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Earth Observation Satellites & Ground Monitoring  Solutions – an essential synergy for Air Quality and Climate Change

Earth Observation Satellites & Ground Monitoring  Solutions – an essential synergy for Air Quality and Climate Change

April 30, 2020

Atmospheric monitoring and climate analysis are strategic missions in order to improve the understanding of air quality dynamics and climate change evolutions. This in turn is a pre-requisite for providing reliable information reports with real data measurements and to help decision makers and end-users to understand the impacts and causes of air pollution with atmospheric impacts and to act upon it.

Satellite data is key for atmospheric and climate monitoring by providing a continuous and global view of the Earth parameters. These data are essential inputs for forecast models by improving their accuracy.

By combining satellite observations with models of the atmosphere and measurements from ground-based instruments, like Cimel Remote Sensing Solutions, it is possible to measure accurately and forecast aerosols (particles suspended in the air), as well as quantify gases level (ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide…) and several other kind of environmental parameters (planetary boundary layer, water leaving reflectance for Ocean color, solar radiation, water vapor, atmospheric concentration profiles PM2.5/PM10…).

Cimel solutions keep working continuously and automatically, to help the calibration of satellite instruments and validate their data. Furthermore, Cimel is always active to support the various research activities from the worldwide scientific community.

In this video, different aerosols are highlighted by color, including dust (orange), sea salt (blue), nitrates (pink) and carbonaceous (red), with brighter regions corresponding to higher aerosol amounts.

See more on: https://lnkd.in/edPSdrM

Credit: NASA Goddard Space Flight Center

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GPS roll-over

GPS roll-over the 3rd of November 2019 on the CE318-T

Important for existing CE318-T customers:

The GPS week counter has been reset the 3rd of November 2019.

Location data reports remained correct while the date and week number are affected. 

The CIMEL CE318-T photometer is impacted by the GPS week counter reset.

It is necessary to use the last version of the firmware for the photometer to remain operational.

Please see the related process bellow to check and update the right firmware version at your earliest convenience to fix the desynchronization.

You will need a computer and to be on site to connect on the control unit and update the firmware.

If you have any question or concern regarding the GPS roll-over issue, feel free to contact us.

Download the procedure here.

N.B.: If you are registered in AERONET, please contact the NASA AERONET team.

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Aerosol optical depth comparison between GAW-PFR and AERONET-Cimel radiometers from long-term (2005–2015) 1 min synchronous measurements

CE318-T Izaña

Aerosol optical depth comparison between GAW-PFR and AERONET-Cimel radiometers from long-term (2005–2015) 1 min synchronous measurements

August 9, 2019

A comprehensive comparison of more than 70 000 synchronous 1 min aerosol optical depth (AOD) data from three Global Atmosphere Watch precision-filter radiometers (GAW-PFR), traceable to the World AOD reference, and 15 Aerosol Robotic Network Cimel radiometers (AERONET-Cimel), calibrated individually with the Langley plot technique, was performed for four common or “near” wavelengths, 380, 440, 500 and 870 nm, in the period 2005–2015.

The goal of this study is to assess whether, despite the marked technical differences between both networks (AERONET, GAW-PFR) and the number of instruments used, their long-term AOD data are comparable and consistent.

The percentage of data meeting the World Meteorological Organization (WMO) traceability requirements (95 % of the AOD differences of an instrument compared to the WMO standards lie within specific limits) is >92 % at 380 nm, >95 % at 440 nm and 500 nm, and 98 % at 870 nm, with the results being quite similar for both AERONET version 2 (V2) and version 3 (V3). For the data outside these limits, the contribution of calibration and differences in the calculation of the optical depth contribution due to Rayleigh scattering and O3 and NO2 absorption have a negligible impact. For AOD >0.1, a small but non-negligible percentage (∼1.9 %) of the AOD data outside the WMO limits at 380 nm can be partly assigned to the impact of dust aerosol forward scattering on the AOD calculation due to the different field of view of the instruments. Due to this effect the GAW-PFR provides AOD values, which are ∼3 % lower at 380 nm and ∼2 % lower at 500 nm compared with AERONET-Cimel. The comparison of the Ångström exponent (AE) shows that under non-pristine conditions (AOD >0.03 and AE <1) the AE differences remain <0.1. This long-term comparison shows an excellent traceability of AERONET-Cimel AOD with the World AOD reference at 440, 500 and 870 nm channels and a fairly good agreement at 380 nm, although AOD should be improved in the UV range.

Citation: Cuevas, E., Romero-Campos, P. M., Kouremeti, N., Kazadzis, S., Räisänen, P., García, R. D., Barreto, A., Guirado-Fuentes, C., Ramos, R., Toledano, C., Almansa, F., and Gröbner, J.: Aerosol optical depth comparison between GAW-PFR and AERONET-Cimel radiometers from long-term (2005–2015) 1 min synchronous measurements, Atmos. Meas. Tech., 12, 4309–4337, https://doi.org/10.5194/amt-12-4309-2019, 2019.

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Sunbelt Spectra comparison with Standard ASTM G173: the Chilean case

Sunbelt Spectra comparison with Standard ASTM G173: the Chilean case

December, 2017

Two spectra of solar direct normal irradiance (including circumsolar) are estimated based on spatio-temporal averages of the relevant atmospheric parameters extracted from two different databases: MODIS satellite sensor retrievals and AERONET sun photometer network. The satellite database is used to calculate an average spectrum for the area of the Atacama Desert. The AERONET database is used for two purposes: (i) to apply bias-removal linear methods to correct the MODIS parameters over Atacama, and (ii) to calculate an average local spectrum for the Paranal station. The SMARTS radiative transfer model is used to obtain the three spectra developed in this study. Both the Atacama and Paranal spectra are compared against each other and also to the world reference, ASTM G173. In one of the cases, significant differences are found for short wavelengths. In order to quantify the relative importance of these spectral differences, the propagation of errors due to the use of each spectrum is evaluated for CSP applications over the Atacama Desert, considering twelve different scenarios involving the reflectance, transmittance or absorptance of various materials.

Citation: Marzo, Aitor & Polo, Jesus & Wilbert, Stefan & Gueymard, Chris & Jessen, Wilko & Ferrada, Pablo & Alonso-Montesinos, Joaquín & Ballestrín, Jesús. (2017). Sunbelt Spectra comparison with Standard ASTM G173: the Chilean case. AIP Conference Proceedings. 2033. 10.1063/1.5067195.

READ THE ARTICLE

Image source: Pixabay

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FIREX – AQ Mission

FIREX – AQ Mission

Approximately half of fire emissions in the US are from Northwestern wildfires and half are from prescribed fires that burn mostly in the Southeast US. Wildfires burn slightly more fuel and therefore have overall larger emissions, but prescribed fires dominate the area burned and the number of fires. FIREX-AQ will investigate both wild and prescribed fires. Wildfires generally result in exposures with larger pollution concentrations over larger areas, and cause both local and regional air quality impacts. Their emissions are often transported thousands of miles and can impact large regions of the US at a time. Prescribed fires are usually smaller and less intense than most wildfires but occur more frequently and throughout the whole year. They are usually ignited during periods that minimize population expose and air quality impacts, but can cause regional backgrounds to increase, are generally in closer proximity to populations, and are responsible for a large fraction of the US PM2.5 emissions.

This summer, NOAA and NASA are teaming up on a massive research campaign called FIREX-AQ that will use satellites, aircraft, drones, mobile and ground stations to study smoke from wildfires and agricultural crop fires across the U.S. 

Objective: To improve understanding of wildfire and agricultural fire impacts on air quality, weather, and climate.

Cimel provides a CE376 micro-LiDAR as well as its network of CE318-T photometers through AERONET. These solutions will provide detailed measurements of aerosols emitted from wildfires and agricultural fires to address science topics and evaluate impacts on local and regional air quality, and how satellite data can be used to estimate emissions more accurately.

The Primary Mission Partners are:

Photo: P. Cullis, NOAA / CIRES