Satellite mapping of air temperature under polar night conditions

Figures & data

Figure 1. Geographical scheme of the Apatity test site.

Legend: 1 – urban areas; 2 – industrial areas; 3 – roads; 4 – lakes & ponds; 5 – mask of the mountain group; 6 – iButton loggers; 7 – AWS; 8 – WMO station (ID WMO 22213).

Figure 2. ASTER digital elevation model.

Legend: 1 – according to AWS; 2 – at the WMO station; 3 and 4 – periods with the stable stratification of the lower atmosphere; 3 – wind speed is less than 2 m/s; 4 – wind speed is 0 m/s.

Figure 3. Air temperature variations. The arrow indicates the long period of calm weather under astronomical polar night conditions.

Table 1. Satellite data.^a

No	Satellite	Date	Time GMT	Sun elevation, deg	Wind(m/s)	Cloudiness	$T_a^{\hspace{0.17em}}(x_{\mathit{WMO}},y_{\mathit{WMO}})$ ^oC
1	Landsat 8	05.01.2020	18:32	“Night”, Sun elevation < 6	2	0.25	−14.7
2	Landsat 8	24.04.2019	18:32		1	0.60	4.5
3	Landsat 7	02.03.2019	18:32		0	0	−25.0
4	Landsat 8	31.01.2017	09:21		2	0.50	−11.3
5	Landsat 8	03.02.2019	09:14		0	0.20	−31.1
6	Landsat 8	06.02.2019	09:21		2	0.25	−21.7
7	Landsat 8	11.02.2021	09:21	“Day”, Sun elevation < 6	1	0.35	−21.0
8	Landsat 8	18.02.2021	09:27		0	0.25	−15.8
9	Landsat 8	22.10.2014	09:21		1	0.50	−9.2
10	Landsat 8	22.02.2019	09:21		1	0.50	−12.2
11	Landsat 8	01.03.2016	09:21		0	0.25	−15.3
12	Landsat 8	03.03.2019	09:15		0	0.30	−18.7
13	Landsat 7	06.03.2018	09:15		1	1	−15.7
14	Landsat 8	07.03.2018	09:15		0	0.30	−18.0
15	Landsat 8	08.03.2021	09:15		1	0.25	−20.0
16	Landsat 7	08.03.2018	09:17		0	0.80	−24.6

^a$T_a^{\hspace{0.17em}}(x_{\mathit{WMO}},y_{\mathit{WMO}})$ – for the moment of satellite shooting.

Figure 4. Map of T_S(x,y) – the land surface temperature retrieved from Landsat 8 satellite image. Time: ~09:00 GMT; Date: 07.03.2018.

Legend: 1 – “Night”; 2 – “Day”(a) WMO data and Landsat data for different times of the day.Legend: 1 – the Lake Imandra shore (WMO); 2 – the hilltop (AWS, see Figure 1).(b) Air temperature (logger and AWS) and surface temperature (Landsat) for different relief altitudes.

Figure 5. Correlation between the air temperature and the surface temperature. Temperature data in the plots are those observed at the satellite shooting moments indicated in Table 1.

Figure 6. Map of R(x,y) – coefficients of correlation between T_S(x,y,τ) (Landsat) and $T_a\left(x_{\mathit{WMO}},y_{\mathit{WMO}},{\tau }_i\right)$; τ_i is the time of i-th satellite shooting. Date: 01.02.2018.

Figure 7. Maps of coefficients of Equation (4)(4) $T_a\left(\mathit{x},\mathit{y},\mathit{\tau }\right)=\mathit{F}\left(\mathit{x},\mathit{y}\right)\times T_a\left(x_{\mathit{WMO}},y_{\mathit{WMO}},\mathit{\tau }\right)+\mathit{G}\left(\mathit{x},\mathit{y}\right)$(4) , compiled from the results of multiple satellite imagery (Table 1) and of the standard observations at WMO 22213 weather station.

(a) Map of coefficient F(x,y).(b) Map of coefficient G(x,y).

Figure 8. Map of air temperature, compiled on the base of the satellite and WMO weather station data. Time: 00:00 GMT; 01.02.2018. This time is between the times of satellite surveys (see Table 1).

Legend: 1 – mask; 2 – roads; 3 – proposed new districts; 4 – proposed highways interconnecting the new districts. A - CHP plant; B - municipal wastewater treatment plant; C and D – lowlands.

Legend: 1 – mask; 2 – roads; 3 – proposed new districts; 4 – proposed highways interconnecting the new districts.

Figure 9. Dependence of errors σ on the relief altitude.

Data availability statement

The raw land surface temperature data can be obtained from the LAADS DAAC – NASA (Level-1 and Atmosphere Archive and Distribution System Web Interface). https://ladsweb.modaps.eosdis.nasa.gov