
Horizontal Plane ◽  
Cloud Cover ◽  
Weather Conditions ◽  
Clear Sky ◽  
Solar Tracking ◽  
Sky Conditions ◽  
The Impact ◽  
Estimation Models

After shading a light on the extraterrestrial solar radiation in the chapter 3 it is important to evaluate the global terrestrial solar radiation and its components. The information on terrestrial solar radiation is required in several different forms depending on the kinds of calculations and kind of application that are to be done. Of course, terrestrial solar radiation on the horizontal plane depends on the different weather conditions such as cloud cover, relative humidity, and ambient temperature. Therefore, the impact of the atmosphere on solar radiation should be considered. One of the most important points of terrestrial solar radiation evaluation is its determination during clear sky conditions. Therefore, in this chapter, the equations that determine the air mass basing on available theories are given and the clear sky conditions are introduced with shading a light on the previous work in identifying clear sky conditions. Taking into consideration that, clear sky solar radiation estimation is of great importance for solar tracking, a detailed review of main available models is given in this chapter. As daily, monthly, seasonally, biannually and yearly mean daily solar radiations are required information for designing and installing long term tracking systems, different available methods are commented regarding their applicability for the estimation of solar radiation information in the desired format from the data that are available. An important accent is paid also on the assessment and comparison of monthly mean daily solar radiation estimation models.

scholarly journals THE INFLUENCE OF CLIMATE ON THE RESPIRATORY FUNCTION OF THE HEALTHY POPULATION OF VLADIVOSTOK AND PATIENTS WITH BRONCHOPULMONARY PATHOLOGY

2018 ◽  
Vol 97 (5) ◽  
pp. 418-423
Author(s):  
L. V. Veremchuk ◽  
E. E. Mineeva ◽  
Tatyana I. Vitkina ◽  
T. A. Gvozdenko
Keyword(s):  
Respiratory Function ◽  
Pulmonary Ventilation ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Bronchial Obstruction ◽  
Healthy Population ◽  
Uncontrolled Asthma ◽  
Monsoon Climate ◽  
Climatic Impact ◽  
The Impact

Introduction. The climatic factors affect the mucous membrane of the respiratory tract contacting with the environment. The investigation of pulmonary ventilation plays a leading role in the diagnosis of bronchial obstruction in response to an external stimulus. Material and methods. The study included a healthy population of the city and patients with chronic catarrhal nonobstructive bronchitis (CCNB), controlled and uncontrolled asthma (131 people). The respiratory function (RF) was estimated by spirography and body plethysmography. Meteorological conditions were evaluated from the point of view of contrasting weather changes (on the survey day, on 1st and 2nd days before the survey). The degree of the climatic impact on RF was determined by the statistical module “Discriminant analysis”, used to a group of RF indices relatively adverse levels of impact of the monsoon climate. Results. The low level of the responsiveness in a healthy urban population was identified. The negative impact of climatic indices on the respiratory system in CCNB patients was observed mainly in extreme weather conditions. The influence of climatic conditions on patients with asthma depends on the level of the disease control. Discussion. The influence of climatic conditions was found to be within the adaptive and compensatory responses in a group of healthy people and CCNB patients. We assumed the use of basic drugs in patients with asthma without signs of bronchial obstruction to reduce the susceptibility of the receptors of the bronchi to the negative climatic impact. The greatest negative RF response to the impact of monsoon climate manifested both in static and in dynamic weather conditions, was observed in patients with uncontrolled asthma. It was associated with the impaired pulmonary ventilation. Conclusion. The results indicate the Far East monsoon climate to be an important risk factor for the exacerbation in patients with respiratory diseases.

scholarly journals The Strength of Low-Cloud Feedbacks and Tropical Climate: A CESM Sensitivity Study

2019 ◽  
Vol 32 (9) ◽  
pp. 2497-2516 ◽  
Author(s):  
Ehsan Erfani ◽  
Natalie J. Burls
Keyword(s):  
Climate Sensitivity ◽  
Cloud Cover ◽  
Hydrological Cycle ◽  
Tropical Climate ◽  
Cloud Feedback ◽  
Cloud Feedbacks ◽  
Feedback Strength ◽  
Low Cloud ◽  
Low Cloud Cover ◽  
The Impact

Abstract Variability in the strength of low-cloud feedbacks across climate models is the primary contributor to the spread in their estimates of equilibrium climate sensitivity (ECS). This raises the question: What are the regional implications for key features of tropical climate of globally weak versus strong low-cloud feedbacks in response to greenhouse gas–induced warming? To address this question and formalize our understanding of cloud controls on tropical climate, we perform a suite of idealized fully coupled and slab-ocean climate simulations across which we systematically scale the strength of the low-cloud-cover feedback under abrupt 2 × CO2 forcing within a single model, thereby isolating the impact of low-cloud feedback strength. The feedback strength is varied by modifying the stratus cloud fraction so that it is a function of not only local conditions but also global temperature in a series of abrupt 2 × CO2 sensitivity experiments. The unperturbed decrease in low cloud cover (LCC) under 2 × CO2 is greatest in the mid- and high-latitude oceans, and the subtropical eastern Pacific and Atlantic, a pattern that is magnified as the feedback strength is scaled. Consequently, sea surface temperature (SST) increases more in these regions as well as the Pacific cold tongue. As the strength of the low-cloud feedback increases this results in not only increased ECS, but also an enhanced reduction of the large-scale zonal and meridional SST gradients (structural climate sensitivity), with implications for the atmospheric Hadley and Walker circulations, as well as the hydrological cycle. The relevance of our results to simulating past warm climate is also discussed.

Simulating the impact of future climate change on runoff processes in selected catchments of Slovakia

2021 ◽  
Author(s):  
Roman Výleta ◽  
Milica Aleksić ◽  
Patrik Sleziak ◽  
Kamila Hlavcova
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Climate Model ◽  
Hydrological Cycle ◽  
Future Climate Change ◽  
Time Horizons ◽  
The Future ◽  
The Impact ◽  
Impacts Of Climate Change

<p>The future development of the runoff conditions, as a consequence of climate change, is of great interest for water managers. Information about the potential impacts of climate change on the hydrological regime is needed for long-term planning of water resources and flood protection.</p><p>The aim of this study is to evaluate the possible impacts of climate change on the runoff regime in five selected catchments located in the territory of Slovakia. Changes in climatic characteristics (i.e., precipitation and air temperature) for future time horizons were prepared by a regional climate model KNMI using the A1B emission scenario. The selected climatic scenario predicts a general increase in air temperature and precipitation (higher in winter than in summer). For simulations of runoff under changed conditions, a lumped rainfall-runoff model (the TUW model) was used. This model belongs to a group of conceptual models and follows a structure of a widely used Swedish HBV model. The TUW model was calibrated for the period of 2011 – 2019. We assumed that this period would be similar (to recent/warmer climate) in terms of the average daily air temperatures and daily precipitation totals. The future changes in runoff due to climate change were evaluated by comparing the simulated long-term mean monthly runoff for the current state (1981-2010) and modelled scenarios in three time periods (2011-2040, 2041-2070, and 2071-2100). The results indicate that changes in the long-term runoff seasonality and extremality of hydrological cycle could be expected in the future. The runoff should increase in winter months compared to the reference period. This increase is probably related to a rise in temperature and anticipated snowmelt. Conversely, during the summer periods, a decrease in the long-term runoff could be assumed. According to modelling, these changes will be more pronounced in the later time horizons.</p><p>It should be noted that the results of the simulation are dependent on the availability of the inputs, the hydrological/climate model used, the schematization of the simulated processes, etc. Therefore, they need to be interpreted with a sufficient degree of caution</p>

scholarly journals An update on the uncertainties of water vapor measurements using cryogenic frost point hygrometers

2016 ◽  
Vol 9 (8) ◽  
pp. 3755-3768 ◽  
Author(s):  
Holger Vömel ◽  
Tatjana Naebert ◽  
Ruud Dirksen ◽  
Michael Sommer
Keyword(s):  
Water Vapor ◽  
Lower Troposphere ◽  
Dew Point ◽  
Data Series ◽  
Mixing Ratio ◽  
Stratospheric Water Vapor ◽  
Frost Point ◽  
Tropical Tropopause ◽  
The Impact

Abstract. Long time series of observations of essential climate variables in the troposphere and stratosphere are often impacted by inconsistencies in instrumentation and ambiguities in the interpretation of the data. To reduce these problems of long-term data series, all measurements should include an estimate of their uncertainty and a description of their sources. Here we present an update of the uncertainties for tropospheric and stratospheric water vapor observations using the cryogenic frost point hygrometer (CFH). The largest source of measurement uncertainty is the controller stability, which is discussed here in detail. We describe a method to quantify this uncertainty for each profile based on the measurements. We also show the importance of a manufacturer-independent ground check, which is an essential tool to continuously monitor the uncertainty introduced by instrument variability. A small bias, which has previously been indicated in lower tropospheric measurements, is described here in detail and has been rectified. Under good conditions, the total from all sources of uncertainty of frost point or dew point measurements using the CFH can be better than 0.2 K. Systematic errors, which are most likely to impact long-term climate series, are verified to be less than 0.1 K. The impact of the radiosonde pressure uncertainty on the mixing ratio for properly processed radiosondes is considered small. The mixing ratio uncertainty may be as low as 2 to 3 %. The impact of the ambient temperature uncertainty on relative humidity (RH) is generally larger than that of the frost point uncertainty. The relative RH uncertainty may be as low as 2 % in the lower troposphere and 5 % in the tropical tropopause region.

scholarly journals The stability and calibration of water vapor isotope ratio measurements during long-term deployments

2015 ◽  
Vol 8 (5) ◽  
pp. 5425-5466 ◽  
Author(s):  
A. Bailey ◽  
D. Noone ◽  
M. Berkelhammer ◽  
H. C. Steen-Larsen ◽  
P. Sato
Keyword(s):  
Water Vapor ◽  
Concentration Dependence ◽  
Hydrological Cycle ◽  
Dew Point ◽  
Vapor Concentration ◽  
Mauna Loa ◽  
Laser Absorption ◽  
Low Humidity ◽  
The Stability

Abstract. With the recent advent of commercial laser absorption spectrometers, field studies measuring stable isotope ratios of hydrogen and oxygen in water vapor have proliferated. These pioneering analyses have provided invaluable feedback about best strategies for optimizing instrumental accuracy, yet questions still remain about instrument performance and calibration approaches for multi-year field deployments. With clear scientific potential for using these instruments to carry out long-term monitoring of the hydrological cycle, this study examines the long-term stability of the isotopic biases associated with three cavity-enhanced laser absorption spectrometers – calibrated with different systems and approaches – at two remote field sites: Mauna Loa Observatory, Hawaii, USA, and Greenland Environmental Observatory, Summit, Greenland. The analysis pays particular attention to the stability of measurement dependencies on water vapor concentration and also evaluates whether these so-called concentration-dependences are sensitive to statistical curve-fitting choices or measurement hysteresis. The results suggest evidence of monthly-to-seasonal concentration-dependence variability – which likely stems from low signal-to-noise at the humidity-range extremes – but no long-term directional drift. At Mauna Loa, where the isotopic analyzer is calibrated by injection of liquid water standards into a vaporizer, the largest source of inaccuracy in characterizing the concentration-dependence stems from an insufficient density of calibration points at low humidity. In comparison, at Greenland, the largest source of inaccuracy is measurement hysteresis associated with interactions between the reference vapor, generated by a custom dew point generator (DPG), and the sample tubing. Nevertheless, prediction errors associated with correcting the concentration-dependence are small compared to total measurement uncertainty. At both sites, a dominant source of uncertainty is instrumental precision at low humidity, which cannot be reduced by improving calibration strategies. Challenges in monitoring long-term isotopic drift are also discussed in light of the different calibration systems evaluated.

scholarly journals Impact of Kalpana-1-Derived Water Vapor Winds on Indian Ocean Tropical Cyclone Forecasts

2010 ◽  
Vol 138 (3) ◽  
pp. 987-1003 ◽  
Author(s):  
S. K. Deb ◽  
C. M. Kishtawal ◽  
P. K. Pal
Keyword(s):  
Water Vapor ◽  
Indian Ocean ◽  
Wrf Model ◽  
Initial Position ◽  
Space Applications ◽  
Sea Level Pressure ◽  
Position Errors ◽  
Ocean Region ◽  
Wrf Modeling ◽  
The Impact

Abstract The water vapor winds from the operational geostationary Indian National Satellite (INSAT) Kalpana-1 have recently become operational at the Space Applications Centre (SAC). A series of experimental forecasts are attempted here to evaluate the impact of water vapor winds derived from Kalpana-1 for the track and intensity prediction of two Bay of Bengal tropical cyclones (TCs), Sidr and Nargis, using the Weather Research and Forecasting (WRF) modeling system. The assimilation of water vapor winds has made some impact in the initial position errors as well as track forecasts when compared with the corresponding control experiments for both TCs. However, no statistically significant improvement is noticed in the simulations of TC intensities [i.e., minimum sea level pressure (MSLP) and maximum surface winds forecasts when satellite winds are used for assimilation]. Moreover, the performance of Kalpana-1 winds is evaluated by repeating the same sets of experiments using Meteosat-7 winds derived at the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and compared with observed data. The simulation of initial position errors, and track and intensity forecasts using the assimilation of water vapor winds from both satellites are comparable. Though, these results are preliminary with respect to the Kalpana-1 winds, the present study can provide some insight to the WRF model users over the Indian Ocean region.

scholarly journals Evaluating Nature-Based Solution for Flood Reduction in Spercheios River Basin under Current and Future Climate Conditions

2021 ◽  
Vol 13 (7) ◽  
pp. 3885
Author(s):  
Christos Spyrou ◽  
Michael Loupis ◽  
Νikos Charizopoulos ◽  
Ilektra Apostolidou ◽  
Angeliki Mentzafou ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Maximum Velocity ◽  
Weather Conditions ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Climate Conditions ◽  
The Impact

Nature-based solutions (NBS) are being deployed around the world in order to address hydrometeorological hazards, including flooding, droughts, landslides and many others. The term refers to techniques inspired, supported and copied from nature, avoiding large constructions and other harmful interventions. In this work the development and evaluation of an NBS applied to the Spercheios river basin in Central Greece is presented. The river is susceptible to heavy rainfall and bank overflow, therefore the intervention selected is a natural water retention measure that aims to moderate the impact of flooding and drought in the area. After the deployment of the NBS, we examine the benefits under current and future climate conditions, using various climate change scenarios. Even though the NBS deployed is small compared to the rest of the river, its presence leads to a decrease in the maximum depth of flooding, maximum velocity and smaller flooded areas. Regarding the subsurface/groundwater storage under current and future climate change and weather conditions, the NBS construction seems to favor long-term groundwater recharge.

A Weather Index for Analysing Grain Yield Instability in China, 1952–81

1984 ◽  
Vol 97 ◽  
pp. 68-83 ◽  
Author(s):  
Y. Y. Kueh
Keyword(s):  
Grain Yield ◽  
Weather Conditions ◽  
Water Control ◽  
Weather Impact ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Regression Techniques ◽  
Long Term Trends ◽  
The Impact

This article applies standard regression techniques to examine the impact of adverse weather conditions on average grain yield per sown hectare in contemporary China. By isolating the weather impact I hope (a) to quantify the possible influence of frequent policy and organizational changes which have been so characteristic of Chinese agriculture since 1949; and (b) to show to what extent grain production in China has become more “weather-proof” after three decades of massive investment in water control and other modern inputs. I shall deal mainly with the long-term trends from 1952 to 1981, with special reference to the extraordinary 1959–61 period, during which total grain output and yield declined by an average of 21 and 12 per cent respectively (or 25 and 18 per cent for the two trough years of 1960 and 1961), measured against the benchmark year of 1957.

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