Sea ice concentration algorithms using brightness temperatures (<inline-formula><tex-math notation="LaTeX">$T_{B}$</tex-math></inline-formula>) from satellite microwave radiometers are used to compute sea ice concentration (<inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula>), sea ice extent, and generate sea ice climate data records. Therefore, it is important to minimize the sensitivity of <inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula> estimates to geophysical noise caused by snow/sea ice thermal microwave emission signature variations, and presence of WV and clouds in the atmosphere and/or near-surface winds. In this study, we investigate the effect of geophysical noise leading to systematic <inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula> biases and affecting <inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula> standard deviations (STD) using simulated top of the atmosphere <inline-formula><tex-math notation="LaTeX">$T_{B}$</tex-math></inline-formula>s over open water and 100% sea ice. We consider three case studies for the Arctic and the Antarctic and eight different <inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula> algorithms, representing different families of algorithms based on the selection of channels and methodologies. Our simulations show that, over open water and low <inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula>, algorithms using gradients between V-polarized 19-GHz and 37-GHz <inline-formula><tex-math notation="LaTeX">$T_{B}$</tex-math></inline-formula>s show the lowest sensitivity to the geophysical noise, while the algorithms exclusively using near-90-GHz channels have by far the highest sensitivity. Over sea ice, the atmosphere plays a much smaller role than over open water, and the <inline-formula><tex-math notation="LaTeX">$c_{\text{ice}}$</tex-math></inline-formula> STD for all algorithms is smaller than over open water. The hybrid and low-frequency (6 GHz) algorithms have the lowest sensitivity to noise over sea ice, while the polarization type of algorithms has the highest noise levels.