CN101672768B - Method for acquiring atmospheric horizontal visibility field under maritime dense fog condition - Google Patents

Abstract

The invention relates to a method for acquiring an atmospheric horizontal visibility field under a maritime dense fog condition, which comprises the following steps: collecting survey station sounding data and the like of grid point meteorology and a related sea region, and performing quality control for the survey station sounding data to remove errors; determining a calculation region, a horizontal grid point number and a horizontal grid interval of a regional atmospheric model system RAMS model, interpolating the grid point meteorology data to all horizontal grid points of the RAMS model, preparing an initial condition and boundary condition field, and performing numerical integration for the RAMS model; and outputting and reserving forecast result data files, performing quantitative calculation by using an atmospheric horizontal visibility calculation formula, finally drawing the calculation result into a chromatic atmospheric visibility distribution graph, and outputting images in terms of a JPG format. The method can effectively overcome the defects that the maritime atmospheric visibility observation station data is rare, the satellite remote sensing method cannot judge whether the cloud is grounded and the like in the prior art, provides quick and quantitative maritime atmospheric horizontal visibility field for various maritime activities, and has broad application prospect.

Description

The acquisition methods of atmospheric horizontal visibility field under maritime dense fog condition

Technical field

The present invention relates to a kind of acquisition methods of atmospheric horizontal visibility field under maritime dense fog condition.

Background technology

Sea fog is meant that occurring in the sky, ocean (or island, strand) is suspended in a large amount of water droplets in the atmospheric boundary layer or ice crystal and makes the weather phenomenon of atmospheric horizontal visibility less than a km, U.S. meteorology institute is defined as mist in " cloud that in fact mist is exactly ground connection ", in other words the essence of mist and cloud is consistent, whether only need see ground connection.Because sea fog can seriously reduce marine atmosphere visibility, workers and peasants' fish production and sea, land and sky communications and transportation to marine and coastland all have obstruction, therefore to the research of sea fog with predict the great attention that always is subjected to numerous workers in meteorology and all orders of society.

As everyone knows, the research about marine atmosphere visibility at present mainly contains two kinds of methods, and a kind of is to utilize the atmospheric visibility visualizer of observation website to carry out ocean weather station observation, and another kind of method is to utilize satellite to carry out remote sensing observations on a large scale.The advantage of preceding kind method is to obtain quantitative atmospheric visibility observation data, and shortcoming is that marine cloth point observation has a lot of difficulties, observation station rareness, paucity.The advantage of back kind method is to obtain that the scope of data is big, speed is fast, and the data of obtaining can be dynamic, synchronous, intuitively, is to observe from top to bottom but shortcoming is satellite remote sensing, and whether this working method often can't be judged " cloud ground connection ".

Therefore how to overcome the shortcoming of above-mentioned two kinds of methods, for marine atmosphere visibility field provides effective, quantitative rapidly spatial and temporal distributions figure, for preventing and reducing because the atmosphere low visibility that sea fog is followed to the loss that various marine activities cause, has important scientific meaning and social economic value.

Summary of the invention

The deficiency that the objective of the invention is to overcome prior art is (as marine atmosphere visibility survey station observation data rareness, the satellite remote sensing method can't be judged whether ground connection of cloud), a kind of quantitative acquisition methods of atmospheric horizontal visibility field under maritime dense fog condition is provided, with the quantitative distribution plan of output marine atmosphere horizontal visibility field, realize the quick forecast of marine atmosphere horizontal visibility field.

The present invention is difficult for low clouds and dense fog are distinguished for overcoming the satellite remote sensing method, the layout deficiency of difficulty and atmospheric visibility observational data rareness of marine observation website, select international advanced regional atmospheric modular system (the Regional Atmospheric ModelingSystem that cloud and mist is had goodish analog capability for use, hereinafter to be referred as RAMS) analog result be basic document, the RAMS atmospherical model is a three-dimensional mesoscale atmospherical model of being led exploitation by world-renowned physics of clound and fog scholar professor Cotton of the upright university in Colorado, have advanced international standard aspect the numerical simulation study of physics of clound and fog, obtaining generally acknowledging widely and using.

Concrete steps of the present invention are as follows:

(1) at first be to be concerned about compiling of the various observational datas in marine site, comprise the sounding data of lattice point meteorological data (Geopotential Height Fields on the different barospheres, wind direction, wind speed, temperature field, relative humidity field), relevant survey station and the lattice point data of extra large surface temperature field (Sea Surface Temperature is called for short SST);

(2) the above-mentioned various observational datas of collecting are carried out quality control, pick out mistake;

(3) determine that the zoning of RAMS pattern, the HORIZONTAL PLAID of pattern count and the HORIZONTAL PLAID distance, and will be inserted on the horizontal grid point of RAMS pattern in lattice point meteorological data on the different barospheres and the SST data, and adopt successive correction analysis to assimilate into the sounding data of each the relevant survey station in the zoning, promptly assimilate to horizontal grid point, for the numerical integration of RAMS pattern provides starting condition and boundary condition field;

(4) to the numerical integration of RAMS pattern, begin the pattern integration after promptly can be according to actual needs setting the longest integral time of pattern with computer speed, and per hour at interval RAMS model predictions result data files output reservation;

(5) quantitative Analysis of atmospheric horizontal visibility: the per hour forecast result of the RAMS pattern at interval who utilizes step (4) processing to obtain, adopt the atmospheric horizontal visibility computing formula:

X _VIS＝-ln(0.02)/β

Atmospheric horizontal visibility on quantitative Analysis is gone to sea, X in the formula _VISBe atmospheric visibility, β is an atmospheric extinction coefficient;

(6) result's output: utilize meteorological special-purpose mapping software that result of calculation is depicted as the colored atmospheric visibility horizontal distribution of standard figure, and the result is pressed the output of JPG picture format.

Obviously, the present invention who constructs thus realized utilizing computing machine to marine atmosphere horizontal visibility field carry out automatically, the forecast of quantification, can provide efficiently for various marine activities, quantitative atmospheric visibility information, have broad application prospects.

Fig. 1 is an overview flow chart of the present invention.

Embodiment

As Fig. 1, as overview flow chart of the present invention, lattice point wherein, sounding and SST are all slightly writing of corresponding data.

Detailed step of the present invention is as follows:

(1) data is compiled: under linux system, utilize the shell script to write and revise the wget order, regularly download global objective analysis (Final Analysis every day, hereinafter to be referred as FNL) lattice point data (station address http://dss.ucar.edu/datasets/ds083.2/data, this data is a global range, comprising the SST data, spatial resolution is 1 ° x1 °, the time interval is 6 hours), and the sounding data of each relevant sounding station (station address: http://weather.uwoy.edu/upperair/sounding.html);

(7) (2) quality control: the various data of collecting are carried out quality control, pick out mistake, particularly examine checking the size of survey station numbering, latitude and longitude information, each isopressure surface numerical value, geopotential unit, temperature, dew point, relative humidity, mixing ratio, wind direction, wind speed and each physical quantity of megadyne temperature of sounding data and unit etc. by computer program;

(8) (3) zoning: according to the research needs determine that the HORIZONTAL PLAID of zoning, the pattern of RAMS pattern is counted and HORIZONTAL PLAID apart from (vertical demixing of RAMS pattern is to get already usually, generally be divided into 38～40 layers, 2/3rds the number of plies is distributed in the atmospheric boundary layer).For the stability of Assured Mode time integral and consider and save computing time that choose horizontal lattice point usually between 100～180, HORIZONTAL PLAID is apart between 6km～8km;

(4) data interpolation: according to RAMS mode computation zone of having determined and lattice point configuration, to be inserted on the net point of RAMS pattern in lattice point meteorological data on the different barospheres and the SST data, and adopt successive correction analysis to assimilate the sounding data of each the relevant survey station in the zoning.Final data is deposited with the ASCII character form, filename was named in proper order with year, month, day, time, first row of file content comprises the information such as time, lattice point number, lattice distance of presents, physical quantity to put in proper order be geopotential unit (Z), temperature (T), wind speed thing component (U), wind speed north and south component (V) and relative humidity (RH);

(5) pattern integration: initial field, boundary condition field and the data-preparing of SST field that RAMS mode time integration is needed are good, be stored under the file directory of appointment, and begin RAMS pattern integration after setting the longest integral time of RAMS pattern as required, and at interval RAMS model predictions result is per hour exported reservation;

(6) calculate visibility: utilize the atmospheric horizontal visibility computing formula

X _VIS＝-ln(0.02)/β

X wherein _VISBe atmospheric visibility, its unit is km, and β is an atmospheric extinction coefficient, and its unit is km ^-1The present invention has considered to comprise Yun Shui (β comprehensively _Cw), cloud ice (β _Ci), rainwater (β _Rain) and snow (β _Snow) to the influence of atmosphere, promptly above-mentioned atmospheric extinction coefficient β=β _Cw+ β _Ci+ β _Rain+ β _Snow, wherein ${\mathrm{\β}}_{\mathrm{cw}}=144.7C_{\mathrm{cw}}^{0.88}$ ， ${\mathrm{\β}}_{\mathrm{ci}}=163.9C_{\mathrm{ci}}^{1.00}$ ， ${\mathrm{\β}}_{\mathrm{rain}}=1.1C_{\mathrm{rain}}^{0.75}$ ， ${\mathrm{\β}}_{\mathrm{snow}}=10.4C_{\mathrm{snow}}^{0.78}$ , C wherein _Cw, C _Ci, C _Rain, C _SnowBe respectively the density of the air that contains Yun Shui, cloud ice, rainwater and snow, unit is gm ^-3

(7) result's issue: the colored atmospheric visibility horizontal distribution figure (with colour code classification and two kinds of form performances of numerical value isoline and stack mutually) that the special-purpose meteorological mapping software of result of calculation utilization is depicted as standard, to clearly mark primary image information such as colour code yardstick and isoline numerical value among the figure, and the result exported automatically by JPG picture format backstage, offer relevant department and use.

Claims (3)

1. the quantitative acquisition methods of an atmospheric horizontal visibility field under maritime dense fog condition, concrete grammar or step are as follows:

(1) at first be to compile the lattice point meteorological data that comprises atmosphere Geopotential Height Fields, wind direction, wind speed, temperature field, relative humidity field and the lattice point data of extra large surface temperature field, and the survey station sounding data in the relevant marine site;

(2) the above-mentioned various observational datas of collecting are carried out quality control, pick out mistake;

(3) determine that the zoning of regional atmospheric modular system RAMS pattern, the HORIZONTAL PLAID of pattern count and the HORIZONTAL PLAID distance, with lattice point meteorological data and extra large surface temperature interpolation field to the whole horizontal grid point of RAMS pattern, and the survey station sounding data in the marine site of will being correlated with assimilates to horizontal grid point with successive correction analysis, for the numerical integration of RAMS pattern provides starting condition and boundary condition;

(4) set the longest integral time of pattern according to actual needs,, and at interval model predictions result data files output per hour kept RAMS pattern integration;

(5) quantitative Analysis of atmospheric horizontal visibility: the per hour forecast result of the RAMS pattern at interval who utilizes step (4) processing to obtain, adopt the atmospheric horizontal visibility computing formula:

X _VIS＝-ln(0.02)/β

X wherein _VISBe atmospheric visibility, its unit is km, and β is an atmospheric extinction coefficient, and its unit is km ^-1, the atmospheric horizontal visibility field on quantitative Analysis is gone to sea;

(6) utilize meteorological special-purpose mapping software that the atmospheric horizontal visibility field of datumization is depicted as the colored atmospheric visibility horizontal distribution of standard figure at last, and the result is pressed the output of JPG picture format.

2. the quantitative acquisition methods of atmospheric horizontal visibility field under maritime dense fog condition as claimed in claim 1 is characterized in that above-mentioned atmospheric extinction coefficient β comprises cloud water extinction coefficient β _Cw, cloud deglaciating light factor beta _Ci, rainwater extinction coefficient β _RainWith snow extinction coefficient β _Snow, and have: β=β _Cw+ β _Ci+ β _Rain+ β _Snow, wherein

C wherein _Cw, C _Ci, C _Rain, C _SnowBe respectively the density of the air that contains Yun Shui, cloud ice, rainwater and snow, unit is gm ^-3

3. the quantitative acquisition methods of atmospheric horizontal visibility field under maritime dense fog condition as claimed in claim 1, it is characterized in that above-mentioned the various observational datas of collecting being carried out quality control, pick out mistake and be and to check the size of survey station numbering, longitude and latitude, each isopressure surface numerical value, geopotential unit, temperature, dew point, relative humidity, mixing ratio, wind direction, wind speed and each physical quantity of megadyne temperature of sounding data and unit by computer program and to examine.