数据说明
Relative Humidity (rel_hum )
上传时间：2019-05-22 14:04:26 浏览次数：作者与来源：admin
This parameter is the water vapour pressure as a percentage of the value at which the air becomes saturated (the point at which water vapour begins to condense into liquid water or deposition into ice). For temperatures over 0°C (273.15 K) it is calculated for saturation over water. At temperatures below -23°C it is calculated for saturation over ice. Between -23°C and 0°C this parameter is calculated by interpolating between the ice and water values using a quadratic function.
Long_name: Relative humidity at 1000 mb
Unit: %
Resolution: 1x1 degree, daily, monthly
Duration: Jan. 2000 – Dec. 2016
Source: NCEP FNL Operational Model Global Tropospheric Analyses
Processing: All the original 6-hours data in a day are averaged to get the daily data, and all the daily data in a month are averaged to get the monthly data.
Long_name: Relative humidity at 1000 mb
Unit: %
Resolution: 1x1 degree, daily, monthly
Duration: Jan. 2000 – Dec. 2016
Source: NCEP FNL Operational Model Global Tropospheric Analyses
Processing: All the original 6-hours data in a day are averaged to get the daily data, and all the daily data in a month are averaged to get the monthly data.
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The 6-hour cycling GDAS, Gridded Statistical Interpolation (GSI) analysis is posted at 1x1 degree global records 4X/day is the output of the GSI analysis using the NCEP collection of conventional and non-conventional observations, tropical cyclone relocation.
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The ENS consists of 22 extra 16-day perturbed forecasts, 11 at 0000 UDT and 11 at 1200 UDT. The ensemble starts at the same T126 L28 resolution described above, but the ensemble also drops resolution during the forecasts. After hour 84, the GFS drops to T62 L28 resolution. This horizontal resolution is roughly equivalent to a global 210 km mesh. This vertical resolution is the same as for the T126 L28 resolution.
The parallels often contain modifications to the operational system that will soon be implemented. However, not every parallel experiment is eventually implemented. Sometimes the raw parallel data files are made available to forecast users. Users should be forewarned that the parallel forecasts may fail or run late. The parallels are not maintained as operational systems. They are only provided to users for evaluation purposes.
There are several designated slots for the parallel experiments to run, each denoted by a letter. The parallel X (PRX) is the primary parallel used to test changes that will soon be implemented into the operational global system. Its control is the high resolution operational FNL and MRF. The parallel Z is identical to the operational FNL and MRF but at low resolution and usually acts as the control for other low-resolution parallels.
The Global Modeling Branch has been running parallel experiments for decades and documenting them in journal papers, technical procedures bulletins, and internal technical notes. The public HTML documentation of the parallel experiments, however, began in June 1999.
The archive time series is continuously extended to a near-current date. It is not maintained in real-time.
Uncertainties:
Reanalyses are a special type of analysis done with a fixed software system. Both the data assimilation and the forecast model software are “frozen” for the time span of a reanalysis. This inoculates them from changes in software. Both analyses and reanalyses experience shifts due to changes in observation systems (e.g. when a new satellite comes on-line or an old one is decommissioned). Researchers using reanalysis time series should carefully check times of observed shifts with times of observation system shifts.
All the contents of this page are quoted from National Centers for Environmental Prediction (NCEP). All project documentation and related publications can be found at the website:https://rda.ucar.edu/datasets/ds083.2/#docs/more.html
The parallels often contain modifications to the operational system that will soon be implemented. However, not every parallel experiment is eventually implemented. Sometimes the raw parallel data files are made available to forecast users. Users should be forewarned that the parallel forecasts may fail or run late. The parallels are not maintained as operational systems. They are only provided to users for evaluation purposes.
There are several designated slots for the parallel experiments to run, each denoted by a letter. The parallel X (PRX) is the primary parallel used to test changes that will soon be implemented into the operational global system. Its control is the high resolution operational FNL and MRF. The parallel Z is identical to the operational FNL and MRF but at low resolution and usually acts as the control for other low-resolution parallels.
The Global Modeling Branch has been running parallel experiments for decades and documenting them in journal papers, technical procedures bulletins, and internal technical notes. The public HTML documentation of the parallel experiments, however, began in June 1999.
The archive time series is continuously extended to a near-current date. It is not maintained in real-time.
Uncertainties:
Reanalyses are a special type of analysis done with a fixed software system. Both the data assimilation and the forecast model software are “frozen” for the time span of a reanalysis. This inoculates them from changes in software. Both analyses and reanalyses experience shifts due to changes in observation systems (e.g. when a new satellite comes on-line or an old one is decommissioned). Researchers using reanalysis time series should carefully check times of observed shifts with times of observation system shifts.
All the contents of this page are quoted from National Centers for Environmental Prediction (NCEP). All project documentation and related publications can be found at the website:https://rda.ucar.edu/datasets/ds083.2/#docs/more.html
