This website works best with a newer web browser such as Chrome, Firefox, Safari or Microsoft Edge. Internet Explorer is not supported by this website.

CIMSS and JPSS and AMS in 2024: Part II

AMS__PMOSS_2024_GreenwaldDownloadCIMSS Scientists who work with JPSS data had numerous presentations at the American Meteorological Society’s Annual Meeting held at the end of January in Baltimore. This blog post discusses a poster by Tom Greenwald who (along with co-authors) investigated how microwave data from AMSR-2 can be used to... Read More

CIMSS Scientists who work with JPSS data had numerous presentations at the American Meteorological Society’s Annual Meeting held at the end of January in Baltimore. This blog post discusses a poster by Tom Greenwald who (along with co-authors) investigated how microwave data from AMSR-2 can be used to estimate sea ice concentration in regions where very high-resolution Synthetic Aperture Radar (SAR) data are not present. The AMSR-2 images were validated using very high-resolution Landsat visible imagery; that is, this was done in regions of clear skies to show that the microwave data would be producing useful information in regions of clouds. The high-resolution AMSR-2 Sea Ice Concentration data are used, as the poster notes, to “track the ice edge and marginal ice zone (MIZ) with a degree of confidence not achieved with the standard AMSR2 sea ice concentration.”

A dedicated CIMSS Satellite Blog reader might recall past blog posts that also discussed this technique, here and here. AMSR-2 gives high-resolution, quality sea ice detection to augment SAR observations. Future work includes a more thorough comparison between this product and legacy products. A Quick Guide on this product is available here.

View only this post Read Less

Wind-driven grass fires in Nebraska

5-minute CONUS Sector GOES-16 (GOES-East) True Color RGB images + Nighttime Microphysics RGB images from the CSPP GeoSphere site (above) showed large smoke plumes produced by 2 wind-driven grass fires in central Nebraska (just north of North Platte) on 26 February 2024. The burn scar associated with the larger (southernmost) fire was very apparent, as... Read More

GOES-16 True Color RGB images + Nighttime Microphysics RGB images, from 1601 on 26 February to 0016 UTC on 27 February [click to play MP4 animation]

5-minute CONUS Sector GOES-16 (GOES-East) True Color RGB images + Nighttime Microphysics RGB images from the CSPP GeoSphere site (above) showed large smoke plumes produced by 2 wind-driven grass fires in central Nebraska (just north of North Platte) on 26 February 2024. The burn scar associated with the larger (southernmost) fire was very apparent, as a west-to-east oriented swath of darker brown shades. After sunset, the hot fire signatures showed up as clusters of darker purple pixels in Nighttime Microphysics RGB imagery.

Suomi-NPP VIIRS True Color RGB and False Color RGB images valid at 1950 UTC; Interstates are plotted in red, with State Highways plotted in violet [click to enlarge]

In a toggle between Suomi-NPP VIIRS True Color RGB and False Color RGB images valid at 1950 UTC (above), a more detailed view of the burn scar was seen in the True Color RGB image — with the hot thermal signatures of active fires exhibiting brighter shades of pink to red. The head of the fire was close to the Lincoln County / Custer County line at that time. A sequence of 3 VIIRS Shortwave Infrared (3.74 µm) images from NOAA-20 and Suomi-NPP (below) provided a high-resolution view of how quickly the fire’s leading edge moved eastward in a time span of about 1 hour and 40 minutes. The VIIRS data used to create these images were received and processed using the CIMSS/SSEC Direct Broadcast ground station.

VIIRS Shortwave Infrared (3.74 µm) images from NOAA-20 and Suomi-NPP on 26 February [click to enlarge]

1-minute Mesoscale Domain Sector GOES-16 Fire Temperature RGB images along with the Fire Power, Fire Mask and Fire Temperature derived products (below) provided a closer view of the southern grass fire thermal signature and its rapid eastward run toward (and eventually across) the Lincoln County / Custer County line (the Fire Power, Fire Mask and Fire Temperature derived products are components of the GOES Fire Detection and Characterization Algorithm FDCA). Distinct thermal signatures of the fire were evident beginning at 1644 UTC — which advanced quickly eastward due to winds gusting as high as 42 knots (49 mph) at North Platte (KLBF).

GOES-16 Fire Temperature RGB (top left), Fire Power (top right), Fire Mask (bottom left) and Fire Temperature (bottom right) derived products, from 1600 UTC on 26 February to 0000 UTC on 27 February; Interstates and State Highways are plotted in violet [click to play animated GIF | MP4]

Parts of this fast-moving grass fire burned very hot at times — in fact, a cursor sample of GOES-16 Fire Temperature RGB and Fire Mask at 2000 UTC (below) showed that the fire exhibited a maximum 3.9 µm infrared brightness temperature of 138.71ºC (which is the saturation temperature of the GOES-16 ABI Band 7 detectors). The Fire Mask product helps to quickly identify such “Saturated Fire” pixels by highlighting them as bright yellow. In addition, maximum Fire Power values exceeded 2500 MW.

Cursor sample of GOES-16 Fire Temperature RGB (top left) and Fire Mask (bottom left) at 2000 UTC on 26 February [click to enlarge]

Suomi-NPP (mislabeled as NOAA-20) VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images, valid at 0808 UTC on 27 February [click to enlarge]

During the following nighttime hours, a toggle between Suomi-NPP (mislabeled as NOAA-20) VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images (above) showed the area of the grass fire at 0808 UTC (2:08 AM CST) on 27 February. Due to ample illumination from the Moon — which was in the Waning Gibbous phase, at 92% of Full — darker areas of burned grassland could be seen, extending just across the Lincoln County / Custer County border. Although most of the fire had ended (since wind speeds decreased dramatically after sunset), a few clusters of warmer pixels remained along the perimeter of the burn scar.

 

View only this post Read Less

Model estimates of information available from the GXS

The GXS is the sounder that is proposed to be part of the GeoXO constellation of satellites that will launch starting in the 2030s as a replacement to the GOES-R satellites. (Note: GOES-U is now scheduled to launch no earlier than mid-May 2024). Beyond the GXS uses of radiance assimilation... Read More

Sounder information of thetae(500) – thetae(850) (left) from a model simulation and model estimates of thetae(500) – thetae(850) (right); 1200 UTC 6 September – 0545 UTC 7 September 2019; See text for details.

The GXS is the sounder that is proposed to be part of the GeoXO constellation of satellites that will launch starting in the 2030s as a replacement to the GOES-R satellites. (Note: GOES-U is now scheduled to launch no earlier than mid-May 2024). Beyond the GXS uses of radiance assimilation into global and regional models, there will be many applications associated with nowcasting. This post highlights one related to convection. What kind of capabilities will the GXS bring? That’s shown in the animation above. The left-hand imagery shows the thetae(500) – thetae(850) values computed from simulated sounder data: The extra fine spatial resolution (1-km) nature run (XNR1K) from the ECMWF model was averaged over the Sounder field of view (FOV), and a radiative transfer model was used to create Top of Atmosphere (TOA) radiances at all GXS sounder channels. Subsequently, temperature/moisture profiles were retrieved from these simulated sounder TOA observations using a deep neural network model. The retrievals are derived based on GXS radiances only (no NWP forecast used as first guess or background). Theta-e values at 850 hPa, 500 hPa were calculated from the retrieved T/Q profiles. The right-hand imagery shows thetae(500) – thetae(850) values calculated from the averaged XNR1K profiles (averaged to the Sounder field of view), which are used here as truth for validation.

There is remarkable similarity between the two fields, meaning the sounder data can give accurate estimates of potential instability, that is, thetae(500) – thetae(850). If thetae is decreasing strongly with height, atmospheric lift will lead to the rapid release of instability driven by strong latent heat release. In the animation above, strong convection develops near the strong negative values of thetae(500) – thetae(850) (red values); you can also see stable regions (in green/blue) near strong convection where cool downdrafts have stabilized the atmosphere. That’s also apparent in the shorter animations below: 2000 UTC on 6 September – 0000 UTC on 7 September and 0200 UTC – 0545 UTC on 7 September. The simulated GXS data here can alert a forecaster to where convection might (or might not) soon occur. There is a marked tendency for the convection to occur near gradients of potential instability.

Sounder information of thetae(500) – thetae(850) (left) from a model simulation and model estimates of thetae(500) – thetae(850) (right); 2000 UTC 6 September – 0000 UTC 7 September 2019.
Sounder information of thetae(500) – thetae(850) (left) from a model simulation and model estimates of thetae(500) – thetae(850) (right); 0200 UTC 7 September – 0545 UTC 7 September 2019.

The following figure shows forecast model output estimates of precipitation at 1700, 1800 and 1900 UTC on 6 September 2019. The focus here is on the convection moving from Kansas into Nebraska, circled in purple. Figures below that describe how the convection relates to sounder-derived potential instability.

Hourly Precipitation at 1700, 1800 and 1900 UTC on 6 September 2019 (click to enlarge)

Convection develops at the leading edge of the diagnosed instability, the boundary between deep reds and yellows. The model output and sounding-consistent retrievals based on the model output show pools of stability near the developing convection (yellows and greens in the enhancement).

Close-in view of Potential Instability at 1800, 1830, 1900, 1930 UTC on 6 September (Click to enlarge) Annotations added to highlight features.

View only this post Read Less

Eruption of Popocatépetl in Mexico

GOES-16 (GOES-East) Split Window Difference (10.3-12.3 µm) along with SO2 RGB and Ash RGB images (above) displayed signatures of volcanic clouds produced by a sequence of eruptions of Popocatépetl in Mexico on 21 February 2024. Although these volcanic clouds apppeared to be predominantly ash-dominated (shades of pink to magenta in the Ash RGB,... Read More

GOES-16 Split Window Difference (10.3-12..3 µm, top) along with SO2 RGB and Ash RGB images (bottom), from 0701 on 21 February to 0001 UTC on 22 February [click to play animated GIF | MP4]

GOES-16 (GOES-East) Split Window Difference (10.3-12.3 µm) along with SO2 RGB and Ash RGB images (above) displayed signatures of volcanic clouds produced by a sequence of eruptions of Popocatépetl in Mexico on 21 February 2024. Although these volcanic clouds apppeared to be predominantly ash-dominated (shades of pink to magenta in the Ash RGB, and shades of blue in the SO2 RGB), there were brief indications of an SO2-ash mixture — in a toggle between the 2 RGB image types at 1846 UTC (below), note the shades of green near the volcano summit (suggestive of SO2 dominance) and shades of orange in the Ash RGB with shades of pink to red in the SO2 RGB (suggestive of an ash/SO2 mixture) a few miles downwind of the summit.

GOES-16 Split Window Difference (10.3-12..3 µm, top) along with SO2 RGB and Ash RGB images (bottom), at 1846 UTC on 21 February  [click to enlarge]

GOES-16 Nighttime Microphysics RGB + daytime True Color RGB images (below) showed the west-southwest transport of the volcanic cloud (shades of pink to magenta) during the nighttime hours into the next morning, followed by additional volcanic cloud pulses that moved to the southwest during the afternoon hours

GOES-16 Nighttime Microphysics RGB + daytime True Color RGB images, from 0701-2356 UTC on 21 February [click to play MP4 animation]

For the afternoon eruption phase that began around 1700 UTC, GOES-16 False Color RGB, Ash Height, Ash Effective Radius and Ash Loading products from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) indicated that the (predominantly ash) cloud reached heights of 6-7 km at times, with the ash consisting of generally small particles at relatively low levels of ash loading.

GOES-16 False Color RGB (top left), Ash Height (top right), Ash Effective Radius (bottom left) and Ash Loading (bottom right), from 1601 UTC on 21 February to 0001 UTC on 22 February [click to play animated GIF | MP4]

_____________________________

GOES-16 Split Window Difference (10.3-12..3 µm, top) along with SO2 RGB and Ash RGB images (bottom), from 1001 UTC on 22 February to 0001 UTC on 23 February [click to play animated GIF | MP4]

On the following day (22 February), GOES-16 Split Window Difference along with SO2 RGB and Ash RGB images (above) showed the volcanic clouds produced by 2 additional eruptive periods — with the first cloud drifting southward, followed by the additional clouds drifting to the east-southeast.

During these eruptions, there were more notable indications of an SO2-ash mixture — for example, in a toggle between the 2 RGB image types at 1701 UTC (below), note the darker shades of orange in the Ash RGB along with brighter shades of pink to violet in the SO2 RGB (suggestive of an ash/SO2 mixture) immediately east of the volcano summit.

GOES-16 Split Window Difference (10.3-12..3 µm, top) along with SO2 RGB and Ash RGB images (bottom), at 1701 UTC on 22 February [click to enlarge]

GOES-16 Nighttime Microphysics RGB + daytime True Color RGB images (below) showed the southward transport of volcanic clouds during the nighttime hours into the following morning, with additional volcanic cloud pulses that moved to the east during the afternoon hours.

GOES-16 Nighttime Microphysics RGB + daytime True Color RGB images, from 1001-2346 UTC on 22 February [click to play MP4 animation]

View only this post Read Less