Sample of Preliminary, Unvalidated TEMPO Data Products Now Available on Earthdata Search

[ASDC - ingridgs]

To help users become familiar with Tropospheric Emissions: Monitoring of Pollution (TEMPO) data products, the Atmospheric Science Data Center (ASDC) is releasing two weeks of preliminary, unvalidated TEMPO observations obtained during nominal operations from December 17-30, 2023, and eight days of commissioning observations, including first light, obtained during August 2023. Data products from this release are processed using the TEMPO Science Data Processing Center (SDPC) software that is operational as of January 2024. The release includes all baseline products except for the ozone profile product, which has not yet been placed into production.
These products are unvalidated and have not yet reached the Beta Product Maturity level defined in the TEMPO validation plan.
The products are not optimized for operational use, and anomalies may exist.
This release is intended only for users to gain familiarity with file format and content.
These unvalidated TEMPO products should not be used in publications or presentations, and users should refrain from making conclusive public statements regarding the science and applications of the TEMPO data products until the products are designated to be at the provisional validation status according to the validation plan.

A readme file describing the data products in this preliminary release and associated known issues can be found here.

For inquiries about this preliminary TEMPO data release, please contact larc-dl-asdc-tempo@mail.nasa.gov or post/view questions on the Earthdata Forum.

The TEMPO data may be accessed through Earthdata Search.

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[mneedham]

I am having an issue when accessing the preliminary unvalidated L3 TEMPO products. The netcdf files appear to only have one variable "weight" without any of the other fields. I have found this for both the column HCHO and column NO2

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Accessed via earthdata (using registration / password) and then downloaded via the generated download script
Accessed 3/6/2024
Earthdata name: "TEMPO gridded formaldehyde total column (UNVALIDATED)"

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Here's the output after reading in the file "TEMPO_HCHO_L3_V01_20231230T225114Z_S011.nc" with a python script using the xarray package:

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<xarray.Dataset>
Dimensions: (longitude: 2611, latitude: 940, time: 1)
Coordinates:
* longitude (longitude) float32 -155.0 -154.9 -154.9 ... -24.58 -24.52 -24.48
* latitude (latitude) float32 17.02 17.08 17.12 17.17 ... 63.88 63.92 63.97
* time (time) datetime64[ns] 2023-12-30T22:51:32.164999936
Data variables:
weight (latitude, longitude) float32 ...
Attributes: (12/39)
history: 2023-12-31T03:05:25Z: L2_regrid -v /tem...
scan_num: 11
time_coverage_start: 2023-12-30T22:51:14Z
time_coverage_end: 2023-12-30T23:31:00Z
time_coverage_start_since_epoch: 1388011892.165
time_coverage_end_since_epoch: 1388014278.7543037
... ...
title: TEMPO Level 3 formaldehyde product
collection_shortname: TEMPO_HCHO_L3
collection_version: 1
keywords: EARTH SCIENCE>ATMOSPHERE>AIR QUALITY>VO...
summary: Formaldehyde Level 3 files provide trac...
coremetadata: \nGROUP = INVENTORYMET...

[ASDC - dka3]

Hello and thanks for the question,

It looks like you are opening the file with `xarray`'s `open_dataset()` method in Python.

Currently, `xarray` does not open multiple groups concurrently from a netCDF4 file (e.g., see this issue: https://github.com/pydata/xarray/issues/4840). It defaults to opening the "root group" of the netCDF4, which only has the coordinate variables and `weight`, as you are seeing. To access the other groups from a TEMPO file, I would suggest trying one of two approaches:

1) Use the `group` keyword parameter with `xarray.open_dataset()`, as described in its documentation here: https://docs.xarray.dev/en/stable/generated/xarray.open_dataset.html. For example:

Code: Select all

import xarray as xr

dataset = xr.open_dataset(tempo_filepath, group='product')

2) Use the in-development `datatree` package, which provides support for opening multi-group netCDF4 files as a tree-like object. Documentation for `datatree` can be found here: https://xarray-datatree.readthedocs.io/en/latest/index.html

[nana_wuwuwu]

Hi all,

I'm curious why TEMPO doesn't provide tropospheric HCHO columns like TROPOMI does, but only total HCHO columns. Thanks for your help!

[ASDC - hazem.mahmoud88]

Hello nana_wuwuwu,

Thank you for your question!

Formaldehyde predominantly resides in the troposphere, where most of pollutants and other trace gases are formed. The concentration of formaldehyde in the stratosphere is generally much lower compared to the troposphere. So, TEMPO's HCHO total column measurement is a robust indicator for the troposphere emissions. While TEMPO's primary mission objectives do not include the tropospheric formaldehyde retrieval, potential future developments could involve incorporating this capability into the mission's scope.

Best,
HM