Search found 252 matches

by GES DISC - jimacker
Thu Jun 01, 2023 11:34 am America/New_York
Forum: Questions/Comments
Question: Wind speed and direction for terrestrial ecology
Replies: 4

Re: Wind speed and direction for terrestrial ecology

Further information: GLDAS only has windspeed, not direction. This URL selects the GLDAS windspeed variables (different temporal resolutions). https://giovanni.gsfc.nasa.gov/giovanni/#service=TmAvMp&starttime=&endtime=&variableFacets=dataFieldMeasurement%3AWind%3BdataProductPlatformInstr...
by GES DISC - jimacker
Thu Jun 01, 2023 11:28 am America/New_York
Forum: Questions/Comments
Question: Wind speed and direction for terrestrial ecology
Replies: 4

Re: Wind speed and direction for terrestrial ecology

Chloe, I would recommend using our Giovanni system, https://giovanni.gsfc.nasa.gov/ . It provides windspeed and wind direction data from both the Global Land Data Assimilation System (GLDAS) and the Modern-Era Retrospective analysis for Research and Applications Version 2 (MERRA-2). Giovanni is not ...
by GES DISC - jimacker
Wed May 31, 2023 12:41 pm America/New_York
Forum: Questions/Comments
Question: Magnitude and Unit of PM2.5, MERRA-2: Conversion Necessary?
Replies: 4

Re: Magnitude and Unit of PM2.5, MERRA-2: Conversion Necessary?

From our MERRA-2 staff: you may have seen this, but this also confirms the conversion factor. Here is the related information about converting the surface PM2.5 units from kg/m3 to micro-grams/m3 PM2.5 = (DUSMASS25 + OCSMASS+ BCSMASS + SSSMASS25 + SO4SMASS*1.375) *1.e9 # To convert MERRA-2 aerosol o...
by GES DISC - jimacker
Wed May 31, 2023 11:24 am America/New_York
Forum: Questions/Comments
Question: Magnitude and Unit of PM2.5, MERRA-2: Conversion Necessary?
Replies: 4

Re: Magnitude and Unit of PM2.5, MERRA-2: Conversion Necessary?

Hello. In answer to your first question, this is a simple units conversion, so the multiplication factor would be generally applicable. I am not an atmospheric scientist, but I expect that the use of μg / m^3 is much more common, both because the numbers are easy to comprehend and because of the act...
by GES DISC - jimacker
Tue May 30, 2023 1:48 pm America/New_York
Forum: Questions/Comments
Question: Sentinel 5P NO2 Tropospheric vertical column data mapping
Replies: 2

Re: Sentinel 5P NO2 Tropospheric vertical column data mapping

I apologize for the delay in this reply, as we have considered various causes of negative values in the data retrieval. Assuming the negative values aren't coming from fill values, they are not that uncommon, and can arise for a number of reasons. E.g. the atmosphere modelled is not a good represent...
by GES DISC - jimacker
Tue May 30, 2023 1:15 pm America/New_York
Forum: Questions/Comments
Question: Magnitude and Unit of PM2.5, MERRA-2: Conversion Necessary?
Replies: 4

Re: Magnitude and Unit of PM2.5, MERRA-2: Conversion Necessary?

Hello, We will have our MERRA-2 staff examine your question; however, you appear to be doing the calculation correctly. The conversion for kg to μg (micrograms) is 10^9. So, multiplying your value (rounded) of 4.6e-8 kg / m^3 by 10^9 gives a value of 45, which is in the range you were expecting. The...
by GES DISC - jimacker
Tue May 30, 2023 11:34 am America/New_York
Forum: Questions/Comments
Question: mangrove Forest Ecosystems
Replies: 2

Re: mangrove Forest Ecosystems

Hello,

What type of data are you seeking regarding the mangroves?
by GES DISC - jimacker
Fri May 26, 2023 3:33 pm America/New_York
Forum: Questions/Comments
Question: Questions about data synthesis
Replies: 9

Re: Questions about data synthesis

That's very strange. When I click on the link, it provides a pop-up asking for permission to go to an external site, then when I say OK, it goes to Giovanni. Perhaps you have a pop-up blocker that is interfering with the pop-up? You can copy https://giovanni.gsfc.nasa.gov into your browser search wi...
by GES DISC - jimacker
Fri May 26, 2023 2:30 pm America/New_York
Forum: Questions/Comments
Question: Questions about data synthesis
Replies: 9

Re: Questions about data synthesis

I am sorry, I misconfigured the link. This is correct: https://giovanni.gsfc.nasa.gov
by GES DISC - jimacker
Thu May 25, 2023 2:46 pm America/New_York
Forum: Questions/Comments
Question: AIRS L3 TqJoint data
Replies: 7

Re: AIRS L3 TqJoint data

Hello. We have had a productive discussion about your question. The following combines the comments from several data experts. Also, see the associated image below. For more AIRS questions, you can also go here: Ask AIRS The missing data over north-Europe and north-Canada in the figures you show is ...