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Mission News Archive

July 1, 2021

We finished our summer campaign this past week with four more ACTIVATE flights (Research Flights 90-93) between June 28 and 30. These flights focused on extensive data collection in typical summertime shallow cumulus clouds. A notable feature in these flights was sampling behind ship vessels near the coast that yielded especially large enhancements in particle concentration parameters.

June 28, 2021

Four flights were conducted last week, with two single flight days on June 22 and 24, and a double flight day on June 26. Saturday’s conditions (June 26) were in particular very good for ACTIVATE with a scattered shallow cumulus cloud scene throughout the day that both planes were able to jointly characterize. The past week also was linked to high variability in aerosol conditions with the northward advancement of African dust into our study region.

June 21, 2021

This past week included three single-flight days on Tuesday-Thursday (June 15-17). The first flight of this week (June 15) was a statistical cloud survey but proved to be a challenging flight to execute as the King Air encountered pervasive cirrus along the track and the Falcon dealt with low clouds at varying altitude ranges. The June 16 flight targeted mostly clear skies with observations of moderate aerosol loading. This flight also included an overflight of Langley Research Center at the end to intercompare with the AERONET site and the High Altitude Lidar Observatory (HALO) HSRL/water vapor lidar that was conducting upward looking ground tests. The last flight of the week (June 17) included a coordinated run along the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite overpass and then two reverse headings to capture in cloud data in vicinity of the ASTER overpass for additional contextual data. The flights on June 16-17 both saw non-spherical particles near the coast and drizzle over the ocean was observed on June 17.

June 14, 2021

This past week included two double-flight days on Monday-Tuesday (June 7-8). June 7 was notable in that the second flight (RF 80) was a “process study” flight, which accounts for approximately 10% of ACTIVATE flights. We targeted an area with a cluster of clouds and conducted a total of 10 Falcon legs in cloud at different altitudes ranging from ~2 to ~13 kft. These legs and a subsequent downward spiral resulted in 10 cloud water samples for a single cloud system. Simultaneously, the King Air conducted a ‘wheel and spoke” pattern far above to allow the remote sensors to characterize the environment and cloud that the Falcon was directly sampling. A total of 14 dropsondes were launched by the King Air in the ~3 hr flight. This flight and the other “process study” flight in this summer campaign (RF77 on June 2) will provide a remarkable dataset to investigate aerosol-cloud-meteorology interactions with very detailed measurements for single evolving cloud systems.

June 7, 2021

Four successful joint flights occurred last week. The double flight day on Wednesday June 2 was particularly noteworthy. Our morning flight conducted our typical statistical survey flight plan to an area south of the Virginia coast where there was a cumulus cloud field, with some regions evolving into deeper, more organized, convection. Based on that flight and satellite imagery, we set up the second flight to execute a “process study” pattern where the Falcon conducted a series of transects through a selected cloud cluster to characterize the vertical microphysical properties of the developing cluster immediately followed by an environmental profile in the surrounding cloud-free region. Simultaneously, the King Air conducted a “wheel and spoke” pattern centered around the cloud system, with multiple dropsondes launched above, and on the periphery of the cloud cluster alongside remote sensing transects to characterize the cloud and aerosol system underneath. Data from both planes will be used to characterize the range of cloud types observed on that day, with a focus on understanding the processes that drive shallow cumulus organization.

June 1, 2021

The last two weeks were busy with 9 joint flights, including three separate double-sortie days. The May 21 morning flight in particular was intriguing with a mixture of different conditions offshore with the two aircraft flying mostly straight to the east and then returning on the same track to NASA LaRC. Closer to shore, the aircraft observed a stratus deck with a prominent aerosol layer just above cloud as observed by the HSRL-2. These clouds then transitioned progressively into a more scattered cumulus cloud field to the east. At the far eastern end of the track there was a cold pool that we sampled within and just outside. Throughout this and the other flights this past week, there was evidence both either (or both) smoke and dust in the free troposphere. Measurement data will help unravel how these various aerosol types interact with the different types of clouds such as in the May 21 flights. On May 19, we also coordinated the flight along the CALIPSO satellite track where both aircraft and the satellite had successful made measurements.

May 17, 2021

After a short break after the Winter 2021 campaign, ACTIVATE took back to the skies this past week to start the Summer 2021 campaign. We conducted 4 successful joint flights between May 13-15 with interesting cloud conditions in each flight. The lower-flying Falcon characterized multiple layers of clouds and observed both warm and mixed-phase precipitation. Remote sensing observations on the higher-flying King Air detected aerosol layers aloft in the free troposphere potentially from dust and smoke on separate flights.

April 5, 2021

ACTIVATE wrapped up its winter 2021 flight campaign with five joint research flights this past week (RF 57-61) capped off by a double-flight day on Friday (4/2) to capitalize on another cold air outbreak event. Those two flights included an increased number of dropsondes (~10 per flight) to get extensive temporal and spatial characterization of the vertical atmospheric structure as the cold air outbreak cloud field evolved during the day. Notable in the other flights last week was successful coordination with ASTER and CALIPSO overpasses in our flight region.

March 29, 2021

We executed a joint flight (RF 56) on Tuesday March 23rd on a day marked by fairly ‘clean’ conditions in terms of very low aerosol and cloud drop number concentrations in the marine boundary layer. Cloud fraction on this day was markedly lower than a typical cold air outbreak type of day, which is helpful for ACTIVATE which is aiming to generate statistics in a wide range of conditions associated with aerosols, clouds, and meteorology.

March 22, 2021

The previous week posed significant weather challenges but Saturday (March 20, 2020) did finally provide low clouds evolving in a cold air outbreak. Interesting features in that joint flight (Research Flight 55) were Asian dust residing aloft above the boundary layer clouds, in addition to an interesting layer of depolarizing aerosol right above clouds near the end of flight as observed by the HSRL-2; it is unclear what the source of that layer was, but data analysis with the Falcon data will help unravel those details.

March 15, 2021

ACTIVATE conducted four more successful joint flights (Research Flights 51-54) this past week. We characterized a variety of cloud conditions including post-frontal clouds associated with another cold air outbreak on Monday (March 8) in contrast to the following day (Tuesday March 9) where there was a sharp inversion with uniform cloud top heights and generally thin clouds. Flights this past week were marked by influence from local and regional burning emissions. The second of two flights on Friday (March 12) was coordinated with a CALIPSO overpass.

March 8, 2021

ACTIVATE executed three successful joint flights (Research Flights 48-50) this past week. On Thursday March 4th we coordinated our flight with a NASA A-Train overpass over an area with some scattered marine boundary layer clouds. The back-to-back flights on Friday March 5th served two objectives to capitalize on an excellent cold air outbreak event: (i) characterize the aerosol and meteorological characteristics upwind of the cloud field farther downwind; and (ii) characterize the evolution of the cloud field with the desire to capture the transition from overcast cloudy conditions to open cell structure. Noteworthy features in these flights were dust layers from long-range transport and significant new particle formation.

Febraury 5, 2021

ACTIVATE’s had its first joint flight of the winter 2021 campaign on February 3. We were successful to sample a transition from overcast stratocumulus clouds to broken cumulus clouds near our farthest southeast point of the flight track. There was extensive mixed-phase precipitation in areas closer to shore but pure liquid clouds farther offshore coinciding with the open cell cloud field. Although at low optical depth, an interesting aerosol layer was observed above 6 km that most likely was dust due to its depolarizing nature.

January 30, 2020

This past week ACTIVATE took to the skies again to begin our 2021 winter campaign. In contrast to last year, we started a bit earlier in the month of January to capitalize on a higher frequency of cold air outbreak events. Friday’s flights (January 29) were particularly ideal with both aircraft sampling along cloud streets aligned with the predominant wind direction coming from the north/northwest. We observed a transition from supercooled droplets to mixed phase precipitation with distance away from shore.

September 30, 2020

On the final stretch of the summer campaign, we executed 5 more flights (Research Flights 36-40) between 9/21 – 9/30. There were a number of highlights during these flights including continued sampling of western U.S. wildfire plumes, a CALIPSO underflight (9/23), and a “process study” flight on 9/29. The process study comprised a deep analysis of a cloudy area involving multiple stacked legs and soundings with the Falcon and a “wheel and spoke” pattern directly above with the King Air. Of note in these last flights were the remarkable gradients in cloud droplet number concentrations, and not just between flights but also within a given flight. One of the major goals of ACTIVATE is to explain these gradients with the large suite of data being collected. The weather in the last week was especially challenging to plan flights around, but with careful planning and real-time decision making in flight, the aircraft probed areas free of strong convection and with the types of low clouds we desired. Now there will be a break until our third campaign, which will be in wintertime of 2021. Until then....data analysis!

September 19, 2020

Two joint flights took place on Tuesday and Wednesday of this past week (9/15-9/16) that had important attributes. The first included successful detection and characterization of biomass burning plumes from the West Coast. Preliminary HSRL-2 data highlight how the smoke was elevated (~4-8 km). Although the signature of smoke was not clearly observed in the boundary layer, it could indirectly impact cloud fraction underneath and that is an important type of question that ACTIVATE data could be used for. The second flight was the first “Process Study” flight of the summer campaign where we set up in an area with clouds just east of ZIBUT to conduct a ‘wall pattern’ with the Falcon, simultaneous with the King Air flying overhead and doing a number of legs to characterize the area. This flight was an exceptional one for examining cloud processing of air as most of the route taken to and from the wall location was in clear air downwind of where the clouds were.

September 12, 2020

Our possible flight days in the past week between September 7-11 were challenged by complex weather including storms and convection near the airfield that prevented flights early in the week. This is not unusual for the region in September. Since conditions slowly improved during the week, two flights (RF 32-33) were executed on Thursday and Friday (September 10-11) including one in coordination with the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard TERRA. That particular flight on September 11 required a significant amount of communication and coordination between the two aircraft and ground crew to overcome weather and ground delay issues to position the planes at exactly the right spot for the ASTER track to avoid cirrus and cloud-free conditions. After the admirable amount of teamwork by the flight scientists, pilots, and ground crew, the conditions obtained were nearly perfect with a broken cloud scene in the boundary layer that is ideal for the science desired to be done in coordination with ASTER data. ASTER provides high resolution cloud images helpful to combine with the King Air camera and remote sensing data and Falcon in situ observations to study cloud size distributions and spatial patterns, cloud top heights, fractal dimensions, and cloud fraction.

September 8, 2020

Between August 25 and September 3, five joint research flights were conducted sampling an array of conditions. Notably, research flights 28-29 (August 26 and 28) were marked by smoke influence stemming from western United States wildfires, predominantly from California. Multiple aerosol layers were detected by both aircraft with a unique module conducted in clear air where the Falcon spiraled from low to high altitude while passing through smoke, simultaneous with the King Air doing an overpass. This module was conducted on both smoke flights and will prove to be useful for remote sensing retrieval assessment. Flight 29 was specifically designed to be a CALIPSO underflight and the conditions were very ideal (clear air, no cirrus, enhanced aerosol concentrations) with a series of six dropsondes launched by the King Air along the underflight track.

August 21, 2020

After a successful winter campaign marked by 22 total flights between 14 February and 12 March was cut short due to the COVID-19 pandemic, ACTIVATE has returned to doing science flights. ACTIVATE was approved to conduct the second of six planned deployments in the August-September time frame as compared to the originally planned May-June period. This unique opportunity offers the chance to examine a broader range of conditions associated with atmospheric chemistry and meteorology beyond what the originally planned flight months allow for (Feb-Mar, May-Jun). The first four science flights of the summer campaign were conducted between 13-21 August, and the team is moving cautiously with a safety-first approach including the use of masks on the two aircraft and using rigorous cleaning procedures. Flights thus far have been successful in sampling both clear air and summertime cumulus clouds.

March 16, 2020

Seven joint flights were conducted between March 6th and 12th. This included two separate days of back-to-back flights. Five of the joint flights worked areas to the south of Virginia off of the Carolina coasts over the open ocean to be able to capitalize on having the low clouds we desire, having the least amount of high cloud interference (which affects remote sensing data quality), and also reduced the amount of icing that impacts sample collection on the HU-25 Falcon. The first joint flight on March 12 was special in that we conducted the first coordinated underflight during a satellite overpass. We specifically targeted the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and made sure to do this in a line of clouds without heavy interference from cirrus clouds. The scientific goal of that coordination is to characterize cloud morphology, as defined by cloud sizes, nearest neighbor distance, and fraction, and then to relate that information to cloud microphysical properties.

March 2, 2020

The last week has been very busy with seven more joint flights between 27 February and 2 March. This included two separate days of studying post-frontal cloud conditions with back-to-back flights. On those days we did a first flight to characterize vertically and spatially a large circle containing a dynamic cloud field. For the second flight on those days, the aircraft returned to the centerpoint of that circle and flew downwind to probe the evolution of the original cloud field in a Lagrangian fashion. A highlight of these flights was the UC12 launching 11 separate dropsondes around the circumference of the circle, which will be used to calculate quantities useful for comparison to and improvement of models. A particularly intriguing flight day was 29 February when the forecasts suggested we would be doing clear air sampling, but there actually were low clouds during the flight highlighting again how important ACTIVATE is to improve models’ ability to simulate marine boundary layer clouds.

February 26, 2020 Mission News

The first ACTIVATE joint research flight took place on 14 February 2020 out of NASA Langley Research Center. The UC-12 and HU-25 Falcon flew in close coordination and watching the ACTIVATE sampling concept finally implemented was very exciting. To date we have conducted 3 joint flights, and 5 single flights with the HU-25 Falcon sampling a range of conditions including warm and mixed-phase clouds, solid cloud scenes and scattered cumulus clouds, post-frontal clouds, and clear air. The satellite data during some flights have shown that droplet concentrations are decaying with offshore distance, as confirmed by in-situ data. Early data show intriguing differences in microphysical data as the two aircraft transect through the gradients of cold and warm waters due to the presence of the Gulf Stream. In situ imaging data show the presence of a wide range of ice shapes including column-like needle structures. We are approaching an intensive stretch of fly-days this weekend again as the weather so far has been better for our science objectives than weekdays. On that note, our forecasting team has been phenomenal in putting the planes in the right places on the right days.

July 1, 2021

We finished our summer campaign this past week with four more ACTIVATE flights (Research Flights 90-93) between June 28 and 30. These flights focused on extensive data collection in typical summertime shallow cumulus clouds. A notable feature in these flights was sampling behind ship vessels near the coast that yielded especially large enhancements in particle concentration parameters.

June 28, 2021

Four flights were conducted last week, with two single flight days on June 22 and 24, and a double flight day on June 26. Saturday’s conditions (June 26) were in particular very good for ACTIVATE with a scattered shallow cumulus cloud scene throughout the day that both planes were able to jointly characterize. The past week also was linked to high variability in aerosol conditions with the northward advancement of African dust into our study region.

June 21, 2021

This past week included three single-flight days on Tuesday-Thursday (June 15-17). The first flight of this week (June 15) was a statistical cloud survey but proved to be a challenging flight to execute as the King Air encountered pervasive cirrus along the track and the Falcon dealt with low clouds at varying altitude ranges. The June 16 flight targeted mostly clear skies with observations of moderate aerosol loading. This flight also included an overflight of Langley Research Center at the end to intercompare with the AERONET site and the High Altitude Lidar Observatory (HALO) HSRL/water vapor lidar that was conducting upward looking ground tests. The last flight of the week (June 17) included a coordinated run along the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite overpass and then two reverse headings to capture in cloud data in vicinity of the ASTER overpass for additional contextual data. The flights on June 16-17 both saw non-spherical particles near the coast and drizzle over the ocean was observed on June 17.

June 14, 2021

This past week included two double-flight days on Monday-Tuesday (June 7-8). June 7 was notable in that the second flight (RF 80) was a “process study” flight, which accounts for approximately 10% of ACTIVATE flights. We targeted an area with a cluster of clouds and conducted a total of 10 Falcon legs in cloud at different altitudes ranging from ~2 to ~13 kft. These legs and a subsequent downward spiral resulted in 10 cloud water samples for a single cloud system. Simultaneously, the King Air conducted a ‘wheel and spoke” pattern far above to allow the remote sensors to characterize the environment and cloud that the Falcon was directly sampling. A total of 14 dropsondes were launched by the King Air in the ~3 hr flight. This flight and the other “process study” flight in this summer campaign (RF77 on June 2) will provide a remarkable dataset to investigate aerosol-cloud-meteorology interactions with very detailed measurements for single evolving cloud systems.

June 7, 2021

Four successful joint flights occurred last week. The double flight day on Wednesday June 2 was particularly noteworthy. Our morning flight conducted our typical statistical survey flight plan to an area south of the Virginia coast where there was a cumulus cloud field, with some regions evolving into deeper, more organized, convection. Based on that flight and satellite imagery, we set up the second flight to execute a “process study” pattern where the Falcon conducted a series of transects through a selected cloud cluster to characterize the vertical microphysical properties of the developing cluster immediately followed by an environmental profile in the surrounding cloud-free region. Simultaneously, the King Air conducted a “wheel and spoke” pattern centered around the cloud system, with multiple dropsondes launched above, and on the periphery of the cloud cluster alongside remote sensing transects to characterize the cloud and aerosol system underneath. Data from both planes will be used to characterize the range of cloud types observed on that day, with a focus on understanding the processes that drive shallow cumulus organization.

June 1, 2021

The last two weeks were busy with 9 joint flights, including three separate double-sortie days. The May 21 morning flight in particular was intriguing with a mixture of different conditions offshore with the two aircraft flying mostly straight to the east and then returning on the same track to NASA LaRC. Closer to shore, the aircraft observed a stratus deck with a prominent aerosol layer just above cloud as observed by the HSRL-2. These clouds then transitioned progressively into a more scattered cumulus cloud field to the east. At the far eastern end of the track there was a cold pool that we sampled within and just outside. Throughout this and the other flights this past week, there was evidence both either (or both) smoke and dust in the free troposphere. Measurement data will help unravel how these various aerosol types interact with the different types of clouds such as in the May 21 flights. On May 19, we also coordinated the flight along the CALIPSO satellite track where both aircraft and the satellite had successful made measurements.

May 17, 2021

After a short break after the Winter 2021 campaign, ACTIVATE took back to the skies this past week to start the Summer 2021 campaign. We conducted 4 successful joint flights between May 13-15 with interesting cloud conditions in each flight. The lower-flying Falcon characterized multiple layers of clouds and observed both warm and mixed-phase precipitation. Remote sensing observations on the higher-flying King Air detected aerosol layers aloft in the free troposphere potentially from dust and smoke on separate flights.

April 5, 2021

ACTIVATE wrapped up its winter 2021 flight campaign with five joint research flights this past week (RF 57-61) capped off by a double-flight day on Friday (4/2) to capitalize on another cold air outbreak event. Those two flights included an increased number of dropsondes (~10 per flight) to get extensive temporal and spatial characterization of the vertical atmospheric structure as the cold air outbreak cloud field evolved during the day. Notable in the other flights last week was successful coordination with ASTER and CALIPSO overpasses in our flight region.

March 29, 2021

We executed a joint flight (RF 56) on Tuesday March 23rd on a day marked by fairly ‘clean’ conditions in terms of very low aerosol and cloud drop number concentrations in the marine boundary layer. Cloud fraction on this day was markedly lower than a typical cold air outbreak type of day, which is helpful for ACTIVATE which is aiming to generate statistics in a wide range of conditions associated with aerosols, clouds, and meteorology.

March 22, 2021

The previous week posed significant weather challenges but Saturday (March 20, 2020) did finally provide low clouds evolving in a cold air outbreak. Interesting features in that joint flight (Research Flight 55) were Asian dust residing aloft above the boundary layer clouds, in addition to an interesting layer of depolarizing aerosol right above clouds near the end of flight as observed by the HSRL-2; it is unclear what the source of that layer was, but data analysis with the Falcon data will help unravel those details.

March 15, 2021

ACTIVATE conducted four more successful joint flights (Research Flights 51-54) this past week. We characterized a variety of cloud conditions including post-frontal clouds associated with another cold air outbreak on Monday (March 8) in contrast to the following day (Tuesday March 9) where there was a sharp inversion with uniform cloud top heights and generally thin clouds. Flights this past week were marked by influence from local and regional burning emissions. The second of two flights on Friday (March 12) was coordinated with a CALIPSO overpass.

March 8, 2021

ACTIVATE executed three successful joint flights (Research Flights 48-50) this past week. On Thursday March 4th we coordinated our flight with a NASA A-Train overpass over an area with some scattered marine boundary layer clouds. The back-to-back flights on Friday March 5th served two objectives to capitalize on an excellent cold air outbreak event: (i) characterize the aerosol and meteorological characteristics upwind of the cloud field farther downwind; and (ii) characterize the evolution of the cloud field with the desire to capture the transition from overcast cloudy conditions to open cell structure. Noteworthy features in these flights were dust layers from long-range transport and significant new particle formation.

Febraury 5, 2021

ACTIVATE’s had its first joint flight of the winter 2021 campaign on February 3. We were successful to sample a transition from overcast stratocumulus clouds to broken cumulus clouds near our farthest southeast point of the flight track. There was extensive mixed-phase precipitation in areas closer to shore but pure liquid clouds farther offshore coinciding with the open cell cloud field. Although at low optical depth, an interesting aerosol layer was observed above 6 km that most likely was dust due to its depolarizing nature.

January 30, 2020

This past week ACTIVATE took to the skies again to begin our 2021 winter campaign. In contrast to last year, we started a bit earlier in the month of January to capitalize on a higher frequency of cold air outbreak events. Friday’s flights (January 29) were particularly ideal with both aircraft sampling along cloud streets aligned with the predominant wind direction coming from the north/northwest. We observed a transition from supercooled droplets to mixed phase precipitation with distance away from shore.