Supporting Information for

Aircraft observed diurnal variations of the planetary boundary layer under heat

waves

Yuanjie Zhang1,2, Liang Wang2, Joseph A. Santanello Jr.3, Zaitao Pan4,1, Zhiqiu Gao1,

Dan Li2*

1Climate and Weather Disasters Collaborative Innovation Center, Key Laboratory for

Aerosol-Cloud-Precipitation of China Meteorological Administration, School of

Atmospheric Physics, Nanjing University of Information Science and Technology,

Nanjing, China

2Department of Earth and Environment, Boston University, Boston, MA, USA

3Hydrological Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt,

MD, USA

4Department of Earth and Atmospheric Sciences, Saint Louis University, St. Louis,

MO, USA

* Corresponding author: Dan Li (lidan@bu.edu)

Content of this file

Text S1 to S2

Figures S1 to S3

Text S1

Here we compare the NARR data to the AMDAR data. As two examples, Figures S1 and S2 show summer averaged profiles at 06 and 18 UTC from AMDAR and NARR in 2007 at SDF and PHL, respectively. Since NARR and AMDAR data do not have the same temporal and vertical resolutions, comparisons are conducted for profiles available in both NARR and AMDAR data and the AMDAR data are linearly interpolated into the NARR pressure levels. It is clear that overall the AMDAR data agree reasonably well with the NARR data in terms of mean and variability.

Figure S1

Figure S1. Summer averaged AMDAR and NARR profiles at 06 (top) and 18 UTC (bottom) in 2007 over SDF. Red and blue dot lines indicate the standard variations of AMDAR and NARR profiles, respectively. (a, e) Temperature (T), (b, f) specific humidity (q), (c, g) zonal wind (U), and (d, h) meridional wind (V).

Figure S2

Figure S2. Similar to Figure S1, but at PHL.

Text S2

Figure S3 shows the HW-related changes in temperature, wind vector and specific humidity for HWs in the Atlantic Seaboard region (Figure S3a-c), South region (Figure S3d-f) and Plateau region (Figure S3g-i). These changes are averaged over pressure levels 1000-850 hPa, 1000-850 hPa and 850-700 hPa for the Atlantic Seaboard, South and Plateau regions, respectively, which roughly correspond to the PBL.

Overall the HW-related changes from NARR agree well with those from AMDAR shown in Figure 11. In the Atlantic Seaboard region, increases in the PBL temperature and specific humidity from NARR data are observed, with similar magnitudes as those from AMDAR data (c.f. Figure S3a to the Atlantic Seaboard region in Figure 11a, and c.f. Figure S3c to the Atlantic Seaboard region in Figure 11g). The HW-related changes in wind vector from the west to the east in NARR are consistent with increases in the zonal wind in AMDAR data (c.f. Figure S3b to Figure 11c and 11e).

In the South region, the HW-related changes in temperature (humidity) in NARR show a warm (wet) core in the north of Texas, which generally capture the HW-related increases (decreases) in temperature (humidity) in parts of Texas shown by the AMDAR data (c.f. Figure S3d to the South region in Figure 11a, and c.f., Figure S3f and the South region in Figure 11g). The HW-related changes in wind vector from the land to the sea in NARR are also consistent to changes in the zonal and meridional wind from AMDAR data in the region (c.f. Figure S3e to the South region in Figure 11c and 11e).

In the Plateau region, the HW-related increases in temperature cover the entire plateau area in NARR. The HW-related decreases in humidity in the southeast of the plateau are consistent with those shown by the two AMDAR airports in the eastern part of the Plateau region, although changes in humidity in NARR are much weaker than those in AMDAR data (c.f. Figure S3i to the Plateau region in Figure 11g). The HW-related changes in wind vector in NARR are small in the Plateau region, except in the southern part. The HW-related changes in wind vector in NARR in the southern part of the Plateau region is consistent with changes in zonal wind in AMDAR data at the south airport (c.f. Figure S3h to the Plateau region in Figure 11c). The good agreement in terms of HW signatures between AMDAR and NARR suggests that using NARR geopotential height fields and surface latent heat fluxes to illustrate the synoptic-scale atmospheric circulation patterns and land-atmosphere feedbacks associated with HWs is reasonable.

Figure S3

Figure S3. Differences in temperature (K), wind vector (m/s), and specific humidity (g/kg) from NARR daily data between HW and non-HW periods (HW minus non-HW) in (a-c) the Atlantic Seaboard region, (d-f) the South region, and (g-i) the Plateau region during 2007-2016. These changes are averaged over pressure levels 1000-850 hPa, 1000-850 hPa and 850-700 hPa for the Atlantic Seaboard, South and Plateau regions, respectively.

Reference

Zhang, Y., Li, D., Lin, Z., Santanello, J.A., Gao, Z., 2019. Development and evaluation of a long-term data record of planetary boundary layer profiles from aircraft meteorological reports. J. Geophys. Res.: Atmos. 124. https://doi.org/10.1029/2018JD029529.