Scott Lindstrom « CIMSS Satellite Blog

Using GEOKOMPSAT-2 and Himawari-8 Imagery to create Stereoscopic Imagery

November 14th, 2019 | Scott Lindstrom

Visible (0.64 µm) Imagery from Himawari-8 (left) and GEOKOMPSAT-2A (right) at 0400 and 0500 UTC on 14 Nov 2019 (Click to enlarge)

Geostationary data from KMA‘s GEOKOMPSAT-2 satellite (over the Equator at 128º E Longitude, shown above at right) and from JMA‘s Himawari-8 Satellite (over the Equator at 140º E Longitude, shown above at left) can be used to create stereoscopic imagery. The imagery above, from 0400 and 0500 UTC on 14 November 2019, centered at 15º N, 150º E, shows Typhoon Fengshen. Visible imagery from both satellites show a well-developed central cluster of thunderstorms with little apparent indication of wind shear. Stereoscopic views of the storm allow the vertical structure of the system to be perceived.

Data processing for these images was accomplished using Geo2Grid, a software package that incorporates Satpy. (Previous Blog posts discussing Geo2Grid are here and here).

Very grateful acknowledgement of these data from KMA and from JMA is extended. Thank you!

Added: Click here for an animation from 0300 to 0550 UTC on 14 November. (Warning: Large animated gif at 159 M).

Posted in GK2A, Himawari-8 | No Comments »

Gridded NUCAPS in AWIPS, part II

November 12th, 2019 | Scott Lindstrom

NUCAPS horizontal plots of 850-hPa temperature, 1643-1705 UTC on 12 November 2019, and the NUCAPS Sounding Availability plots (Click to enlarge)

As noted in this post from October, horizontal fields of thermodynamic variables that have been derived from NUCAPS vertical profiles are now available in AWIPS. The fields give a swath of observations derived from infrared and microwave sounders in regions of the troposphere where observations by Radiosondes happen only occasionally. In this case, NUCAPS observed the strong cold front moving southward into the north Atlantic. Temperatures over eastern Canada at 850 hPa were in the teens below 0 Celsius, and in the teens (Celsius) out over the Atlantic.

850-hPa Temperatures derived from NUCAPS Soundings, 1653 UTC on 12 November 2019 (Click to enlarge)

Lower-tropospheric temperatures are an important variable to know when early-season cold airmasses are cold enough that the temperature difference between 850 hPa and surface water bodies — such as rivers and lakes — is sufficient to support Lake (or River) Effect clouds and precipitation. River-effect flurries hit mid-town Memphis on the 12th of November, and the 0.86 “Veggie” image (0.86 µm, this wavelength was chosen because land/water contrasts are large in it) image, below, shows a band extending from the Mississippi River in northwest Tennessee southward into central Memphis. NUCAPS data at 850 on this day showed 850-mb temperatures around -10 C at 0900 UTC.

GOES-16 0.86 “Veggie” Band (0.86 µm) imagery, 1346 UTC on 12 November 2019 (Click to enlarge). Shelby County in Tennessee is outlined, and the arrow points to a River-Effect snow band that dropped flurries over mid-town Memphis.

Posted in NUCAPS, Winter weather | No Comments »

Stereoscopic views of the Kincade Fire in California

October 30th, 2019 | Scott Lindstrom

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery on 24 October 2019, 1500-2350 UTC (Click to animate)

GOES-16 and GOES-17 satellite imagery can be remapped and combined to create stereoscopic imagery. To achieve the 3-dimensional effect, cross your eyes until three scenes are visible, and focus on the middle image. You can also achieve this by placing a finger halfway between your eyes and the screen, and focusing on your finger, then focusing on the image behind. (Here’s a website that might help). The imagery above, from 24 October 2019, shows high clouds rotating anti-cyclonically above the smoke produced from the Kincade Fire (previous blog posts on this fire are here and here). The smoke plume extended far out into the Pacific Ocean. A Full-resolution image animation is shown below.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery on 24 October 2019, 1500-2350 UTC (Click to animate)

Animations for 25 October, 26 October, 27 October, 28 October and 29 October are shown below, in order.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC on 25 October 2019 to 0050 UTC on 26 October 2019 (Click to animate)

On the 25th and 26th of October, prevailing winds moved smoke into the Bay Area. On both days, the fire appeared less vigorous in the visible imagery than on the 24th, at top, or on the 27th; at least, it appeared to be producing less smoke.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC on 26 October 2019 to 0050 UTC on 27 October 2019 (Click to animate)

On the 27th, below, the fire resembled the scene on 24 October, with a large smoke plume extending far southwest into the Pacific Ocean.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC to 2350 UTC on 27 October 2019 (Click to animate)

On the 28th, below, smoke generation has decreased, and the smoke pall appears over the Bay Area again. A full-resolution version is available here.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC to 2350 UTC on 28 October 2019 (Click to animate)

The scene on the 29th, below (Full resolution available here) is shown below. The smoke plume is extensive.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC to on 29 October 2019 to 0050 UTC on 30 October 2019 (Click to animate)

How did the smoke plume change from day to day? The animation below shows data at 2350 UTC on 24-29 October.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery at 2350 UTC from 24 to 29 October 2019 (Click to enlarge)

Posted in Fire detection, GOES-16, GOES-17 | No Comments »

Gridded NUCAPS fields are available in AWIPS

October 29th, 2019 | Scott Lindstrom

NUCAPS Sounding Availability points from AWIPS, 1304 UTC on 29 October 2019, and the Temperature at 500 hPa at the same time (Click to enlarge)

Gridded NUCAPS fields (Here’s a NASA SpoRT VLab page on the product) are now available in AWIPS, effective with AWIPS Build 19.3.1. The imagery above includes a swath of NUCAPS points (called up via ‘NUCAPS Sounding Availability’) under the Satellite Tab, and the ‘S-NPP and NOAA-20’ choice there (even though, at present, only NOAA-20 NUCAPS profiles are supplied to AWIPS). A ‘Gridded NUCAPS’ choice is available right about the NUCAPS Sounding Availability, and this allows a user to choose Temperature, Dewpoint Temperature, Equivalent Potential Temperature, Lapse Rates (and more!) at different standard mandatory pressure levels (or layers, for Lapse Rates). Interpolation in the vertical has moved the native NUCAPS pressure levels (mentioned here) to standard pressure levels.

The plot above also shows the temperature at 500 hPa for the same time, 1304 UTC. Gridded NUCAPS fields do not cover the entire extent of the NUCAPS Sounding Availability plots. In addition, values are present for all sounding color dot points — green, yellow and red — on the theory that a user can identify the bad data visually.

The animation below shows a series of gridded fields over northern Canada, covering much of the the Sounding Availability plot. Because of the timestamps on these different grids, they do not all time match the swath of NUCAPS Sounding Availability points. On this day, the size of some of the fields produced was quite small. The size of the gridded region is limited by computational resources on AWIPS, and the upper limit is 20 lines of NUCAPS soundings — 600 soundings total that are horizontally and vertically interpolated. The size is also affected by the order in which the soundings appear in AWIPS. If a small chunk (say, 7 lines of soundings) comes in, then that small chunk will be processed into a horizontal grid. It’s more common that grid sizes will be closer to what occurred at 1304 UTC.

Temperature at 500 mb from NUCAPS Soundings, 1304 – 1311 UTC on 29 October 2019 (Click to enlarge)

If you look in the Product Browser on AWIPS, you will find far more data than are available under the ‘Gridded NUCAPS’ menu under ‘NOAA-20 and S-NPP’ under the satellite tab. (Here’s just a small sample!) For example, you can plot Ozone estimates from NUCAPS, as shown below — loaded as a grid then converted to an image. Expect the presentation of NUCAPS horizontal fields in AWIPS to evolve with time. In the meantime, this is a valuable data set to determine (for example) the likelihood of snow v. rain based on the 925 Temperature and Dewpoint Depression.