scholarly journals Evaluation of the hydrological cycle of MATCH driven by NCEP reanalysis data: comparison with GOME water vapor field measurements

2004 ◽  
Vol 4 (6) ◽  
pp. 7917-7984 ◽  
Author(s):  
R. Lang ◽  
M. G. Lawrence
Keyword(s):  
Water Vapor ◽  
Regional Differences ◽  
Hydrological Cycle ◽  
Transport Model ◽  
Global Precipitation Climatology Project ◽  
Reanalysis Data ◽  
Model Parameters ◽  
Residence Times ◽  
Ncep Reanalysis ◽  
Inter Tropical Convergence Zone

Abstract. This study examines two key parameters of the hydrological cycle, water vapor (WV) and precipitation rates (PR), as modelled by the chemistry transport model MATCH (Model of Atmospheric Transport and Chemistry) driven by National Centers for Environmental Prediction (NCEP) reanalysis data (NRA). For model output evaluation we employ WV total column data from the Global Ozone Monitoring Experiment (GOME) on ERS-2, which is the only instrument capable measuring WV on a global scale and over all surface types with a substantial data record from 1995 to the present. We find that MATCH and NRA WV and PR distributions are closely related, but that significant regional differences in both parameters exist in magnitude and distribution patterns when compared to the observations. We also find that WV residual patterns between model and observations show remarkable similarities to residuals observed in the PR when comparing MATCH and NRA output to observations comprised by the Global Precipitation Climatology Project (GPCP). We conclude that deficiencies in model parameters shared by MATCH and NRA, like, for example, in the evapotranspiration rates, are likely to lead to the observed differences. Regional differences between MATCH modelled WV columns and the observations can be as large as 2 cm on the basis of a three years monthly average. Differences in the global mean WV values are, however, below 1 mm. Regional differences in the PR between MATCH and GPCP can be above 5 mm per day and MATCH computes on average a higher PR than what has been observed. As a consequence, this leads to shorter model WV residence times by about 1 day as compared to NRA data and the observations. We find that MATCH has problems in modelling the WV content in regions of strong upward convection like, for example, along the Inter Tropical Convergence Zone, where it appears to be generally too dry as compared to the observations. The study therefore suggests that a too rapid conversion of WV to precipitate in MATCH, especially in instances of strong convection, leads to regionally too dry model results and in turn to generally too low WV residence times. The study additionally demonstrates the value of the GOME WV record for model evaluation.

scholarly journals Evaluation of the hydrological cycle of MATCH driven by NCEP reanalysis data: comparison with GOME water vapor measurements

2005 ◽  
Vol 5 (4) ◽  
pp. 887-908 ◽  
Author(s):  
R. Lang ◽  
M. G. Lawrence
Keyword(s):  
Water Vapor ◽  
Regional Differences ◽  
Hydrological Cycle ◽  
Transport Model ◽  
Global Precipitation Climatology Project ◽  
Global Scale ◽  
Reanalysis Data ◽  
Model Parameters ◽  
Ncep Reanalysis ◽  
Inter Tropical Convergence Zone

Abstract. This study examines two key parameters of the hydrological cycle, water vapor (WV) and precipitation rates (PR), as modelled by the chemistry transport model MATCH (Model of Atmospheric Transport and Chemistry) driven by National Centers for Environmental Prediction (NCEP) reanalysis data (NRA). For model output evaluation we primarily employ WV total column data from the Global Ozone Monitoring Experiment (GOME) on ERS-2, which is the only instrument capable measuring WV on a global scale and over all surface types with a substantial data record from 1995 to the present. We find that MATCH and NRA WV and PR distributions are closely related, but that significant regional differences in both parameters exist in magnitude and distribution patterns when compared to the observations. We also find that WV residual patterns between model and observations show remarkable similarities to residuals observed in the PR when comparing MATCH and NRA output to observations comprised by the Global Precipitation Climatology Project (GPCP). We conclude that deficiencies in model parameters shared by MATCH and NRA, like in the surface evaporation rates and regional transport patterns, are likely to lead to the observed differences. Monthly average regional differences between MATCH modelled WV columns and the observations can be as large as 2 cm, based on the analysis of three years. Differences in the global mean WV values are, however, below 0.1 cm. Regional differences in the PR between MATCH and GPCP can be above 0.5 cm per day and MATCH computes on average a higher PR than what has been observed. The lower water vapor content of MATCH is related to shorter model WV residence times by up to 1 day as compared to the observations. We find that MATCH has problems in modelling the WV content in regions of strong upward convection like, for example, along the Inter Tropical Convergence Zone, where it appears to be generally too dry as compared to the observations. We discuss possible causes for this bias and demonstrate the value of the GOME WV record for model evaluation.

scholarly journals Hydrological controls on the tropospheric ozone greenhouse gas effect

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Le Kuai ◽  
Kevin W. Bowman ◽  
Helen M. Worden ◽  
Robert L. Herman ◽  
Susan S. Kulawik
Keyword(s):  
Water Vapor ◽  
Greenhouse Gas ◽  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Hydrological Cycle ◽  
Longwave Radiation ◽  
Hadley Cell ◽  
Water Vapor Absorption ◽  
Inter Tropical Convergence Zone ◽  
Tropospheric O3

The influence of the hydrological cycle in the greenhouse gas (GHG) effect of tropospheric ozone (O3) is quantified in terms of the O3 longwave radiative effect (LWRE), which is defined as the net reduction of top-of-atmosphere flux due to total tropospheric O3 absorption. The O3 LWRE derived from the infrared spectral measurements by Aura’s Tropospheric Emission Spectrometer (TES) show that the spatiotemporal variation of LWRE is relevant to relative humidity, surface temperature, and tropospheric O3 column. The zonally averaged subtropical LWRE is ~0.2 W m–2 higher than the zonally averaged tropical LWRE, generally due to lower water vapor concentrations and less cloud coverage at the downward branch of the Hadley cell in the subtropics. The largest values of O3 LWRE over the Middle East (>1 W/m2) are further due to large thermal contrasts and tropospheric ozone enhancements from atmospheric circulation and pollution. Conversely, the low O3 LWRE over the Inter-Tropical Convergence Zone (on average 0.4 W m–2) is due to strong water vapor absorption and cloudiness, both of which reduce the tropospheric O3 absorption in the longwave radiation. These results show that changes in the hydrological cycle due to climate change could affect the magnitude and distribution of ozone radiative forcing.

Diagnosis of Subtropical Humidity Dynamics Using Tracers of Last Saturation

2005 ◽  
Vol 62 (9) ◽  
pp. 3353-3367 ◽  
Author(s):  
Joseph Galewsky ◽  
Adam Sobel ◽  
Isaac Held
Keyword(s):  
Water Vapor ◽  
General Circulation ◽  
Large Scale ◽  
Transport Model ◽  
Thermal Relaxation ◽  
Circulation Model ◽  
Reanalysis Data ◽  
Tracer Transport ◽  
Dry Air ◽  
Model Match

Abstract A technique for diagnosing the mechanisms that control the humidity in a general circulation model (GCM) or observationally derived meteorological analysis dataset is presented. The technique involves defining a large number of tracers, each of which represents air that has last been saturated in a particular region of the atmosphere. The time-mean tracer fields show the typical pathways that air parcels take between one occurrence of saturation and the next. The tracers provide useful information about how different regions of the atmosphere influence the humidity elsewhere. Because saturation vapor pressure is a function only of temperature and assuming mixing ratio is conserved for unsaturated parcels, these tracer fields can also be used together with the temperature field to reconstruct the water vapor field. The technique is first applied to an idealized GCM in which the dynamics are dry and forced using the Held–Suarez thermal relaxation, but the model carries a passive waterlike tracer that is emitted at the surface and lost due to large-scale condensation with zero latent heat release and no condensate retained. The technique provides an accurate reconstruction of the simulated water vapor field. In this model, the dry air in the subtropical troposphere is produced primarily by isentropic transport and is moistened somewhat by mixing with air from lower levels, which has not been saturated since last contact with the surface. The technique is then applied to the NCEP–NCAR reanalysis data from December–February (DJF) 2001/02, using the offline tracer transport model MATCH. The results show that the dryness of the subtropical troposphere is primarily controlled by isentropic transport of very dry air by midlatitude eddies and that diabatic descent from the tropical upper troposphere plays a secondary role in controlling the dryness of the subtropics.

scholarly journals Interannual variability in hindcasts of atmospheric chemistry: the role of meteorology

2009 ◽  
Vol 9 (14) ◽  
pp. 5261-5280 ◽  
Author(s):  
P. Hess ◽  
N. Mahowald
Keyword(s):  
Water Vapor ◽  
Surface Temperature ◽  
Interannual Variability ◽  
Atmospheric Chemistry ◽  
El Niño ◽  
Hydrological Cycle ◽  
Transport Model ◽  
El Nino ◽  
Climate Simulation ◽  
Relative Variability

Abstract. Two 40-year meteorological datasets are used to drive the Model of Ozone and Related Tracers chemical transport model, version 2 (MOZART2) in hindcast simulations. One dataset is from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, the second dataset uses meteorology from the Community Atmosphere Model (CAM3) forced with observed interannually varying sea surface temperatures. All emissions, except those from lightning are annually constant. Analysis of these simulations focuses on the period between 1979–1999, due to meteorological discontinuities in the NCEP reanalysis during the 1970s. The meteorology using CAM3 captures observed trends in temperature and water vapor; the simulation using NCEP meteorology does not. This paper examines the regional and global interannual variability of various chemical and meteorological fields: CO, OH, O3 and HNO3, the surface photolysis rate of NO2 (as a proxy for overhead cloudiness), lightning NO emissions, water vapor, planetary boundary layer height, and temperature. The variability due to changes in emissions is not considered in this analysis. In both the NCEP and CAM3 simulations the relative variability of CO, OH, O3 and HNO3 are qualitatively similar, with variability maxima both in the tropics and the high latitudes. Locally, relative variability generally ranges between 3 and 10%; globally the tropospheric variability generally ranges from half to one percent, but can be higher. For most fields the leading global Empirical Orthogonal Function explains approximately 10% of the variability and correlates significantly with El Niño. In both simulations the first principal component of a multiple tracer, globally averaged analysis shows a strong coupling between surface temperature, measures of the hydrological cycle, CO and OH, but is not correlated with El Niño. In both simulations we examine the global response of the selected variables to changes in global surface temperature, and compare with a climate simulation over the 21st century.

scholarly journals Interannual variability in hindcasts of atmospheric chemistry: the role of meteorology

2009 ◽  
Vol 9 (1) ◽  
pp. 3485-3534
Author(s):  
P. Hess ◽  
N. Mahowald
Keyword(s):  
Water Vapor ◽  
Surface Temperature ◽  
Interannual Variability ◽  
Atmospheric Chemistry ◽  
El Niño ◽  
Hydrological Cycle ◽  
Transport Model ◽  
El Nino ◽  
Climate Simulation ◽  
Relative Variability

Abstract. Two 40-year meteorological datasets are used to drive the Model of Ozone and Related Tracers chemical transport model, version 2 (MOZART2) in hindcast simulations. One dataset is from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, the second dataset uses meteorology from the Community Atmosphere Model (CAM3) forced with observed interannually varying sea surface temperatures. All emissions, except those from lightning are annually constant. Analysis of these simulations is from 1979–1999, due to meteorological discontinuities in the NCEP reanalysis during the 1970s. The meteorology using CAM3 captures observed trends in temperature, water vapor, precipitation and cloudiness; the simulation using NCEP meteorology does not. This paper examines the regional and global interannual variability of various chemical and meteorological fields: CO, OH, O3 and HNO3, the surface photolysis rate of NO2 (as a proxy for overhead cloudiness), lightning NO emissions, water vapor, planetary boundary layer height, and temperature. The variability due to changes in emissions is not considered in this analysis. In both the NCEP and CAM3 simulations the relative variability of CO, OH, O3 and HNO3 are qualitatively similar, with variability maxima both in the tropics and the high latitudes. Locally, relative variability generally ranges between 3 and 10%; globally the tropospheric variability generally ranges from half to one percent, but can be higher. For most fields the leading Empirical Orthogonal Function explains approximately 10% of the variability and correlates significantly with El Niño. In both simulations the first principal component of a multiple tracer, globally averaged analysis shows a strong coupling between surface temperature, measures of the hydrological cycle, CO and OH, but is not correlated with El Niño. In both simulations we examine the global response of the selected variables to changes in global surface temperature, and compare with a climate simulation over the 21st century.

scholarly journals COMPARISON OF GNSS PWV AND ERA5-DERIVED PWV BASED ON GNSS PWV IN HONG KONG, CHINA

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 987-993
Author(s):  
Z. W. Li ◽  
C. Z. Tang ◽  
S. H. Tang ◽  
Y. Zhang
Keyword(s):  
Hong Kong ◽  
Water Vapor ◽  
Hydrological Cycle ◽  
Precipitable Water ◽  
Weather Forecast ◽  
Reanalysis Data ◽  
Vital Role ◽  
Small Range ◽  
Data Set ◽  
Medium Range Weather Forecast

Abstract. Water vapor is the most abundant atmospheric gas, and it plays a vital role in the evolution of the Earth's climate. Precipitable water vapor (PWV) is a key factor in monitoring the climate and hydrological cycle. The use of GNSS to estimate PWV is a very effective method. This paper uses 17 satellite positioning reference stations in SatRef, Hong Kong, China, in 2017 to calculate the PWV and introduce the latest reanalysis data set of the European Medium Range Weather Forecast Ingenued Center (ECMWF) ERA5 into this study. The accuracy of THE PWV derived from ERA5 was evaluated using the GNSS-derived PWV. In Hong Kong, the annual bias and RMSE values of GNSS-derived ZTD and ERA5-derived ZTDs are 1.16 cm and 1.78 cm respectively, while the annual RMSE values of GNSS-derived PWV and ERA5-derived PWV are 0.51 cm and 0.57 cm, respectively. The daily changes of GNSS PWV in 2017 are analyzed, and the results show that the ZTD effect of THE ERA5 reanalysis data derived in the small range area is not very ideal, but the accuracy of the PWV derived from ERA5 is better.

Parameter Determination for Chloride and Tritium Transport in Undisturbed Lysimeters during Steady Flow

1992 ◽  
Vol 23 (2) ◽  
pp. 89-104 ◽  
Author(s):  
Ole H. Jacobsen ◽  
Feike J. Leij ◽  
Martinus Th. van Genuchten
Keyword(s):  
Experimental Data ◽  
Unsaturated Flow ◽  
Transport Model ◽  
Time Moment ◽  
Breakthrough Curves ◽  
Coarse Sand ◽  
Retardation Factor ◽  
Parameter Determination ◽  
Model Parameters ◽  
Water Fraction

Breakthrough curves of Cl and 3H2O were obtained during steady unsaturated flow in five lysimeters containing an undisturbed coarse sand (Orthic Haplohumod). The experimental data were analyzed in terms of the classical two-parameter convection-dispersion equation and a four-parameter two-region type physical nonequilibrium solute transport model. Model parameters were obtained by both curve fitting and time moment analysis. The four-parameter model provided a much better fit to the data for three soil columns, but performed only slightly better for the two remaining columns. The retardation factor for Cl was about 10 % less than for 3H2O, indicating some anion exclusion. For the four-parameter model the average immobile water fraction was 0.14 and the Peclet numbers of the mobile region varied between 50 and 200. Time moments analysis proved to be a useful tool for quantifying the break through curve (BTC) although the moments were found to be sensitive to experimental scattering in the measured data at larger times. Also, fitted parameters described the experimental data better than moment generated parameter values.

Long-term variation of water vapor content and precipitation in the Haihe river basin

2014 ◽  
Vol 6 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Chun Chang ◽  
Ping Feng ◽  
Fawen Li ◽  
Yunming Gao
Keyword(s):  
Water Vapor ◽  
River Basin ◽  
Reanalysis Data ◽  
Water Vapor Content ◽  
Haihe River Basin ◽  
Haihe River ◽  
Annual Water ◽  
Environmental Prediction ◽  
High Consistency ◽  
The Haihe River Basin

Based on the Haihe river basin National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data from 1948 to 2010 and the precipitation data of 53 hydrological stations during 1957–2010, this study analyzed the variation of water vapor content and precipitation, and investigated the correlation between them using several statistical methods. The results showed that the annual water vapor content decreased drastically from 1948 to 2010. It was comparatively high from the late 1940s to the late 1960s and depreciated from the early 1970s. From the southeast to the northwest of the Haihe river basin, there was a decrease in water vapor content. For vertical distribution, water vapor content from the ground to 700 hPa pressure level accounted for 72.9% of the whole atmospheric layer, which indicated that the water vapor of the Haihe river basin was mainly in the air close to the ground. The precipitation in the Haihe river basin during 1957–2010 decreased very slightly. According to the correlation analysis, the precipitation and water vapor content changes showed statistically positive correlation, in addition, their break points were both in the 1970s. Furthermore, the high consistency between the precipitation efficiency and precipitation demonstrates that water vapor content is one of the important factors in the formation of precipitation.

scholarly journals Review on Applications of 17O in Hydrological Cycle

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4468
Author(s):  
Yalalt Nyamgerel ◽  
Yeongcheol Han ◽  
Minji Kim ◽  
Dongchan Koh ◽  
Jeonghoon Lee
Keyword(s):  
Water Vapor ◽  
General Circulation ◽  
Hydrological Cycle ◽  
General Circulation Models ◽  
Convective Precipitation ◽  
Subsurface Water ◽  
Polar Regions ◽  
Sea Ice Concentration ◽  
Moisture Source ◽  
Depositional Processes

The triple oxygen isotopes (16O, 17O, and 18O) are very useful in hydrological and climatological studies because of their sensitivity to environmental conditions. This review presents an overview of the published literature on the potential applications of 17O in hydrological studies. Dual-inlet isotope ratio mass spectrometry and laser absorption spectroscopy have been used to measure 17O, which provides information on atmospheric conditions at the moisture source and isotopic fractionations during transport and deposition processes. The variations of δ17O from the developed global meteoric water line, with a slope of 0.528, indicate the importance of regional or local effects on the 17O distribution. In polar regions, factors such as the supersaturation effect, intrusion of stratospheric vapor, post-depositional processes (local moisture recycling through sublimation), regional circulation patterns, sea ice concentration and local meteorological conditions determine the distribution of 17O-excess. Numerous studies have used these isotopes to detect the changes in the moisture source, mixing of different water vapor, evaporative loss in dry regions, re-evaporation of rain drops during warm precipitation and convective storms in low and mid-latitude waters. Owing to the large variation of the spatial scale of hydrological processes with their extent (i.e., whether the processes are local or regional), more studies based on isotopic composition of surface and subsurface water, convective precipitation, and water vapor, are required. In particular, in situ measurements are important for accurate simulations of atmospheric hydrological cycles by isotope-enabled general circulation models.

scholarly journals Application of Dynamically Constrained Interpolation Methodology in Simulating National-Scale Spatial Distribution of PM2.5 Concentrations in China

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 272
Author(s):  
Ning Li ◽  
Junli Xu ◽  
Xianqing Lv
Keyword(s):  
Transport Model ◽  
Ground Level ◽  
Kriging Interpolation ◽  
Model Parameters ◽  
National Scale ◽  
Constrained Interpolation ◽  
Simulation Accuracy ◽  
Interpolation Accuracy ◽  
Geographical Regions ◽  
The Right

Numerous studies have revealed that the sparse spatiotemporal distributions of ground-level PM2.5 measurements affect the accuracy of PM2.5 simulation, especially in large geographical regions. However, the high precision and stability of ground-level PM2.5 measurements make their role irreplaceable in PM2.5 simulations. This article applies a dynamically constrained interpolation methodology (DCIM) to evaluate sparse PM2.5 measurements captured at scattered monitoring sites for national-scale PM2.5 simulations and spatial distributions. The DCIM takes a PM2.5 transport model as a dynamic constraint and provides the characteristics of the spatiotemporal variations of key model parameters using the adjoint method to improve the accuracy of PM2.5 simulations. From the perspective of interpolation accuracy and effect, kriging interpolation and orthogonal polynomial fitting using Chebyshev basis functions (COPF), which have been proved to have high PM2.5 simulation accuracy, were adopted to make a comparative assessment of DCIM performance and accuracy. Results of the cross validation confirm the feasibility of the DCIM. A comparison between the final interpolated values and observations show that the DCIM is better for national-scale simulations than kriging or COPF. Furthermore, the DCIM presents smoother spatially interpolated distributions of the PM2.5 simulations with smaller simulation errors than the other two methods. Admittedly, the sparse PM2.5 measurements in a highly polluted region have a certain degree of influence on the interpolated distribution accuracy and rationality. To some extent, adding the right amount of observations can improve the effectiveness of the DCIM around existing monitoring sites. Compared with the kriging interpolation and COPF, the results show that the DCIM used in this study would be more helpful for providing reasonable information for monitoring PM2.5 pollution in China.

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