On the surface fluxes characteristics and roughness lengths at Zhongshan station, Antarctica

Figures & data

Figure 1. The (a) geographical location, (b) local topography and (c) the observation tower of Zhongshan station.

Table 1. The type of sensors and their key technical indexes.

Sensor type	Measurement range	Precision accuracy
CS100	P: 600–1100 hPa	< 0.5 hPa
IRR-P	Ts: −55∼ + 80°C	± 0.2°C (−15∼ + 60°C) ± 0.5°C (−55∼ + 80°C)
CNR1	DSR,USR : 0.3–3.0 µm DLR,ULR : 5–50 µm	10–35 µν/(wm^2) 5–35 µν/(wm^2)
HMP54C	Ta: −40–60°C RH: 0–100%	< 0.5°C 1–90%, < 2% 90–100%, < 3%
WindSonic	Ws: 0–60 ms	±2%
CSAT3	$u^{\mathrm{\prime }},v^{\mathrm{\prime }}$ :−65 ∼ +65 m s^−1 $w^{\mathrm{\prime }}$ :−65 ∼ +65 m s^−1 $T{v}^{\mathrm{\prime }}$ :−50 ∼ +60°C	$u^{\mathrm{\prime }},v^{\mathrm{\prime }}$ : ±0.04 m s^−1 $w^{\mathrm{\prime }}$ : ±0.02 m s^−1 $T{v}^{\mathrm{\prime }}$: ±0.025°C
LI-7500	$q^{\mathrm{\prime }}$ :0∼42 g/m^3 CO2 :0∼5148 mg/m^3	$q^{\mathrm{\prime }}$: ±0.02 g/m^3 CO2: ± 0.2 mg/m^3

Figure 2. Seasonal averaged diurnal variation of (a) wind speed at 3.9 m height, (b) wind direction at 3.9 m height, (c) air temperature at 3.9 m height (solid lines) and radiative temperature of surface (dashed lines), (d) humidity at 3.9 m height collected at the Zhongshan station tower from March 2008 to February 2009.

Figure 3. The seasonal averaged diurnal variation of (a) DSR, (b) USR, (c) DLR, (d) ULR and (e) Rn during the period from March 2008 to February 2009 at Zhongshan station.

Figure 4. The seasonal averaged diurnal variation of (a) momentum flux (τ), (b) sensible heat flux (SH) and (c) latent heat flux (LE) during the period from March 2008 to February 2009 at Zhongshan station.

Figure 5. The monthly averaged (a) net radiation flux (Rn), sensible heat flux (SH), latent heat flux (LE) and soil heat flux (G), (b) precipitation, evaporation (or sublimation) and their difference (precipitation minus evaporation) during the period from March 2008 to February 2009 at Zhongshan station.

Figure 6. The calculated log(z/z₀m) versus wind speed (blue dots), its 0.5 m s⁻¹ bin averaged values (red dots), the partially linear regression (black dashed line) and the overall averaged value (black solid line).

Table 2. The regression slope between u_*cal and u_*ec, and the bias and standard error of u_*cal from u_*ec, for the two methods of z₀m deduction.

The statistics	Partially linear regression	Constant z0m
Regression slope of u*cal – u*ec	0.956	0.978
$\text{Bias}=\sum _{i=1}^n\left|u_{{\ast }_{cal}}-u_{\ast ec}\right|/n$	0.060	0.065
$\text{Normalized standard error ( NSE) }=\sqrt{{\sum }_{i=1}^n{\left|u_{\ast cal}-u_{\ast ec}\right|}^2/{\sum }_{i=1}^n{\left|u_{\ast ec}\right|}^2}$	0.158	0.170

Figure 7. The calculated log(z₀h/z₀m) versus log(Re∗). The dots are the bin averaged log(z₀h/z₀m) with 0.1 interval of log(Re∗). Observation sample numbers for each stratification condition are shown in the bottom part. Black, red and blue colors represent for neutral, unstable and stable condition, respectively. Red circles indicate that the observation sample number in the bin are larger than 100. A87, S08, Z95, Z97 and a whole averaged z₀h are also shown as black solid, black dashed, green solid, green dashed and cyan solid lines.

Figure 8. The calculated θ* with (a) A87, (b) S08, (c) Z95, (d) C97 and (e) the constant value of 1.2 × 10⁻⁴ and 10-min averaged wind and temperature observations at 3.7 m height. Blue dots are the original data, and red dots are the 0.05 bin averaged values.

Table 3. The regression slope between θ_*cal and θ_*ec when −0.5 ≤ θ_*ec ≤ 0.2, and the bias and standard error of θ_*cal from θ_*ec, for the five methods of z₀h deduction.

The statistics	A87	S08	Z95	Z97	z0h = 1.2 × 10^−4m
Regression slope of
θ*cal –θ*ec for −0.5 ≤ θ*ec ≤ 0.2	0.912	1.475	1.176	1.580	0.993
Bias	0.078	0.108	0.089	0.119	0.085
Normalized standard error	0.659	0.779	0.673	0.820	0.689

Figure 9. The calculated u_* (upper panels) and θ_* (lower panels) with z_0m = 3.6 × 10⁻³ m and z_0h = 1.2 × 10⁻⁴m and 10-min averaged wind and temperature observations at 2.5, 3.9, and 5.9m height. Blue dots are the original data, and red dots are the 0.05 bin averaged values.

Table 4. The regression slope between u_*cal and u_*ec, or θ_*cal and θ_*ec when −0.5 ≤ θ_*ec ≤ 0.2, and the bias and standard error of u_*cal from u_*ec, or θ_*cal from θ_*ec, with z_0m = 3.6 × 10⁻³ m and z₀h = 1.2 × 10⁻⁴ m and 10-min averaged wind and temperature observations at 2.5, 3.9, and 5.9 m height.

The statistics	u* 2.5 m	u* 3.9 m	u* 5.9 m	θ* 2.5 m	θ* 3.9 m	θ* 5.9 m
Regression slope of u*cal–u*ec or θ*cal–*ec for −0.5 ≤ θ*ec ≤ 0.2	1.087	1.021	1.101	0.923	0.914	0.900
Bias	0.064	0.057	0.068	0.103	0.097	0.096
NSE	0.273	0.239	0.313	0.909	0.905	0.905