ARL Weekly News – April 28, 2023

Recent Events

Maryland Day at the University of Maryland: April 29, 2023.

NOAA’s Air Resources Car was on display at the University of Maryland’s annual event on Saturday, April 29, 2023 at the McKeldin Mall during Maryland Day at the University of Maryland College Park. ARL scientists Xinrong Ren and Phil Stratton took the Air Resources Car to campus in order to describe the goals and science behind the imposing looking van.

Visitors were invited to see what the instrumentation was observing about the local greenhouse gasses and air quality, and were also invited to exhale into the instrumentation to see how the air composition changed. Nearby activities and events such as the propane-fired barbeques at a food truck, and nearby diesel powered engines also spiked readings on some atmospheric measurements installed in the van.

ARL’s Phil Stratton, center, explains some of the ARC's atmospheric measurements to UMD students
Right to left: ARL director Ariel Stein, with visitor, Phil Stratton and Margaret Simon

AMS Agricultural and Forest Meteorology Meeting

ARL Presentations at the AMS Agricultural and Forest Meteorology conference in Minneapolis during May 2-5, included:

  • Sensitivity of Soil Respiration to Variability in Temperature and Moisture in a Semi-Arid Grassland, by Praveena Krishnan, T. P. Meyers, M. Heuer, and J. Kochendorfer
  • Some Considerations in Accounting For All The Surface Energy Balance Components in Forest, Agricultural and Grassland Ecosystems, by Tilden P. Meyers
  • The Walker Branch and Chestnut Ridge Ameriflux Sites; Can They be Combined to Create a Multi-Decadal Quasi-Continuous Dataset, by John Kochendorfer, P. Krishnan, T. P. Meyers, M. Heuer, R. Saylor, T. Wilson, and T. R. Lee
  • Beyond the Big-Leaf Model for NOAA’s Unified Air Quality Forecasting Capabilities, by Patrick Campbell, Paul Makar, Zachary Moon, Wei-Ting Hung, Barry Baker, Youhua Tang, Fanglin Yang, Raffaele Montuoro, and Rick Saylor.
  • A Model for Forest Canopy Effects on Weather and Atmospheric Composition in the NOAA Unified Forecast System, by Zachary Moon, Patrick Campbell, Wei-Ting Hung, and Barry Baker.
  • Development and evaluation of a machine learning based wildfire spread prediction model for regional air quality forecasting, by Wei-Ting Hung, Barry Baker, Patrick Campbell, Youhua Tang, Zachary Moon, and Gill-Ran Jeong.
ARL team members at the AMS conference include (left to right): Wei Ting Hung, Zach Moon, Praveena Krishnan, Tilden Meyers, John Kochendorfer, and Patrick Campbell.

Coupled ocean-atmosphere summer heatwaves in the New Zealand region: an update

Salinger M.J., Diamond H.J., Bell J., Behrens E., Blair Fitzharris B., Herod N., McLuskie M., Parker AK., Ratz H., Renwick J., Scofield C., Shears NT., Smith RO., Sutton PJ. and Troigh MCT. Coupled ocean-atmosphere summer heatwaves in the New Zealand region: an update, Weather and Climate, 42, 2023 –

Howard Diamond was a co-author in a recently published paper in the New Zealand Meteorological Society’s 42nd annual journal, Weather and Climate, which is the third in a series of papers looking at some recent unparalleled heatwaves having occurred during the austral warm season (Nov-March) of 2021/22 in the New Zealand region. This followed a very warm summer in 2018/19, although not as intense as the 1934/35 or 2017/18 events.  Diamond and his colleagues reviewed the characteristics of the three warmest austral summers (Dec-Feb) in the region (approximately 4 million km2) of 1934/35, 2017/18, and 2018/19. These southern hemispheric summers experienced the most intense coupled ocean-atmosphere heatwaves on record.  In particular, such heat events are most intense during La Niña seasons, and with persistent La Niña conditions in place over the past several seasons, this was indeed the case.  A preliminary investigation of the recently concluded 2022/23 austral warm season did not rank it with these other four events, and that is most probably the result of a waning  La Niña that is most likely (62% chance according the NOAA’s Climate Prediction Center) going to be replaced by El Niño conditions in the May-July 2023 timeframe.

Paper  Abstract: During austral warm seasons (November – March, NDJFM) of 1934/35, 2017/18, 2018/19 and 2021/22 the New Zealand (NZ) region experienced the most intense coupled ocean/atmosphere (MHW/AHW) heatwaves on record. Average temperature anomalies over land and sea were +1.2 to 1.4°C above average. Common to all four events were maximum sea surface temperature (SST) anomalies to the west of the South Island of NZ. Atmospheric circulation anomalies showed a pattern of blocking high pressure over the Tasman Sea and Pacific Ocean to the south, and southeast of NZ, and reduced trough activity over and to the east of NZ, accompanied by strongly positive Southern Annular Mode conditions.  Hindcasts for 2017/18, 2018/19 and 2021/22 NDJFM indicate that positive temperature anomalies around 1°C occurred in the Tasman Sea, and near 1.5°C for the Chatham Rise. The temperature anomalies in the upper 50m of the ocean are consistent with the 500hPa atmospheric height anomalies. The temperature anomalies in the upper 50m of the ocean are consistent with the 500hPa atmospheric height anomalies and associated winds. The eastern Tasman Sea during August 2021 to July 2022 experienced the highest annual number of MHW days during the satellite-era (1981-present) from OISSTv2.1 data. Under 1.5°C of global warming the four events would have ERIs of 2-3 years, and with 2°C of warming all would be considered cool years relative to the +2°C climate. For the 1957-2022 period, the two most intense heatwaves have ERIs of between 30 to 150 years.  Major loss of glacial ice occurred from Southern Alps glaciers with rapid melt of seasonal snow in all cases.  Slow advances in grape phenology since 1948 may be associated with increases in temperature over the same period. Cherries and apricot harvest dates advanced by one to two weeks. Marine impacts may be linked to starvation of kororā/Little Penguin (Eudyptula minor) chicks in the Bay of Plenty. Chicks weighed less and had a lower body condition score in 2020 and 2021 compared to 2019 and rescue calls in 2021 reached the highest volumes since 2015. The first record of warm-water prey species in the diet of yellow eyed penguins at Moeraki occurred, as well as widespread sea-sponge bleaching around northern and southern NZ.