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okenso [2025/02/06 16:19] – created adminokenso [2025/02/06 16:54] (current) – admin
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-= La Nina and Oklahoma Summer Precipitation =+==== La Nina and Oklahoma Summer Precipitation ====
  
-<<TableOfContents(4)>> +//from 2012?// 
- +=== NCEP analysis ===
-== NCEP analysis ==+
 Figures are from:  Figures are from: 
 [[http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/composites/EC_LNP_index.shtml | ENSO Temperature & Precipitation Composites]] [[http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/composites/EC_LNP_index.shtml | ENSO Temperature & Precipitation Composites]]
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 Note the relatively large signal in Oklahoma and northern Texas in the upper left of the figure immediately below.  There is some "folk lore" here in Norman Oklahoma that La Nina summers tend to be dry.  The figure below supports that conjecture.  Note the relatively large signal in Oklahoma and northern Texas in the upper left of the figure immediately below.  There is some "folk lore" here in Norman Oklahoma that La Nina summers tend to be dry.  The figure below supports that conjecture. 
  
-{{attachment:lanina.jja.precip.gif}}+{{:lanina.jja.precip.gif}}
 ------ ------
 Here is the corresponding El Nino image.  The El Nino effect is not investigated on this page. Here is the corresponding El Nino image.  The El Nino effect is not investigated on this page.
  
-{{attachment:elnino.jja.precip.gif}}+{{:elnino.jja.precip.gif}}
 ------ ------
-== Reinvestigate NCEP data ==+=== Reinvestigate NCEP data ===
  
 Obtain daily data from [[ftp://ftp.cpc.ncep.noaa.gov/precip/CPC_UNI_PRCP/GAUGE_CONUS/]] for years 1948 through 2010. (The missing data for day 20070226 was faked by substituting an average of 20070225 and 20070227).  Composite into 756 months. Analyze with Python: Obtain daily data from [[ftp://ftp.cpc.ncep.noaa.gov/precip/CPC_UNI_PRCP/GAUGE_CONUS/]] for years 1948 through 2010. (The missing data for day 20070226 was faked by substituting an average of 20070225 and 20070227).  Composite into 756 months. Analyze with Python:
  
-{{attachment:jjarain.png}}+{{:jjarain.png}}
  
 See a slide show of [[http://12characters.net/explore/maplots.html |  the annual cycle of precipitation]]. See a slide show of [[http://12characters.net/explore/maplots.html |  the annual cycle of precipitation]].
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 My composite images retain the resolution in the original dataset.  The pixels, or bins, in the NCEP composite (see inset) appear larger. There seems to be good agreement between the image and the inset, indicating the data has been composited correctly: My composite images retain the resolution in the original dataset.  The pixels, or bins, in the NCEP composite (see inset) appear larger. There seems to be good agreement between the image and the inset, indicating the data has been composited correctly:
  
-{{attachment:laninajjachangeINSET.png}}+{{:laninajjachangeINSET.png}}
 ------ ------
 Same image as above, but a percent change: Same image as above, but a percent change:
  
-{{attachment:jjarainpercent.png}}+{{:jjarainpercent.png}}
  
 ------ ------
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 Here is plot of all the t-values: Here is plot of all the t-values:
  
-{{attachment:jjatvalue.png}}+{{:jjatvalue.png}}
  
  
-The average t-value in the box is {{{t=-1.25}}}.  The t-value of average rain in the box is {{{t=-1.55}}}, and {{{p=.07}}}.  The fraction of the valid data area that lies within the box is {{{f=0.048}}}.  Note that in my [[http://tinyurl.com/windfarm-precip | windfarm study]] I looked for {{{p<.05f}}} to declare significance. Some details of the statistical analysis will appear below.+The average t-value in the box is ''t=-1.25''.  The t-value of average rain in the box is ''t=-1.55'', and ''p=.07''.  The fraction of the valid data area that lies within the box is ''f=0.048''.  Note that in my [[http://tinyurl.com/windfarm-precip | windfarm study]] I looked for ''p<.05'' to declare significance. Some details of the statistical analysis will appear below.
  
 ------ ------
 Here is the anomaly in the box for all years 1948-2010.  Note the if we could kick 1950 out of the set of La Nina years, we could have a convincing case that La Nina years are significantly drier: Here is the anomaly in the box for all years 1948-2010.  Note the if we could kick 1950 out of the set of La Nina years, we could have a convincing case that La Nina years are significantly drier:
  
-{{attachment:rainbar.png}}+{{:rainbar.png}}
  
 ------ ------
 Here is an image from Kim et al. (2011) that I was familiar with (but note it was prepared for the months July through October). The image suggests there is justification for kicking out 1950: the East Pacific Cooling is very modest; the normalized Nino-3 index of Kim et al. (2011) was only about {{{-0.2}}}. Also, in 1974 it was only {{{-0.3}}}, which had a slightly wet summer.  All the other years designated as La Nina by NCEP have a normalized Nino-3 index of {{{<-0.75}}}.  In the image I have written an '''A''' to indicate NCEP's La Nin'''A''' designation.       Here is an image from Kim et al. (2011) that I was familiar with (but note it was prepared for the months July through October). The image suggests there is justification for kicking out 1950: the East Pacific Cooling is very modest; the normalized Nino-3 index of Kim et al. (2011) was only about {{{-0.2}}}. Also, in 1974 it was only {{{-0.3}}}, which had a slightly wet summer.  All the other years designated as La Nina by NCEP have a normalized Nino-3 index of {{{<-0.75}}}.  In the image I have written an '''A''' to indicate NCEP's La Nin'''A''' designation.      
  
-{{attachment:nino3nino4.png}}+{{:nino3nino4.png}}
  
 I downloaded the [[http://www.cpc.ncep.noaa.gov/data/indices/ersst3b.nino.mth.81-10.ascii | ersstb data]] and as able to reproduce the above plot.  Coincidently, 1950 is the one year that has a discernible difference: I downloaded the [[http://www.cpc.ncep.noaa.gov/data/indices/ersst3b.nino.mth.81-10.ascii | ersstb data]] and as able to reproduce the above plot.  Coincidently, 1950 is the one year that has a discernible difference:
  
-{{attachment:JASOindices.png}}+{{:JASOindices.png}}
  
 But the above is from the detrend of the seasonal composite time series.  An alternative is to detrend the entire time series of the anomalies in the data file, up to the end time (December 2006, for Kim et al.), before making the seasonal composites.  This looks closer to the Kim et al. figure: But the above is from the detrend of the seasonal composite time series.  An alternative is to detrend the entire time series of the anomalies in the data file, up to the end time (December 2006, for Kim et al.), before making the seasonal composites.  This looks closer to the Kim et al. figure:
  
-{{attachment:JASOindicesD.png}} +{{:JASOindicesD.png}} 
  
 ------- -------
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 So having convinced myself I was using the data correctly, I plotted the indices for June through August. Here 1950 looks more consistent as a La Nina year: So having convinced myself I was using the data correctly, I plotted the indices for June through August. Here 1950 looks more consistent as a La Nina year:
  
-{{attachment:JJAindices.png}}+{{:JJAindices.png}}
  
  
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 1950, a wet La Nina year in Oklahoma: 1950, a wet La Nina year in Oklahoma:
  
-{{attachment:jjad1950.png}}+{{:jjad1950.png}}
  
- * To see such a figure for all years, go to [[http://12characters.net/explore/JJAanomaly.html | slide show of JJA rain fall anomalies]]. +  * To see such a figure for all years, go to [[http://12characters.net/explore/JJAanomaly.html | slide show of JJA rain fall anomalies]]. 
- * [[http://12characters.net/explore/jjasst.html | slide show of JJA SST anomalies ]] +  * [[http://12characters.net/explore/jjasst.html | slide show of JJA SST anomalies ]] 
- * [[http://12characters.net/explore/jja500.html | slide show of JJA 500 mb anomalies ]]+  * [[http://12characters.net/explore/jja500.html | slide show of JJA 500 mb anomalies ]]
  
-== Statistical Analysis ==+=== Statistical Analysis ===
  
  
-=== retain 1950 as La Nina year ===+== retain 1950 as La Nina year ==
  
-{{{+<file>
 n=15 n=15
 mean= -286.23 (.1 mm)  mean= -286.23 (.1 mm) 
Line 92: Line 91:
 2*p= 0.14 2*p= 0.14
 90% confidence interval: -612.44 < true mean < 39.96  90% confidence interval: -612.44 < true mean < 39.96 
-resample method 90% interval: -575.3 < true mean < 12.01  +resample method 90% interval: -575.3 < true mean < 12.01 
 +</file>  
  
-=== kick 1950 out as La Nina year === +== kick 1950 out as La Nina year == 
- -575.301945808 12.0111291557 + 
-{{{+<file>
 n= 14   n= 14  
 mean= -415.32 (.1 mm) mean= -415.32 (.1 mm)
Line 104: Line 104:
 90% confidence interval: -667.95   < true mean < -162.69 90% confidence interval: -667.95   < true mean < -162.69
 resample method 90% interval: -644.5 < true mean <  -192.54  resample method 90% interval: -644.5 < true mean <  -192.54 
-}}}+</file> 
 + 
 +=== Climate Forecasting and Monitoring Links ===
  
-== Climate Forecasting and Monitoring Links == 
  
- 1. [[http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml | NCEP ENSO page]] has animations of recent SST. +  - [[http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml | NCEP ENSO page]] has animations of recent SST. 
- 1. [[http://www.bom.gov.au/climate/enso/indices.shtml | Australia Bureau of Meteorology ENSO monitoring page]] +  - [[http://www.bom.gov.au/climate/enso/indices.shtml | Australia Bureau of Meteorology ENSO monitoring page]] 
- 1. [[http://www.bom.gov.au/climate/ahead/ENSO-summary.shtml | Australia Bureau of Meteorology Model Outlooks of ENSO Conditions]] +  - [[http://www.bom.gov.au/climate/ahead/ENSO-summary.shtml | Australia Bureau of Meteorology Model Outlooks of ENSO Conditions]] 
- 1. [[http://www.bom.gov.au/climate/enso/ | Australia ENSO wrap-up]]  +  - [[http://www.bom.gov.au/climate/enso/ | Australia ENSO wrap-up]]  
- 1. [[http://www.srh.noaa.gov/oun/climate/graphs.php | Yearly Climate Graphs for Selected Locations in Central/Western Oklahoma and Western North Texas ]] +  - [[http://www.srh.noaa.gov/oun/climate/graphs.php | Yearly Climate Graphs for Selected Locations in Central/Western Oklahoma and Western North Texas ]] 
- 1. [[http://climate.ok.gov/index.php/drought/year_to_date/oklahoma_south-central_u.s | OCS drought monitoring]]+  -  [[http://climate.ok.gov/index.php/drought/year_to_date/oklahoma_south-central_u.s | OCS drought monitoring]]
  
 On 5 June 2012: [[http://www.bom.gov.au/climate/enso/ | Australia ENSO wrap-up]] states: ''No climate models favour a return to La Niña.'' As of 16 June 2012, [[http://climate.ok.gov/index.php/drought/year_to_date/oklahoma_south-central_u.s | OCS drought monitoring]] shows no drought this year in Oklahoma. On 5 June 2012: [[http://www.bom.gov.au/climate/enso/ | Australia ENSO wrap-up]] states: ''No climate models favour a return to La Niña.'' As of 16 June 2012, [[http://climate.ok.gov/index.php/drought/year_to_date/oklahoma_south-central_u.s | OCS drought monitoring]] shows no drought this year in Oklahoma.
  
-== Appendix ==+=== Appendix === 
 +<file txt rainbox.txt > 
 +# in the following: st=1 -> La Nina , st=-1-> El Nino 
 +# delta is the JJA anomaly in units of 0.1 mm  
 +#year st delta  
 +1948 0  596.25 
 +1949 0 -103.40 
 +1950 1 1520.96 
 +1951 0  373.87 
 +1952 0 -1149.30 
 +1953 0 -313.70 
 +1954 1 -1358.54 
 +1955 1 -609.56 
 +1956 1 -1181.49 
 +1957 -1 -258.58 
 +1958 0  538.12 
 +1959 0  424.53 
 +1960 0  463.94 
 +1961 0  530.71 
 +1962 0  585.26 
 +1963 -1 -366.67 
 +1964 1 -496.76 
 +1965 -1   47.62 
 +1966 0   55.40 
 +1967 0   44.13 
 +1968 0  143.21 
 +1969 0 -263.35 
 +1970 1 -1019.90 
 +1971 1   85.14 
 +1972 -1  -91.75 
 +1973 1 -239.61 
 +1974 1   30.85 
 +1975 1  137.25 
 +1976 0 -724.09 
 +1977 0  -44.96 
 +1978 0 -768.82 
 +1979 0  511.22 
 +1980 0 -1283.33 
 +1981 0  130.76 
 +1982 -1   10.99 
 +1983 0 -905.43 
 +1984 0 -772.69 
 +1985 1  136.71 
 +1986 0  373.37 
 +1987 -1   85.75 
 +1988 1 -519.55 
 +1989 0 1125.00 
 +1990 0 -540.43 
 +1991 -1  127.18 
 +1992 -1 1236.93 
 +1993 0 -185.67 
 +1994 -1 -184.31 
 +1995 0  641.34 
 +1996 0 1306.06 
 +1997 -1  496.62 
 +1998 1 -838.16 
 +1999 1 -236.21 
 +2000 0 -132.17 
 +2001 0 -915.12 
 +2002 -1    6.17 
 +2003 0   31.09 
 +2004 -1 1120.59 
 +2005 0  597.69 
 +2006 0 -471.55 
 +2007 0 1316.23 
 +2008 0  577.01 
 +2009 -1  271.83 
 +2010 1  295.32 
 +</file>
  
-{{attachment:rainbox.txt}} 
  
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