scholarly journals Improved Historical Analysis of Oceanic Total Precipitable Water*

2015 ◽  
Vol 28 (8) ◽  
pp. 3099-3121 ◽  
Author(s):  
Thomas M. Smith ◽  
Phillip A. Arkin
Keyword(s):  
Nineteenth Century ◽  
Water Cycle ◽  
Historical Analysis ◽  
Extended Period ◽  
Precipitable Water ◽  
Change Analysis ◽  
Global Mode ◽  
Climate Modes ◽  
Total Precipitable Water ◽  
Dynamic Reanalysis

Abstract The amount of water vapor in the atmosphere, total precipitable water (TPW), is an important part of the global water cycle, and a clearer understanding of ocean-area TPW is critical for understanding climate variations. This study uses satellite-period statistics and historical data to analyze monthly oceanic TPW beginning in the nineteenth century. Input data for analyzing the historical TPW includes outputs from an extended dynamic reanalysis and estimates of TPW based on historical sea surface temperature (SST). Methods are developed to optimally use the various inputs to produce an improved analysis. Cross-validation testing is used to guide analysis development. Some evaluation of the resulting analysis indicates several strong climate modes. A global mode indicates multidecadal increases in TPW since the nineteenth century, with strongest increases in the tropics and adjacent to land monsoon regions. Strongest multidecadal changes in the global mode are 1910–40 and since 1980. An ENSO mode for the extended period indicates a trend since the 1980s, opposite to the tendency in the global mode. There is no apparent multidecadal variation in the ENSO mode before 1980, suggesting that its multidecadal relationship with the global mode can change. Analysis of SST over the same period shows climate modes consistent with the TPW modes, and for the satellite period there are consistent variations in the satellite data, showing the strong link between SST and oceanic TPW.

scholarly journals Global Changes of the Water Cycle Intensity

2005 ◽  
Vol 18 (10) ◽  
pp. 1591-1608 ◽  
Author(s):  
Michael G. Bosilovich ◽  
Siegfried D. Schubert ◽  
Gregory K. Walker
Keyword(s):  
Twentieth Century ◽  
Water Cycle ◽  
Precipitable Water ◽  
The United States ◽  
Upward Trend ◽  
Time Step ◽  
Cycling Rate ◽  
Total Precipitable Water ◽  
Climate Simulations ◽  
Simulated Precipitation

Abstract In this study, numerical simulations of the twentieth-century climate are evaluated, focusing on the changes in the intensity of the global water cycle. A new model diagnostic of atmospheric water vapor cycling rate is developed and employed that relies on constituent tracers predicted at the model time step. This diagnostic is compared to a simplified traditional calculation of cycling rate, based on monthly averages of precipitation and total water content. The mean sensitivity of both diagnostics to variations in climate forcing is comparable. However, the new diagnostic produces systematically larger values with more variability. Climate simulations were performed using SSTs of the early (1902–21) and late (1979–98) twentieth century along with the appropriate CO2 forcing. In general, the increase of global precipitation with the increases in SST that occurred between the early and late twentieth century is small. However, an increase of atmospheric temperature leads to a systematic increase in total precipitable water. As a result, the residence time of water in the atmosphere increased, indicating a reduction of the global cycling rate. This result was explored further using a number of 50-yr climate simulations from different models forced with observed SST. The anomalies and trends in the cycling rate and hydrologic variables of different GCMs are remarkably similar. The global annual anomalies of precipitation show a significant upward trend related to the upward trend of surface temperature, during the latter half of the twentieth century. While this implies an increase in the simulated hydrologic cycle intensity, a concomitant increase of total precipitable water again leads to a decrease in the calculated global cycling rate. An analysis of the land/sea differences shows that the simulated precipitation over land has a decreasing trend, while the oceanic precipitation has an upward trend consistent with previous studies and the available observations. The decreasing continental trend in precipitation is located primarily over tropical land regions, with some other regions, such as North America, experiencing an increasing trend. Precipitation trends are diagnosed further using the water tracers to delineate the precipitation that occurs because of continental evaporation, as opposed to oceanic evaporation. These model diagnostics show that over global land areas, the recycling of continental moisture is decreasing in time. However, the recycling changes are not spatially uniform so that some regions, most notably over the United States, experience continental recycling of water that increases in time.

scholarly journals A Comparison of Total Precipitable Water between Reanalyses and NVAP

2005 ◽  
Vol 18 (11) ◽  
pp. 1790-1807 ◽  
Author(s):  
Arief Sudradjat ◽  
Ralph R. Ferraro ◽  
Michael Fiorino
Keyword(s):  
Spatial Pattern ◽  
Water Cycle ◽  
Precipitable Water ◽  
Atmospheric Model ◽  
Department Of Energy ◽  
Total Precipitable Water ◽  
Convergence Zones ◽  
Environmental Prediction ◽  
The Tropics ◽  
The U.S

Abstract This study compares monthly total precipitable water (TPW) from the National Aeronautics and Space Administration (NASA) Water Vapor Project (NVAP) and reanalyses of the National Centers for Environmental Prediction (NCEP) (R-1), NCEP–Department of Energy (DOE) Atmospheric Model Intercomparison Project (AMIP-II) (R-2), and the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) from January 1988 through December 1999. Based on the means, NVAP exhibits systematic wetter land regions relative to the other datasets reflecting differences in their analyses due to paucity in radiosonde observations. ERA-40 is wetter in the atmospheric convergence zones than the U.S. reanalyses and NVAP ranges in between. Differences in the annual cycle between the reanalyses (especially R-2) and NVAP are also noticeable over the tropical oceans. Analyses on the interannual variabilities show that the ENSO-related spatial pattern in ERA-40 follows more coherently that of NVAP than those of the U.S. reanalyses. The 1997/98 El Niño’s effect on TPW is shown to be strongest only in NVAP, R-1, and ERA-40 during the period of study. All the datasets show TPW decreases in the Tropics following the 1991 Mt. Pinatubo eruption. By subtracting SST-estimated TPW from the datasets, only NVAP and ERA-40 can well represent the spatial pattern of convergence and/or moist-air advection zones in the Tropics. Even though all the datasets are viable for water cycle and climate analyses with discrepancies (wetness and dryness) to be aware of, this study has found that NVAP and ERA-40 perform better than the U.S. reanalyses during the 12-yr period.

scholarly journals The Retrieval of Total Precipitable Water over Global Land Based on FY-3D/MWRI Data

2020 ◽  
Vol 12 (9) ◽  
pp. 1508 ◽  
Author(s):  
Baolong Du ◽  
Dabin Ji ◽  
Jiancheng Shi ◽  
Yongqian Wang ◽  
Tianjie Lei ◽  
...  
Keyword(s):  
Water Cycle ◽  
Precipitable Water ◽  
Weather Conditions ◽  
Surface Emissivity ◽  
Ancillary Data ◽  
Spatial And Temporal Scales ◽  
Total Precipitable Water ◽  
Key Factor ◽  
Estimation Function ◽  
Improved Algorithm

Total precipitable water (TPW) is an important key factor in the global water cycle and climate change. The knowledge of TPW characteristics at spatial and temporal scales could help us to better understand our changing environment. Currently, many algorithms are available to retrieve TPW from optical and microwave sensors. There are still no available TPW data over land from FY-3D MWRI, which was launched by China in 2017. However, the TPW product over land is a key element for the retrieval of many ecological environment parameters. In this paper, an improved algorithm was developed to retrieve TPW over land from the brightness temperature of FY-3D MWRI. The major improvement is that surface emissivity, which is a key parameter in the retrieval of TPW in all-weather conditions, was developed and based on an improved algorithm according to the characteristics of FY-3D MWRI. The improvement includes two aspects, one is selection of appropriate ancillary data in estimating surface emissivity parameter Δε18.7/Δε23.8 in clear sky conditions, and the other is an improvement of the Δε18.7/Δε23.8 estimation function in cloudy conditions according to the band configuration of FY-3D MWRI. Finally, TPW retrieved was validated using TPW observation from the SuomiNet GPS and global distributed Radiosonde Observations (RAOB) networks. According to the validation, TPW retrieved using observations from FY-3D MWRI and ancillary data from Aqua MODIS had the best quality. The root mean square error (RMSE) and correlation coefficient between the retrieved TPW and observed TPW from RAOB were 5.47 and 0.94 mm, respectively.

Prerequisites for the reforms of the Russian Empire in the 1860s: a historical analysis

2020 ◽  
Vol 2020 (10-2) ◽  
pp. 176-184
Author(s):  
Dmitry Nechevin ◽  
Leonard Kolodkin
Keyword(s):  
Nineteenth Century ◽  
Foreign Policy ◽  
Western Europe ◽  
Historical Analysis ◽  
Russian Empire ◽  
Economic Relations ◽  
The Sixties ◽  
The Russian Empire ◽  
Political Economic

The article is devoted to the prerequisites of the reforms of the Russian Empire of the sixties of the nineteenth century, their features, contradictions: the imperial status of foreign policy and the lagging behind the countries of Western Europe in special political, economic relations. The authors studied the activities of reformers and the nobility on the peasant question, as well as legitimate conservatism.

scholarly journals The past and present of pandemic management: health diplomacy, international epidemiological surveillance, and COVID-19

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Flavio D’Abramo
Keyword(s):  
Nineteenth Century ◽  
Historical Analysis ◽  
Epidemiological Surveillance ◽  
Health Diplomacy ◽  
The Past ◽  
Colonial Expansion ◽  
Administrative Systems

AbstractThe establishment of international sanitary institutions, which took place in the context of rivalry among the great European powers and their colonial expansion in Asia, allowed for the development of administrative systems of international epidemiological surveillance as a response to the cholera epidemics at the end of the nineteenth century. In this note, I reflect on how a historical analysis of the inception of international epidemiological surveillance and pandemic management helps us to understand what is happening in the COVID-19 pandemic today.

‘Our passion for legality’: international law and imperialism in late nineteenth-century Britain

2008 ◽  
Vol 34 (3) ◽  
pp. 403-423 ◽  
Author(s):  
CASPER SYLVEST
Keyword(s):  
Nineteenth Century ◽  
International Law ◽  
South African ◽  
Historical Analysis ◽  
World Politics ◽  
Late Nineteenth Century ◽  
Contemporary World ◽  
Late Nineteenth ◽  
Congo Free State

AbstractThis article deploys a historical analysis of the relationship between law and imperialism to highlight questions about the character and role of international law in global politics. The involvement of two British international lawyers in practices of imperialism in Africa during the late nineteenth century is critically examined: the role of Travers Twiss (1809–1897) in the creation of the Congo Free State and John Westlake’s (1828–1913) support for the South African War. The analysis demonstrates the inescapably political character of international law and the dangers that follow from fusing a particular form of liberal moralism with notions of legal hierarchy. The historical cases raise ethico-political questions, the importance of which is only heightened by the character of contemporary world politics and the attention accorded to international law in recent years.

Evaluation of daily and diurnal signals of total precipitable water (TPW) over the Indian Ocean based on TMI retrieved 3-day composite estimates and radiosonde data

2007 ◽  
Vol 27 (6) ◽  
pp. 761-770 ◽  
Author(s):  
V. Sajith ◽  
Jimmy O. Adegoke ◽  
Santosh K. Raghavan ◽  
H. S. Ram Mohan ◽  
Vinod Kumar ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Precipitable Water ◽  
Radiosonde Data ◽  
Total Precipitable Water ◽  
The Indian Ocean

Analysis of the interannual variability in satellite gravity solutions : impact of climate modes on water mass displacements across continents and oceans

2021 ◽  
Author(s):  
Julia Pfeffer ◽  
Anny Cazenave ◽  
Anne Barnoud
Keyword(s):  
Climate Variability ◽  
Mass Transport ◽  
Interannual Variability ◽  
North Atlantic ◽  
North Pacific ◽  
Water Mass ◽  
Water Cycle ◽  
Satellite Gravity ◽  
Climate Modes ◽  
Shallow Seas

<p>The acquisition of time-lapse satellite gravity measurements during the GRACE and GRACE Follow On (FO) missions revolutionized our understanding of the Earth system, through the accurate quantification of the mass transport at global and regional scales. Largely related to the water cycle, along with some geophysical signals, decadal trends and seasonal cycles dominate the mass transport signals, constituting about 80 % of the total variability measured during GRACE (FO) missions. We focus here on the interannual variability, constituting the remaining 20 % of the signal, once linear trends and seasonal signals have been removed. Empirical orthogonal functions (EOFs) highlight the most prominent signals, including short-lived signals triggered by major earthquakes, interannual oscillations in the water cycle driven by the El Nino Southern Oscillation (ENSO) and significant decadal variability, potentially related to the Pacific Decadal Oscillation (PDO). The interpretation of such signals remains however limited due to the arbitrary nature of the statistical decomposition in eigen values. To overcome these limitations, we performed a LASSO (Least Absolute Shrinkage and Selection Operator) regression of eight climate indices, including ENSO, PDO, NPGO (North Pacific Gyre Oscillation), NAO (North Atlantic Oscillation), AO (Arctic Oscillation), AMO (Atlantic Multidecadal Oscillation), SAM (Southern Annular Mode) and IOD (Indian Ocean Dipole). The LASSO regularization, coupled with a cross-validation, proves to be remarkably successful in the automatic selection of relevant predictors of the climate variability for any geographical location in the world. As expected, ENSO and PDO impact the global water cycle both on land and in the ocean. The NPGO is also a major actor of the global climate, showing similarities with the PDO in the North Pacific. AO is generally favored over NAO, especially in the Mediteranean Sea and North Atlantic. SAM has a preponderant influence on the interannual variability of ocean bottom pressures in the Southern Ocean, and, in association with ENSO, modulates the interannual variability of ice mass loss in West Antarctica. AMO has a strong influence on the interannual water cycle along the Amazon river, due to the exchange of moisture in tropical regions. IOD has little to no impact on the interannual water cycle. All together, climate modes generate changes in the water mass distribution of about 100 mm for land, 50 mm for shallow seas and 15 mm for oceans. Climate modes account for a secondary but significant portion of the total interannual variability (at maximum 60% for shallow seas, 50 % for land and 40% for oceans). While such processes are insufficient to fully explain the complex nature of the interannual variability of water mass transport on a global scale, climate modes can be used to correct the GRACE (FO) measurements for a significant part of the natural climate variability and uncover smaller signals masked by such water mass transports.</p>

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