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RE: Averaged months of SST really affected by months with no data?

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ER
Erin Reed, modified 4 Years ago.

Averaged months of SST really affected by months with no data?

Youngling Posts: 3 Join Date: 6/30/17 Recent Posts

Hi everyone,

I've been playing around with monthly average SST data, trying to look at seasonal comparisons in SST across years and within a year. I just noticed that When I averaged three months together it produced a map with large blank spots. When I investigated each individual year, 1 year has very sparse data and the other two have data throughout my range pretty well covered. Can you tell me why this sparsely covered month is given so much weight? Is this a quirk of the data sets or is something amiss in my code? Would be good to figure this out so I pay more attention in how I interpret the data in the future.

Thank you!

Erin

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MA
Melanie Abecassis, modified 4 Years ago.

RE: Averaged months of SST really affected by months with no data?

Youngling Posts: 65 Join Date: 6/12/17 Recent Posts

Hi Erin,
​​​​​​​Which dataset are you using? Can you send me the ERDDAP URL?
​​​​​​​
 

MA
Melanie Abecassis, modified 4 Years ago.

RE: Averaged months of SST really affected by months with no data?

Youngling Posts: 65 Join Date: 6/12/17 Recent Posts

It looks like the issue might be the way you set the color breaks. If you're working with several different months, the range of values for SST is gonna be very different from one month to another. and if your values get out of the range you set, it will plot as blank.
​​​​​​​So you need to get the range of values for all your months and find a range that cover all months.
​​​​​​​Then you can set your breaks this way, instead of using a histogram: comment out the line that says breaks=h$breaks. and instead use: breaks=seq(min,max,0.1), with min and max being values that make sense for your data.

ER
Erin Reed, modified 4 Years ago.

RE: Averaged months of SST really affected by months with no data?

Youngling Posts: 3 Join Date: 6/30/17 Recent Posts
Oh that's a good point! That's probably very likely considering its a middle month. I'll try that. I don't have the exact URl any more but here is the code.
  
ERDDAP_Node="https://oceanwatch.pifsc.noaa.gov/erddap/"
  dataInfo <- rerddap::info('CRW_sst_v1_0_monthly', url=ERDDAP_Node)  


On Thu, Oct 29, 2020 at 11:07 AM Melanie Abecassis <VLab.Notifications@noaa.gov> wrote:

It looks like the issue might be the way you set the color breaks. If you're working with several different months, the range of values for SST is gonna be very different from one month to another. and if your values get out of the range you set, it will plot as blank.
​​​​​​​So you need to get the range of values for all your months and find a range that cover all months.
​​​​​​​Then you can set your breaks this way, instead of using a histogram: comment out the line that says breaks=h$breaks. and instead use: breaks=seq(min,max,0.1), with min and max being values that make sense for your data.


--
Melanie Abecassis CoastWatch Virtual Lab Forum https://vlab.noaa.gov/web/coastwatch/coastwatch-knowledge-base/forum/-/message_boards/view_message/12360773 VLab.Notifications@noaa.gov



--
Erin M. Reed, MSc
JIMAR Fish Life History Bio-Sampling Specialist
NOAA Fisheries-Inouye Regional Center
NMFS/PIFSC/FRMD/Erin Reed
1845 Wasp Boulevard, Building 176
Honolulu, Hawaii 96818
+1(808) 725-5352

ER
Erin Reed, modified 4 Years ago.

RE: Averaged months of SST really affected by months with no data?

Youngling Posts: 3 Join Date: 6/30/17 Recent Posts
That did the trick, thank you!!

On Thu, Oct 29, 2020 at 11:11 AM Erin Reed <VLab.Notifications@noaa.gov> wrote:

Oh that's a good point! That's probably very likely considering its a middle month. I'll try that. I don't have the exact URl any more but here is the code.
  
ERDDAP_Node="https://oceanwatch.pifsc.noaa.gov/erddap/"
  dataInfo <- rerddap::info('CRW_sst_v1_0_monthly', url=ERDDAP_Node)  


On Thu, Oct 29, 2020 at 11:07 AM Melanie Abecassis <VLab.Notifications@noaa.gov> wrote:

It looks like the issue might be the way you set the color breaks. If you're working with several different months, the range of values for SST is gonna be very different from one month to another. and if your values get out of the range you set, it will plot as blank.
​​​​​​​So you need to get the range of values for all your months and find a range that cover all months.
​​​​​​​Then you can set your breaks this way, instead of using a histogram: comment out the line that says breaks=h$breaks. and instead use: breaks=seq(min,max,0.1), with min and max being values that make sense for your data.


--
Melanie Abecassis CoastWatch Virtual Lab Forum https://vlab.noaa.gov/web/coastwatch/coastwatch-knowledge-base/forum/-/message_boards/view_message/12360773 VLab.Notifications@noaa.gov



--
Erin M. Reed, MSc
JIMAR Fish Life History Bio-Sampling Specialist
NOAA Fisheries-Inouye Regional Center
NMFS/PIFSC/FRMD/Erin Reed
1845 Wasp Boulevard, Building 176
Honolulu, Hawaii 96818
+1(808) 725-5352


--
Erin Reed CoastWatch Virtual Lab Forum http://vlab.noaa.gov/web/coastwatch/coastwatch-knowledge-base/forum/-/message_boards/view_message/12361115 VLab.Notifications@noaa.gov



--
Erin M. Reed, MSc
JIMAR Fish Life History Bio-Sampling Specialist
NOAA Fisheries-Inouye Regional Center
NMFS/PIFSC/FRMD/Erin Reed
1845 Wasp Boulevard, Building 176
Honolulu, Hawaii 96818
+1(808) 725-5352

MA
Melanie Abecassis, modified 4 Years ago.

RE: Averaged months of SST really affected by months with no data?

Youngling Posts: 65 Join Date: 6/12/17 Recent Posts
yay!!

On Thu, Oct 29, 2020 at 5:15 PM Erin Reed <VLab.Notifications@noaa.gov> wrote:

That did the trick, thank you!!

On Thu, Oct 29, 2020 at 11:11 AM Erin Reed <VLab.Notifications@noaa.gov> wrote:

Oh that's a good point! That's probably very likely considering its a middle month. I'll try that. I don't have the exact URl any more but here is the code.
  
ERDDAP_Node="https://oceanwatch.pifsc.noaa.gov/erddap/"
  dataInfo <- rerddap::info('CRW_sst_v1_0_monthly', url=ERDDAP_Node)  


On Thu, Oct 29, 2020 at 11:07 AM Melanie Abecassis <VLab.Notifications@noaa.gov> wrote:

It looks like the issue might be the way you set the color breaks. If you're working with several different months, the range of values for SST is gonna be very different from one month to another. and if your values get out of the range you set, it will plot as blank.
​​​​​​​So you need to get the range of values for all your months and find a range that cover all months.
​​​​​​​Then you can set your breaks this way, instead of using a histogram: comment out the line that says breaks=h$breaks. and instead use: breaks=seq(min,max,0.1), with min and max being values that make sense for your data.


--
Melanie Abecassis CoastWatch Virtual Lab Forum https://vlab.noaa.gov/web/coastwatch/coastwatch-knowledge-base/forum/-/message_boards/view_message/12360773 VLab.Notifications@noaa.gov



--
Erin M. Reed, MSc
JIMAR Fish Life History Bio-Sampling Specialist
NOAA Fisheries-Inouye Regional Center
NMFS/PIFSC/FRMD/Erin Reed
1845 Wasp Boulevard, Building 176
Honolulu, Hawaii 96818
+1(808) 725-5352


--
Erin Reed CoastWatch Virtual Lab Forum http://vlab.noaa.gov/web/coastwatch/coastwatch-knowledge-base/forum/-/message_boards/view_message/12361115 VLab.Notifications@noaa.gov



--
Erin M. Reed, MSc
JIMAR Fish Life History Bio-Sampling Specialist
NOAA Fisheries-Inouye Regional Center
NMFS/PIFSC/FRMD/Erin Reed
1845 Wasp Boulevard, Building 176
Honolulu, Hawaii 96818
+1(808) 725-5352


--
Erin Reed CoastWatch Virtual Lab Forum http://vlab.noaa.gov/web/coastwatch/coastwatch-knowledge-base/forum/-/message_boards/view_message/12361123 VLab.Notifications@noaa.gov



--
________________________________________________________
Melanie Abecassis
OceanWatch Operations Manager
NOAA CoastWatch/OceanWatch/PolarWatch 
NOAA/NESDIS/STAR
Satellite Oceanography and Climatology Division
NOAA Center for Weather and Climate Prediction (NCWCP) 
5830 University Research Court
College Park, MD 20740, USA
Earth System Science Interdisciplinary Center (ESSIC)/
Cooperative Institute for Satellite Earth System Studies (CISESS)
University of Maryland
__________________________________________________________