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--- aerocom:faq_aerocom [2014-12-19 12:53:20]
michaels
+++ aerocom:faq_aerocom [2022-05-31 09:29:31] (current)
@@ Line 1: / Line 1: @@
-====== Frequently asked questions AeroCom ======
+ATTENTION - THIS WIKI PAGE IS NO LONGER UPDATED - PLEASE GO TO [[http://aerocom.met.no/|aerocom.met.no]]FOR LATEST INFO
-on AeroCom Web Interface and Catalogue
+====== Frequently asked questions AeroCom Web Interface ======
+==== Which observational data are used? ====
+Observational data stem from ACTRIS, EMEP, GAW, NOAA, AERONET, PHOTONS, SKYNET, NDACC, ESA, NASA and other networks. The data source can be found on Time Series and Profile plots. If several networks are used for a parameter, a menu pops up showing the reference networks.
+PIs, instruments, institutions are shown on time series and profile plots based on metadata information provided through EBAS, EARLINET, EMEP. Suggestions to complete these are very welcome !!
+The "OBSERVATIONS-ONLY" Category in the Dataset Menu can be used to see (almost) all observations currently available for model-data comparisons.
+==== Which version of the data? ====
+We use irregular updates. EBAS/EMEP/ACTRIS/EARLINET data are updated every 1-3 months. Aeronet data approxiamtely every year, except AERONET-NRT data (monthly). Not all plots are renewed at all times. You can check for the revision date on time series plots, see lower left below graph (Rev. YYYYMMDD), which represents the date when the data were updated. See also the "image created YYYY.MM.DD HH.MM" tag, which indicates when a particular plot was created.
+==== Which stations are used? ====
+An overview can be gathered from the SITELOCATION plot
+[[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=explicit&Choice=&Type0=SITELOCATION&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_NO2&Station0=EUROPE&Year0=an2008&Period0=mJJAmonthly&Ref0=EBAS&Parameter1=SCONC_NO2&Station1=EUROPE&Period1=mJJAmonthly&Type1=SITELOCATION&Ref1=EBAS&Run1=EMEP_svn2892_141119DS_vgNH4fix&Year1=an2008&PERFORMANCE=syn&INFO=nohover&ChoiceMode=&STATE=8&|Example]] and Time series plots [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=2abbrev&Choice=&Type0=SERIES&Run0=EMEP_svn2892_141127DS_RGbase&Parameter0=SCONC_NO2&Station0=NO-BirkenesII&Year0=an2012&Period0=mAMJ&Ref0=EBAS&Type1=SERIES&Run1=EMEP_svn2892_141119DS_vgNH4fix&Parameter1=SCONC_NO2&Station1=NO-Birkenes&Year1=an2008&Period1=mAMJ&Ref1=EBAS&PERFORMANCE=ind&INFO=hover&ChoiceMode=&STATE=15&|Example]]
-==== Known bugs/problems/wishes ====
--mountain sites are compared from surface level model output, use relative height\\
@@ Line 12: / Line 28: @@
 [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=explicit&Choice=&Type0=SCATTERLOG&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_PM10&Station0=EUROPE&Year0=an2008&Period0=YEARLY&Ref0=EBAS&PERFORMANCE=ind&INFO=nohover&ChoiceMode=&STATE=9&|Example]]) and in SCORE pot [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=2abbrev&Choice=&Type0=SCORE&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_PM10&Station0=EUROPE&Year0=an2008&Period0=mALLYEAR&Ref0=EBAS&Type1=MAP&Run1=EMEP_svn2892_141119DS_vgNH4fix&Parameter1=SCONC_PM10&Station1=EUROPE&Year1=an2008&Period1=mALLYEAR&Ref1=Default&PERFORMANCE=syn&INFO=nohover&ChoiceMode=&STATE=13&|Example]]
-==== Share with colleague? Report Error? ====
+==== Can I share with colleague? Report Error? ====
 To share what you see on the aerocom webinterface with a colleague, click on mail-share button upper right, (should open an email with URL link) or click on Button "Show URL link to current", below images, and copy link from popup window appearing. Use this also to report errors to Michael.
@@ Line 29: / Line 45: @@
 Use 2/4/6 panels, push "SYNCHRONISE PANEL"  [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=2abbrev&Choice=&Type0=SCATTERLOG&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_NO2&Station0=WORLD&Year0=an2008&Period0=mJJAmonthly&Ref0=EBAS&Parameter1=SCONC_NH3&Station1=WORLD&Period1=mJJAmonthly&Type1=SCATTERLOG&Ref1=EBAS&Run1=EMEP_svn2892_141119DS_vgNH4fix&Year1=an2008&PERFORMANCE=syn&INFO=nohover&ChoiceMode=&STATE=7&|Example]]
-==== Which data are used? ====
-See for instance SITELOCATION plot [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=explicit&Choice=&Type0=SITELOCATION&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_NO2&Station0=EUROPE&Year0=an2008&Period0=mJJAmonthly&Ref0=EBAS&Parameter1=SCONC_NO2&Station1=EUROPE&Period1=mJJAmonthly&Type1=SITELOCATION&Ref1=EBAS&Run1=EMEP_svn2892_141119DS_vgNH4fix&Year1=an2008&PERFORMANCE=syn&INFO=nohover&ChoiceMode=&STATE=8&|Example]] and Time series plots [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=2abbrev&Choice=&Type0=SERIES&Run0=EMEP_svn2892_141127DS_RGbase&Parameter0=SCONC_NO2&Station0=NO-BirkenesII&Year0=an2012&Period0=mAMJ&Ref0=EBAS&Type1=SERIES&Run1=EMEP_svn2892_141119DS_vgNH4fix&Parameter1=SCONC_NO2&Station1=NO-Birkenes&Year1=an2008&Period1=mAMJ&Ref1=EBAS&PERFORMANCE=ind&INFO=hover&ChoiceMode=&STATE=15&|Example]]
-==== Which version of the data? ====
-We get regularly, every 1-2 months a new update of data from eg Aeronet, EBAS. This might imply that the observational  data have changed. You can check for the revision date below, left the time series images.
 ==== Table of all comparisons? ====
@@ Line 48: / Line 58: @@
 ==== Difference to reference version? ====
-DIFFMAP plots are available for some parameters.
+DIFFMAP plots are available for some parameters. They show the difference in percent to a reference field as map.
-==== Display two model versions ====
+==== Display and compare two model/data versions ====
-using two panels, use "synchronise panels" button to see corresponding images
+Use two panels, use "synchronise panels" to see corresponding images
 [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=2abbrev&Choice=&Type0=HISTO&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_HNO3&Station0=EUROPE&Year0=an2008&Period0=mALLYEARdaily&Ref0=EBAS&Parameter1=SCONC_NH3&Station1=EUROPE&Period1=mALLYEARdaily&Type1=HISTO&Ref1=EBAS&Run1=EMEP_svn2892_141119DS_RG&Year1=an2008&PERFORMANCE=syn&INFO=hover&ChoiceMode=&STATE=7&|Example]]
+(note: the year is not changed on the second panel, so that this setting can also be used to compare different years)
 ==== Meaning of the variables ====
-Long description is visible by hovering over menu ite, and - if the info text (appearing above image when hovering over image) is not hidden
+A long description is visible by hovering over the Parameter menu item, and - in the info text (appearing above image when hovering over image)
 [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=explicit&Choice=&Type0=STATMAP-BIAS&Run0=EMEP_svn2892_141119DS_no2fac&Parameter0=SCONC_NO2&Station0=EUROPE&Year0=an2008&Period0=mALLYEAR&Ref0=EBAS&PERFORMANCE=ind&INFO=hover&ChoiceMode=&STATE=4&|Example]]
-==== Missing variable? ====
+==== Missing variable for a given model/data? ====
-Not all variables  make it sometimes into the AeroCom catalogue. If you have specific idea or request, send email to Michael with variable name.
+Not all variables  make it by default into the AeroCom catalogue. If you have specific idea or request, send email to Michael with variable name.
 ==== 3D diagnostics? ====
-not yet implemented in standard AeroCom.  To save space, ideally monthly 3D mixing ratios and profiles @stations (see HTAP-2 format and station list) can be output by the model. Ozone sondes and CALIOP profiles are candidates for near future standard diagnostics.
+Ozone sonde and vertical extinction profiles are now implemented in AeroCom. Filter models on variables VMR3D_O3 AND EC5323D_AER: [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=EMEP&MODELLIST=EMEP_SVN_TEST&FULL=explicit&INFO=nohover&PERFORMANCE=ind&YEARFILTER=ALLYEARS&PSFILTER=EC5323D_AER&Type0=PROFILE&Ref0=EARLINET&Run0=EMEP_svn2982_150422ST_Trend&Parameter0=EC5323D_AER&Station0=BucharestRomania&Year0=an2012&Period0=mDJF|Example]]
 ==== Which year is used? ====
-The year in the menu refers to the observations year used and generally to the meteorology of that year. Year may be different in the model wrt to emissions.  Also a model simulation of year x maybe be compared to year y in observations. A different year for the model shows up in eg y-axis of SCATTERLOG file. Note that 9999 is used for a climatology for either model or observations, typically comprising 5-10 years.
+The year in the menu refers to the year of observation used. Note that anCLIM (or 9999) is used to point to a climatology for either model or observations, typically comprising 5-10 years. The meaning of the "year" may be more complicated for model data, because meteorology or emissions may come from another year.  Thus a model simulation of year x maybe be compared to year y in observations. Eventually the reference item contains than also the reference year. [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=ACTRIS&MODELLIST=VERTICAL-PROFILING&FULL=explicit&INFO=nohover&PERFORMANCE=ind&YEARFILTER=ALLYEARS&PSFILTER=ALLVARS&Type0=PROFILE&Ref0=EARLINET_9999&Run0=EMEPglob.v2801&Parameter0=EC5323D_AER&Station0=CorkIreland&Year0=an2012&Period0=mJJA|Example]]
+A different year for the observation and model shows up also in eg x and y-axis of SCATTERLOG plot.
@@ Line 80: / Line 93: @@
 Versions can be removed from website, but that requires email to Jan & Michael.
-==== What means RMSspatial/temporal? ====
+==== Definition of Statistics used in Score tables and in Scatter plots ====
-For daily data analysis, RMS is split into the "spatial" RMS, calculated from monthly/seasonal/yearly averages and the "temporal" RMS, which is the residual (RMS^2temp=RMS^2-RMS^2spatial)
+Explanation for abbreviations used on scatter plots and in score tables:
+"#": Number of "observations" used for statistics (eg daily, monthly or yearly values)
+"#st": Number of sites
+"Obs": Observational mean constructed from all values in scatter plot (e.g. means from yearly station means are different from all daily value means : [[http://aerocom.met.no/cgi-bin/aerocom/surfobs_annualrs.pl?PROJECT=cci-Aerosol&MODELLIST=CCI-AEROSOL-products&FULL=2abbrev&INFO=nohover&PERFORMANCE=ind&YEARFILTER=ALLYEARS&PSFILTER=ALLVARS&Type0=SCATTERLOG&Ref0=AERONETSun2.0&Run0=AATSR_SU_v4.2&Parameter0=OD550_AER&Station0=WORLD&Year0=an2002&Period0=YEARLY&Type1=SCATTERLOG&Ref1=AERONETSun2.0&Run1=AATSR_SU_v4.2&Parameter1=OD550_AER&Station1=WORLD&Year1=an2002&Period1=mALLYEARdaily|Example]])
+"Mod": Model/Dataset mean constructed from all values in scatter plot, eg correspond to "Obs" values consistently.
+"NMB": Normalized mean bias, = (Mod-Obs)/Obs
+"RMS": Root Mean Square Error: SQRT(Sum( (y'-x')^2)/#)
+"R": Pearson Correlation Coefficient
+"RMSbc": Bias corrected RMS: SQRT(Sum( (ybc'-x')^2)/#) ; ybc' contains all model/data values corrected for the NMB bias. ybc=y*(Sum(x)/Sum(y))
+"RMSspatial": RMS from yearly mean station vales in observations and models. Model values consistently chosen for times when observations are available.
+"RMStemporal": Residual RMS after subtracting RMSspatial from RMS ( RMStemporal = SQRT( RMS^2 - RMSspatial^2 ), assuming error propagation and no covariance in temporal and spatial fields)
+...additional statistics in score tables
+"Spearman Rank Correlation": https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient
+"Spatial yearly Mean Corr Coeff": Pearson correlation coefficient from yearly mean values
+"Seasonal Anomaly Corr Coeff": Correlation coefficient of local anomalies wrt to annual mean.
+"Slope fit forced through zero": Regression of model on obs data, slope
+"Regression coefficient": Regression of model on obs data, regression
+"Regression constant, offset": Y intercept
+"STDDEV(Model)/STDDEV(Data)". Ratio of standard deviations
+"Score (mean relative bias )": sum(abs(tm-td))/# [ tm= model values, td= obs values ]
+"Taylor score": 4*(1+r)/((1+0.9)*(sm/sd+sd/sm)*(sm/sd+sd/sm) ) [ sm= Stddev of model, sd=Stddev of observations ]
+==== Known bugs/problems/wishes ====
+-mountain sites are compared from surface level model output, use relative height\\